WorldWideScience

Sample records for satellite mission study

  1. A preliminary study of level 1A data processing of a low–low satellite to satellite tracking mission

    Directory of Open Access Journals (Sweden)

    Peng Xu

    2015-09-01

    Full Text Available With the Gravity Recovery and Climate Experiment (GRACE mission as the prime example, an overview is given on the management and processing of Level 1A data of a low–low satellite to satellite tracking mission. To illustrate the underlying principle and algorithm, a detailed study is made on the K-band ranging (KBR assembly, which includes the measurement principles, modeling of noises, the generation of Level 1A data from that of Level 0 as well as Level 1A to Level 1B data processing.

  2. Mission studies on constellation of LEO satellites with remote-sensing and communication payloads

    Science.gov (United States)

    Chen, Chia-Ray; Hwang, Feng-Tai; Hsueh, Chuang-Wei

    2017-09-01

    Revisiting time and global coverage are two major requirements for most of the remote sensing satellites. Constellation of satellites can get the benefit of short revisit time and global coverage. Typically, remote sensing satellites prefer to choose Sun Synchronous Orbit (SSO) because of fixed revisiting time and Sun beta angle. The system design and mission operation will be simple and straightforward. However, if we focus on providing remote sensing and store-and-forward communication services for low latitude countries, Sun Synchronous Orbit will not be the best choice because we need more satellites to cover the communication service gap in low latitude region. Sometimes the design drivers for remote sensing payloads are conflicted with the communication payloads. For example, lower orbit altitude is better for remote sensing payload performance, but the communication service zone will be smaller and we need more satellites to provide all time communication service. The current studies focus on how to provide remote sensing and communication services for low latitude countries. A cost effective approach for the mission, i.e. constellation of microsatellites, will be evaluated in this paper.

  3. Magnetic Satellite Missions and Data

    DEFF Research Database (Denmark)

    Olsen, Nils; Kotsiaros, Stavros

    2011-01-01

    Although the first satellite observations of the Earth’s magnetic field were already taken more than 50 years ago, continuous geomagnetic measurements from space are only available since 1999. The unprecedented time-space coverage of this recent data set opened revolutionary new possibilities...... for exploring the Earth’s magnetic field from space. In this chapter we discuss characteristics of satellites measuring the geomagnetic field and report on past, present and upcoming magnetic satellite missions. We conclude with some basics about space magnetic gradiometry as a possible path for future...... exploration of Earth’s magnetic field with satellites....

  4. Orbit determination for ISRO satellite missions

    Science.gov (United States)

    Rao, Ch. Sreehari; Sinha, S. K.

    Indian Space Research Organisation (ISRO) has been successful in using the in-house developed orbit determination and prediction software for satellite missions of Bhaskara, Rohini and APPLE. Considering the requirements of satellite missions, software packages are developed, tested and their accuracies are assessed. Orbit determination packages developed are SOIP, for low earth orbits of Bhaskara and Rohini missions, ORIGIN and ODPM, for orbits related to all phases of geo-stationary missions and SEGNIP, for drift and geo-stationary orbits. Software is tested and qualified using tracking data of SIGNE-3, D5-B, OTS, SYMPHONIE satellites with the help of software available with CNES, ESA and DFVLR. The results match well with those available from these agencies. These packages have supported orbit determination successfully throughout the mission life for all ISRO satellite missions. Member-Secretary

  5. On the estimation of physical height changes using GRACE satellite mission data – A case study of Central Europe

    Directory of Open Access Journals (Sweden)

    Godah Walyeldeen

    2017-12-01

    Full Text Available The dedicated gravity satellite missions, in particular the GRACE (Gravity Recovery and Climate Experiment mission launched in 2002, provide unique data for studying temporal variations of mass distribution in the Earth’s system, and thereby, the geometry and the gravity fi eld changes of the Earth. The main objective of this contribution is to estimate physical height (e.g. the orthometric/normal height changes over Central Europe using GRACE satellite mission data as well as to analyse them and model over the selected study area. Physical height changes were estimated from temporal variations of height anomalies and vertical displacements of the Earth surface being determined over the investigated area. The release 5 (RL05 GRACE-based global geopotential models as well as load Love numbers from the Preliminary Reference Earth Model (PREM were used as input data. Analysis of the estimated physical height changes and their modelling were performed using two methods: the seasonal decomposition method and the PCA/ EOF (Principal Component Analysis/Empirical Orthogonal Function method and the differences obtained were discussed. The main fi ndings reveal that physical height changes over the selected study area reach up to 22.8 mm. The obtained physical height changes can be modelled with an accuracy of 1.4 mm using the seasonal decomposition method.

  6. How can present and future satellite missions support scientific studies that address ocean acidification?

    Science.gov (United States)

    Salisbury, Joseph; Vandemark, Douglas; Jonsson, Bror; Balch, William; Chakraborty, Sumit; Lohrenz, Steven; Chapron, Bertrand; Hales, Burke; Mannino, Antonio; Mathis, Jeremy T.; Reul, Nicolas; Signorini, Sergio; Wanninkhof, Rik; Yates, Kimberly K.

    2016-01-01

    Space-based observations offer unique capabilities for studying spatial and temporal dynamics of the upper ocean inorganic carbon cycle and, in turn, supporting research tied to ocean acidification (OA). Satellite sensors measuring sea surface temperature, color, salinity, wind, waves, currents, and sea level enable a fuller understanding of a range of physical, chemical, and biological phenomena that drive regional OA dynamics as well as the potentially varied impacts of carbon cycle change on a broad range of ecosystems. Here, we update and expand on previous work that addresses the benefits of space-based assets for OA and carbonate system studies. Carbonate chemistry and the key processes controlling surface ocean OA variability are reviewed. Synthesis of present satellite data streams and their utility in this arena are discussed, as are opportunities on the horizon for using new satellite sensors with increased spectral, temporal, and/or spatial resolution. We outline applications that include the ability to track the biochemically dynamic nature of water masses, to map coral reefs at higher resolution, to discern functional phytoplankton groups and their relationships to acid perturbations, and to track processes that contribute to acid variation near the land-ocean interface.

  7. Versatile Satellite Architecture and Technology: A New Architecture for Low Cost Satellite Missions for Solar-Terrestrial Studies

    Science.gov (United States)

    Cook, T. A.; Chakrabarti, S.; Polidan, R.; Jaeger, T.; Hill, L.

    2011-12-01

    Early in the 20th century, automobiles appeared as extraordinary vehicles - and now they are part of life everywhere. Late in the 20th century, internet and portable phones appeared as innovations - and now omni-present requirements. At mid-century, the first satellites were launched into space - and now 50 years later - "making a satellite" remains in the domain of highly infrequent events. Why do all universities and companies not have their own satellites? Why is the work force capable of doing so remarkably small? Why do highly focused science objectives that require just a glimpse from space never get a chance to fly? Historically, there have been two primary impediments to place an experiment in orbit - high launch costs and the high cost of spacecraft systems and related processes. The first problem appears to have been addressed through the availability of several low-cost (hands-on training for these participants and will leave an important legacy in developing a scientifically and technically competent workforce.

  8. Feasibility study for Japanese Air Quality Mission from Geostationary Satellite: Infrared Imaging Spectrometer

    Science.gov (United States)

    Sagi, K.; Kasai, Y.; Philippe, B.; Suzuki, K.; Kita, K.; Hayashida, S.; Imasu, R.; Akimoto, H.

    2009-12-01

    A Geostationary Earth Orbit (GEO) satellite is potentially able to monitor the regional distribution of pollution with good spatial and temporal resolution. The Japan Society of Atmospheric Chemistry (JSAC) and the Japanese Space Exploration Agency (JAXA) initiated a concept study for air quality measurements from a GEO satellite targeting the Asian region [1]. This work presents the results of sensitivity studies for a Thermal Infrared (TIR) (650-2300cm-1) candidate instrument. We performed a simulation study and error analysis to optimize the instrumental operating frequencies and spectral resolution. The scientific requirements, in terms of minimum precision (or error) values, are 10% for tropospheric O3 and CO and total column of HN3 and nighttime HNO2 and 25% for O3 and CO with separating 2 or 3 column in troposphere. Two atmospheric scenarios, one is Asian background, second is polluted case, were assumed for this study. The forward calculations and the retrieval error analysis were performed with the AMATERASU model [2] developed within the NICT-THz remote sensing project. Retrieval error analysis employed the Optimal Estimation Method [3]. The geometry is off-nadir observation on Tokyo from the geostationary satellite at equator. Fine spectral resolution will allow to observe boundary layer O3 and CO. We estimate the observation precision in the spectral resolution from 0.1cm-1 to 1cm-1 for 0-2km, 2-6km, and 6-12km. A spectral resolution of 0.3 cm-1 gives good sensitivity for all target molecules (e.g. tropospheric O3 can be detected separated 2 column with error 30%). A resolution of 0.6 cm-1 is sufficient to detect tropospheric column amount of O3 and CO (in the Asian background scenario), which is within the required precision and with acceptable instrumental SNR values of 100 for O3 and 30 for CO. However, with this resolution, the boundary layer ozone will be difficult to detect in the background abundance. In addition, a spectral resolution of 0.6 cm

  9. Remote Sounding of the Earth's Atmospheric Limb From a Micro-Satellite Platform: a Feasibility Study of the ALTIUS Mission

    Science.gov (United States)

    Vrancken, D.; Paijmans, B.; Fussen, D.; Neefs, E.; Loodts, N.; Dekemper, E.; Vahellemont, F.; Devos, L.; Moelans, W.; Nevejans, D.; Schroeven-Deceuninck, H.; Bernaerts, D.; Zender, J.

    2008-08-01

    There is more and more interest in the understanding and the monitoring of the physics and chemistry of the Earth's atmosphere and its impact on the climate change. Currently a significantly high number of sounders provide the required data to monitor the changes in atmosphere composition, but a dramatic drop in operational atmosphere monitoring missions is expected around 2010. This drop is mainly visible in sounders capable of a high vertical resolution. Currently, instruments on ENVISAT and METOP provide relevant data but this is envisaged to be insufficient to ensure full spatial and temporal coverage and redundancy in the measurement data set. ALTIUS (Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere) is a remote sounding experiment proposed by the Belgian Institute for Space Aeronomy (BIRA/IASB) for which a feasibility study was initiated with BELSPO (Belgian Science Policy) and ESA support. The main objective of this study phase was to establish a mission concept, to define the required payload and to establish a satellite platform design. The study was led by the BIRA/IASB team and performed in close collaboration with OIP (payload developer) and Verhaert Space (spacecraft developer). The mission scenario includes bright limb observations in basically all directions, solar occultations around the terminator passages and star occultations during eclipse. These observation modes allow imaging the atmosphere with a high vertical resolution. The spacecraft will be operated in a 10:00 sun-synchronous orbit at an altitude of 695 km, allowing a 3-day revisit time. The envisaged payload for the ALTIUS mission is an imaging spectrometer, observing in the UV, the VIS and the NIR spectral ranges. For each spectral range, an AOTF (Acousto-Optical Tunable Filter) will permit to perform observations of selectable small wavelength domains. A typical set of 10 wavelengths will be recorded within 1 second. The different operational modes impose a

  10. Teamwork Reasoning and Multi-Satellite Missions

    Science.gov (United States)

    Marsella, Stacy C.; Plaunt, Christian (Technical Monitor)

    2002-01-01

    NASA is rapidly moving towards the use of spatially distributed multiple satellites operating in near Earth orbit and Deep Space. Effective operation of such multi-satellite constellations raises many key research issues. In particular, the satellites will be required to cooperate with each other as a team that must achieve common objectives with a high degree of autonomy from ground based operations. The multi-agent research community has made considerable progress in investigating the challenges of realizing such teamwork. In this report, we discuss some of the teamwork issues that will be faced by multi-satellite operations. The basis of the discussion is a particular proposed mission, the Magnetospheric MultiScale mission to explore Earth's magnetosphere. We describe this mission and then consider how multi-agent technologies might be applied in the design and operation of these missions. We consider the potential benefits of these technologies as well as the research challenges that will be raised in applying them to NASA multi-satellite missions. We conclude with some recommendations for future work.

  11. Signature of biased range in the non-dynamical Chern-Simons modified gravity and its measurements with satellite-satellite tracking missions: theoretical studies

    Science.gov (United States)

    Qiang, Li-E.; Xu, Peng

    2015-08-01

    Having great accuracy in the range and range rate measurements, the GRACE mission and the planed GRACE follow on mission can in principle be employed to place strong constraints on certain relativistic gravitational theories. In this paper, we work out the range observable of the non-dynamical Chern-Simons modified gravity for the satellite-to-satellite tracking (SST) measurements. We find out that a characteristic time accumulating range signal appears in non-dynamical Chern-Simons gravity, which has no analogue found in the standard parity-preserving metric theories of gravity. The magnitude of this Chern-Simons range signal will reach a few times of cm for each free flight of these SST missions, here is the dimensionless post-Newtonian parameter of the non-dynamical Chern-Simons theory. Therefore, with the 12 years data of the GRACE mission, one expects that the mass scale of the non-dynamical Chern-Simons gravity could be constrained to be larger than eV. For the GRACE FO mission that scheduled to be launched in 2017, the much stronger bound that eV is expected.

  12. The Infrared Astronomical Satellite (IRAS) mission

    Science.gov (United States)

    Neugebauer, G.; Habing, H. J.; Van Duinen, R.; Aumann, H. H.; Beichman, C. A.; Baud, B.; Beintema, D. A.; Boggess, N.; Clegg, P. E.; De Jong, T.

    1984-01-01

    The Infrared Astronomical Satellite (IRAS) consists of a spacecraft and a liquid helium cryostat that contains a cooled IR telescope. The telescope's focal plane assembly is cooled to less than 3 K, and contains 62 IR detectors in the survey array which are arranged so that every source crossing the field of view can be seen by at least two detectors in each of four wavelength bands. The satellite was launched into a 900 km-altitude near-polar orbit, and its cryogenic helium supply was exhausted on November 22, 1983. By mission's end, 72 percent of the sky had been observed with three or more hours-confirming scans, and 95 percent with two or more hours-confirming scans. About 2000 stars detected at 12 and 25 microns early in the mission, and identified in the SAO (1966) catalog, have a positional uncertainty ellipse whose axes are 45 x 9 arcsec for an hours-confirmed source.

  13. Artificial intelligence in a mission operations and satellite test environment

    Science.gov (United States)

    Busse, Carl

    1988-01-01

    A Generic Mission Operations System using Expert System technology to demonstrate the potential of Artificial Intelligence (AI) automated monitor and control functions in a Mission Operations and Satellite Test environment will be developed at the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL). Expert system techniques in a real time operation environment are being studied and applied to science and engineering data processing. Advanced decommutation schemes and intelligent display technology will be examined to develop imaginative improvements in rapid interpretation and distribution of information. The Generic Payload Operations Control Center (GPOCC) will demonstrate improved data handling accuracy, flexibility, and responsiveness in a complex mission environment. The ultimate goal is to automate repetitious mission operations, instrument, and satellite test functions by the applications of expert system technology and artificial intelligence resources and to enhance the level of man-machine sophistication.

  14. Sustained Satellite Missions for Climate Data Records

    Science.gov (United States)

    Halpern, David

    2012-01-01

    Satellite CDRs possess the accuracy, longevity, and stability for sustained moni toring of critical variables to enhance understanding of the global integrated Earth system and predict future conditions. center dot Satellite CDRs are a critical element of a global climate observing system. center dot Satellite CDRs are a difficult challenge and require high - level managerial commitment, extensive intellectual capital, and adequate funding.

  15. The Emergent Capabilities of Distributed Satellites and Methods for Selecting Distributed Satellite Science Missions

    Science.gov (United States)

    Corbin, B. A.; Seager, S.; Ross, A.; Hoffman, J.

    2017-12-01

    Distributed satellite systems (DSS) have emerged as an effective and cheap way to conduct space science, thanks to advances in the small satellite industry. However, relatively few space science missions have utilized multiple assets to achieve their primary scientific goals. Previous research on methods for evaluating mission concepts designs have shown that distributed systems are rarely competitive with monolithic systems, partially because it is difficult to quantify the added value of DSSs over monolithic systems. Comparatively little research has focused on how DSSs can be used to achieve new, fundamental space science goals that cannot be achieved with monolithic systems or how to choose a design from a larger possible tradespace of options. There are seven emergent capabilities of distributed satellites: shared sampling, simultaneous sampling, self-sampling, census sampling, stacked sampling, staged sampling, and sacrifice sampling. These capabilities are either fundamentally, analytically, or operationally unique in their application to distributed science missions, and they can be leveraged to achieve science goals that are either impossible or difficult and costly to achieve with monolithic systems. The Responsive Systems Comparison (RSC) method combines Multi-Attribute Tradespace Exploration with Epoch-Era Analysis to examine benefits, costs, and flexible options in complex systems over the mission lifecycle. Modifications to the RSC method as it exists in previously published literature were made in order to more accurately characterize how value is derived from space science missions. New metrics help rank designs by the value derived over their entire mission lifecycle and show more accurate cumulative value distributions. The RSC method was applied to four case study science missions that leveraged the emergent capabilities of distributed satellites to achieve their primary science goals. In all four case studies, RSC showed how scientific value was

  16. Nano-Satellite Secondary Spacecraft on Deep Space Missions

    Science.gov (United States)

    Klesh, Andrew T.; Castillo-Rogez, Julie C.

    2012-01-01

    NanoSat technology has opened Earth orbit to extremely low-cost science missions through a common interface that provides greater launch accessibility. They have also been used on interplanetary missions, but these missions have used one-off components and architectures so that the return on investment has been limited. A natural question is the role that CubeSat-derived NanoSats could play to increase the science return of deep space missions. We do not consider single instrument nano-satellites as likely to complete entire Discovery-class missions alone,but believe that nano-satellites could augment larger missions to significantly increase science return. The key advantages offered by these mini-spacecrafts over previous planetary probes is the common availability of advanced subsystems that open the door to a large variety of science experiments, including new guidance, navigation and control capabilities. In this paper, multiple NanoSat science applications are investigated, primarily for high risk/high return science areas. We also address the significant challenges and questions that remain as obstacles to the use of nano-satellites in deep space missions. Finally, we provide some thoughts on a development roadmap toward interplanetary usage of NanoSpacecraft.

  17. Multi-agent robotic systems and applications for satellite missions

    Science.gov (United States)

    Nunes, Miguel A.

    A revolution in the space sector is happening. It is expected that in the next decade there will be more satellites launched than in the previous sixty years of space exploration. Major challenges are associated with this growth of space assets such as the autonomy and management of large groups of satellites, in particular with small satellites. There are two main objectives for this work. First, a flexible and distributed software architecture is presented to expand the possibilities of spacecraft autonomy and in particular autonomous motion in attitude and position. The approach taken is based on the concept of distributed software agents, also referred to as multi-agent robotic system. Agents are defined as software programs that are social, reactive and proactive to autonomously maximize the chances of achieving the set goals. Part of the work is to demonstrate that a multi-agent robotic system is a feasible approach for different problems of autonomy such as satellite attitude determination and control and autonomous rendezvous and docking. The second main objective is to develop a method to optimize multi-satellite configurations in space, also known as satellite constellations. This automated method generates new optimal mega-constellations designs for Earth observations and fast revisit times on large ground areas. The optimal satellite constellation can be used by researchers as the baseline for new missions. The first contribution of this work is the development of a new multi-agent robotic system for distributing the attitude determination and control subsystem for HiakaSat. The multi-agent robotic system is implemented and tested on the satellite hardware-in-the-loop testbed that simulates a representative space environment. The results show that the newly proposed system for this particular case achieves an equivalent control performance when compared to the monolithic implementation. In terms on computational efficiency it is found that the multi

  18. Mars Relays Satellite Orbit Design Considerations for Global Support of Robotic Surface Missions

    Science.gov (United States)

    Hastrup, Rolf; Cesarone, Robert; Cook, Richard; Knocke, Phillip; McOmber, Robert

    1993-01-01

    This paper discusses orbit design considerations for Mars relay satellite (MRS)support of globally distributed robotic surface missions. The orbit results reported in this paper are derived from studies of MRS support for two types of Mars robotic surface missions: 1) the mars Environmental Survey (MESUR) mission, which in its current definition would deploy a global network of up to 16 small landers, and 2)a Small Mars Sample Return (SMSR) mission, which included four globally distributed landers, each with a return stage and one or two rovers, and up to four additional sets of lander/rover elements in an extended mission phase.

  19. Level-2 product generation for the Swarm satellite constellation mission

    DEFF Research Database (Denmark)

    Olsen, Poul Erik Holmdahl; Tøffner-Clausen, Lars; Olsen, Nils

    In order to take advantage of the unique constellation aspect of ESA's Swarm constellation mission, considerably advanced data analysis tools have been developed. The Swarm ESL/SCARF (Satellite Constellation Application and Research Facility), a consortium of several research institutions, derives...

  20. Plasma propulsion for geostationary satellites for telecommunication and interplanetary missions

    International Nuclear Information System (INIS)

    Dudeck, M; Doveil, F; Arcis, N; Zurbach, S

    2012-01-01

    The advantages of electric propulsion for the orbit maintenance of geostationary satellites for telecommunications are described. Different types of plasma sources for space propulsion are presented. Due to its large performances, one of them, named Hall effect thruster is described in detail and two recent missions in space (Stentor and Smart1) using French Hall thrusters are briefly presented.

  1. A satellite constellation optimization for a regional GNSS remote sensing mission

    Science.gov (United States)

    Gavili Kilaneh, Narin; Mashhadi Hossainali, Masoud

    2017-04-01

    Due to the recent advances in the Global Navigation Satellite System Remote sensing (GNSS¬R) applications, optimization of a satellite orbit to investigate the Earth's properties seems significant. The comparison of the GNSS direct and reflected signals received by a Low Earth Orbit (LEO) satellite introduces a new technique to remotely sense the Earth. Several GNSS¬R missions including Cyclone Global Navigation Satellite System (CYGNSS) have been proposed for different applications such as the ocean wind speed and height monitoring. The geometric optimization of the satellite orbit before starting the mission is a key step for every space mission. Since satellite constellation design varies depending on the application, we have focused on the required geometric criteria for oceanography applications in a specified region. Here, the total number of specular points, their spatial distribution and the accuracy of their position are assumed to be sufficient for oceanography applications. Gleason's method is used to determine the position of specular points. We considered the 2-D lattice and 3-D lattice theory of flower constellation to survey whether a circular orbit or an elliptical one is suitable to improve the solution. Genetic algorithm is implemented to solve the problem. To check the visibility condition between the LEO and GPS satellites, the satellite initial state is propagated by a variable step size numerical integration method. Constellation orbit parameters achieved by optimization provide a better resolution and precession for the specular points in the study area of this research.

  2. Human exploration mission studies

    Science.gov (United States)

    Cataldo, Robert L.

    1989-01-01

    The Office of Exploration has established a process whereby all NASA field centers and other NASA Headquarters offices participate in the formulation and analysis of a wide range of mission strategies. These strategies were manifested into specific scenarios or candidate case studies. The case studies provided a systematic approach into analyzing each mission element. First, each case study must address several major themes and rationale including: national pride and international prestige, advancement of scientific knowledge, a catalyst for technology, economic benefits, space enterprise, international cooperation, and education and excellence. Second, the set of candidate case studies are formulated to encompass the technology requirement limits in the life sciences, launch capabilities, space transfer, automation, and robotics in space operations, power, and propulsion. The first set of reference case studies identify three major strategies: human expeditions, science outposts, and evolutionary expansion. During the past year, four case studies were examined to explore these strategies. The expeditionary missions include the Human Expedition to Phobos and Human Expedition to Mars case studies. The Lunar Observatory and Lunar Outpost to Early Mars Evolution case studies examined the later two strategies. This set of case studies established the framework to perform detailed mission analysis and system engineering to define a host of concepts and requirements for various space systems and advanced technologies. The details of each mission are described and, specifically, the results affecting the advanced technologies required to accomplish each mission scenario are presented.

  3. Turbulence Heating ObserveR – satellite mission proposal

    Czech Academy of Sciences Publication Activity Database

    Vaivads, A.; Retinò, A.; Souček, Jan; Khotyaintsev, Y. V.; Valentini, F.; Escoubet, C. P.; Alexandrova, O.; André, M.; Bale, S. D.; Balikhin, M.; Burgess, D.; Camporeale, E.; Caprioli, D.; Chen, C. H. K.; Clacey, E.; Cully, C. M.; Keyser de, J.; Eastwood, J. P.; Fazakerley, A. N.; Eriksson, S.; Goldstein, M. L.; Graham, D. B.; Haaland, S.; Hoshino, M.; Ji, H.; Karimabadi, H.; Kucharek, H.; Lavraud, B.; Marcucci, F.; Matthaeus, W. H.; Moore, T. E.; Nakamura, R.; Narita, Y.; Němeček, Z.; Norgren, C.; Opgenoorth, H.; Palmroth, M.; Perrone, D.; Pinçon, J.-L.; Rathsman, P.; Rothkaehl, H.; Sahraoui, F.; Servidio, S.; Sorriso-Valvo, L.; Vainio, L.; Vörös, Z.; Wimmer-Schweingruber, R. F.

    2016-01-01

    Roč. 82, č. 5 (2016), 905820501/1-905820501/16 ISSN 0022-3778 Institutional support: RVO:68378289 Keywords : plasma heating * plasma properties * space plasma physics Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.160, year: 2016 https://www.cambridge.org/core/journals/journal-of-plasma-physics/article/div-classtitleturbulence-heating-observer-satellite-mission-proposaldiv/01BB69B09206CE04C48BEDA8F24ED33C/core-reader

  4. A Battery Certification Testbed for Small Satellite Missions

    Science.gov (United States)

    Cameron, Zachary; Kulkarni, Chetan S.; Luna, Ali Guarneros; Goebel, Kai; Poll, Scott

    2015-01-01

    A battery pack consisting of standard cylindrical 18650 lithium-ion cells has been chosen for small satellite missions based on previous flight heritage and compliance with NASA battery safety requirements. However, for batteries that transit through the International Space Station (ISS), additional certification tests are required for individual cells as well as the battery packs. In this manuscript, we discuss the development of generalized testbeds for testing and certifying different types of batteries critical to small satellite missions. Test procedures developed and executed for this certification effort include: a detailed physical inspection before and after experiments; electrical cycling characterization at the cell and pack levels; battery-pack overcharge, over-discharge, external short testing; battery-pack vacuum leak and vibration testing. The overall goals of these certification procedures are to conform to requirements set forth by the agency and identify unique safety hazards. The testbeds, procedures, and experimental results are discussed for batteries chosen for small satellite missions to be launched from the ISS.

  5. Definition of technology development missions for early space station satellite servicing, volume 2

    Science.gov (United States)

    1983-01-01

    The results of all aspects of the early space station satellite servicing study tasks are presented. These results include identification of servicing tasks (and locations), identification of servicing mission system and detailed objectives, functional/operational requirements analyses of multiple servicing scenarios, assessment of critical servicing technology capabilities and development of an evolutionary capability plan, design and validation of selected servicing technology development missions (TDMs), identification of space station satellite servicing accommodation needs, and the cost and schedule implications of acquiring both required technology capability development and conducting the selected TDMs.

  6. Definition of technology development missions for early Space Station satellite servicing. Volume 1: Executive summary

    Science.gov (United States)

    1984-01-01

    The Executive Summary volume 1, includes an overview of both phases of the Definition of Technology Development Missions for Early Space Station Satellite Servicing. The primary purpose of Phase 1 of the Marshall Space Flight Center (MSFC) Satellite Servicing Phase 1 study was to establish requirements for demonstrating the capability of performing satellite servicing activities on a permanently manned Space Station in the early 1990s. The scope of Phase 1 included TDM definition, outlining of servicing objectives, derivation of initial Space Station servicing support requirements, and generation of the associated programmatic schedules and cost. The purpose of phase 2 of the satellite servicing study was to expand and refine the overall understanding of how best to use the manned space station as a test bed for demonstration of satellite servicing capabilities.

  7. PoPSat: The Polar Precipitation Satellite Mission

    Science.gov (United States)

    Binder, Matthias J.; Agten, Dries; Arago-Higueras, Nadia; Borderies, Mary; Diaz-Schümmer, Carlos; Jamali, Maryam; Jimenez-Lluva, David; Kiefer, Joshua; Larsson, Anna; Lopez-Gilabert, Lola; Mione, Michele; Mould, Toby JD; Pavesi, Sara; Roth, Georg; Tomicic, Maja

    2017-04-01

    The terrestrial water cycle is one of many unique regulatory systems on planet Earth. It is directly responsible for sustaining biological life on land and human populations by ensuring sustained crop yields. However, this delicate balanced system continues to be influenced significantly by a changing climate, which has had drastic impacts particularly on the polar regions. Precipitation is a key process in the weather and climate system, due to its storage, transport and release of latent heat in the atmosphere. It has been extensively investigated in low latitudes, in which detailed models have been established for weather prediction. However, a gap has been left in higher latitudes above 65°, which show the strongest response to climate changes and where increasing precipitations have been foreseen in the future. In order to establish a global perspective of atmospheric processes, space observation of high-latitude areas is crucial to produce globally consistent data. The increasing demand for those data has driven a critical need to devise a mission which fills the gaps in current climate models. The authors propose the Polar Precipitation Satellite (PoPSat), an innovative satellite mission to provide enhanced observation of light and medium precipitation, focusing on snowfall and light rain in high latitudes. PoPSat is the first mission aimed to provide high resolution 3D structural information about snow and light precipitation systems and cloud structure in the covered areas. The satellite is equipped with a dual band (Ka and W band) phased-array radar. These antennas provide a horizontal resolution of 2 km and 4 km respectively which will exceed all other observations made to date at high-latitudes, while providing the additional capability to monitor snowfall. The data gathered will be compatible and complementary with measurements made during previous missions. PoPSat has been designed to fly on a sun-synchronous, dawn-dusk orbit at 460 km. This orbit

  8. Induction studies with satellite data

    DEFF Research Database (Denmark)

    Olsen, Nils

    1999-01-01

    The natural variations of the Earth's magnetic field of periods spanning from milliseconds to decades can be used to infer the conductivity-depth profile of the Earth's interior. Satellites provide a good spatial coverage of magnetic measurements, and forthcoming missions will probably allow...... for observations lasting several years, which helps to reduce the statistical error of the estimated response functions. Two methods are used to study the electrical conductivity of the Earth's mantle in the period range from hours to months. In the first, known as the potential method, a spherical harmonic...... days, this difference probably is not caused purely by differences in mantle conductivity (for which one would expect less difference for the longer periods). Further studies with data from recently launched and future satellites are needed....

  9. A global high resolution mean sea surface from multi mission satellite altimetry

    DEFF Research Database (Denmark)

    Knudsen, Per

    1999-01-01

    Satellite altimetry from the GEOSAT and the ERS-1 geodetic missions provide altimeter data with a very dense coverage. Hence, the heights of the sea surface may be recovered very detailed. Satellite altimetry from the 35 days repeat cycle mission of the ERS satellites and, especially, from the 10...

  10. Definition of technology development missions for early space station satellite servicing, volume 1

    Science.gov (United States)

    1983-01-01

    The testbed role of an early manned space station in the context of a satellite servicing evolutionary development and flight demonstration technology plan which results in a satellite servicing operational capability is defined. A satellite servicing technology development mission (a set of missions) to be performed on an early manned space station is conceptually defined.

  11. SWOT, The Surface Water and Ocean Topography Satellite Mission (Invited)

    Science.gov (United States)

    Alsdorf, D.; Andreadis, K.; Bates, P. D.; Biancamaria, S.; Clark, E.; Durand, M. T.; Fu, L.; Lee, H.; Lettenmaier, D. P.; Mognard, N. M.; Moller, D.; Morrow, R. A.; Rodriguez, E.; Shum, C.

    2009-12-01

    Surface fresh water is essential for life, yet we have surprisingly poor knowledge of its variability in space and time. Similarly, ocean circulation fundamentally drives global climate variability, yet the ocean current and eddy field that affects ocean circulation and heat transport at the sub-mesoscale resolution and particularly near coastal and estuary regions, is poorly known. About 50% of the vertical exchange of water properties (nutrients, dissovled CO2, heat, etc) in the upper ocean is taking place at the sub-mesoscale. Measurements from the Surface Water and Ocean Topography satellite mission (SWOT) will make strides in understanding these processes and improving global ocean models for studying climate change. SWOT is a swath-based interferometric-altimeter designed to acquire elevations of ocean and terrestrial water surfaces at unprecedented spatial and temporal resolutions. The mission will provide measurements of storage changes in lakes, reservoirs, and wetlands as well as estimates of discharge in rivers. These measurements are important for global water and energy budgets, constraining hydrodynamic models of floods, carbon evasion through wetlands, and water management, especially in developing nations. Perhaps most importantly, SWOT measurements will provide a fundamental understanding of the spatial and temporal variations in global surface waters, which for many countries are the primary source of water. An on-going effort, the “virtual mission” (VM) is designed to help constrain the required height and slope accuracies, the spatial sampling (both pixels and orbital coverage), and the trade-offs in various temporal revisits. Example results include the following: (1) Ensemble Kalman filtering of VM simulations recover water depth and discharge, reducing the discharge RMSE from 23.2% to 10.0% over an 84-day simulation period, relative to a simulation without assimilation. (2) Ensemble-based data assimilation of SWOT like measurements yields

  12. Japanese Global Precipitation Measurement (GPM) mission status and application of satellite-based global rainfall map

    Science.gov (United States)

    Kachi, Misako; Shimizu, Shuji; Kubota, Takuji; Yoshida, Naofumi; Oki, Riko; Kojima, Masahiro; Iguchi, Toshio; Nakamura, Kenji

    2010-05-01

    . Collaboration with GCOM-W is not only limited to its participation to GPM constellation but also coordination in areas of algorithm development and validation in Japan. Generation of high-temporal and high-accurate global rainfall map is one of targets of the GPM mission. As a proto-type for GPM era, JAXA has developed and operates the Global Precipitation Map algorithm in near-real-time since October 2008, and hourly and 0.1-degree resolution binary data and images available at http://sharaku.eorc.jaxa.jp/GSMaP/ four hours after observation. The algorithms are based on outcomes from the Global Satellite Mapping for Precipitation (GSMaP) project, which was sponsored by the Japan Science and Technology Agency (JST) under the Core Research for Evolutional Science and Technology (CREST) framework between 2002 and 2007 (Okamoto et al., 2005; Aonashi et al., 2009; Ushio et al., 2009). Target of GSMaP project is to produce global rainfall maps that are highly accurate and in high temporal and spatial resolution through the development of rain rate retrieval algorithms based on reliable precipitation physical models by using several microwave radiometer data, and comprehensive use of precipitation radar and geostationary infrared imager data. Near-real-time GSMaP data is distributed via internet and utilized by end users. Purpose of data utilization by each user covers broad areas and in world wide; Science researches (model validation, data assimilation, typhoon study, etc.), weather forecast/service, flood warning and rain analysis over river basin, oceanographic condition forecast, agriculture, and education. Toward the GPM era, operational application should be further emphasized as well as science application. JAXA continues collaboration with hydrological communities to utilize satellite-based precipitation data as inputs to future flood prediction and warning system, as well as with meteorological agencies to proceed further data utilization in numerical weather prediction

  13. Study on Earth Radiation Budget mission scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Dlhopolsky, R; Hollmann, R; Mueller, J; Stuhlmann, R [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    1998-12-31

    The goal of this study is to study optimized satellite configurations for observation of the radiation balance of the earth. We present a literature survey of earth radiation budget missions and instruments. We develop a parametric tool to simulate realistic multiple satellite mission scenarios. This tool is a modular computer program which models satellite orbits and scanning operation. We use Meteosat data sampled at three hour intervals as a database to simulate atmospheric scenes. Input variables are satellite equatorial crossing time and instrument characteristics. Regional, zonal and global monthly averages of shortwave and longwave fluxes for an ideal observing system and several realistic satellite scenarios are produced. Comparisons show that the three satellite combinations which have equatorial crossing times at midmorning, noon and midafternoon provide the best shortwave monitoring. Crossing times near sunrise and sunset should be avoided for the shortwave. Longwave diurnal models are necessary over and surfaces and cloudy regions, if there are only two measurements made during daylight hours. We have found in the shortwave inversion comparison that at least 15% of the monthly regional errors can be attributed to the shortwave anisotropic models used. (orig.) 68 refs.

  14. Study on Earth Radiation Budget mission scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Dlhopolsky, R.; Hollmann, R.; Mueller, J.; Stuhlmann, R. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    1997-12-31

    The goal of this study is to study optimized satellite configurations for observation of the radiation balance of the earth. We present a literature survey of earth radiation budget missions and instruments. We develop a parametric tool to simulate realistic multiple satellite mission scenarios. This tool is a modular computer program which models satellite orbits and scanning operation. We use Meteosat data sampled at three hour intervals as a database to simulate atmospheric scenes. Input variables are satellite equatorial crossing time and instrument characteristics. Regional, zonal and global monthly averages of shortwave and longwave fluxes for an ideal observing system and several realistic satellite scenarios are produced. Comparisons show that the three satellite combinations which have equatorial crossing times at midmorning, noon and midafternoon provide the best shortwave monitoring. Crossing times near sunrise and sunset should be avoided for the shortwave. Longwave diurnal models are necessary over and surfaces and cloudy regions, if there are only two measurements made during daylight hours. We have found in the shortwave inversion comparison that at least 15% of the monthly regional errors can be attributed to the shortwave anisotropic models used. (orig.) 68 refs.

  15. The Delta low-inclination satellite concept, an opportunity to enhance the science return of the Swarm mission

    DEFF Research Database (Denmark)

    Hulot, Gauthier; Leger, Jean-Michel; Olsen, Nils

    ESA’s Swarm mission aims at studying all sources of Earth’s magnetic field. It consists of two satellites (Alpha and Charlie), which fly side-by-side on near polar orbits at an altitude of slightly less than 500 km, and of a third satellite (Bravo) on a similar but slightly more polar and higher ...

  16. The German joint research project "concepts for future gravity satellite missions"

    Science.gov (United States)

    Reubelt, Tilo; Sneeuw, Nico; Fichter, Walter; Müller, Jürgen

    2010-05-01

    Within the German joint research project "concepts for future gravity satellite missions", funded by the Geotechnologies programme of the German Federal Ministry of Education and Research, options and concepts for future satellite missions for precise (time-variable) gravity field recovery are investigated. The project team is composed of members from science and industry, bringing together experts in geodesy, satellite systems, metrology, sensor technology and control systems. The majority of team members already contributed to former gravity missions. The composition of the team guarantees that not only geodetic aspects and objectives are investigated, but also technological and financial constraints are considered. Conversely, satellite, sensor and system concepts are developed and improved in a direct exchange with geodetic and scientific claims. The project aims to develop concepts for both near and mid-term future satellite missions, taking into account e.g. advanced satellite formations and constellations, improved orbit design, innovative metrology and sensor systems and advances in satellite systems.

  17. The Iodine Satellite (iSAT) Hall Thruster Demonstration Mission Concept and Development

    Science.gov (United States)

    Dankanich, John W.; Polzin, Kurt A.; Calvert, Derek; Kamhawi, Hani

    2014-01-01

    The use of iodine propellant for Hall thrusters has been studied and proposed by multiple organizations due to the potential mission benefits over xenon. In 2013, NASA Marshall Space Flight Center competitively selected a project for the maturation of an iodine flight operational feed system through the Technology Investment Program. Multiple partnerships and collaborations have allowed the team to expand the scope to include additional mission concept development and risk reduction to support a flight system demonstration, the iodine Satellite (iSAT). The iSAT project was initiated and is progressing towards a technology demonstration mission preliminary design review. The current status of the mission concept development and risk reduction efforts in support of this project is presented.

  18. Virtual Mission First Results Supporting the WATER HM Satellite Concept

    Science.gov (United States)

    Alsdorf, D.; Andreadis, K.; Lettenmaier, D.; Moller, D.; Rodriguez, E.; Bates, P.; Mognard, N.; Participants, W.

    2007-12-01

    Surface fresh water is essential for life, yet we have surprisingly poor knowledge of its variability in space and time. Similarly, ocean circulation and ocean-atmosphere interactions fundamentally drive weather and climate variability, yet the global ocean current and eddy field (e.g., the Gulf Stream) that affects ocean circulation is poorly known. The Water And Terrestrial Elevation Recovery Hydrosphere Mapper satellite mission concept (WATER HM or SWOT per the NRC Decadal Survey) is a swath-based interferometric-altimeter designed to acquire elevations of ocean and terrestrial water surfaces at unprecedented spatial and temporal resolutions. WATER HM will have tremendous implications for estimation of the global water cycle, water management, ocean and coastal circulation, and assessment of many water-related impacts from climate change (e.g., sea level rise, carbon evasion, etc.). We describe a hydrological "virtual mission" (VM) for WATER HM which consists of: (a) A hydrodynamic-instrument simulation model that maps variations in water levels along river channels and across floodplains. These are then assimilated to estimate discharge and to determine trade-offs between resolutions and mission costs. (b) Measurements from satellites to determine feasibility of existing platforms for measuring storage changes and estimating discharge. First results demonstrate that: (1) Ensemble Kalman filtering of VM simulations recover water depth and discharge, reducing the discharge RMSE from 23.2% to 10.0% over an 84- day simulation period, relative to a simulation without assimilation. The filter also shows that an 8-day overpass frequency produces discharge relative errors of 10.0%, while 16-day and 32-day frequencies result in errors of 12.1% and 16.9%, respectively. (2) SRTM measurements of water surfaces along the Mississippi, Missouri, Ohio, and Amazon rivers, as well as smaller tributaries, show height standard deviations of 5 meters or greater (SRTM is the

  19. Formation flying within a constellation of nano-satellites the QB50 mission

    NARCIS (Netherlands)

    Gill, E.K.A.; Sundaramoorthy, P.; Bouwmeester, J.; Zandbergen, B.; Reinhard, R.

    2010-01-01

    QB50 is a mission establishing an international network of 50 nano-satellites for multi-point, in-situ measurements in the lower thermosphere and re-entry research. As part of the QB50 mission, the Delft University of Technology intends to contribute two nano-satellites both being equipped with a

  20. The large satellite program of ESA and its relevance for broadcast missions

    Science.gov (United States)

    Fromm, H.-H.; Herdan, B. L.

    1981-03-01

    In an investigation of the market prospects and payload requirements of future communications satellites, it was concluded that during the next 15 years many space missions will demand larger satellite platforms than those currently available. These platforms will be needed in connection with direct-broadcasting satellites, satellites required to enhance capacities in the case of traditional services, and satellites employed to introduce new types of satellite-based communications operating with small terminals. Most of the larger satellites would require the Ariane III capability, corresponding to about 1400 kg satellite mass in geostationary orbit. Attention is given to L-SAT platform capabilities and broadcast payload requirements, taking into account a European direct-broadcast satellite and Canadian direct-broadcast missions.

  1. Radiation Measured for Chinese Satellite SJ-10 Space Mission

    Science.gov (United States)

    Zhou, Dazhuang; Sun, Yeqing; Zhang, Binquan; Zhang, Shenyi; Sun, Yueqiang; Liang, Jinbao; Zhu, Guangwu; Jing, Tao; Yuan, Bin; Zhang, Huanxin; Zhang, Meng; Wang, Wei; Zhao, Lei

    2018-02-01

    Space biological effects are mainly a result of space radiation particles with high linear energy transfer (LET); therefore, accurate measurement of high LET space radiation is vital. The radiation in low Earth orbits is composed mainly of high-energy galactic cosmic rays (GCRs), solar energetic particles, particles of radiation belts, the South Atlantic Anomaly, and the albedo neutrons and protons scattered from the Earth's atmosphere. CR-39 plastic nuclear track detectors sensitive to high LET are the best passive detectors to measure space radiation. The LET method that employs CR-39 can measure all the radiation LET spectra and quantities. CR-39 detectors can also record the incident directions and coordinates of GCR heavy ions that pass through both CR-39 and biosamples, and the impact parameter, the distance between the particle's incident point and the seed's spore, can then be determined. The radiation characteristics and impact parameter of GCR heavy ions are especially beneficial for in-depth research regarding space radiation biological effects. The payload returnable satellite SJ-10 provided an excellent opportunity to investigate space radiation biological effects with CR-39 detectors. The space bio-effects experiment was successfully conducted on board the SJ-10 satellite. This paper introduces space radiation in low Earth orbits and the LET method in radiation-related research and presents the results of nuclear tracks and biosamples hitting distributions of GCR heavy ions, the radiation LET spectra, and the quantities measured for the SJ-10 space mission. The SJ-10 bio-experiment indicated that radiation may produce significant bio-effects.

  2. Advanced satellite servicing facility studies

    Science.gov (United States)

    Qualls, Garry D.; Ferebee, Melvin J., Jr.

    1988-01-01

    A NASA-sponsored systems analysis designed to identify and recommend advanced subsystems and technologies specifically for a manned Sun-synchronous platform for satellite management is discussed. An overview of system design, manned and unmanned servicing facilities, and representative mission scenarios are given. Mission areas discussed include facility based satellite assembly, checkout, deployment, refueling, repair, and systems upgrade. The ferrying of materials and consumables to and from manufacturing platforms, deorbit, removal, repositioning, or salvage of satellites and debris, and crew rescue of any other manned vehicles are also examined. Impacted subsytems discussed include guidance navigation and control, propulsion, data management, power, thermal control, structures, life support, and radiation management. In addition, technology issues which would have significant impacts on the system design are discussed.

  3. Potential fields & satellite missions: what they tell us about the Earth's core?

    Science.gov (United States)

    Mandea, M.; Panet, I.; Lesur, V.; de Viron, O.; Diament, M.; Le Mouël, J.

    2012-12-01

    Since the advent of satellite potential field missions, the search to find information they can carry about the Earth's core has been motivated both by an interest in understanding the structure of dynamics of the Earth's interior and by the possibility of applying new space data analysis. While it is agreed upon that the magnetic field measurements from space bring interesting information on the rapid variations of the core magnetic field and flows associated with, the question turns to whether the core process can have a signature in the space gravity data. Here, we tackle this question, in the light of the recent data from the GRACE mission, that reach an unprecedented precision. Our study is based on eight years of high-resolution, high-accuracy gravity and magnetic satellite data, provided by the GRACE and CHAMP satellite missions. From the GRACE CNES/GRGS geoid solutions, we have emphasized the long-term variability by using a specific post-processing technique. From the CHAMP magnetic data we have computed models for the core magnetic field and its temporal variations, and the flow at the top of the core. A correlation analysis between the gravity and magnetic gridded series indicates that the inter-annual changes in the core magnetic field - under a region from the Atlantic to Indian Oceans - coincide with similar changes in the gravity field. These results should be considered as a constituent when planning new Earth's observation space missions and future innovations relevant to both gravity (after GRACE Follow-On) and magnetic (after Swarm) missions.

  4. Improved Traceability of a Small Satellite Mission Concept to Requirements Using Model Based System Engineering

    Science.gov (United States)

    Reil, Robin L.

    2014-01-01

    Model Based Systems Engineering (MBSE) has recently been gaining significant support as a means to improve the "traditional" document-based systems engineering (DBSE) approach to engineering complex systems. In the spacecraft design domain, there are many perceived and propose benefits of an MBSE approach, but little analysis has been presented to determine the tangible benefits of such an approach (e.g. time and cost saved, increased product quality). This paper presents direct examples of how developing a small satellite system model can improve traceability of the mission concept to its requirements. A comparison of the processes and approaches for MBSE and DBSE is made using the NASA Ames Research Center SporeSat CubeSat mission as a case study. A model of the SporeSat mission is built using the Systems Modeling Language standard and No Magic's MagicDraw modeling tool. The model incorporates mission concept and requirement information from the mission's original DBSE design efforts. Active dependency relationships are modeled to demonstrate the completeness and consistency of the requirements to the mission concept. Anecdotal information and process-duration metrics are presented for both the MBSE and original DBSE design efforts of SporeSat.

  5. Magnetic dipole moment estimation and compensation for an accurate attitude control in nano-satellite missions

    Science.gov (United States)

    Inamori, Takaya; Sako, Nobutada; Nakasuka, Shinichi

    2011-06-01

    Nano-satellites provide space access to broader range of satellite developers and attract interests as an application of the space developments. These days several new nano-satellite missions are proposed with sophisticated objectives such as remote-sensing and observation of astronomical objects. In these advanced missions, some nano-satellites must meet strict attitude requirements for obtaining scientific data or images. For LEO nano-satellite, a magnetic attitude disturbance dominates over other environmental disturbances as a result of small moment of inertia, and this effect should be cancelled for a precise attitude control. This research focuses on how to cancel the magnetic disturbance in orbit. This paper presents a unique method to estimate and compensate the residual magnetic moment, which interacts with the geomagnetic field and causes the magnetic disturbance. An extended Kalman filter is used to estimate the magnetic disturbance. For more practical considerations of the magnetic disturbance compensation, this method has been examined in the PRISM (Pico-satellite for Remote-sensing and Innovative Space Missions). This method will be also used for a nano-astrometry satellite mission. This paper concludes that use of the magnetic disturbance estimation and compensation are useful for nano-satellites missions which require a high accurate attitude control.

  6. An Evaluation of Antarctica as a Calibration Target for Passive Microwave Satellite Missions

    Science.gov (United States)

    Kim, Edward

    2012-01-01

    Passive microwave remote sensing at L-band (1.4 GHz) is sensitive to soil moisture and sea surface salinity, both important climate variables. Science studies involving these variables can now take advantage of new satellite L-band observations. The first mission with regular global passive microwave observations at L-band is the European Space Agency's Soil Moisture and Ocean Salinity (SMOS), launched November, 2009. A second mission, NASA's Aquarius, was launched June, 201l. A third mission, NASA's Soil Moisture Active Passive (SMAP) is scheduled to launch in 2014. Together, these three missions may provide a decade-long data record -- provided that they are intercalibrated. The intercalibration is best performed at the radiance (brightness temperature) level, and Antarctica is proving to be a key calibration target. However, Antarctica has thus far not been fully characterized as a potential target. This paper will present evaluations of Antarctica as a microwave calibration target for the above satellite missions. Preliminary analyses have identified likely target areas, such as the vicinity of Dome-C and larger areas within East Antarctica. Physical sources of temporal and spatial variability of polar firn are key to assessing calibration uncertainty. These sources include spatial variability of accumulation rate, compaction, surface characteristics (dunes, micro-topography), wind patterns, and vertical profiles of density and temperature. Using primarily SMOS data, variability is being empirically characterized and attempts are being made to attribute observed variability to physical sources. One expected outcome of these studies is the potential discovery of techniques for remotely sensing--over all of Antarctica--parameters such as surface temperature.

  7. Definition of technology development missions for early Space Station satellite servicing. Volume 2: Technical

    Science.gov (United States)

    Cable, D. A.; Diewald, C. A.; Hills, T. C.; Parmentier, T. J.; Spencer, R. A.; Stone, G. E.

    1984-01-01

    Volume 2 contains the Technical Report of the approach and results of the Phase 2 study. The phase 2 servicing study was initiated in June 1983, and is being reported in this document. The scope of the contract was to: (1) define in detail five selected technology development missions (TDM); (2) conduct a design requirement analysis to refine definitions of satellite servicing requirements at the space station; and (3) develop a technology plan that would identify and schedule prerequisite precursor technology development, associated. STS flight experiments and space station experiments needed to provide onorbit validation of the evolving technology.

  8. Auto Mission Planning System Design for Imaging Satellites and Its Applications in Environmental Field

    Directory of Open Access Journals (Sweden)

    He Yongming

    2016-10-01

    Full Text Available Satellite hardware has reached a level of development that enables imaging satellites to realize applications in the area of meteorology and environmental monitoring. As the requirements in terms of feasibility and the actual profit achieved by satellite applications increase, we need to comprehensively consider the actual status, constraints, unpredictable information, and complicated requirements. The management of this complex information and the allocation of satellite resources to realize image acquisition have become essential for enhancing the efficiency of satellite instrumentation. In view of this, we designed a satellite auto mission planning system, which includes two sub-systems: the imaging satellite itself and the ground base, and these systems would then collaborate to process complicated missions: the satellite mainly focuses on mission planning and functions according to actual parameters, whereas the ground base provides auxiliary information, management, and control. Based on the requirements analysis, we have devised the application scenarios, main module, and key techniques. Comparison of the simulation results of the system, confirmed the feasibility and optimization efficiency of the system framework, which also stimulates new thinking for the method of monitoring environment and design of mission planning systems.

  9. Optimizing Orbit-Instrument Configuration for Global Precipitation Mission (GPM) Satellite Fleet

    Science.gov (United States)

    Smith, Eric A.; Adams, James; Baptista, Pedro; Haddad, Ziad; Iguchi, Toshio; Im, Eastwood; Kummerow, Christian; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Following the scientific success of the Tropical Rainfall Measuring Mission (TRMM) spearheaded by a group of NASA and NASDA scientists, their external scientific collaborators, and additional investigators within the European Union's TRMM Research Program (EUROTRMM), there has been substantial progress towards the development of a new internationally organized, global scale, and satellite-based precipitation measuring mission. The highlights of this newly developing mission are a greatly expanded scope of measuring capability and a more diversified set of science objectives. The mission is called the Global Precipitation Mission (GPM). Notionally, GPM will be a constellation-type mission involving a fleet of nine satellites. In this fleet, one member is referred to as the "core" spacecraft flown in an approximately 70 degree inclined non-sun-synchronous orbit, somewhat similar to TRMM in that it carries both a multi-channel polarized passive microwave radiometer (PMW) and a radar system, but in this case it will be a dual frequency Ku-Ka band radar system enabling explicit measurements of microphysical DSD properties. The remainder of fleet members are eight orbit-synchronized, sun-synchronous "constellation" spacecraft each carrying some type of multi-channel PMW radiometer, enabling no worse than 3-hour diurnal sampling over the entire globe. In this configuration the "core" spacecraft serves as a high quality reference platform for training and calibrating the PMW rain retrieval algorithms used with the "constellation" radiometers. Within NASA, GPM has advanced to the pre-formulation phase which has enabled the initiation of a set of science and technology studies which will help lead to the final mission design some time in the 2003 period. This presentation first provides an overview of the notional GPM program and mission design, including its organizational and programmatic concepts, scientific agenda, expected instrument package, and basic flight

  10. Studying the Formation, Evolution, and Habitability of the Galilean Satellites

    Science.gov (United States)

    McGrath, M.; Waite, J. H. Jr.; Brockwell, T.; McKinnon, W.; Wyrick, D.; Mousis, O.; Magee, B.

    2013-01-01

    Highly sensitive, high-mass resolution mass spectrometry is an important in situ tool for the study of solar system bodies. In this talk we detail the science objectives, develop the rationale for the measurement requirements, and describe potential instrument/mission methodologies for studying the formation, evolution, and habitability of the Galilean satellites. We emphasize our studies of Ganymede and Europa as described in our instrument proposals for the recently selected JUICE mission and the proposed Europa Clipper mission.

  11. FireBird - a small satellite fire monitoring mission: Status and first results

    Science.gov (United States)

    Lorenz, Eckehard; Rücker, Gernot; Terzibaschian, Thomas; Klein, Doris; Tiemann, Joachim

    2014-05-01

    The scientific mission FireBird is operated by the German Aerospace Center (DLR) and consists of two small satellites. The first satellite - TET-1 - was successfully launched from Baikonur, Russia in July 2012. Its first year in orbit was dedicated to a number of experiments within the framework of the DLR On Orbit Verification (OOV) program which is dedicated to technology testing in space. After successful completion of its OOV phase, TET-1 was handed over to the DLR FireBird mission and is now a dedicated Earth Observation mission. Its primary goal is sensing of hot phenomena such as wildfires, volcanoes, gas flares and industrial hotspots. The second satellite, BiROS is scheduled for launch in the second or third quarter of 2015. The satellite builds on the heritage of the DLR BIRD (BIspectral Infrared Detection) mission and delivers quantitative information (such as Fire Radiative Power, FRP) at a spatial resolution of 350 m, superior to any current fire enabled satellite system such as NPP VIIRS, MODIS or Meteosat SEVIRI. The satellite is undergoing a four month validation phase during which satellite operations are adapted to the new mission goals of FireBIRD and processing capacities are established to guarantee swift processing and delivery of high quality data. The validation phase started with an informal Operational Readiness Review and will be completed with a formal review, covering all aspects of the space and ground segments. The satellite is equipped with a camera with a 42 m ground pixel size in the red, green and near infrared spectral range, and a 370 m ground pixel size camera in the mid and thermal infrared with a swath of 185 km. The satellite can be pointed towards a target in order to enhance observation frequency. First results of the FireBird mission include a ground validation experiment and acquisitions over fires across the world. Once the validation phase is finished the data will be made available to a wide scientific community.

  12. Small Explorer project: Submillimeter Wave Astronomy Satellite (SWAS). Mission operations and data analysis plan

    Science.gov (United States)

    Melnick, Gary J.

    1990-01-01

    The Mission Operations and Data Analysis Plan is presented for the Submillimeter Wave Astronomy Satellite (SWAS) Project. It defines organizational responsibilities, discusses target selection and navigation, specifies instrument command and data requirements, defines data reduction and analysis hardware and software requirements, and discusses mission operations center staffing requirements.

  13. Relativity mission with two counter-orbiting polar satellites

    International Nuclear Information System (INIS)

    Van Patten, R.A.; Everitt, C.W.F.

    1975-01-01

    In 1918, J. Lense and H. Thirring calculated that a moon in orbit around a massive rotating planet would experience a nodal dragging effect due to general relativity. An experiment to measure this effect with two counter-orbiting drag-free satellites in polar earth orbit is described. For a 2 1 / 2 year experiment, the measurement accuracy should approach 1 percent. In addition to precision tracking data from existing ground stations, satellite-to-satellite Doppler ranging data are taken at points of passing near the poles. New geophysical information on both earth harmonics and tidal effects is inherent in the polar ranging data. (auth)

  14. Cost-Effective Icy Bodies Exploration using Small Satellite Missions

    Science.gov (United States)

    Jonsson, Jonas; Mauro, David; Stupl, Jan; Nayak, Michael; Aziz, Jonathan; Cohen, Aaron; Colaprete, Anthony; Dono-Perez, Andres; Frost, Chad; Klamm, Benjamin; hide

    2015-01-01

    It has long been known that Saturn's moon Enceladus is expelling water-rich plumes into space, providing passing spacecraft with a window into what is hidden underneath its frozen crust. Recent discoveries indicate that similar events could also occur on other bodies in the solar system, such as Jupiter's moon Europa and the dwarf planet Ceres in the asteroid belt. These plumes provide a possible giant leap forward in the search for organics and assessing habitability beyond Earth, stepping stones toward the long-term goal of finding extraterrestrial life. The United States Congress recently requested mission designs to Europa, to fit within a cost cap of $1B, much less than previous mission designs' estimates. Here, innovative cost-effective small spacecraft designs for the deep-space exploration of these icy worlds, using new and emerging enabling technologies, and how to explore the outer solar system on a budget below the cost horizon of a flagship mission, are investigated. Science requirements, instruments selection, rendezvous trajectories, and spacecraft designs are some topics detailed. The mission concepts revolve around a comparably small-sized and low-cost Plume Chaser spacecraft, instrumented to characterize the vapor constituents encountered on its trajectory. In the event that a plume is not encountered, an ejecta plume can be artificially created by a companion spacecraft, the Plume Maker, on the target body at a location timed with the passage of the Plume Chaser spacecraft. Especially in the case of Ceres, such a mission could be a great complimentary mission to Dawn, as well as a possible future Europa Clipper mission. The comparably small volume of the spacecraft enables a launch to GTO as a secondary payload, providing multiple launch opportunities per year. Plume Maker's design is nearly identical to the Plume Chaser, and fits within the constraints for a secondary payload launch. The cost-effectiveness of small spacecraft missions enables the

  15. Adding a Mission to the Joint Polar Satellite System (JPSS) Common Ground System (CGS)

    Science.gov (United States)

    Miller, S. W.; Grant, K. D.; Jamilkowski, M. L.

    2014-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS). Developed and maintained by Raytheon Intelligence, Information and Services (IIS), the CGS is a multi-mission enterprise system serving NOAA, NASA and their national and international partners. The CGS provides a wide range of support to a number of missions: 1) Command and control and mission management for the Suomi National Polar-orbiting Partnership (S-NPP) mission today, expanding this support to the JPSS-1 satellite and the Polar Free Flyer mission in 2017 2) Data acquisition via a Polar Receptor Network (PRN) for S-NPP, the Japan Aerospace Exploration Agency's (JAXA) Global Change Observation Mission - Water (GCOM-W1), POES, and the Defense Meteorological Satellite Program (DMSP) and Coriolis/WindSat for the Department of Defense (DoD) 3) Data routing over a global fiber Wide Area Network (WAN) for S-NPP, JPSS-1, Polar Free Flyer, GCOM-W1, POES, DMSP, Coriolis/WindSat, the NASA Space Communications and Navigation (SCaN, which includes several Earth Observing System [EOS] missions), MetOp for the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the National Science Foundation (NSF) 4) Environmental data processing and distribution for S-NPP, GCOM-W1 and JPSS-1 With this established infrastructure and existing suite of missions, the CGS

  16. A Prototype Knowledge-Based System for Satellite Mission Planning.

    Science.gov (United States)

    1986-12-01

    used by different groups in an operational environment. 6 II. Literature Review As management science has recognized, it is not practical to separate...schedule only one satellite per set of requirements. A -4 .............. er.- Appendix B O9perational Conce~t Usin a Knowlede -Based System There are many

  17. Design Concepts for a Small Space-Based GEO Relay Satellite for Missions Between Low Earth and near Earth Orbits

    Science.gov (United States)

    Bhasin, Kul B.; Warner, Joseph D.; Oleson, Steven; Schier, James

    2014-01-01

    the number of links looking above and below GEO; the detailed design of a GEO SSBS spacecraft bus and its accommodation of the communication payload, and a summary of the trade study that resulted in the selection of the Falcon 9 launch vehicle to deploy the SSBS and its impact on cost reductions per satellite. ======================================================================== Several initiatives have taken place within NASA1 and international space agencies2 to create a human exploration strategy for expanding human presence into the solar system; these initiatives have been driven by multiple factors to benefit Earth. Of the many elements in the strategy one stands out: to send robotic and human missions to destinations beyond Low Earth Orbit (LEO), including cis-lunar space, Near-Earth Asteroids (NEAs), the Moon, and Mars and its moons.3, 4 The time frame for human exploration to various destinations, based on the public information available,1,4 is shown in Figure 1. Advance planning is needed to define how future space communications services will be provided in the new budget environment to meet future space communications needs. The spacecraft for these missions can be dispersed anywhere from below LEO to beyond GEO, and to various destinations within the solar system. NASA's Space Communications and Navigation (SCaN) program office provides communication and tracking services to space missions during launch, in-orbit testing, and operation phases. Currently, SCaN's space networking relay satellites mainly provide services to users below GEO, at Near Earth Orbit (NEO), below LEO, and in deep space. The potential exists for using a space-based relay satellite, located in the vicinity of various solar system destinations, to provide communication space links to missions both below and above its orbit. Such relays can meet the needs of human exploration missions for maximum connectivity to Earth locations and for reduced latency. In the past, several studies

  18. An Evaluation of Recent Gravity Models wrt. Altimeter Satellite Missions

    Science.gov (United States)

    Lemoine, Frank G.; Zelensky, N. P.; Luthcke, S. B.; Beckley, B. D.; Chinn, D. S.; Rowlands, D. D.

    2003-01-01

    With the launch of CHAMP and GRACE, we have entered a new phase in the history of satellite geodesy. For the first time, geopotential models are now available based almost exclusively on satellite-satellite tracking either with GPS in the case of the CHAMP-based geopotential models, or co-orbital intersatellite ultra-precise ranging in the case of GRACE. Different groups have analyzed these data, and produced a series of geopotential models (e.g., EIGENlS, EIGEN2, GGM0lS, GGMOlC) that incorporate the new data. We will compare the performance of these "newer" geopotential models with the standard models now used for computations, (e.g., JGM-3, BGM-96, PGS7727, and GRIMS-C1) for TOPEX, JASON, Geosat-Follow-On (GFO), and Envisat using standard metrics such as SLR RMS of fit, altimeter crossovers, and orbit overlaps. Where covariances are available we can evaluate the predicted geographically correlated orbit error. These predicted results can be compared with the Earth-fixed differences between dynamic and reduced-dynamic orbits to test the predictive accuracy of the covariances, as well as to calibrate the error of the solutions.

  19. Improvement of global and regional mean sea level derived from satellite altimetry multi missions

    Science.gov (United States)

    Ablain, M.; Faugere, Y.; Larnicol, G.; Picot, N.; Cazenave, A.; Benveniste, J.

    2012-04-01

    With the satellite altimetry missions, the global mean sea level (GMSL) has been calculated on a continual basis since January 1993. 'Verification' phases, during which the satellites follow each other in close succession (Topex/Poseidon--Jason-1, then Jason-1--Jason-2), help to link up these different missions by precisely determining any bias between them. Envisat, ERS-1 and ERS-2 are also used, after being adjusted on these reference missions, in order to compute Mean Sea Level at high latitudes (higher than 66°N and S), and also to improve spatial resolution by combining all these missions together. The global mean sea level (MSL) deduced from TOPEX/Poseidon, Jason-1 and Jason-2 provide a global rate of 3.2 mm from 1993 to 2010 applying the post glacial rebound (MSL aviso website http://www.jason.oceanobs.com/msl). Besides, the regional sea level trends bring out an inhomogeneous repartition of the ocean elevation with local MSL slopes ranging from + 8 mm/yr to - 8 mm/year. A study published in 2009 [Ablain et al., 2009] has shown that the global MSL trend unceratainty was estimated at +/-0.6 mm/year with a confidence interval of 90%. The main sources of errors at global and regional scales are due to the orbit calculation and the wet troposphere correction. But others sea-level components have also a significant impact on the long-term stability of MSL as for instance the stability of instrumental parameters and the atmospheric corrections. Thanks to recent studies performed in the frame of the SALP project (supported by CNES) and Sea-level Climate Change Initiative project (supported by ESA), strong improvements have been provided for the estimation of the global and regional MSL trends. In this paper, we propose to describe them; they concern the orbit calculation thanks to new gravity fields, the atmospheric corrections thanks to ERA-interim reanalyses, the wet troposphere corrections thanks to the stability improvement, and also empirical corrections

  20. History of satellite missions and measurements of the Earth Radiation Budget (1957-1984)

    Science.gov (United States)

    House, F. B.; Gruber, A.; Hunt, G. E.; Mecherikunnel, A. T.

    1986-01-01

    The history of satellite missions and their measurements of the earth radiation budget from the beginning of the space age until the present time are reviewed. The survey emphasizes the early struggle to develop instrument systems to monitor reflected shortwave and emitted long-wave exitances from the earth, and the problems associated with the interpretation of these observations from space. In some instances, valuable data sets were developed from satellite measurements whose instruments were not specifically designed for earth radiation budget observations.

  1. Prototype Design and Mission Analysis for a Small Satellite Exploiting Environmental Disturbances for Attitude Stabilization

    Science.gov (United States)

    2016-03-01

    AND MISSION ANALYSIS FOR A SMALL SATELLITE EXPLOITING ENVIRONMENTAL DISTURBANCES FOR ATTITUDE STABILIZATION by Halis C. Polat March 2016...FOR A SMALL SATELLITE EXPLOITING ENVIRONMENTAL DISTURBANCES FOR ATTITUDE STABILIZATION 5. FUNDING NUMBERS 6. AUTHOR(S) Halis C. Polat 7...need a robust and accurate attitude control system. Due to the mass- and volume-constrained design environment of CubeSat, conventional methods are

  2. Schedule Optimization of Imaging Missions for Multiple Satellites and Ground Stations Using Genetic Algorithm

    Science.gov (United States)

    Lee, Junghyun; Kim, Heewon; Chung, Hyun; Kim, Haedong; Choi, Sujin; Jung, Okchul; Chung, Daewon; Ko, Kwanghee

    2018-04-01

    In this paper, we propose a method that uses a genetic algorithm for the dynamic schedule optimization of imaging missions for multiple satellites and ground systems. In particular, the visibility conflicts of communication and mission operation using satellite resources (electric power and onboard memory) are integrated in sequence. Resource consumption and restoration are considered in the optimization process. Image acquisition is an essential part of satellite missions and is performed via a series of subtasks such as command uplink, image capturing, image storing, and image downlink. An objective function for optimization is designed to maximize the usability by considering the following components: user-assigned priority, resource consumption, and image-acquisition time. For the simulation, a series of hypothetical imaging missions are allocated to a multi-satellite control system comprising five satellites and three ground stations having S- and X-band antennas. To demonstrate the performance of the proposed method, simulations are performed via three operation modes: general, commercial, and tactical.

  3. Space Network IP Services (SNIS): An Architecture for Supporting Low Earth Orbiting IP Satellite Missions

    Science.gov (United States)

    Israel, David J.

    2005-01-01

    The NASA Space Network (SN) supports a variety of missions using the Tracking and Data Relay Satellite System (TDRSS), which includes ground stations in White Sands, New Mexico and Guam. A Space Network IP Services (SNIS) architecture is being developed to support future users with requirements for end-to-end Internet Protocol (IP) communications. This architecture will support all IP protocols, including Mobile IP, over TDRSS Single Access, Multiple Access, and Demand Access Radio Frequency (RF) links. This paper will describe this architecture and how it can enable Low Earth Orbiting IP satellite missions.

  4. The EXIST Mission Concept Study

    Science.gov (United States)

    Fishman, Gerald J.; Grindlay, J.; Hong, J.

    2008-01-01

    EXIST is a mission designed to find and study black holes (BHs) over a wide range of environments and masses, including: 1) BHs accreting from binary companions or dense molecular clouds throughout our Galaxy and the Local Group, 2) supermassive black holes (SMBHs) lying dormant in galaxies that reveal their existence by disrupting passing stars, and 3) SMBHs that are hidden from our view at lower energies due to obscuration by the gas that they accrete. 4) the birth of stellar mass BHs which is accompanied by long cosmic gamma-ray bursts (GRBs) which are seen several times a day and may be associated with the earliest stars to form in the Universe. EXIST will provide an order of magnitude increase in sensitivity and angular resolution as well as greater spectral resolution and bandwidth compared with earlier hard X-ray survey telescopes. With an onboard optical-infra red (IR) telescope, EXIST will measure the spectra and redshifts of GRBs and their utility as cosmological probes of the highest z universe and epoch of reionization. The mission would retain its primary goal of being the Black Hole Finder Probe in the Beyond Einstein Program. However, the new design for EXIST proposed to be studied here represents a significant advance from its previous incarnation as presented to BEPAC. The mission is now less than half the total mass, would be launched on the smallest EELV available (Atlas V-401) for a Medium Class mission, and most importantly includes a two-telescope complement that is ideally suited for the study of both obscured and very distant BHs. EXIST retains its very wide field hard X-ray imaging High Energy Telescope (HET) as the primary instrument, now with improved angular and spectral resolution, and in a more compact payload that allows occasional rapid slews for immediate optical/IR imaging and spectra of GRBs and AGN as well as enhanced hard X-ray spectra and timing with pointed observations. The mission would conduct a 2 year full sky survey in

  5. Fluxgate Magnetometry on the Experimental Albertan Satellite #1 (Ex-Alta-1) CubeSat Mission: Steps Toward a Magnetospheric Constellation Mission

    Science.gov (United States)

    Mann, I. R.; Miles, D.; Nokes, C.; Cupido, C.; Elliott, D.; Ciurzynski, M.; Barona, D.; Narod, B. B.; Bennest, J.; Pakhotin, I.; Kale, A.; Bruner, B.; Haluza-DeLay, T.; Forsyth, C.; Rae, J.; Lange, C.; Sameoto, D.; Milling, D. K.

    2017-12-01

    Making low noise magnetic measurements is a significant challenge to the use of cube-satellite (CubeSat) platforms for scientific constellation class missions for studies of geospace. We describe the design, validation, and test, and initial on-orbit results from a miniature, low-mass, low-power, and low-magnetic noise boom-mounted fluxgate magnetometer flown on the University of Alberta Experimental Albertan Satellite #1 (Ex-Alta-1) Cube Satellite, launched in 2017 from the International Space Station as part of the QB50 constellation mission. The miniature instrument achieves a magnetic noise floor of 150-200 pT/√Hz at 1 Hz, consumes 400 mW of power, has a mass of 121 g (sensor and boom), stows on the hull, and deploys on a 60 cm boom from a three-unit CubeSat reducing the noise from the onboard reaction wheel to less than 1.5 nT at the sensor. The instrument's capabilities are being demonstrated and validated in space with flight on Ex-Alta-1. We present on-orbit data from the boom-deployment and initial operations of the fluxgate sensor and illustrate the potential scientific returns and utility of using CubeSats carrying such fluxgate magnetometers to constitute a magnetospheric constellation mission. We further illustrate the value of scientific constellations using example data from the low-Earth orbit European Space Agency Swarm mission. Swarm data reveal significant changes in the spatiotemporal characteristics of the magnetic fields in the coupled magnetosphere-ionosphere system, even when the spacecraft are separated by only approximately 10 s along track and approximately 1.4° in longitude. This indicates the likely energetic significance of Alfven wave dynamics, and we use Swarm measurements to illustrate the value of satellite constellations for diagnosing magnetosphere-ionosphere coupling even in low-Earth orbit.

  6. A Satellite Mortality Study to Support Space Systems Lifetime Prediction

    Science.gov (United States)

    Fox, George; Salazar, Ronald; Habib-Agahi, Hamid; Dubos, Gregory

    2013-01-01

    Estimating the operational lifetime of satellites and spacecraft is a complex process. Operational lifetime can differ from mission design lifetime for a variety of reasons. Unexpected mortality can occur due to human errors in design and fabrication, to human errors in launch and operations, to random anomalies of hardware and software or even satellite function degradation or technology change, leading to unrealized economic or mission return. This study focuses on data collection of public information using, for the first time, a large, publically available dataset, and preliminary analysis of satellite lifetimes, both operational lifetime and design lifetime. The objective of this study is the illustration of the relationship of design life to actual lifetime for some representative classes of satellites and spacecraft. First, a Weibull and Exponential lifetime analysis comparison is performed on the ratio of mission operating lifetime to design life, accounting for terminated and ongoing missions. Next a Kaplan-Meier survivor function, standard practice for clinical trials analysis, is estimated from operating lifetime. Bootstrap resampling is used to provide uncertainty estimates of selected survival probabilities. This study highlights the need for more detailed databases and engineering reliability models of satellite lifetime that include satellite systems and subsystems, operations procedures and environmental characteristics to support the design of complex, multi-generation, long-lived space systems in Earth orbit.

  7. Monte Carlo Analysis as a Trajectory Design Driver for the Transiting Exoplanet Survey Satellite (TESS) Mission

    Science.gov (United States)

    Nickel, Craig; Parker, Joel; Dichmann, Don; Lebois, Ryan; Lutz, Stephen

    2016-01-01

    The Transiting Exoplanet Survey Satellite (TESS) will be injected into a highly eccentric Earth orbit and fly 3.5 phasing loops followed by a lunar flyby to enter a mission orbit with lunar 2:1 resonance. Through the phasing loops and mission orbit, the trajectory is significantly affected by lunar and solar gravity. We have developed a trajectory design to achieve the mission orbit and meet mission constraints, including eclipse avoidance and a 30-year geostationary orbit avoidance requirement. A parallelized Monte Carlo simulation was performed to validate the trajectory after injecting common perturbations, including launch dispersions, orbit determination errors, and maneuver execution errors. The Monte Carlo analysis helped identify mission risks and is used in the trajectory selection process.

  8. The Study of a Super Low Altitude Satellite

    Science.gov (United States)

    Noda, Atsushi; Homma, Masanori; Utashima, Masayoshi

    This paper reports the result of a study for super low altitude satellite. The altitude of this satellite's orbit is lower than ever. The altitude of a conventional earth observing satellite is generally around from 600km to 900km. The lowest altitude of earth observing satellite launched in Japan was 350km; the Tropical Rainfall Measuring Mission (TRMM). By comparison, the satellite reported in this paper is much lower than that and it is planned to orbit below 200km. Furthermore, the duration of the flight planned is more than two years. Any satellite in the world has not achieved to keep such a low altitude that long term. The satellite in such a low orbit drops quickly because of the strong air drag. Our satellite will cancel the air drag effect by ion engine thrust. To realize this idea, a drag-free system will be applied. This usually leads a complicated and expensive satellite system. We, however, succeeded in finding a robust control law for a simple system even under the unpredictable change of air drag. When the altitude of the satellite is lowered successfully, the spatial resolution of an optical sensor can be highly improved. If a SAR is equipped with the satellite, it enables the drastic reduction of electric power consumption and the fabulous spatial resolution improvement at the same time.

  9. Definition phase of Grand Tour missions/radio science investigations study for outer planets missions

    Science.gov (United States)

    Tyler, G. L.

    1972-01-01

    Scientific instrumentation for satellite communication and radio tracking systems in the outer planet exploration mission is discussed. Mission planning considers observations of planetary and satellite-masses, -atmospheres, -magnetic fields, -surfaces, -gravitational fields, solar wind composition, planetary radio emissions, and tests of general relativity in time delay and ray bending experiments.

  10. Estimating water storage changes and sink terms in Volta Basin from satellite missions

    Directory of Open Access Journals (Sweden)

    Vagner G. Ferreira

    2014-01-01

    Full Text Available The insufficiency of distributed in situ hydrological measurements is a major challenge for hydrological studies in many regions of the world. Satellite missions such as the Gravity Recovery and Climate Experiment (GRACE and the Tropical Rainfall Measurement Mission (TRMM can be used to improve our understanding of water resources beyond surface water in poorly gauged basins. In this study we combined GRACE and TRMM to investigate monthly estimates of evaporation plus runoff (sink terms using the water balance equation for the period from January 2005 to December 2010 within the Volta Basin. These estimates have been validated by comparison with time series of sink terms (evaporation plus surface and subsurface runoff from the Global Land Data Assimilation System (GLDAS. The results, for the period under consideration, show strong agreement between both time series, with a root mean square error (RMSE of 20.2 mm/month (0.67 mm/d and a correlation coefficient of 0.85. This illustrates the ability of GRACE to predict hydrological quantities, e.g. evaporation, in the Volta Basin. The water storage change data from GRACE and precipitation data from TRMM all show qualitative agreement, with evidence of basin saturation at approximately 73 mm in the equivalent water column at the annual and semi-annual time scales.

  11. The NOAA Satellite Observing System Architecture Study

    Science.gov (United States)

    Volz, Stephen; Maier, Mark; Di Pietro, David

    2016-01-01

    NOAA is beginning a study, the NOAA Satellite Observing System Architecture (NSOSA) study, to plan for the future operational environmental satellite system that will follow GOES and JPSS, beginning about 2030. This is an opportunity to design a modern architecture with no pre-conceived notions regarding instruments, platforms, orbits, etc. The NSOSA study will develop and evaluate architecture alternatives to include partner and commercial alternatives that are likely to become available. The objectives will include both functional needs and strategic characteristics (e.g., flexibility, responsiveness, sustainability). Part of this study is the Space Platform Requirements Working Group (SPRWG), which is being commissioned by NESDIS. The SPRWG is charged to assess new or existing user needs and to provide relative priorities for observational needs in the context of the future architecture. SPRWG results will serve as input to the process for new foundational (Level 0 and Level 1) requirements for the next generation of NOAA satellites that follow the GOES-R, JPSS, DSCOVR, Jason-3, and COSMIC-2 missions.

  12. Quantification of surface water volume changes in the Mackenzie Delta using satellite multi-mission data

    Science.gov (United States)

    Normandin, Cassandra; Frappart, Frédéric; Lubac, Bertrand; Bélanger, Simon; Marieu, Vincent; Blarel, Fabien; Robinet, Arthur; Guiastrennec-Faugas, Léa

    2018-02-01

    Quantification of surface water storage in extensive floodplains and their dynamics are crucial for a better understanding of global hydrological and biogeochemical cycles. In this study, we present estimates of both surface water extent and storage combining multi-mission remotely sensed observations and their temporal evolution over more than 15 years in the Mackenzie Delta. The Mackenzie Delta is located in the northwest of Canada and is the second largest delta in the Arctic Ocean. The delta is frozen from October to May and the recurrent ice break-up provokes an increase in the river's flows. Thus, this phenomenon causes intensive floods along the delta every year, with dramatic environmental impacts. In this study, the dynamics of surface water extent and volume are analysed from 2000 to 2015 by combining multi-satellite information from MODIS multispectral images at 500 m spatial resolution and river stages derived from ERS-2 (1995-2003), ENVISAT (2002-2010) and SARAL (since 2013) altimetry data. The surface water extent (permanent water and flooded area) peaked in June with an area of 9600 km2 (±200 km2) on average, representing approximately 70 % of the delta's total surface. Altimetry-based water levels exhibit annual amplitudes ranging from 4 m in the downstream part to more than 10 m in the upstream part of the Mackenzie Delta. A high overall correlation between the satellite-derived and in situ water heights (R > 0.84) is found for the three altimetry missions. Finally, using altimetry-based water levels and MODIS-derived surface water extents, maps of interpolated water heights over the surface water extents are produced. Results indicate a high variability of the water height magnitude that can reach 10 m compared to the lowest water height in the upstream part of the delta during the flood peak in June. Furthermore, the total surface water volume is estimated and shows an annual variation of approximately 8.5 km3 during the whole study period, with

  13. Evolutionary design of a satellite thermal control system: Real experiments for a CubeSat mission

    International Nuclear Information System (INIS)

    Escobar, Emanuel; Diaz, Marcos; Zagal, Juan Cristóbal

    2016-01-01

    Highlights: • GAs applied to automate design of CubeSat passive thermal control system (coating). • Simulation adapted with real physical data (mockup experiment in vacuum chamber). • Obtained coating patterns consistently outperform engineered solutions (by 5 K). • Evolved coating patterns are far superior (by 8 K) than unpainted aluminum. - Abstract: This paper studies the use of artificial evolution to automate the design of a satellite passive thermal control system. This type of adaptation often requires the use of computer simulations to evaluate fitness of a large number of candidate solutions. Simulations are required to be expedient and accurate so that solutions can be successfully transferred to reality. We explore a design process that involves three steps. On a first step candidate solutions (implemented as surface paint tiling patterns) are tested using a FEM model and ranked according to their quality to meet mission temperature requirements. On a second step the best individual is implemented as a real physical satellite mockup and tested inside a vacuum chamber, having light sources imitating the effect of solar light. On a third step the simulation model is adapted with data obtained during the real evaluation. These updated models can be further employed for continuing genetic search. Current differences between our simulation and our real physical setup are in the order of 1.45 K mean squared error for faces pointing toward the light source and 2.4 K mean squared errors for shadowed faces. We found that evolved tiling patterns can be 5 K below engineered patterns and 8 K below using unpainted aluminum satellite surfaces.

  14. Implementation and Test of the Automatic Flight Dynamics Operations for Geostationary Satellite Mission

    Directory of Open Access Journals (Sweden)

    Sangwook Park

    2009-12-01

    Full Text Available This paper describes the Flight Dynamics Automation (FDA system for COMS Flight Dynamics System (FDS and its test result in terms of the performance of the automation jobs. FDA controls the flight dynamics functions such as orbit determination, orbit prediction, event prediction, and fuel accounting. The designed FDA is independent from the specific characteristics which are defined by spacecraft manufacturer or specific satellite missions. Therefore, FDA could easily links its autonomous job control functions to any satellite mission control system with some interface modification. By adding autonomous system along with flight dynamics system, it decreases the operator’s tedious and repeated jobs but increase the usability and reliability of the system. Therefore, FDA is used to improve the completeness of whole mission control system’s quality. The FDA is applied to the real flight dynamics system of a geostationary satellite, COMS and the experimental test is performed. The experimental result shows the stability and reliability of the mission control operations through the automatic job control.

  15. Validation of High Wind Retrievals from the Cyclone Global Navigation Satellite System (CYGNSS) Mission

    Science.gov (United States)

    McKague, D. S.; Ruf, C. S.; Balasubramaniam, R.; Clarizia, M. P.

    2017-12-01

    The Cyclone Global Navigation Satellite System (CYGNSS) mission, launched in December of 2016, provides all-weather observations of sea surface winds. Using GPS-based bistatic reflectometry, the CYGNSS satellites can estimate sea surface winds even through a hurricane eye wall. This, combined with the high temporal resolution of the CYGNSS constellation (median revisit time of 2.8 hours), yields unprecedented ability to estimate hurricane strength winds. While there are a number of other sources of sea surface wind estimates, such as buoys, dropsondes, passive and active microwave from aircraft and satellite, and models, the combination of all-weather, high accuracy, short revisit time, high spatial coverage, and continuous operation of the CYGNSS mission enables significant advances in the understanding, monitoring, and prediction of cyclones. Validating CYGNSS wind retrievals over the bulk of the global wind speed distribution, which peaks at around 7 meters per second, is relatively straight-forward, requiring spatial-temporal matching of observations with independent sources (such as those mentioned above). Validating CYGNSS wind retrievals for "high" winds (> 20 meters per second), though, is problematic. Such winds occur only in intense storms. While infrequent, making validation opportunities also infrequent and problematic due to their intense nature, such storms are important to study because of the high potential for damage and loss of life. This presentation will describe the efforts of the CYGNSS Calibration/Validation team to gather measurements of high sea surface winds for development and validation of the CYGNSS geophysical model function (GMF), which forms the basis of retrieving winds from CYGNSS observations. The bulk of these observations come from buoy measurements as well as aircraft ("hurricane hunter") measurements from passive microwave and dropsondes. These data are matched in space and time to CYGNSS observations for training of the

  16. Science Mission Definition Studies for TROPIX

    Science.gov (United States)

    Fennell, J. F.

    1997-01-01

    This document summarizes the results of mission definition studies for solar electric propulsion missions that have been carried out over the last approximately three years. The major output from the studies has been two proposals which were submitted to NASA in response to Announcements of Opportunity for missions and an ongoing Global Magnetospheric Dynamics mission study. The bulk of this report consists of copies of the proposals and preliminary materials from the GMD study that will be completed in the coming months.

  17. Review of a relativity and geodesy mission with counter-orbiting polar satellites

    International Nuclear Information System (INIS)

    Van Patten, R.A.

    1977-01-01

    A new test of general relativity, capable of measuring the Lense-Thirring precession on a satellite orbit was proposed in 1974. We have recently realized that the remarkable geophysical output of this experiment can be enriched by allowing the point of encounter between the two satellites to progress from the poles to the equator during the course of the mission. There is reason to believe that by performing the experiment in this mode, all tesseral harmonics up to about 60th order could be separated and determined to accuracies up to three orders of magnitude better than current knowledge, and still obtain a 1% Lense-Thirring measurement. (orig.) [de

  18. Trajectory Design to Mitigate Risk on the Transiting Exoplanet Survey Satellite (TESS) Mission

    Science.gov (United States)

    Dichmann, Donald

    2016-01-01

    The Transiting Exoplanet Survey Satellite (TESS) will employ a highly eccentric Earth orbit, in 2:1 lunar resonance, reached with a lunar flyby preceded by 3.5 phasing loops. The TESS mission has limited propellant and several orbit constraints. Based on analysis and simulation, we have designed the phasing loops to reduce delta-V and to mitigate risk due to maneuver execution errors. We have automated the trajectory design process and use distributed processing to generate and to optimize nominal trajectories, check constraint satisfaction, and finally model the effects of maneuver errors to identify trajectories that best meet the mission requirements.

  19. Mercury Lander Mission Concept Study Summary

    Science.gov (United States)

    Eng, D. A.

    2018-05-01

    Provides a summary of the Mercury Lander Mission Concept Study performed as part of the last Planetary Decadal Survey. The presentation will focus on engineering trades and the challenges of developing a Mercury lander mission.

  20. Lessons Learned from Engineering a Multi-Mission Satellite Operations Center

    Science.gov (United States)

    Madden, Maureen; Cary, Everett, Jr.; Esposito, Timothy; Parker, Jeffrey; Bradley, David

    2006-01-01

    NASA's Small Explorers (SMEX) satellites have surpassed their designed science-lifetimes and their flight operations teams are now facing the challenge of continuing operations with reduced funding. At present, these missions are being re-engineered into a fleet-oriented ground system at Goddard Space Flight Center (GSFC). When completed, this ground system will provide command and control of four SMEX missions and will demonstrate fleet automation and control concepts. As a path-finder for future mission consolidation efforts, this ground system will also demonstrate new ground-based technologies that show promise of supporting longer mission lifecycles and simplifying component integration. One of the core technologies being demonstrated in the SMEX Mission Operations Center is the GSFC Mission Services Evolution Center (GMSEC) architecture. The GMSEC architecture uses commercial Message Oriented Middleware with a common messaging standard to realize a higher level of component interoperability, allowing for interchangeable components in ground systems. Moreover, automation technologies utilizing the GMSEC architecture are being evaluated and implemented to provide extended lights-out operations. This mode of operation will provide routine monitoring and control of the heterogeneous spacecraft fleet. The operational concepts being developed will reduce the need for staffed contacts and is seen as a necessity for fleet management. This paper will describe the experiences of the integration team throughout the re-enginering effort of the SMEX ground system. Additionally, lessons learned will be presented based on the team's experiences with integrating multiple missions into a fleet-automated ground system.

  1. Analysis and implementation of communications systems for small satellite missions

    Science.gov (United States)

    Hammerman, Morgan

    STEM (science, technology, engineering, and math) is a wave of the future for teaching. It combines multiple topics that promote critical thinking. This study targeted one aspect of the first-grade curriculum, sorting using properties. This unit used STEM teaching methods to test if hands-on, game based methods would enhance learning. The setting used for this study was a first-grade classroom in an upper middle-class suburb. The students took a pre-test before the unit began and a post-test at the end of the unit. These assessments were used to evaluate their progress in sorting and identifying properties of various objects. One major research focus was to look at group dynamics in the classroom. This was done by dividing the students into small groups to promote working collaboratively with their peers. The results of this study showed that hands on activity or game based learning are effective tools when teaching properties. It was inconclusive whether these results were due to game based learning or the hands-on activities. The study also revealed that group work is a successful tool that can be used while teaching properties.

  2. Mars Relay Satellite: Key to Enabling Low-Cost Exploration Missions

    Science.gov (United States)

    Hastrup, R.; Cesarone, R.; Miller, A.

    1993-01-01

    Recently, there has been increasing evidence of a renewed focus on Mars exploration both by NASA and the international community. The thrust of this renewed interest appears to be manifesting itself in numerous low-cost missions employing small, light weight elements, which utilize advanced technologies including integrated microelectronics. A formidable problem facing these low-cost missions is communications with Earth. Providing adequate direct-link performance has very significant impacts on spacecraft power, pointing, mass and overall complexity. Additionally, for elements at or near the surface of Mars, there are serious connectivity constraints, especially at higher latitudes, which lose view of Earth for up to many months at a time. This paper will discuss the role a Mars relay satellite can play in enabling and enhancing low-cost missions to Mars...

  3. PRIMA Platform capability for satellite missions in LEO and MEO (SAR, Optical, GNSS, TLC, etc.)

    Science.gov (United States)

    Logue, T.; L'Abbate, M.

    2016-12-01

    PRIMA (Piattaforma Riconfigurabile Italiana Multi Applicativa) is a multi-mission 3-axis stabilized Platform developed by Thales Alenia Space Italia under ASI contract.PRIMA is designed to operate for a wide variety of applications from LEO, MEO up to GEO and for different classes of satellites Platform Family. It has an extensive heritage in flight heritage (LEO and MEO Satellites already fully operational) in which it has successfully demonstrated the flexibility of use, low management costs and the ability to adapt to changing operational conditions.The flexibility and modularity of PRIMA provides unique capability to satisfy different Payload design and mission requirements, thanks to the utilization of recurrent adaptable modules (Service Module-SVM, Propulsion Module-PPM, Payload Module-PLM) to obtain mission dependent configuration. PRIMA product line development is continuously progressing, and is based on state of art technology, modular architecture and an Integrated Avionics. The aim is to maintain and extent multi-mission capabilities to operate in different environments (LEO to GEO) with different payloads (SAR, Optical, GNSS, TLC, etc.). The design is compatible with a wide range of European and US equipment suppliers, thus maximising cooperation opportunity. Evolution activities are mainly focused on the following areas: Structure: to enable Spacecraft configurations for multiple launch; Thermal Control: to guarantee thermal limits for new missions, more demanding in terms of environment and payload; Electrical: to cope with higher power demand (e.g. electrical propulsion, wide range of payloads, etc.) considering orbital environment (e.g. lighting condition); Avionics : AOCS solutions optimized on mission (LEO observation driven by agility and pointing, agility not a driver for GEO). Use of sensors and actuators tailored for specific mission and related environments. Optimised Propulsion control. Data Handling, SW and FDIR mission customization

  4. Satellite to study earth's magnetic field

    Science.gov (United States)

    1979-01-01

    The Magnetic Field Satellite (Magsat) designed to measure the near earth magnetic field and crustal anomalies is briefly described. A scalar magnetometer to measure the magnitude of the earth's crustal magnetic field and a vector magnetometer to measure magnetic field direction as well as magnitude are included. The mission and its objectives are summarized along with the data collection and processing system.

  5. An Evaluation of Antarctica as a Calibration Target for Passive Microwave Satellite Missions with Climate Data Record Applications

    Science.gov (United States)

    Kim, Edward

    2011-01-01

    Passive microwave remote sensing at L-band (1.4 GHz) is sensitive to soil moisture and sea surface salinity, both important climate variables. Science studies involving these variables can now take advantage of new satellite L-band observations. The first mission with regular global passive microwave observations at L-band is the European Space Agency's Soil Moisture and Ocean Salinity (SMOS), launched November, 2009. A second mission, NASA's Aquarius, was launched June, 201 I. A third mission, NASA's Soil Moisture Active Passive (SMAP) is scheduled to launch in 2014. Together, these three missions may provide a decade-long data record-provided that they are intercalibrated. The intercalibration is best performed at the radiance (brightness temperature) level, and Antarctica is proving to be a key calibration target. However, Antarctica has thus far not been fully characterized as a potential target. This paper will present evaluations of Antarctica as a microwave calibration target for the above satellite missions. Preliminary analyses have identified likely target areas, such as the vicinity of Dome-C and larger areas within East Antarctica. Physical sources of temporal and spatial variability of polar firn are key to assessing calibration uncertainty. These sources include spatial variability of accumulation rate, compaction, surface characteristics (dunes, micro-topography), wind patterns, and vertical profiles of density and temperature. Using primarily SMOS data, variability is being empirically characterized and attempts are being made to attribute observed variability to physical sources. One expected outcome of these studies is the potential discovery of techniques for remotely sensing--over all of Antarctica-parameters such as surface temperature.

  6. Pi-Sat: A Low Cost Small Satellite and Distributed Spacecraft Mission System Test Platform

    Science.gov (United States)

    Cudmore, Alan

    2015-01-01

    Current technology and budget trends indicate a shift in satellite architectures from large, expensive single satellite missions, to small, low cost distributed spacecraft missions. At the center of this shift is the SmallSatCubesat architecture. The primary goal of the Pi-Sat project is to create a low cost, and easy to use Distributed Spacecraft Mission (DSM) test bed to facilitate the research and development of next-generation DSM technologies and concepts. This test bed also serves as a realistic software development platform for Small Satellite and Cubesat architectures. The Pi-Sat is based on the popular $35 Raspberry Pi single board computer featuring a 700Mhz ARM processor, 512MB of RAM, a flash memory card, and a wealth of IO options. The Raspberry Pi runs the Linux operating system and can easily run Code 582s Core Flight System flight software architecture. The low cost and high availability of the Raspberry Pi make it an ideal platform for a Distributed Spacecraft Mission and Cubesat software development. The Pi-Sat models currently include a Pi-Sat 1U Cube, a Pi-Sat Wireless Node, and a Pi-Sat Cubesat processor card.The Pi-Sat project takes advantage of many popular trends in the Maker community including low cost electronics, 3d printing, and rapid prototyping in order to provide a realistic platform for flight software testing, training, and technology development. The Pi-Sat has also provided fantastic hands on training opportunities for NASA summer interns and Pathways students.

  7. CHASER: An Innovative Satellite Mission Concept to Measure the Effects of Aerosols on Clouds and Climate

    Science.gov (United States)

    Renno, N.; Williams, E.; Rosenfeld, D.; Fischer, D.; Fischer, J.; Kremic, T.; Agrawal, A.; Andreae, M.; Bierbaum, R.; Blakeslee, R.; Boerner, A.; Bowles, N.; Christian, H.; Dunion, J.; Horvath, A.; Huang, X.; Khain, A.; Kinne, S.; Lemos, M.-C.; Penner, J.

    2012-04-01

    The formation of cloud droplets on aerosol particles, technically known as the activation of cloud condensation nuclei (CCN), is the fundamental process driving the interactions of aerosols with clouds and precipitation. Knowledge of these interactions is foundational to our understanding of weather and climate. The Intergovernmental Panel on Climate Change (IPCC) and the Decadal Survey (NRC 2007) indicate that the uncertainty in how clouds adjust to aerosol perturbations dominates the uncertainty in the overall quantification of the radiative forcing attributable to human activities. The Clouds, Hazards, and Aerosols Survey for Earth Researchers (CHASER) mission concept responds to the IPCC and Decadal Survey concerns by studying the activation of CCN and their interactions with clouds and storms. CHASER proposes to revolutionize our understanding of the interactions of aerosols with clouds by making the first global measurements of the fundamental physical entity linking them: activated cloud condensation nuclei. The CHASER mission was conceptualized to measure all quantities necessary for determining the interactions of aerosols with clouds and storms. Measurements by current satellites allow the determination of crude profiles of cloud particle size but not of the activated CCN that seed them. CHASER uses a new technique (Freud et al. 2011; Rosenfeld et al. 2012) and high-heritage instruments to produce the first global maps of activated CCN and the properties of the clouds associated with them. CHASER measures the CCN concentration and cloud thermodynamic forcing simultaneously, allowing their effects to be distinguished. Changes in the behavior of a group of weather systems in which only one of the quantities varies (a partial derivative of the intensity with the desirable quantity) allow the determination of each effect statistically. The high uncertainties of current climate predictions limit their much-needed use in decision-making. CHASER mitigates this

  8. Revisiting the South Atlantic Anomaly after 3 years of Swarm satellite mission

    Science.gov (United States)

    Pavón-Carrasco, F. Javier; Campuzano, Saioa A.; De Santis, Angelo

    2017-04-01

    Covering part of Southern America and the South Atlantic Ocean, the South Atlantic Anomaly (SAA) is nowadays one of the most important and largest features of the geomagnetic field at the Earth's surface. It is characterized by lower intensity values than expected for those geomagnetic latitudes. Thanks to the global geomagnetic models, the spatial and temporal geometry of the Earth's magnetic field can be defined at the core-mantle boundary, showing the origin of the SAA as a reversal polarity patch that is growing with a pronounced rate of -2.54ṡ105 nT per century and with western drift. Since the Swarm satellite mission of the European Space Agency was launched at the end of 2013, the three twin satellites are picking up the most accurate values of the geomagnetic field up to now. In this work, we use the satellite magnetic data from Swarm mission along with the observatory ground data of surrounding areas to evaluate the spatial and temporal evolution of the SAA during the Swarm-life.

  9. Trends in the Global Small Satellite Ecosystem: Implications for Science Missions

    Science.gov (United States)

    Behrens, J.; Lal, B.

    2017-12-01

    Activity in the small satellite industry has increased in the recent years. New actors and nations have joined the evolving market globally in both the private and public sector. Progress in the smallsat sector has been driven, in part, by growing capabilities and falling costs of smallsats. Advancements include the miniaturization of technology for the small satellite platform, increased data processing capabilities, the ubiquitous presence of GPS enabling location and attitude determination, improvements in ground system costs and signal processing capabilities, and the deployment of inexpensive COTS parts. The emerging trends in the state of the art for smallsat technology, paired with planned smallsat constellation missions by both private and public actors, open the opportunity for new earth and remote sensing scientific endeavors. This presentation will characterize the drivers influencing the development of smallsat technology and the industry more generally. An overview will be provided for trends in the state of the art of smallsat technology, and secondary trends that influence the smallsat sector including infrastructure, demand, the satellite launch market, and the policy environment. These trends are mapped onto current and projected Earth observation needs, as identified by academic and governmental communities, to identify those that could be fulfilled by smallsats in the near and long term. A set of notional science missions that could be enabled, based on the various drivers identified, will be presented for both the near (3 years) and farther term (10 years).

  10. Mission planning for space based satellite surveillance experiments with the MSX

    Science.gov (United States)

    Sridharan, R.; Fishman, T.; Robinson, E.; Viggh, H.; Wiseman, A.

    1994-01-01

    The Midcourse Space Experiment is a BMDO-sponsored scientific satellite set for launch within the year. The satellite will collect phenomenology data on missile targets, plumes, earth limb backgrounds and deep space backgrounds in the LWIR, visible and ultra-violet spectral bands. It will also conduct functional demonstrations for space-based space surveillance. The Space-Based Visible sensor, built by Lincoln Laboratory, Massachusetts Institute of Technology, is the primary sensor on board the MSX for demonstration of space surveillance. The SBV Processing, Operations and Control Center (SPOCC) is the mission planning and commanding center for all space surveillance experiments using the SBV and other MSX instruments. The guiding principle in the SPOCC Mission Planning System was that all routine functions be automated. Manual analyst input should be minimal. Major concepts are: (I) A high level language, called SLED, for user interface to the system; (2) A group of independent software processes which would generally be run in a pipe-line mode for experiment commanding but can be run independently for analyst assessment; (3) An integrated experiment cost computation function that permits assessment of the feasibility of the experiment. This paper will report on the design, implementation and testing of the Mission Planning System.

  11. Onboard autonomous mission re-planning for multi-satellite system

    Science.gov (United States)

    Zheng, Zixuan; Guo, Jian; Gill, Eberhard

    2018-04-01

    This paper presents an onboard autonomous mission re-planning system for Multi-Satellites System (MSS) to perform onboard re-planing in disruptive situations. The proposed re-planning system can deal with different potential emergency situations. This paper uses Multi-Objective Hybrid Dynamic Mutation Genetic Algorithm (MO-HDM GA) combined with re-planning techniques as the core algorithm. The Cyclically Re-planning Method (CRM) and the Near Real-time Re-planning Method (NRRM) are developed to meet different mission requirements. Simulations results show that both methods can provide feasible re-planning sequences under unforeseen situations. The comparisons illustrate that using the CRM is average 20% faster than the NRRM on computation time. However, by using the NRRM more raw data can be observed and transmitted than using the CRM within the same period. The usability of this onboard re-planning system is not limited to multi-satellite system. Other mission planning and re-planning problems related to autonomous multiple vehicles with similar demands are also applicable.

  12. Arctic sea level change over the past 2 decades from GRACE gradiometry and multi-mission satellite altimetry

    DEFF Research Database (Denmark)

    Andersen, O. B.; Stenseng, L.; Sørensen, C. S.

    2014-01-01

    The Arctic is still an extremely challenging region for theuse of remote sensing for sea level studies. Despite the availability of 20 years of altimetry, only very limited sea level observations exist in the interior of the Arctic Ocean. However, with Cryosat-2 SAR altimetry the situation...... gradiometer observations from the ESA GOCE mission, we are now able to derive a mean dynamic topography of the Arctic Ocean with unprecedented accuracy to constrain the Arctic Ocean circulation controlling sea level variations in the Arctic. We present both a new estimation of the mean ocean circulation...... and new estimates of large scale sea level changes based on satellite data and perform an estimation of the fresh waterstorage increase over the last decade using temporal gravity changes from the GRACE satellite....

  13. 20 Years Experience with using Low Cost Launch Opportunities for 20 Small Satellite Missions

    Science.gov (United States)

    Meerman, Maarten; Sweeting, Martin, , Sir

    To realise the full potential of modern low cost mini-micro-nano-satellite missions, regular and affordable launch opportunities are required. It is simply not economic to launch individual satellites of 5-300kg on single dedicated launchers costing typically 15-20M per launch. Whilst there have been periodic 'piggy-back' launches of small satellites on US launchers since the 1960's, these have been infrequent and often experienced significant delays due the vagaries of the main (paying!) payload. In 1989, Arianespace provided a critical catalyst to the microsatellite community when it imaginatively developed the ASAP platform on Ariane-4 providing, for the first time, a standard interface and affordable launch contracts for small payloads up to 50kg. During the 1990's, some 20 small satellites have been successfully launched on the Ariane-4 ASAP ring for international customers carrying out a range of operational, technology demonstration and training missions. However, most of these microsatellite missions seek low Earth orbit and especially sun-synchronous orbits, but the number of primary missions into these orbit has declined since 1996 and with it the availability of useful low cost launch opportunities for microsatellites. Whilst Ariane-5 has an enhanced capacity ASAP, it has yet to be widely used due both to the infrequent launches, higher costs, and the GTO orbit required by the majority of customers. China, Japan and India have also provided occasional secondary launches for small payloads, but not yet on a regular basis. Fortunately, the growing interest and demand for microsatellite missions coincided with the emergence of regular, low cost launch opportunities from the former Soviet Union (FSU) - both as secondary 'piggy-back' missions or as multiple microsatellite payloads on converted military ICBMs. Indeed, the FSU now supplies the only affordable means of launching minisatellites (200-500kg) into LEO as dedicated missions on converted missiles as

  14. The Near-Earth Space Surveillance (NESS) Mission: Discovery, Tracking, and Characterization of Asteroids, Comets, and Artificial Satellites with a Microsatellite

    Science.gov (United States)

    Hildebrand, A. R.; Carroll, K. A.; Balam, D. D.; Cardinal, R. D.; Matthews, J. M.; Kuschnig, R.; Walker, G. A. H.; Brown, P. G.; Tedesco, E. F.; Worden, S. P.

    2001-01-01

    The Near-Earth Space Surveillance (NESS) Mission, a microsatellite dedicated to observing near-Earth (NEO) and interior-to-the-Earth (IEO)asteroids and comets plus artificial satellites, is currently being studied under contract to the Canadian Space Agency. Additional information is contained in the original extended abstract.

  15. Application of current and future satellite missions to hydrologic prediction in transboundary rivers

    Science.gov (United States)

    Biancamaria, S.; Clark, E.; Lettenmaier, D. P.

    2010-12-01

    More than 256 major global river basins, which cover about 45% of the continental land surface, are shared among two or more countries. The flow of such a large part of the global runoff across international boundaries has led to tension in many cases between upstream and downstream riparian countries. Among many examples, this is the case of the Ganges and the Brahmaputra Rivers, which cross the boundary between India and Bangladesh. Hydrological data (river discharge, reservoir storage) are viewed as sensitive by India (the upstream country) and are therefore not shared with Bangladesh, which can only monitor river discharge and water depth at the international border crossing. These measurements only allow forecasting of floods in the interior and southern portions of the country two to three days in advance. These forecasts are not long enough either for agricultural water management purposes (for which knowledge of upstream reservoir storage is essential) or for disaster preparedness purposes. Satellite observations of river spatial extent, surface slope, reservoir area and surface elevation have the potential to make tremendous changes in management of water within the basins. In this study, we examine the use of currently available satellite measurements (in India) and in-situ measurements in Bangladesh to increase forecast lead time in the Ganges and Brahmaputra Rivers. Using nadir altimeters, we find that it is possible to forecast the discharge of the Ganges River at the Bangladesh border with lead time 3 days and mean absolute error of around 25%. On the Ganges River, 2-day forecasts are possible with a mean absolute error of around 20%. When combined with optical/infra-red MODIS images, it is possible to map water elevations along the river and its floodplain upstream of the boundary, and to compute water storage. However, the high frequency of clouds in this region results in relatively large errors in the water mask. Due to the nadir altimeter

  16. Evaluating Cloud and Precipitation Processes in Numerical Models using Current and Potential Future Satellite Missions

    Science.gov (United States)

    van den Heever, S. C.; Tao, W. K.; Skofronick Jackson, G.; Tanelli, S.; L'Ecuyer, T. S.; Petersen, W. A.; Kummerow, C. D.

    2015-12-01

    Cloud, aerosol and precipitation processes play a fundamental role in the water and energy cycle. It is critical to accurately represent these microphysical processes in numerical models if we are to better predict cloud and precipitation properties on weather through climate timescales. Much has been learned about cloud properties and precipitation characteristics from NASA satellite missions such as TRMM, CloudSat, and more recently GPM. Furthermore, data from these missions have been successfully utilized in evaluating the microphysical schemes in cloud-resolving models (CRMs) and global models. However, there are still many uncertainties associated with these microphysics schemes. These uncertainties can be attributed, at least in part, to the fact that microphysical processes cannot be directly observed or measured, but instead have to be inferred from those cloud properties that can be measured. Evaluation of microphysical parameterizations are becoming increasingly important as enhanced computational capabilities are facilitating the use of more sophisticated schemes in CRMs, and as future global models are being run on what has traditionally been regarded as cloud-resolving scales using CRM microphysical schemes. In this talk we will demonstrate how TRMM, CloudSat and GPM data have been used to evaluate different aspects of current CRM microphysical schemes, providing examples of where these approaches have been successful. We will also highlight CRM microphysical processes that have not been well evaluated and suggest approaches for addressing such issues. Finally, we will introduce a potential NASA satellite mission, the Cloud and Precipitation Processes Mission (CAPPM), which would facilitate the development and evaluation of different microphysical-dynamical feedbacks in numerical models.

  17. Life Science Research in Outer Space: New Platform Technologies for Low-Cost, Autonomous Small Satellite Missions

    Science.gov (United States)

    Ricco, Antonio J.; Parra, Macarena P.; Niesel, David; McGinnis, Michael; Ehrenfreund, Pascale; Nicholson, Wayne; Mancinelli, Rocco; Piccini, Matthew E.; Beasley, Christopher C.; Timucin, Linda R.; hide

    2009-01-01

    We develop integrated instruments and platforms suitable for economical, frequent space access for autonomous life science experiments and processes in outer space. The technologies represented by three of our recent free-flyer small-satellite missions are the basis of a rapidly growing toolbox of miniaturized biologically/biochemically-oriented instrumentation now enabling a new generation of in-situ space experiments. Autonomous small satellites ( 1 50 kg) are less expensive to develop and build than fullsize spacecraft and not subject to the comparatively high costs and scheduling challenges of human-tended experimentation on the International Space Station, Space Shuttle, and comparable platforms. A growing number of commercial, government, military, and civilian space launches now carry small secondary science payloads at far lower cost than dedicated missions; the number of opportunities is particularly large for so-called cube-sat and multicube satellites in the 1 10 kg range. The recent explosion in nano-, micro-, and miniature technologies, spanning fields from telecommunications to materials to bio/chemical analysis, enables development of remarkably capable autonomous miniaturized instruments to accomplish remote biological experimentation. High-throughput drug discovery, point-of-care medical diagnostics, and genetic analysis are applications driving rapid progress in autonomous bioanalytical technology. Three of our recent missions exemplify the development of miniaturized analytical payload instrumentation: GeneSat-1 (launched: December 2006), PharmaSat (launched: May 2009), and O/OREOS (organism/organics exposure to orbital stresses; scheduled launch: May 2010). We will highlight the overall architecture and integration of fluidic, optical, sensor, thermal, and electronic technologies and subsystems to support and monitor the growth of microorganisms in culture in these small autonomous space satellites, including real-time tracking of their culture

  18. The CYGNSS flight segment; A major NASA science mission enabled by micro-satellite technology

    Science.gov (United States)

    Rose, R.; Ruf, C.; Rose, D.; Brummitt, M.; Ridley, A.

    While hurricane track forecasts have improved in accuracy by ~50% since 1990, there has been essentially no improvement in the accuracy of intensity prediction. This lack of progress is thought to be caused by inadequate observations and modeling of the inner core due to two causes: 1) much of the inner core ocean surface is obscured from conventional remote sensing instruments by intense precipitation in the inner rain bands and 2) the rapidly evolving stages of the tropical cyclone (TC) life cycle are poorly sampled in time by conventional polar-orbiting, wide-swath surface wind imagers. NASA's most recently awarded Earth science mission, the NASA EV-2 Cyclone Global Navigation Satellite System (CYGNSS) has been designed to address these deficiencies by combining the all-weather performance of GNSS bistatic ocean surface scatterometry with the sampling properties of a satellite constellation. This paper provides an overview of the CYGNSS flight segment requirements, implementation, and concept of operations for the CYGNSS constellation; consisting of 8 microsatellite-class spacecraft (historical TC track. The CYGNSS mission is enabled by modern electronic technology; it is an example of how nanosatellite technology can be applied to replace traditional "old school" solutions at significantly reduced cost while providing an increase in performance. This paper provides an overview of how we combined a reliable space-flight proven avionics design with selected microsatellite components to create an innovative, low-cost solution for a mainstream science investigation.

  19. Joint operations planning for space surveillance missions on the MSX satellite

    Science.gov (United States)

    Stokes, Grant; Good, Andrew

    1994-01-01

    The Midcourse Space Experiment (MSX) satellite, sponsored by BMDO, is intended to gather broad-band phenomenology data on missiles, plumes, naturally occurring earthlimb backgrounds and deep space backgrounds. In addition the MSX will be used to conduct functional demonstrations of space-based space surveillance. The JHU/Applied Physics Laboratory (APL), located in Laurel, MD, is the integrator and operator of the MSX satellite. APL will conduct all operations related to the MSX and is charged with the detailed operations planning required to implement all of the experiments run on the MSX except the space surveillance experiments. The non-surveillance operations are generally amenable to being defined months ahead of time and being scheduled on a monthly basis. Lincoln Laboratory, Massachusetts Institute of Technology (LL), located in Lexington, MA, is the provider of one of the principle MSX instruments, the Space-Based Visible (SBV) sensor, and the agency charged with implementing the space surveillance demonstrations on the MSX. The planning timelines for the space surveillance demonstrations are fundamentally different from those for the other experiments. They are generally amenable to being scheduled on a monthly basis, but the specific experiment sequence and pointing must be refined shortly before execution. This allocation of responsibilities to different organizations implies the need for a joint mission planning system for conducting space surveillance demonstrations. This paper details the iterative, joint planning system, based on passing responsibility for generating MSX commands for surveillance operations from APL to LL for specific scheduled operations. The joint planning system, including the generation of a budget for spacecraft resources to be used for surveillance events, has been successfully demonstrated during ground testing of the MSX and is being validated for MSX launch within the year. The planning system developed for the MSX forms a

  20. TYCHO: Demonstrator and operational satellite mission to Earth-Moon-Libration point EML-4 for communication relay provision as a service

    Science.gov (United States)

    Hornig, Andreas; Homeister, Maren

    2015-03-01

    operation time of up to 10 years. It also enables measurements of the libration point environment with the scientific payloads. This includes sensors for space dust, solar and cosmic radiation activity for satellite lifetime estimation and lunar crew protection by providing early-warning systems. The paper describes the mission concept and the pre-design of the demonstrator satellite according to the operational mission requirements, advantages and benefits of this service. The concept was awarded with the Space Generation Advisory Council and OHB Scholarship in 2011 and the concept study is conducted at the Institute of Space Systems (IRS) [1] of the University of Stuttgart and OHB-System, Bremen [2].

  1. Study of chaos in chaotic satellite systems

    Science.gov (United States)

    Khan, Ayub; Kumar, Sanjay

    2018-01-01

    In this paper, we study the qualitative behaviour of satellite systems using bifurcation diagrams, Poincaré section, Lyapunov exponents, dissipation, equilibrium points, Kaplan-Yorke dimension etc. Bifurcation diagrams with respect to the known parameters of satellite systems are analysed. Poincaré sections with different sowing axes of the satellite are drawn. Eigenvalues of Jacobian matrices for the satellite system at different equilibrium points are calculated to justify the unstable regions. Lyapunov exponents are estimated. From these studies, chaos in satellite system has been established. Solution of equations of motion of the satellite system are drawn in the form of three-dimensional, two-dimensional and time series phase portraits. Phase portraits and time series display the chaotic nature of the considered system.

  2. Performance Analysis of Satellite Missions for Multi-Temporal SAR Interferometry

    Directory of Open Access Journals (Sweden)

    Fabio Bovenga

    2018-04-01

    Full Text Available Multi-temporal InSAR (MTI applications pose challenges related to the availability of coherent scattering from the ground surface, the complexity of the ground deformations, atmospheric artifacts, and visibility problems related to ground elevation. Nowadays, several satellite missions are available providing interferometric SAR data at different wavelengths, spatial resolutions, and revisit time. A new and interesting opportunity is provided by Sentinel-1, which has a spatial resolution comparable to that of previous ESA C-band sensors, and revisit times improved by up to 6 days. According to these different SAR space-borne missions, the present work discusses current and future opportunities of MTI applications in terms of ground instability monitoring. Issues related to coherent target detection, mean velocity precision, and product geo-location are addressed through a simple theoretical model assuming backscattering mechanisms related to point scatterers. The paper also presents an example of a multi-sensor ground instability investigation over Lesina Marina, a village in Southern Italy lying over a gypsum diapir, where a hydration process, involving the underlying anhydride, causes a smooth uplift and the formation of scattered sinkholes. More than 20 years of MTI SAR data have been processed, coming from both legacy ERS and ENVISAT missions, and latest-generation RADARSAT-2, COSMO-SkyMed, and Sentinel-1A sensors. Results confirm the presence of a rather steady uplift process, with limited to null variations throughout the whole monitored time-period.

  3. Performance Analysis of Satellite Missions for Multi-Temporal SAR Interferometry.

    Science.gov (United States)

    Bovenga, Fabio; Belmonte, Antonella; Refice, Alberto; Pasquariello, Guido; Nutricato, Raffaele; Nitti, Davide O; Chiaradia, Maria T

    2018-04-27

    Multi-temporal InSAR (MTI) applications pose challenges related to the availability of coherent scattering from the ground surface, the complexity of the ground deformations, atmospheric artifacts, and visibility problems related to ground elevation. Nowadays, several satellite missions are available providing interferometric SAR data at different wavelengths, spatial resolutions, and revisit time. A new and interesting opportunity is provided by Sentinel-1, which has a spatial resolution comparable to that of previous ESA C-band sensors, and revisit times improved by up to 6 days. According to these different SAR space-borne missions, the present work discusses current and future opportunities of MTI applications in terms of ground instability monitoring. Issues related to coherent target detection, mean velocity precision, and product geo-location are addressed through a simple theoretical model assuming backscattering mechanisms related to point scatterers. The paper also presents an example of a multi-sensor ground instability investigation over Lesina Marina, a village in Southern Italy lying over a gypsum diapir, where a hydration process, involving the underlying anhydride, causes a smooth uplift and the formation of scattered sinkholes. More than 20 years of MTI SAR data have been processed, coming from both legacy ERS and ENVISAT missions, and latest-generation RADARSAT-2, COSMO-SkyMed, and Sentinel-1A sensors. Results confirm the presence of a rather steady uplift process, with limited to null variations throughout the whole monitored time-period.

  4. 3-Axis magnetic control: flight results of the TANGO satellite in the PRISMA mission

    Science.gov (United States)

    Chasset, C.; Noteborn, R.; Bodin, P.; Larsson, R.; Jakobsson, B.

    2013-09-01

    PRISMA implements guidance, navigation and control strategies for advanced formation flying and rendezvous experiments. The project is funded by the Swedish National Space Board and run by OHB-Sweden in close cooperation with DLR, CNES and the Danish Technical University. The PRISMA test bed consists of a fully manoeuvrable MANGO satellite as well as a 3-axis controlled TANGO satellite without any Δ V capability. PRISMA was launched on the 15th of June 2010 on board DNEPR. The TANGO spacecraft is the reference satellite for the experiments performed by MANGO, either with a "cooperative" or "non-cooperative" behaviour. Small, light and low-cost were the keywords for the TANGO design. The attitude determination is based on Sun sensors and magnetometers, and the active attitude control uses magnetic torque rods only. In order to perform the attitude manoeuvres required to fulfil the mission objectives, using any additional gravity gradient boom to passively stabilize the spacecraft was not allowed. After a two-month commissioning phase, TANGO separated from MANGO on the 11th of August 2010. All operational modes have been successfully tested, and the pointing performance in flight is in accordance with expectations. The robust Sun Acquisition mode reduced the initial tip-off rate and placed TANGO into a safe attitude in MANGO. At the same time, it points its solar panel towards the Sun, and all payload equipments can be switched on without any restriction. This paper gives an overview of the TANGO Attitude Control System design. It then presents the flight results in the different operating modes. Finally, it highlights the key elements at the origin of the successful 3-axis magnetic control strategy on the TANGO satellite.

  5. A New Model of the Mean Albedo of the Earth: Estimation and Validation from the GRACE Mission and SLR Satellites.

    Science.gov (United States)

    Deleflie, F.; Sammuneh, M. A.; Coulot, D.; Pollet, A.; Biancale, R.; Marty, J. C.

    2017-12-01

    This talk provides new results of a study that we began last year, and that was the subject of a poster by the same authors presented during AGU FM 2016, entitled « Mean Effect of the Albedo of the Earth on Artificial Satellite Trajectories: an Update Over 2000-2015. »The emissivity of the Earth, split into a part in the visible domain (albedo) and the infrared domain (thermic emissivity), is at the origin of non gravitational perturbations on artificial satellite trajectories. The amplitudes and periods of these perturbations can be investigated if precise orbits can be carried out, and reveal some characteristics of the space environment where the satellite is orbiting. Analyzing the perturbations is, hence, a way to characterize how the energy from the Sun is re-emitted by the Earth. When led over a long period of time, such an approach enables to quantify the variations of the global radiation budget of the Earth.Additionally to the preliminary results presented last year, we draw an assessment of the validity of the mean model based on the orbits of the GRACE missions, and, to a certain extent, of some of the SLR satellite orbits. The accelerometric data of the GRACE satellites are used to evaluate the accuracy of the models accounting for non gravitational forces, and the ones induced by the albedo and the thermic emissivity in particular. Three data sets are used to investigate the mean effects on the orbit perturbations: Stephens tables (Stephens, 1980), ECMWF (European Centre for Medium-Range Weather Forecasts) data sets and CERES (Clouds and the Earth's Radiant Energy System) data sets (publickly available). From the trajectography point of view, based on post-fit residual analysis, we analyze what is the data set leading to the lowest residual level, to define which data set appears to be the most suitable one to derive a new « mean albedo model » from accelerometric data sets of the GRACE mission. The period of investigation covers the full GRACE

  6. Study of chaos in chaotic satellite systems

    Indian Academy of Sciences (India)

    Lyapunov exponents are estimated. From these studies, chaosin satellite system has been established. Solution of equations of motion of the satellite system are drawn in the form of three-dimensional, two-dimensional and time series phase portraits. Phase portraits and time series display the chaotic nature of the ...

  7. Report on the Stanford/KACST/AMES UVLED small satellite mission to demonstrate charge management of an electrically isolated proof mass for drag-free operation

    Science.gov (United States)

    Saraf, Shailendhar

    A spacecraft demonstration of ultra-violet (UV) LEDs and UV LED charge management based on research done at Stanford University is being developed jointly by the King Abdulaziz City for Science and Technology (KACST) Saudi Arabia and NASA Ames Research Center, with an expected launch date of June 2014. This paper will report on the payload design and testing, mission preparation, satellite launch and payload bring -up in space. Mission lifetime is expected to be at least one month, during which time the ability for the UV LEDs to mitigate actual space-based charging and the effects of radiation on the UV LED device performance will be studied. Precise control over the potential of an electrically isolated proof mass is necessary for the operation of devices such as a Gravitational Reference Sensor (GRS) and satellite missions such as LISA. The mission will demonstrate that AlGaN UV LEDs operating at 255 nm are an effective low-cost, low-power and compact substitute for Mercury vapor lamps used in previous missions. The goal of the mission is to increase the UV LED device to TRL-9 and the charge management system to TRL-7.

  8. High power communication satellites power systems study

    International Nuclear Information System (INIS)

    Josloff, A.T.; Peterson, J.R.

    1994-01-01

    This paper discusses a DOE-funded study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. This study brings together a preeminent US Industry/Russian team to cooperate on the role of high power communication satellites in the rapidly expanding communications revolution. These high power satellites play a vital role in assuring availability of universally accessible, wide bandwidth communications, for high definition TV, super computer networks and other services. Satellites are ideally suited to provide the wide bandwidths and data rates required and are unique in the ability to provide services directly to the users. As new or relocated markets arise, satellites offer a flexibility that conventional distribution services cannot match, and it is no longer necessary to be near population centers to take advantage of the telecommunication revolution. The geopolitical implications of these substantially enhanced communications capabilities will be significant

  9. Education and Public Outreach for the PICASSO-CENA Satellite-Based Research Mission: K-12 Students Use Sun Photometers to Assist Scientists in Validating Atmospheric Data

    Science.gov (United States)

    Robinson, D. Q.

    2001-05-01

    Hampton University, a historically black university, is leading the Education and Public Outreach (EPO) portion of the PICASSO-CENA satellite-based research mission. Currently scheduled for launch in 2004, PICASSO-CENA will use LIDAR (LIght Detection and Ranging), to study earth's atmosphere. The PICASSO-CENA Outreach program works with scientists, teachers, and students to better understand the effects of clouds and aerosols on earth's atmosphere. This program actively involves students nationwide in NASA research by having them obtain sun photometer measurements from their schools and homes for comparison with data collected by the PICASSO-CENA mission. Students collect data from their classroom ground observations and report the data via the Internet. Scientists will use the data from the PICASSO-CENA research and the student ground-truthing observations to improve predications about climatic change. The two-band passive remote sensing sun photometer is designed for student use as a stand alone instrument to study atmospheric turbidity or in conjunction with satellite data to provide ground-truthing. The instrument will collect measurements of column optical depth from the ground level. These measurements will not only give the students an appreciation for atmospheric turbidity, but will also provide quantitative correlative information to the PICASSO-CENA mission on ground-level optical depth. Student data obtained in this manner will be sufficiently accurate for scientists to use as ground truthing. Thus, students will have the opportunity to be involved with a NASA satellite-based research mission.

  10. Spaceborne observations of a changing Earth - Contribution from ESÁ s operating and approved satellite missions.

    Science.gov (United States)

    Johannessen, J. A.

    2009-04-01

    , managerial and regulatory activities (i.e. weather forecasting, deforestation, flooding, etc.) essential to the safe exploitation of global resources, conservation of sustainable ecosystems, and the compliance with numerous international treaties and conventions, depend absolutely on continuity of satellite missions to maximise socio-economic and environmental benefits. This presentation will highlight some of the multidisciplinary Earth science achievements and operational applications using ESA satellite missions. It will also address some of the key scientific challenges and need for operational monitoring services in the years to come. It capitalizes on the knowledge and awareness outlined in "The Changing Earth - New scientific challenges for ESÁs Living Planet Programme" issued in 2006 together with updated views and approved plans expressed during ESÁs Earth Sciences Advisory Committee (ESAC) meetings and agreed at the recent User Consultation meeting in January 2009.

  11. SLS launched missions concept studies for LUVOIR mission

    Science.gov (United States)

    Stahl, H. Philip; Hopkins, Randall C.

    2015-09-01

    NASA's "Enduring Quests Daring Visions" report calls for an 8- to 16-m Large UV-Optical-IR (LUVOIR) Surveyor mission to enable ultra-high-contrast spectroscopy and coronagraphy. AURA's "From Cosmic Birth to Living Earth" report calls for a 12-m class High-Definition Space Telescope to pursue transformational scientific discoveries. The multi-center ATLAST Team is working to meet these needs. The MSFC Team is examining potential concepts that leverage the advantages of the SLS (Space Launch System). A key challenge is how to affordably get a large telescope into space. The JWST design was severely constrained by the mass and volume capacities of its launch vehicle. This problem is solved by using an SLS Block II-B rocket with its 10-m diameter x 30-m tall fairing and estimated 45 mt payload to SE-L2. Previously, two development study cycles produced a detailed concept called ATLAST-8. Using ATLAST-8 as a point of departure, this paper reports on a new ATLAST-12 concept. ATLAST-12 is a 12-m class segmented aperture LUVOIR with an 8-m class center segment. Thus, ATLAST-8 is now a de-scope option.

  12. SLS Launched Missions Concept Studies for LUVOIR Mission

    Science.gov (United States)

    Stahl, H. Philip; Hopkins, Randall C.

    2015-01-01

    NASA's "Enduring Quests Daring Visions" report calls for an 8- to 16-meter Large UV-Optical-IR (LUVOIR) Surveyor mission to enable ultra-high-contrast spectroscopy and coronagraphy. AURA's "From Cosmic Birth to Living Earth" report calls for a 12-meter class High-Definition Space Telescope to pursue transformational scientific discoveries. The multi-center ATLAST Team is working to meet these needs. The MSFC Team is examining potential concepts that leverage the advantages of the SLS (Space Launch System). A key challenge is how to affordably get a large telescope into space. The JWST design was severely constrained by the mass and volume capacities of its launch vehicle. This problem is solved by using an SLS Block II-B rocket with its 10-m diameter x 30-m tall fairing and 45 mt payload to SE-L2. Previously, two development study cycles produced a detailed concept called ATLAST-8. Using ATLAST-8 as a point of departure, this paper reports on a new ATLAST-12 concept. ATLAST-12 is a 12-meter class segmented aperture LUVOIR with an 8-m class center segment. Thus, ATLAST-8 is now a de-scope option.

  13. Photometric Study of Uranian Satellites

    Science.gov (United States)

    Kesten, Philip R.

    1998-01-01

    The best summary of my work at NASA is expressed in the following abstract, submitted the Division for Planetary Science of the American Astronomical Society and to be presented at the annual meeting in Madison in October. We report photometric measurements of Uranian satellites Miranda, Ariel, Umbriel and Titania (10.4 Aug. 1995), and Neptune's satellite Triton (21.2 Sept. 1995) with the infrared camera (IRCAM) and standard J (1.13 - 1.42 microns), H (1.53 - 1.81 microns), and K (2.00 - 2.41 microns) filters at the 3.8-m UKIRT telescope on Mauna Kea. The individual images frames are 256 x 256 pixels with a platescale of .286 arcsec/pixel, resulting in a 1.22 arc min field of view. This summer brought the IR photometry measurements nearly to a close. As indicated by the abstract above, I will present this work at the annual DPS meeting in October. In anticipation of the opening of the new Carl Sagan Laboratory for Cosmochemisty, of which I will be a participating member, I also devoted a considerable fraction of the summer to learning the biochemistry which underlies the experiments to be conducted. To put the end of the summary close to the beginning, it was a most productive summer.

  14. Integration and Testing Challenges of Small, Multiple Satellite Missions: Experiences from the Space Technology 5 Project

    Science.gov (United States)

    Sauerwein, Timothy A.; Gostomski, Thomas

    2008-01-01

    The ST5 technology demonstration mission led by GSFC of NASA's New Millennium Program managed by JPL consisted of three micro satellites (approximately 30 kg each) deployed into orbit from the Pegasus XL launch vehicle. In order to meet the launch date schedule of ST5, a different approach was required rather than the standard I&T approach used for single, room-sized satellites. The three spacecraft were designed, integrated, and tested at NASA Goddard Space Flight Center. It was determined that there was insufficient time in the schedule to perform three spacecraft I&T activities in series using standard approaches. The solution was for spacecraft #1 to undergo integration and test first, followed by spacecraft #2 and #3 simultaneously. This simultaneous integration was successful for several reasons. Each spacecraft had a Lead Test Conductor who planned and coordinated their spacecraft through its integration and test activities. One team of engineers and technicians executed the integration of all three spacecraft, learning and gaining knowledge and efficiency as spacecraft #1 integration and testing progressed. They became acutely familiar with the hardware, operation and processes for I&T, thus had the experience and knowledge to safely execute I&T for spacecraft #2 and #3. The integration team was extremely versatile; each member could perform many different activities or work any spacecraft, when needed. ST5 was successfully integrated, tested and shipped to the launch site per the I&T schedule that was planned three years previously. The I&T campaign was completed with ST5's successful launch on March 22, 2006.

  15. Microwave and theoretical studies for Cosmic Background Explorer satellite

    International Nuclear Information System (INIS)

    Wilkinson, D.T.

    1983-07-01

    The Cosmic Background Explorer (COBE) satellite, its instruments, and its scientific mission are discussed. The COBE radiometer is considered, and measurement of galactic radio emission with masers is reviewed. Extragalactic radiation and zodiacal dust are mentioned briefly

  16. Satellites

    International Nuclear Information System (INIS)

    Burns, J.A.; Matthews, M.S.

    1986-01-01

    The present work is based on a conference: Natural Satellites, Colloquium 77 of the IAU, held at Cornell University from July 5 to 9, 1983. Attention is given to the background and origins of satellites, protosatellite swarms, the tectonics of icy satellites, the physical characteristics of satellite surfaces, and the interactions of planetary magnetospheres with icy satellite surfaces. Other topics include the surface composition of natural satellites, the cratering of planetary satellites, the moon, Io, and Europa. Consideration is also given to Ganymede and Callisto, the satellites of Saturn, small satellites, satellites of Uranus and Neptune, and the Pluto-Charon system

  17. Virtual Mission Operations Center -Explicit Access to Small Satellites by a Net Enabled User Base

    Science.gov (United States)

    Miller, E.; Medina, O.; Paulsen, P.; Hopkins, J.; Long, C.; Holloman, K.

    2008-08-01

    The Office of Naval Research (ON R), The Office of the Secr etary of Defense (OSD) , Th e Operationally Responsive Space Off ice (ORS) , and th e National Aeronautics and Space Administration (NASA) are funding the development and integration of key technologies and new processes that w ill allow users across th e bread th of operations the ab ility to access, task , retr ieve, and collaborate w ith data from various sensors including small satellites v ia the Intern et and the SIPRnet. The V irtual Mission Oper ations Center (VMO C) facilitates the dynamic apportionmen t of space assets, allows scalable mission man agement of mu ltiple types of sensors, and provid es access for non-space savvy users through an intu itive collaborative w eb site. These key technologies are b eing used as experimentation pathfinders fo r th e Do D's Operationally Responsiv e Sp ace (O RS) initiative and NASA's Sensor W eb. The O RS initiative seeks to provide space assets that can b e rapid ly tailored to meet a commander's in telligen ce or commun ication needs. For the DoD and NASA the V MO C provid es ready and scalab le access to space b ased assets. To the commercial space sector the V MO C may provide an analog to the innovativ e fractional ownersh ip approach represen ted by FlexJet. This pap er delves in to the technology, in tegration, and applicability of th e V MO C to th e DoD , NASA , and co mmer cial sectors.

  18. High power communication satellites power systems study

    Science.gov (United States)

    Josloff, Allan T.; Peterson, Jerry R.

    1995-01-01

    This paper discusses a planned study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. These high power satellites can play a vital role in assuring availability of universally accessible, wide bandwidth communications, for high definition TV, super computer networks and other services. Satellites are ideally suited to provide the wide bandwidths and data rates required and are unique in the ability to provide services directly to the users. As new or relocated markets arise, satellites offer a flexibility that conventional distribution services cannot match, and it is no longer necessary to be near population centers to take advantage of the telecommunication revolution. The geopolitical implications of these substantially enhanced communications capabilities can be significant.

  19. CARINA Satellite Mission to Investigate the Upper Atmosphere below the F-Layer Ionosphere

    Science.gov (United States)

    Siefring, C. L.; Bernhardt, P. A.; Briczinski, S. J., Jr.; Huba, J.; Montgomery, J. A., Jr.

    2017-12-01

    A new satellite design permits broad science measurements from the ocean to the ionosphere by flying below the F-Layer. The satellite called CARINA for Coastal-Ocean, Assimilation, Radio, Ionosphere, Neutral-Drag, and Atmospherics. The unique system capabilities are long duration orbits below the ionosphere and a HF receiver to measure broadband signals. The CARINA science products include recording the ocean surface properties, data for assimilation into global ionosphere models, radio wave propagation measurements, in-situ observations of ionospheric structures, validating neutral drag models and theory, and broadband atmospheric lightning characterization. CARINA will also measure nonlinear wave-generation using ionospheric modification sites in Alaska, Norway, Puerto Rico, and Russia and collaborate with geophysics HF radars (such as Super-DARN) for system calibration. CARINA is a linear 6-U CubeSat with a long antenna extended in the wake direction. The CARINA science mission is supported by three instruments. First, the Electric Field Instrument (EFI) is a radio receiver covering the 2 to 18 MHz range. The receiver can capture both narrow and wide bandwidths for up to 10 minutes. EFI is designed to provide HF signal strength and phase, radar Doppler shift and group delay, and electron plasma density from photoelectron excited plasma waves. Second a Ram Langmuir Probe (RLP) measures high-resolution ion currents at a 10 kHz rate. These measurements yield electron and ion density at the spacecraft. Finally, the Orbiting GPS Receiver (OGR) provides dual frequency GPS position with ionosphere correction. OGR also measures total electron content above the spacecraft and L-Band scintillations. CARINA will be the lowest satellite in orbit at 250 km altitude, <0.01 eccentricity, and up to 4-month lifetime. The design supports unique capabilities with broad applications to the geosciences. Remote sensing of the ocean will sample the HF signals scattered from the rough

  20. Promoting space research and applications in developing countries through small satellite missions

    Science.gov (United States)

    Sweeting, M.

    The high vantage-point of space offers very direct and tangible benefits to developing countries when carefully focused upon their real and particular communications and Earth observation needs. However, until recently, access to space has been effectively restricted to only those countries prepared to invest enormous sums in complex facilities and expensive satellites and launchers: this has placed individual participation in space beyond the sensible grasp of developing countries. However, during the last decade, highly capable and yet inexpensive small satellites have been developed which provide an opportunity for developing countries realistically to acquire and operate their own independent space assets - customized to their particular national needs. Over the last 22 years, the Surrey Space Centre has pioneered, developed and launched 23 nano-micro-minisatellite missions, and has worked in partnership with 12 developing countries to enable them to take their first independent steps into space. Surrey has developed a comprehensive and in-depth space technology know-how transfer and 'hands-on' training programme that uses a collaborative project comprising the design, construction, launch and operation of a microsatellite to acquire an indigenous space capability and create the nucleus of a national space agency and space industry. Using low cost small satellite projects as a focus, developing countries are able to initiate a long term, affordable and sustainable national space programme specifically tailored to their requirements, that is able to access the benefits derived from Earth observation for land use and national security; improved communications services; catalyzing scientific research and indigenous high-technology supporting industries. Perhaps even more important is the long-term benefit to the country provided by stimulating educational and career opportunities for your scientists and engineers and retaining them inside the country rather the

  1. NASA's Gravitational - Wave Mission Concept Study

    Science.gov (United States)

    Stebbins, Robin; Jennrich, Oliver; McNamara, Paul

    2012-01-01

    With the conclusion of the NASA/ESA partnership on the Laser Interferometer Space Antenna (LISA) Project, NASA initiated a study to explore mission concepts that will accomplish some or all of the LISA science objectives at lower cost. The Gravitational-Wave Mission Concept Study consisted of a public Request for Information (RFI), a Core Team of NASA engineers and scientists, a Community Science Team, a Science Task Force, and an open workshop. The RFI yielded were 12 mission concepts, 3 instrument concepts and 2 technologies. The responses ranged from concepts that eliminated the drag-free test mass of LISA to concepts that replace the test mass with an atom interferometer. The Core Team reviewed the noise budgets and sensitivity curves, the payload and spacecraft designs and requirements, orbits and trajectories and technical readiness and risk. The Science Task Force assessed the science performance by calculating the horizons. the detection rates and the accuracy of astrophysical parameter estimation for massive black hole mergers, stellar-mass compact objects inspiraling into central engines. and close compact binary systems. Three mission concepts have been studied by Team-X, JPL's concurrent design facility. to define a conceptual design evaluate kt,y performance parameters. assess risk and estimate cost and schedule. The Study results are summarized.

  2. A miniature, low-power scientific fluxgate magnetometer: A stepping-stone to cube-satellite constellation missions

    Science.gov (United States)

    Miles, D. M.; Mann, I. R.; Ciurzynski, M.; Barona, D.; Narod, B. B.; Bennest, J. R.; Pakhotin, I. P.; Kale, A.; Bruner, B.; Nokes, C. D. A.; Cupido, C.; Haluza-DeLay, T.; Elliott, D. G.; Milling, D. K.

    2016-12-01

    Difficulty in making low noise magnetic measurements is a significant challenge to the use of cube-satellite (CubeSat) platforms for scientific constellation class missions to study the magnetosphere. Sufficient resolution is required to resolve three-dimensional spatiotemporal structures of the magnetic field variations accompanying both waves and current systems of the nonuniform plasmas controlling dynamic magnetosphere-ionosphere coupling. This paper describes the design, validation, and test of a flight-ready, miniature, low-mass, low-power, and low-magnetic noise boom-mounted fluxgate magnetometer for CubeSat applications. The miniature instrument achieves a magnetic noise floor of 150-200 pT/√Hz at 1 Hz, consumes 400 mW of power, has a mass of 121 g (sensor and boom), stows on the hull, and deploys on a 60 cm boom from a three-unit CubeSat reducing the noise from the onboard reaction wheel to less than 1.5 nT at the sensor. The instrument's capabilities will be demonstrated and validated in space in late 2016 following the launch of the University of Alberta Ex-Alta 1 CubeSat, part of the QB50 constellation mission. We illustrate the potential scientific returns and utility of using a CubeSats carrying such fluxgate magnetometers to constitute a magnetospheric constellation using example data from the low-Earth orbit European Space Agency Swarm mission. Swarm data reveal significant changes in the spatiotemporal characteristics of the magnetic fields in the coupled magnetosphere-ionosphere system, even when the spacecraft are separated by only approximately 10 s along track and approximately 1.4° in longitude.

  3. Low-degree gravity change from GPS data of COSMIC and GRACE satellite missions

    Science.gov (United States)

    Lin, Tingjung; Hwang, Cheinway; Tseng, Tzu-Pang; Chao, B. F.

    2012-01-01

    This paper demonstrates estimation of time-varying gravity harmonic coefficients from GPS data of COSMIC and GRACE satellite missions. The kinematic orbits of COSMIC and GRACE are determined to the cm-level accuracy. The NASA Goddard's GEODYN II software is used to model the orbit dynamics of COSMIC and GRACE, including the effect of a static gravity field. The surface forces are estimated per one orbital period. Residual orbits generated from kinematic and reference orbits serve as observables to determine the harmonic coefficients in the weighted-constraint least-squares. The monthly COSMIC and GRACE GPS data from September 2006 to December 2007 (16 months) are processed to estimate harmonic coefficients to degree 5. The geoid variations from the GPS and CSR RL04 (GRACE) solutions show consistent patterns over space and time, especially in regions of active hydrological changes. The monthly GPS-derived second zonal coefficient closely resembles the SLR-derived and CSR RL04 values, and third and fourth zonal coefficients resemble the CSR RL04 values.

  4. A probabilistic analysis of the implications of instrument failures on ESA's Swarm mission for its individual satellite orbit deployments

    Science.gov (United States)

    Jackson, Andrew

    2015-07-01

    On launch, one of Swarm's absolute scalar magnetometers (ASMs) failed to function, leaving an asymmetrical arrangement of redundant spares on different spacecrafts. A decision was required concerning the deployment of individual satellites into the low-orbit pair or the higher "lonely" orbit. I analyse the probabilities for successful operation of two of the science components of the Swarm mission in terms of a classical probabilistic failure analysis, with a view to concluding a favourable assignment for the satellite with the single working ASM. I concentrate on the following two science aspects: the east-west gradiometer aspect of the lower pair of satellites and the constellation aspect, which requires a working ASM in each of the two orbital planes. I use the so-called "expert solicitation" probabilities for instrument failure solicited from Mission Advisory Group (MAG) members. My conclusion from the analysis is that it is better to have redundancy of ASMs in the lonely satellite orbit. Although the opposite scenario, having redundancy (and thus four ASMs) in the lower orbit, increases the chance of a working gradiometer late in the mission; it does so at the expense of a likely constellation. Although the results are presented based on actual MAG members' probabilities, the results are rather generic, excepting the case when the probability of individual ASM failure is very small; in this case, any arrangement will ensure a successful mission since there is essentially no failure expected at all. Since the very design of the lower pair is to enable common mode rejection of external signals, it is likely that its work can be successfully achieved during the first 5 years of the mission.

  5. Satellite remote sensing in epidemiological studies.

    Science.gov (United States)

    Sorek-Hamer, Meytar; Just, Allan C; Kloog, Itai

    2016-04-01

    Particulate matter air pollution is a ubiquitous exposure linked with multiple adverse health outcomes for children and across the life course. The recent development of satellite-based remote-sensing models for air pollution enables the quantification of these risks and addresses many limitations of previous air pollution research strategies. We review the recent literature on the applications of satellite remote sensing in air quality research, with a focus on their use in epidemiological studies. Aerosol optical depth (AOD) is a focus of this review and a significant number of studies show that ground-level particulate matter can be estimated from columnar AOD. Satellite measurements have been found to be an important source of data for particulate matter model-based exposure estimates, and recently have been used in health studies to increase the spatial breadth and temporal resolution of these estimates. It is suggested that satellite-based models improve our understanding of the spatial characteristics of air quality. Although the adoption of satellite-based measures of air quality in health studies is in its infancy, it is rapidly growing. Nevertheless, further investigation is still needed in order to have a better understanding of the AOD contribution to these prediction models in order to use them with higher accuracy in epidemiological studies.

  6. Development of Mission and Spacecraft Dynamics Analysis System for Geostationary Communication Satellite

    Directory of Open Access Journals (Sweden)

    Hyeon Cheol Gong

    1998-06-01

    Full Text Available We consider the motion of the subsystems as separate bodies as well as the entire satellite for the attitude and orbit control of a communication satellite by multi-body modeling technique. Thus, the system can be applied to a general communication satellite as well as a specific communication satellite, i.e. Koreasat I, II. The simulation results can be viewed by two-dimensional graphics and three-dimensional animation. The graphical user interface (GUI makes its usage much simpler. We have simulated a couple of scenarios for Koreasat I, II which are being operated as geostationary communication satellites to verify the system performance.

  7. Study of sea surface temperature distribution, in Angra dos Reis Nuclear Plant region - Mission Angra 01

    International Nuclear Information System (INIS)

    Stevenson, M.R.; Steffen, C.A.; Villagra, H.M.I.

    1982-03-01

    A study of spectral and temporal variations of sea surface temperature, using data obtained from level of satellite, aircraft and surface, with the purpose of evaluate and plot the small scale variations of sea surface temperature, due to thermal discharge from a nuclear the results of the first mission called Angra 1. (maps). (C.G.C.)

  8. Satellite Contributions to Global Change Studies

    Science.gov (United States)

    Parkinson, Claire L.

    2009-01-01

    sophisticated climate models, in situ process studies, and data sets that extend back well before the introduction of satellite technology. Nonetheless, the repetitive, global view provided by satellites is contributing in a major way to our improved recognition of how the Earth im changing, a recognition that is none too soon in view of the magnitude of the impacts that humans can now have.

  9. Comparison of gridded multi-mission and along-track mono-mission satellite altimetry wave heights with in situ near-shore buoy data.

    Digital Repository Service at National Institute of Oceanography (India)

    Shanas, P.R.; SanilKumar, V.; Hithin, N.K.

    and studied the validity of these observations against ship-reported and buoy data. Many studies have been undertaken on how best to use the data available from satellite observation systems in wave models (Mastenbroek, 1994; Young and Glowacki, 1996... Sea wave model. Journal of Geophysical Research 10, 5829–5849. Young, I.R., 1994. Global ocean wave statistics obtained from satellite observations. Applied Ocean Research 16, 235-248. Young, I.R., Glowacki, T.J., 1996. Assimilation of altimeter...

  10. Earth Observatory Satellite system definition study. Report no. 1: Orbit/launch vehicle tradeoff studies and recommendations

    Science.gov (United States)

    1974-01-01

    A study was conducted to determine the recommended orbit for the Earth Observatory Satellite (EOS) Land Resources Mission. It was determined that a promising sun synchronous orbit is 366 nautical miles when using an instrument with a 100 nautical mile swath width. The orbit has a 17 day repeat cycle and a 14 nautical mile swath overlap. Payloads were developed for each mission, EOS A through F. For each mission, the lowest cost booster that was capable of lifting the payload to the EOS orbit was selected. The launch vehicles selected for the missions are identified on the basis of tradeoff studies and recommendations. The reliability aspects of the launch vehicles are analyzed.

  11. Physical study of planets and satellites

    International Nuclear Information System (INIS)

    Mayer, C.H.; Young, A.T.; Belton, M.J.S.; Morrison, D.D.; Teifel, V.G.; Baum, W.A.; Dollfus, A.; Servajean, R.

    1976-01-01

    A critical review of progress made in the physical study of planets and satellites over the period 1973-1975 is presented. Summaries of recent research are followed by short notes on the IAU Planetary Data and Research Centers. (B.R.H.)

  12. Uncontrolled re-entry of satellite parts after finishing their mission in LEO: Titanium alloy degradation by thermite reaction energy

    Science.gov (United States)

    Monogarov, K. A.; Pivkina, A. N.; Grishin, L. I.; Frolov, Yu. V.; Dilhan, D.

    2017-06-01

    Analytical and experimental studies conducted at Semenov Institute of Chemical Physics for investigating the use of pyrotechnic compositions, i.e., thermites, to reduce the risk of the fall of thermally stable parts of deorbiting end-of-life LEO satellites on the Earth are described. The main idea was the use of passive heating during uncontrolled re-entry to ignite thermite composition, fixed on the titanium surface, with the subsequent combustion energy release to be sufficient to perforate the titanium cover. It is supposed, that thus destructed satellite parts will lose their streamline shape, and will burn out being aerodynamically heated during further descending in atmosphere (patent FR2975080). On the base of thermodynamic calculations the most promising thermite compositions have been selected for the experimental phase. The unique test facilities have been developed for the testing of the efficiency of thermite charges to perforate the titanium TA6V cover of 0.8 mm thickness under temperature/pressure conditions duplicated the uncontrolled re-entry of titanium tank after its mission on LEO. Experiments with the programmed laser heating inside the vacuum chamber revealed the only efficient thermite composition among preliminary selected ones to be Al/Co3O4. Experimental searching of the optimal aluminum powder between spherical and flaked nano- and micron-sized ones revealed the possibility to adjust the necessary ignition delay time, according to the titanium cover temperature dependency on deorbiting time. For the titanium tank the maximum temperature is 1100 °C at altitude 68 km and pressure 60 Pa. Under these conditions Al/Co3O4 formulations with nano-Al spherical particles provide the ignition time to be 13.3 s, and ignition temperature as low as 592±5 °C, whereas compositions with the micron-sized spherical Al powder reveal these values to be much higher, i.e., 26.3 s and 869±5 °C, respectively. The analytical and experimental studies described

  13. The Surface Water and Ocean Topography Satellite Mission - An Assessment of Swath Altimetry Measurements of River Hydrodynamics

    Science.gov (United States)

    Wilson, Matthew D.; Durand, Michael; Alsdorf, Douglas; Chul-Jung, Hahn; Andreadis, Konstantinos M.; Lee, Hyongki

    2012-01-01

    The Surface Water and Ocean Topography (SWOT) satellite mission, scheduled for launch in 2020 with development commencing in 2015, will provide a step-change improvement in the measurement of terrestrial surface water storage and dynamics. In particular, it will provide the first, routine two-dimensional measurements of water surface elevations, which will allow for the estimation of river and floodplain flows via the water surface slope. In this paper, we characterize the measurements which may be obtained from SWOT and illustrate how they may be used to derive estimates of river discharge. In particular, we show (i) the spatia-temporal sampling scheme of SWOT, (ii) the errors which maybe expected in swath altimetry measurements of the terrestrial surface water, and (iii) the impacts such errors may have on estimates of water surface slope and river discharge, We illustrate this through a "virtual mission" study for a approximately 300 km reach of the central Amazon river, using a hydraulic model to provide water surface elevations according to the SWOT spatia-temporal sampling scheme (orbit with 78 degree inclination, 22 day repeat and 140 km swath width) to which errors were added based on a two-dimension height error spectrum derived from the SWOT design requirements. Water surface elevation measurements for the Amazon mainstem as may be observed by SWOT were thereby obtained. Using these measurements, estimates of river slope and discharge were derived and compared to those which may be obtained without error, and those obtained directly from the hydraulic model. It was found that discharge can be reproduced highly accurately from the water height, without knowledge of the detailed channel bathymetry using a modified Manning's equation, if friction, depth, width and slope are known. Increasing reach length was found to be an effective method to reduce systematic height error in SWOT measurements.

  14. Assessing the fitness-for-purpose of satellite multi-mission ocean color climate data records: A protocol applied to OC-CCI chlorophyll-a data.

    Science.gov (United States)

    Mélin, F; Vantrepotte, V; Chuprin, A; Grant, M; Jackson, T; Sathyendranath, S

    2017-12-15

    In this work, trend estimates are used as indicators to compare the multi-annual variability of different satellite chlorophyll- a (Chl a ) data and to assess the fitness-for-purpose of multi-mission Chl a products as climate data records (CDR). Under the assumption that single-mission products are free from spurious temporal artifacts and can be used as benchmark time series, multi-mission CDRs should reproduce the main trend patterns observed by single-mission series when computed over their respective periods. This study introduces and applies quantitative metrics to compare trend distributions from different data records. First, contingency matrices compare the trend diagnostics associated with two satellite products when expressed in binary categories such as existence, significance and signs of trends. Contingency matrices can be further summarized by metrics such as Cohen's κ index that rates the overall agreement between the two distributions of diagnostics. A more quantitative measure of the discrepancies between trends is provided by the distributions of differences between trend slopes. Thirdly, maps of the level of significance P of a t -test quantifying the degree to which two trend estimates differ provide a statistical, spatially-resolved, evaluation. The proposed methodology is applied to the multi-mission Ocean Colour-Climate Change Initiative (OC-CCI) Chl a data. The agreement between trend distributions associated with OC-CCI data and single-mission products usually appears as good as when single-mission products are compared. As the period of analysis is extended beyond 2012 to 2015, the level of agreement tends to be degraded, which might be at least partly due to the aging of the MODIS sensor on-board Aqua. On the other hand, the trends displayed by the OC-CCI series over the short period 2012-2015 are very consistent with those observed with VIIRS. These results overall suggest that the OC-CCI Chl a data can be used for multi-annual time

  15. Study of space reactors for exploration missions

    Energy Technology Data Exchange (ETDEWEB)

    Cliquet, Elisa; Ruault, Jean-Marc; Masson, Frederic, E-mail: elisa.cliquet@cnes.fr, E-mail: frederic.masson@cnes.fr [Centre National d' Etudes Spatiales (CNES), Paris (France); Roux, Jean-Pierre; Paris, Nicolas; Cazale, Brice; Manifacier, Laurent, E-mail: jean-pierre.roux@areva.com [AREVA TA, Aix en Provence, (France); Poinot-Salanon, Christine, E-mail: christine.poinot@cea.fr [Comissariado a l' Energie Atomique et Aux Energies alternatives (CEA), Paris (France)

    2013-07-01

    Nuclear propulsion has been studied for many decades. The power density of nuclear fission is much higher than chemical process, and for missions to outer solar system requiring several hundred of kilowatts, or for flexible manned missions to Mars requiring several megawatts, nuclear electric propulsion might be the only option offering a reasonable mass in low earth orbit. Despite the existence of low power experiences - SNAP10 in the 60's or Buk/Topaz in the 60-80's - no high power reactor has been developed: investment cost, long term time frame, high technological challenges and radioactive hazards are the main challenges we must overtake. However, it seems reasonable to look at the technical challenges that have to be overcome for a next generation of nuclear electric systems for space exploration. This paper will present some recent studies going on in France, on space reactors for exploration. Three classes of power have been considered: 10kWe, 100kWe, and several megawatts. Available data from previous studies and developments performed in Russia, USA], and Europe, have been collected and gave us a large overview of potential technical solutions. This was the starting point of a trade-off analysis aiming at the selection of the best options, with regards to the technological readiness level in France and Europe. The resulting preliminary designs will be presented and critical technologies needing maturation activities will be highlighted. (author)

  16. Study of space reactors for exploration missions

    International Nuclear Information System (INIS)

    Cliquet, Elisa; Ruault, Jean-Marc; Masson, Frederic; Roux, Jean-Pierre; Paris, Nicolas; Cazale, Brice; Manifacier, Laurent; Poinot-Salanon, Christine

    2013-01-01

    Nuclear propulsion has been studied for many decades. The power density of nuclear fission is much higher than chemical process, and for missions to outer solar system requiring several hundred of kilowatts, or for flexible manned missions to Mars requiring several megawatts, nuclear electric propulsion might be the only option offering a reasonable mass in low earth orbit. Despite the existence of low power experiences - SNAP10 in the 60's or Buk/Topaz in the 60-80's - no high power reactor has been developed: investment cost, long term time frame, high technological challenges and radioactive hazards are the main challenges we must overtake. However, it seems reasonable to look at the technical challenges that have to be overcome for a next generation of nuclear electric systems for space exploration. This paper will present some recent studies going on in France, on space reactors for exploration. Three classes of power have been considered: 10kWe, 100kWe, and several megawatts. Available data from previous studies and developments performed in Russia, USA], and Europe, have been collected and gave us a large overview of potential technical solutions. This was the starting point of a trade-off analysis aiming at the selection of the best options, with regards to the technological readiness level in France and Europe. The resulting preliminary designs will be presented and critical technologies needing maturation activities will be highlighted. (author)

  17. Utilizing a suite of satellite missions to address poorly constrained hydrological fluxes

    Science.gov (United States)

    Singh, A.; Behrangi, A.; Fisher, J.; Reager, J. T., II; Gardner, A. S.

    2017-12-01

    The amount of water stored in a given region (total water storage) changes in response to changes in the hydrologic balance (inputs minus outputs). Closing this balance is exceedingly difficult due to the sparsity of field observation, large uncertainties in satellite derived estimates and model limitation. Different regions have distinct reliability on different hydrological parameters. For example, at a higher latitude precipitation is more uncertain than evapotranspiration (ET) while at lower/middle latitude the opposite is true. This study explores alternative estimates of regional hydrological fluxes by integrating the total water storage estimated by the GRACE gravity fields, and improved estimates lake storage variation by Landsat based land-water classification and satellite altimetry based water height measurements. In particular, an alternative ET estimate is generated for the Aral Sea region by integrating multi-sensor remote sensing data. In an endorheic lake like the Aral Sea, its volumetric variations are predominately governed by changes in inflow, evaporation from the water body and precipitation on the lake. The Aral Sea water volume is estimated at a monthly time step by the combination of Landsat land-water classification and ocean radar altimetry (Jason 1 and Jason 2) observations using truncated pyramid method. Considering gauge based river runoff as a true observation and given the fact that there is less variability between multiple precipitation datasets (TRMM, GPCP, GPCC, and ERA), ET can be considered as a most uncertain parameter in this region. The estimated lake volume acts as a controlling factor to estimate ET as the residual of the changes in TWS minus inflow plus precipitation. The estimated ET is compared with the MODIS-based evaporation observations.

  18. The Hypersonic Inflatable Aerodynamic Decelerator (HIAD) Mission Applications Study

    Science.gov (United States)

    Bose, David M.; Winski, Richard; Shidner, Jeremy; Zumwalt, Carlie; Johnston, Christopher O.; Komar, D. R.; Cheatwood, F. M.; Hughes, Stephen J.

    2013-01-01

    The objective of the HIAD Mission Applications Study is to quantify the benefits of HIAD infusion to the concept of operations of high priority exploration missions. Results of the study will identify the range of mission concepts ideally suited to HIADs and provide mission-pull to associated technology development programs while further advancing operational concepts associated with HIAD technology. A summary of Year 1 modeling and analysis results is presented covering missions focusing on Earth and Mars-based applications. Recommended HIAD scales are presented for near term and future mission opportunities and the associated environments (heating and structural loads) are described.

  19. Vertical and Horizontal Analysis of Crustal Structure of Southeastern Mediterranean and the Egyptian Coastal Zone, from Bouguer and Satellite Mission Data

    Science.gov (United States)

    Saleh, Salah

    2016-07-01

    The present Tectonic system of Southeastern Mediterranean is driven by the collision of the African and Eurasian plates, the Arabian Eurasian convergence and the displacement of the Anatolian Aegean microplate, which generally represents the characteristic of lithospheric structure of the region. In the scope of this study, Bouguer and the satellite gravity (satellite altimetry) anomalies of southeastern Mediterranean and North Eastern part of Egypt were used for investigating the lithospheric structures. Second order trend analyses were applied firstly to Bouguer and satellite altimetry data for examining the characteristic of the anomaly. Later, the vertical and horizontal derivatives applications were applied to the same data. Generally, the purpose of the applying derivative methods is determining the vertical and horizontal borders of the structure. According to the results of derivatives maps, the study area could mainly divided into important four tectonic subzones depending on basement and Moho depth maps. These subzones are distributed from south to the north as: Nile delta-northern Sinai zone, north Egyptian coastal zone, Levantine basin zone and northern thrusting (Cyprus and its surroundings) zone. These zones are separated from each other by horizontal tectonic boundaries and/or near-vertical faults that display the block-faulting tectonic style of this belt. Finally, the gravity studies were evaluated together with the seismic activity of the region. Consequently, the geodynamical structure of the region is examined with the previous studies done in the region. Thus, the current study indicates that satellite gravity mission data is a valuable source of data in understanding the tectonic boundary behavior of the studied region and that satellite gravity data is an important modern source of data in the geodynamical studies.

  20. Studying the Surfaces of the Icy Galilean Satellites With JIMO

    Science.gov (United States)

    Prockter, L.; Schenk, P.; Pappalardo, R.

    2003-12-01

    The Geology subgroup of the Jupiter Icy Moons Orbiter (JIMO) Science Definition Team (SDT) has been working with colleagues within the planetary science community to determine the key outstanding science goals that could be met by the JIMO mission. Geological studies of the Galilean satellites will benefit from the spacecraft's long orbital periods around each satellite, lasting from one to several months. This mission plan allows us to select the optimal viewing conditions to complete global compositional and morphologic mapping at high resolution, and to target geologic features of key scientific interest at very high resolution. Community input to this planning process suggests two major science objectives, along with corresponding measurements proposed to meet them. Objective 1: Determine the origins of surface features and their implications for geological history and evolution. This encompasses investigations of magmatism (intrusion, extrusion, and diapirism), tectonism (isostatic compensation, and styles of faulting, flexure and folding), impact cratering (morphology and distribution), and gradation (erosion and deposition) processes (impact gardening, sputtering, mass wasting and frosts). Suggested measurements to meet this goal include (1) two dimensional global topographic mapping sufficient to discriminate features at a spatial scale of 10 m, and with better than or equal to 1 m relative vertical accuracy, (2) nested images of selected target areas at a range of resolutions down to the submeter pixel scale, (3) global (albedo) mapping at better than or equal to 10 m/pixel, and (4) multispectral global mapping in at least 3 colors at better than or equal to 100 m/pixel, with some subsets at better than 30 m/pixel. Objective 2. Identify and characterize potential landing sites for future missions. A primary component to the success of future landed missions is full characterization of potential sites in terms of their relative age, geological interest, and

  1. Definition of satellite servicing technology development missions for early space stations. Volume 2: Technical

    Science.gov (United States)

    1983-01-01

    Early space station accommodation, build-up of space station manipulator capability, on-orbit spacecraft assembly test and launch, large antenna structure deployment, service/refurbish satellite, and servicing of free-flying materials processing platform are discussed.

  2. Assured Mission Support Space Architecture (AMSSA) study

    Science.gov (United States)

    Hamon, Rob

    1993-01-01

    The assured mission support space architecture (AMSSA) study was conducted with the overall goal of developing a long-term requirements-driven integrated space architecture to provide responsive and sustained space support to the combatant commands. Although derivation of an architecture was the focus of the study, there are three significant products from the effort. The first is a philosophy that defines the necessary attributes for the development and operation of space systems to ensure an integrated, interoperable architecture that, by design, provides a high degree of combat utility. The second is the architecture itself; based on an interoperable system-of-systems strategy, it reflects a long-range goal for space that will evolve as user requirements adapt to a changing world environment. The third product is the framework of a process that, when fully developed, will provide essential information to key decision makers for space systems acquisition in order to achieve the AMSSA goal. It is a categorical imperative that military space planners develop space systems that will act as true force multipliers. AMSSA provides the philosophy, process, and architecture that, when integrated with the DOD requirements and acquisition procedures, can yield an assured mission support capability from space to the combatant commanders. An important feature of the AMSSA initiative is the participation by every organization that has a role or interest in space systems development and operation. With continued community involvement, the concept of the AMSSA will become a reality. In summary, AMSSA offers a better way to think about space (philosophy) that can lead to the effective utilization of limited resources (process) with an infrastructure designed to meet the future space needs (architecture) of our combat forces.

  3. Innovative Applications of DoD Propulsion Technology for Low-Cost Satellite Missions, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We are proposing to leverage the Missile Defense Agency investments in high-performance propulsion systems for low-cost space missions with large Dv requirements,...

  4. Nuclear electric propulsion mission engineering study. Volume 2: Final report

    Science.gov (United States)

    1973-01-01

    Results of a mission engineering analysis of nuclear-thermionic electric propulsion spacecraft for unmanned interplanetary and geocentric missions are summarized. Critical technologies associated with the development of nuclear electric propulsion (NEP) are assessed, along with the impact of its availability on future space programs. Outer planet and comet rendezvous mission analysis, NEP stage design for geocentric and interplanetary missions, NEP system development cost and unit costs, and technology requirements for NEP stage development are studied.

  5. The NASA X-Ray Mission Concepts Study

    Science.gov (United States)

    Petre, Robert; Ptak, A.; Bookbinder, J.; Garcia, M.; Smith, R.; Bautz, M.; Bregman, J.; Burrows, D.; Cash, W.; Jones-Forman, C.; hide

    2012-01-01

    The 2010 Astrophysics Decadal Survey recommended a significant technology development program towards realizing the scientific goals of the International X-ray Observatory (IXO). NASA has undertaken an X-ray mission concepts study to determine alternative approaches to accomplishing IXO's high ranking scientific objectives over the next decade given the budget realities, which make a flagship mission challenging to implement. The goal of the study is to determine the degree to which missions in various cost ranges from $300M to $2B could fulfill these objectives. The study process involved several steps. NASA released a Request for Information in October 2011, seeking mission concepts and enabling technology ideas from the community. The responses included a total of 14 mission concepts and 13 enabling technologies. NASA also solicited membership for and selected a Community Science Team (CST) to guide the process. A workshop was held in December 2011 in which the mission concepts and technology were presented and discussed. Based on the RFI responses and the workshop, the CST then chose a small group of notional mission concepts, representing a range of cost points, for further study. These notional missions concepts were developed through mission design laboratory activities in early 2012. The results of all these activities were captured in the final X-ray mission concepts study report, submitted to NASA in July 2012. In this presentation, we summarize the outcome of the study. We discuss background, methodology, the notional missions, and the conclusions of the study report.

  6. S-band multiple-access interference study for advanced tracking and data relay satellite systems

    Science.gov (United States)

    Peng, Wei-Chung; Yang, Chau-Chin

    1990-01-01

    The results of a study on the effect of mutual interference among S-band multiple access (SMA) system users of advanced tracking and data relay satellite system (ATDRSS) are presented. In the ATDRSS era, the SMA system is required to support data rates ranging from 10 kb/s to 3 Mb/s. The system will consist of four advanced tracking and data relay satellites (ATDRS) each supporting up to five telemetry links. All users have 10 MHz bandwidth with their carrier frequency equal to 2.2875 GHz. A hybrid SDMA/CDMA scheme is used to mitigate the effect of the interference among system users. SMA system interference probability is evaluated with CLASS software. User link margin degradation due to mutual interference between two users is evaluated. System interference probability is evaluated for the projected 1996 mission model, a reference mission model, and a modified reference mission model.

  7. Sensitivity studies for a space-based methane lidar mission

    Directory of Open Access Journals (Sweden)

    C. Kiemle

    2011-10-01

    Full Text Available Methane is the third most important greenhouse gas in the atmosphere after water vapour and carbon dioxide. A major handicap to quantify the emissions at the Earth's surface in order to better understand biosphere-atmosphere exchange processes and potential climate feedbacks is the lack of accurate and global observations of methane. Space-based integrated path differential absorption (IPDA lidar has potential to fill this gap, and a Methane Remote Lidar Mission (MERLIN on a small satellite in polar orbit was proposed by DLR and CNES in the frame of a German-French climate monitoring initiative. System simulations are used to identify key performance parameters and to find an advantageous instrument configuration, given the environmental, technological, and budget constraints. The sensitivity studies use representative averages of the atmospheric and surface state to estimate the measurement precision, i.e. the random uncertainty due to instrument noise. Key performance parameters for MERLIN are average laser power, telescope size, orbit height, surface reflectance, and detector noise. A modest-size lidar instrument with 0.45 W average laser power and 0.55 m telescope diameter on a 506 km orbit could provide 50-km averaged methane column measurement along the sub-satellite track with a precision of about 1% over vegetation. The use of a methane absorption trough at 1.65 μm improves the near-surface measurement sensitivity and vastly relaxes the wavelength stability requirement that was identified as one of the major technological risks in the pre-phase A studies for A-SCOPE, a space-based IPDA lidar for carbon dioxide at the European Space Agency. Minimal humidity and temperature sensitivity at this wavelength position will enable accurate measurements in tropical wetlands, key regions with largely uncertain methane emissions. In contrast to actual passive remote sensors, measurements in Polar Regions will be possible and biases due to aerosol

  8. On the choice of orbits for an altimetric satellite to study ocean circulation and tides

    Science.gov (United States)

    Parke, Michael E.; Stewart, Robert H.; Farless, David L.; Cartwright, David E.

    1987-01-01

    The choice of an orbit for satellite altimetric studies of the ocean's circulation and tides requires an understanding of the orbital characteristics that influence the accuracy of the satellite's measurements of sea level and the temporal and spatial distribution of the measurements. The orbital characteristics that influence accurate calculations of the satellite's position as a function of time are examined, and the pattern of ground tracks laid down on the ocean's surface as a function of the satellite's altitude and inclination is studied. The results are used to examine the aliases in the measurements of surface geostrophic currents and tides. Finally, these considerations are used to specify possible orbits that may be useful for the upcoming Topex/Poseidon mission.

  9. Global-scale Observations of the Limb and Disk (GOLD) Mission: Science from Geostationary Orbit on-board a Commercial Communications Satellite

    Science.gov (United States)

    Eastes, R.; Deaver, T.; Krywonos, A.; Lankton, M. R.; McClintock, W. E.; Pang, R.

    2011-12-01

    Geostationary orbits are ideal for many science investigations of the Earth system on global scales. These orbits allow continuous observations of the same geographic region, enabling spatial and temporal changes to be distinguished and eliminating the ambiguity inherent to observations from low Earth orbit (LEO). Just as observations from geostationary orbit have revolutionized our understanding of changes in the troposphere, they will dramatically improve our understanding of the space environment at higher altitudes. However, geostationary orbits are infrequently used for science missions because of high costs. Geostationary satellites are large, typically weighing tons. Consequently, devoting an entire satellite to a science mission requires a large financial commitment, both for the spacecraft itself and for sufficient science instrumentation to justify a dedicated spacecraft. Furthermore, the small number of geostationary satellites produced for scientific missions increases the costs of each satellite. For these reasons, it is attractive to consider flying scientific instruments on satellites operated by commercial companies, some of whom have fleets of ~40 satellites. However, scientists' lack of understanding of the capabilities of commercial spacecraft as well as commercial companies' concerns about risks to their primary mission have impeded the cooperation necessary for the shared use of a spacecraft. Working with a commercial partner, the GOLD mission has successfully overcome these issues. Our experience indicates that there are numerous benefits to flying on commercial communications satellites (e.g., it is possible to downlink large amounts of data) and the costs are low if the experimental requirements adequately match the capabilities and available resources of the host spacecraft. Consequently, affordable access to geostationary orbit aboard a communications satellite now appears possible for science payloads.

  10. The GALILEO GALILEI small-satellite mission with FEEP thrusters (G G)

    International Nuclear Information System (INIS)

    Nobili, A. M.; Bramanti, D.; Catastini, G.

    1997-01-01

    The Equivalence Principle, formulated by Einstein generalizing Galileo's and Newton's work, is a fundamental principle of modern physics. As such it should be tested as accurately as possible. Its most direct consequence, namely the Universality of Free Fall, can be tested in space, in a low Earth orbit, the crucial advantage being that the driving signal is about three orders of magnitude stronger than on Earth. GALILEO GALILEI (G G) is a small space mission designed for such a high-accuracy test. At the time of print, G G has been selected by ASI (Agenzia Spaziale Italiana) as a candidate for the next small Italian mission. Ground tests of the proposed apparatus now indicate that an accuracy of 1 part in 10 17 is within the reach of this small mission

  11. FIREBIRD: A Dual Satellite Mission to Examine the Spatial and Energy Coherence Scales of Radiation Belt Electron Microbursts

    Science.gov (United States)

    Klumpar, D. M.; Spence, H. E.; Larsen, B. A.; Blake, J. B.; Springer, L.; Crew, A. B.; Mosleh, E.; Mashburn, K. W.

    2009-12-01

    FIREBIRD (Focused Investigations of Relativistic Electron Burst Intensity, Range, and Dynamics), a mission under NSF’s “CubeSat-based Science Missions for Space Weather and Atmospheric Research”, will address the broad scientific question: What is the role of microburst electron precipitation in radiation belt dynamics? There are four major candidate processes for losses of relativistic electrons from the outer radiation belt [Millan and Thorne, 2007]: wave-particle interactions with whistler-mode chorus, wave-particle interactions with electromagnetic ion-cyclotron (EMIC) waves, outward radial diffusion to the magnetopause, and loss of adiabaticity on stretched magnetic field lines. FIREBIRD will further investigate the role of whistler-mode chorus, by examining the microburst electron precipitation phenomenon attributed to chorus. Microbursts are thought to be a hallmark of rapid radiation belt losses, possibly removing the entire pre-storm outer zone in a single day [Lorentzen 2001b; O'Brien et al., 2004], yet they are also intimately tied to in-situ acceleration mechanisms. FIREBIRD’s two 1.5U (10 x 10 x 15 cm) CubeSats, each weighing up to 2 kg, will be placed into a common high-inclination bead-on-a-string orbit. The two satellites will remain within ~500 km of one another for six to twelve months, allowing characterization over the spatial scale regime from 10 - 500 km. Each satellite will carry an identical co-aligned pair of solid-state detectors sensitive to electrons from 30 keV to ~3 MeV with 100 msec time resolution. Simultaneous dual measurements provided by the twin FIREBIRD satellites will permit, for the first time, the determination of spatial scales of single microburst events. Along with energy-resolved spectra, these measurements will provide the critically needed answers on the radiation belt loss rate attributed to microbursts. There are three critical questions about relativistic electron microbursts that FIREBIRD can answer: 1) What

  12. Ramakrishna Mission initiative impact study: final report

    Energy Technology Data Exchange (ETDEWEB)

    Chaurey, A.

    2000-07-06

    This report has been prepared by the Tata Energy Research Institute (TERI) for the National Renewable Energy Laboratory. It presents the results of the evaluation and impact assessment of solar photovoltaic lighting systems in the region of Sunderbans, West Bengal, that were deployed by a reputable non-governmental organization (Ramakrishna Mission) under the auspices of the INDO-US collaborative project. The objectives of the study were to evaluate the solar photovoltaic systems for their impact on the individual households as well as on the community, to assess the effectiveness of the implementation and financial mechanisms, and to draw a long-term strategy for NREL's activities in Sunderbans based on case studies of similar interventions. Under the project, provision was made to supply 300 domestic lighting systems (DLS) based on 53-Wp module capacity to individual households and a few other systems such as for lighting, medical refrigeration, and pumping water to community centers. For this study, 152 households were surveyed, of which 29 had also been a part of earlier pre- and post-installation surveys, 47 had been a part of the earlier post-installation survey, and 76 were households that were surveyed for the first time. A set of 46, out of the total 152 households, was selected for evaluating the systems for their technical performance with respect to module output, condition of the battery, and daily energy consumption. Of the total 300 modules, 2 had been stolen, 9 out of the total 300 batteries needed to be replaced, and 10 out of the 300 charge controllers were non-functional. The statistics for the surveyed households indicate 32 luminaire-related faults (blackening or flickering of compact fluorescent lights) and 11 other faults related to fuses, switches, etc.

  13. Supporting Meteorological Field Experiment Missions and Postmission Analysis with Satellite Digital Data and Products

    Science.gov (United States)

    2011-08-01

    defined surface that approximates the geoid or the equipotential surface , which would coincide exactly with the mean ocean surface of Earth if the...TCS-08 field project. The hourly estimates of intensity (maximum sustained 1-min surface winds) were used to monitor the typhoon’s rapidly changing...spacecraft is the first mission to test surface wind vector retrievals via a passive sensor (Gaiser et al. 2004). Near-real-time WindSat wind

  14. Calvin and mission | Labuschagne | HTS Teologiese Studies ...

    African Journals Online (AJOL)

    ... missionary expansion of Protestant churches, but necessitate for all times Church mission as a sure consequence of their theology. Calvin's theology can indeed be described as an 'essentially missionary theology'. In the heart of Calvin's theological thinking clearly features the doctrine of justifi cation – because medieval ...

  15. Low Cost High Performance Generator Technology Program. Volume 4. Mission application study

    International Nuclear Information System (INIS)

    1975-07-01

    Results of initial efforts to investigate application of selenide thermoelectric RTG's to specific missions as well as an indication of development requirements to enable satisfaction of emerging RTG performance criteria are presented. Potential mission applications in DoD such as SURVSATCOM, Advance Defense Support Program, Laser Communication Satellite, Satellite Data System, Global Positioning Satellite, Deep Space Surveillance Satellite, and Unmanned Free Swimming Submersible illustrate power requirements in the range of 500 to 1000 W. In contrast, the NASA applications require lower power ranging from 50 W for outer planetary atmospheric probes to about 200 W for spacecraft flights to Jupiter and other outer planets. The launch dates for most of these prospective missions is circa 1980, a requirement roughly compatible with selenide thermoelectric and heat source technology development. A discussion of safety criteria is included to give emphasis to the requirements for heat source design. In addition, the observation is made that the potential accident environments of all launch vehicles are similar so that a reasonable composite set of design specifications may be derived to satisfy almost all applications. Details of the LCHPG application potential is afforded by three designs: an 80 W RTG using improved selenide thermoelectric material, a 55 to 65 W LCHPG using current and improved selenide materials, and the final 500 W LCHPG as reported in Volume 2. The final results of the LCHPG design study have shown that in general, all missions can expect an LCHPG design which yields 10 percent efficiency at 3 W/lb with the current standard selenide thermoelectric materials, with growth potential to 14 percent at greater than 4 W/lb in the mid 1980's time frame

  16. Study of chaos in chaotic satellite systems

    Indian Academy of Sciences (India)

    Ayub Khan

    2017-12-27

    Dec 27, 2017 ... through strange attractor which is framed of the com- plex patterns. The one ... jectory of the Slave satellite be the measured attitude of the Master satellite [12 ... Bifurcation occurs when a tiny smooth change is made to the parameter .... negative and one of these tends to zero which is the required condition ...

  17. The Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS mission: design, execution, and first results

    Directory of Open Access Journals (Sweden)

    D. J. Jacob

    2010-06-01

    Full Text Available The NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS mission was conducted in two 3-week deployments based in Alaska (April 2008 and western Canada (June–July 2008. Its goal was to better understand the factors driving current changes in Arctic atmospheric composition and climate, including (1 influx of mid-latitude pollution, (2 boreal forest fires, (3 aerosol radiative forcing, and (4 chemical processes. The June–July deployment was preceded by one week of flights over California (ARCTAS-CARB focused on (1 improving state emission inventories for greenhouse gases and aerosols, (2 providing observations to test and improve models of ozone and aerosol pollution. ARCTAS involved three aircraft: a DC-8 with a detailed chemical payload, a P-3 with an extensive aerosol and radiometric payload, and a B-200 with aerosol remote sensing instrumentation. The aircraft data augmented satellite observations of Arctic atmospheric composition, in particular from the NASA A-Train. The spring phase (ARCTAS-A revealed pervasive Asian pollution throughout the Arctic as well as significant European pollution below 2 km. Unusually large Siberian fires in April 2008 caused high concentrations of carbonaceous aerosols and also affected ozone. Satellite observations of BrO column hotspots were found not to be related to Arctic boundary layer events but instead to tropopause depressions, suggesting the presence of elevated inorganic bromine (5–10 pptv in the lower stratosphere. Fresh fire plumes from Canada and California sampled during the summer phase (ARCTAS-B indicated low NOx emission factors from the fires, rapid conversion of NOx to PAN, no significant secondary aerosol production, and no significant ozone enhancements except when mixed with urban pollution.

  18. Improving Satellite Compatible Microdevices to Study Biology in Space

    Science.gov (United States)

    Kalkus, Trevor; Snyder, Jessica; Paulino-Lima, Ivan; Rothschild, Lynn

    2017-01-01

    The technology for biology in space lags far behind the gold standard for biological experiments on Earth. To remedy this disparity, the Rothschild lab works on proof of concept, prototyping, and developing of new sensors and devices to further the capabilities of biology research on satellites. One such device is the PowerCell Payload System. One goal for synthetic biology in aiding space travel and colonization is to genetically engineer living cells to produce biochemicals in space. However, such farming in space presupposes bacteria retain their functionality post-launch, bombarded by radiation, and without the 1G of Earth. Our questions is, does a co-culture of cyanobacteria and protein-synthesizing bacteria produce Earth-like yields of target proteins? Is the yield sensitive to variable gravitational forces? To answer these questions, a PowerCell Payload System will spend 1 year aboard the German Aerospace Center's Euglena and Combined Regenerative Organic-food Production In Space (Eu:CROPIS) mission satellite. The PowerCell system is a pair of two 48-well microfluidic cards, each well seeded with bacteria. The system integrates fluidic, thermal, optical, electronic, and control systems to germinate bacteria spores, then measure the protein synthesized for comparison to parallel experiments conducted on the Earth. In developing the PowerCell Payload, we gained insight into the shortcomings of biology experiments on satellites. To address these issues, we have started three new prototyping projects: 1) The development of an extremely stable and radiation resistant cell-free system, allowing for the construction of proteins utilizing only cell components instead of living cells. This can be lyophilized on a substrate, like paper. (2) Using paper as a microfluidic platform that is flexible, stable, cheap, and wicking. The capillary action eliminates the need for pumps, reducing volume, mass, and potential failing points. Electrodes can be printed on the paper to

  19. Integration and Testing Challenges of Small Satellite Missions: Experiences from the Space Technology 5 Project

    Science.gov (United States)

    Sauerwein, Timothy A.; Gostomski, Tom

    2007-01-01

    The Space Technology 5(ST5) payload was successfully carried into orbit on an OSC Pegasus XL launch vehicle, which was carried aloft and dropped from the OSC Lockheed L-1011 from Vandenberg Air Force Base March 22,2006, at 9:03 am Eastern time, 6:03 am Pacific time. In order to reach the completion of the development and successful launch of ST 5, the systems integration and test(I&T) team determined that a different approach was required to meet the project requirements rather than the standard I&T approach used for single, room-sized satellites. The ST5 payload, part of NASA's New Millennium Program headquartered at JPL, consisted of three micro satellites (approximately 30 kg each) and the Pegasus Support Structure (PSS), the system that connected the spacecrafts to the launch vehicle and deployed the spacecrafts into orbit from the Pegasus XL launch vehicle. ST5 was a technology demonstration payload, intended to test six (6) new technologies for potential use for future space flights along with demonstrating the ability of small satellites to perform quality science. The main technology was a science grade magnetometer designed to take measurements of the earth's magnetic field. The three spacecraft were designed, integrated, and tested at NASA Goddard Space Flight Center with integration and environmental testing occurring in the Bldg. 7-1 0-15-29. The three spacecraft were integrated and tested by the same I&T team. The I&T Manager determined that there was insufficient time in the schedule to perform the three I&T spacecraft activities in series used standard approaches. The solution was for spacecraft #1 to undergo integration and test first, followed by spacecraft #2 and #3 simultaneously. This simultaneous integration was successful for several reasons. Each spacecraft had a Lead Test Conductor who planned and coordinated their spacecraft through its integration and test activities. One team of engineers and technicians executed the integration of all

  20. Nuclear electric propulsion mission engineering study. Volume 1: Executive summary

    Science.gov (United States)

    1973-01-01

    Results of a mission engineering analysis of nuclear-thermionic electric propulsion spacecraft for unmanned interplanetary and geocentric missions are summarized. Critical technologies associated with the development of nuclear electric propulsion (NEP) are assessed. Outer planet and comet rendezvous mission analysis, NEP stage design for geocentric and interplanetary missions, NEP system development cost and unit costs, and technology requirements for NEP stage development are studied. The NEP stage design provides both inherent reliability and high payload mass capability. The NEP stage and payload integration was found to be compatible with the space shuttle.

  1. Reusable Reentry Satellite (RRS): Propulsion system trade study

    Science.gov (United States)

    1990-01-01

    The purpose of the Reusable Reentry Satellite (RRS) Propulsion System Trade Study described in this summary report was to investigate various propulsion options available for incorporation on the RRS and to select the option best suited for RRS application. The design requirements for the RRS propulsion system were driven by the total impulse requirements necessary to operate within the performance envelope specified in the RRS System Requirements Documents. These requirements were incorporated within the Design Reference Missions (DRM's) identified for use in this and other subsystem trade studies. This study investigated the following propulsion systems: solid rocket, monopropellant, bipropellant (monomethyl hydrazine and nitrogen tetroxide or MMH/NTO), dual-mode bipropellant (hydrazine and nitrogen tetroxide or N2H4/NTO), liquid oxygen and liquid hydrogen (LO2/LH2), and an advanced design propulsion system using SDI-developed components. A liquid monopropellant blowdown propulsion system was found to be best suited for meeting the RRS requirements and is recommended as the baseline system. This system was chosen because it is the simplest of all investigated, has the fewest components, and is the most cost effective. The monopropellant system meets all RRS performance requirements and has the capability to provide a very accurate deorbit burn which minimizes reentry dispersions. In addition, no new hardware qualification is required for a monopropellant system. Although the bipropellant systems offered some weight savings capability for missions requiring large deorbit velocities, the advantage of a lower mass system only applies if the total vehicle design can be reduced to allow a cheaper launch vehicle to be used. At the time of this trade study, the overall RRS weight budget and launch vehicle selection were not being driven by the propulsion system selection. Thus, the added cost and complexity of more advanced systems did not warrant application.

  2. A Comparative Study of Aerocapture Missions with a Mars Destination

    Science.gov (United States)

    Vaughan, Diane; Miller, Heather C.; Griffin, Brand; James, Bonnie F.; Munk, Michelle M.

    2005-01-01

    Conventional interplanetary spacecraft use propulsive systems to decelerate into orbit. Aerocapture is an alternative approach for orbit capture, in which the spacecraft makes a single pass through a target destination's atmosphere. Although this technique has never been performed, studies show there are substantial benefits of using aerocapture for reduction of propellant mass, spacecraft size, and mission cost. The In-Space Propulsion (ISP) Program, part of NASA's Science Mission Directorate, has invested in aerocapture technology development since 2002. Aerocapture investments within ISP are largely driven by mission systems analysis studies, The purpose of this NASA-funded report is to identify and document the fundamental parameters of aerocapture within previous human and robotic Mars mission studies which will assist the community in identifying technology research gaps in human and robotic missions, and provide insight for future technology investments. Upon examination of the final data set, some key attributes within the aerocapture disciplines are identified.

  3. Testing solar panels for small-size satellites: the UPMSAT-2 mission

    International Nuclear Information System (INIS)

    Roibás-Millán, E; Alonso-Moragón, A; Jiménez-Mateos, A G; Pindado, S

    2017-01-01

    At present, the development of small-size satellites by universities, companies and research institutions has become usual practice, and is spreading rapidly. In this kind of project cost plays a significant role. One of the main areas are the assembly, integration and test (AIT) plans, which carry an associated cost for simulating environmental conditions. For instance, in the power subsystems test and, in particular, in the testing of solar panels, the irradiance and temperature conditions might be optimum so the performance of the system can be shown next to real operational conditions. To reproduce the environmental conditions in terms of irradiance, solar simulators are usually used, which carries an associated increase in cost for testing the equipment. The aim of this paper is to present an alternative and inexpensive way to perform AIT plans on spacecraft power subsystems, from a testing campaign performed using outdoor clean-sky conditions and an isolation system to protect the panels. A post-process of the measured data is therefore needed, taking into account the conditions in which the test has been accomplished. The I–V characteristics obtained are compared with a theoretical 1-diode/2-resistor equivalent electric circuit, achieving enough precision based solely on the manufacturer’s data. (paper)

  4. Testing solar panels for small-size satellites: the UPMSAT-2 mission

    Science.gov (United States)

    Roibás-Millán, E.; Alonso-Moragón, A.; Jiménez-Mateos, A. G.; Pindado, S.

    2017-11-01

    At present, the development of small-size satellites by universities, companies and research institutions has become usual practice, and is spreading rapidly. In this kind of project cost plays a significant role. One of the main areas are the assembly, integration and test (AIT) plans, which carry an associated cost for simulating environmental conditions. For instance, in the power subsystems test and, in particular, in the testing of solar panels, the irradiance and temperature conditions might be optimum so the performance of the system can be shown next to real operational conditions. To reproduce the environmental conditions in terms of irradiance, solar simulators are usually used, which carries an associated increase in cost for testing the equipment. The aim of this paper is to present an alternative and inexpensive way to perform AIT plans on spacecraft power subsystems, from a testing campaign performed using outdoor clean-sky conditions and an isolation system to protect the panels. A post-process of the measured data is therefore needed, taking into account the conditions in which the test has been accomplished. The I-V characteristics obtained are compared with a theoretical 1-diode/2-resistor equivalent electric circuit, achieving enough precision based solely on the manufacturer’s data.

  5. Magnetometer Data in the Classroom as a part of the NASA THEMIS Satellite Mission

    Science.gov (United States)

    Peticolas, L. M.; Bean, J.; Walker, A.

    2011-12-01

    The NASA-funded THEMIS mission was designed to determine the onset time and location of magnetic substorms of Earth's space environment, a prerequisite to understanding space weather. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. he Geomagnetic Event Observation Network by Students (GEONS) project was the flagship, formal education component of the E/PO program. With the placement of magnetometers in the proximity of rural schools throughout the country, middle and high school teachers along with their students benefited from the opportunity to work with 'real-time' data and participated in hands-on space science activities. Particular attention was paid to placing the magnetometer stations at schools in rural communities whose students were traditionally underserved and underrepresented in the sciences. The project offered to the teachers of these students long-term professional development opportunities that centered around THEMIS-related space science and the magnetometer data. The THEMIS E/PO final evaluation report for the main phase of the THEMIS mission covered the period from 2003-2009, describing the impact of this program such as this program placed magnetometers sites at 13 rural, underserved schools/communities, two-fifths of which are on tribal lands; and provided intensive professional development for 20 teachers from 2004 through 2009. A core group of eight teachers estimated reaching more than 2,720 students with THEMIS-related materials/ideas. 75% of these students are minorities in science. Core teachers provided evidence of the project's positive impact on students' attitudes toward science and their choices for courses that position them for STEM-related careers. Core teachers reported sharing THEMIS-related materials/ideas with 275 colleagues. The NewsHour with Jim Lehrer featured the Petersburg, Alaska site potentially reaching more than 5 million viewers in two airings, according to Nielsen

  6. AIM satellite-based research bridges the unique scientific aspects of the mission to informal education programs globally

    Science.gov (United States)

    Robinson, D.; Maggi, B.

    2003-04-01

    The Education and Public Outreach (EPO) component of the satellite-based research mission "Aeronomy of Ice In the Mesosphere" (AIM) will bridge the unique scientific aspects of the mission to informal education organizations. The informal education materials developed by the EPO will utilize AIM data and educate the public about the environmental implications associated with the data. This will assist with creating a scientifically literate workforce and in developing a citizenry capable of making educated decisions related to environmental policies and laws. The objective of the AIM mission is to understand the mechanisms that cause Polar Mesospheric Clouds (PMCs) to form, how their presence affects the atmosphere, and how change in the atmosphere affects them. PMCs are sometimes known as Noctilucent Clouds (NLCs) because of their visibility during the night from appropriate locations. The phenomenon of PMCs is an observable indicator of global change, a concern to all citizens. Recent sightings of these clouds over populated regions have compelled AIM educators to expand informal education opportunities to communities worldwide. Collaborations with informal organizations include: Museums/Science Centers; NASA Sun-Earth Connection Forum; Alaska Native Ways of Knowing Project; Amateur Noctilucent Cloud Observers Organization; National Parks Education Programs; After School Science Clubs; Public Broadcasting Associations; and National Public Radio. The Native Ways of Knowing Project is an excellent example of informal collaboration with the AIM EPO. This Alaska based project will assist native peoples of the state with photographing NLCs for the EPO website. It will also aid the EPO with developing materials for informal organizations that incorporate traditional native knowledge and science, related to the sky. Another AIM collaboration that will offer citizens lasting informal education opportunities is the one established with the United States National Parks

  7. The US/USSR Biological Satellite Program: COSMOS 936 Mission Overview

    Science.gov (United States)

    Souza, K. A.

    1978-01-01

    On August 3, 1977, the Soviet Union launched Cosmos 936, an unmanned spacecraft carrying biology and physics experiments from 9 countries, including both the Soviet Union and U.S. The launch marked the second time the Soviet Union has flown U.S. experiments aboard one of its spacecraft, the first being Cosmos 782 launched Nov. 25, 1975, which remained in orbit 19.5 days. Aboard Cosmos 936 were: 30 young male Wistar SPF rats, 20 of which was exposed to hypogravity during flight while the remainder were subjected to a l x g acceleration by continuous configuration; 2) experiments with plants and fruit flies; 3) radiation physics experiments; and 4) a heat convection experiment. After 18.5 days in orbit, the spacecraft landed in central Asia where a Soviet recovery team began experiment operations, including animal autopsies, within 4.5 hr of landing. Half of the animals were autopsied at the recovery site and the remainder returned to Moscow and allowed to readapt to terrestrial gravity for 25 days after which they, too, were autopsied. Specimens for U.S. were initially prepared at the recovery site or Soviet laboratories and transferred to U.S. laboratories for complete analyses. An overview of the mission focusing on preflight, on-orbit, and postflight activities pertinent to the seven U.S. experiments aboard Cosmos 936 will be presented.

  8. Satellite studies of the stratospheric aerosol

    International Nuclear Information System (INIS)

    McCormick, M.P.; Hamill, P.; Pepin, T.J.; Chu, W.P.; Swissler, T.J.; McMaster, L.R.

    1979-01-01

    The potential climatological and environmental importance of the stratospheric aerosol layer has prompted great interest in measuring the properties of this aerosol. In this paper we report on two recently deployed NASA satellite systems (SAM II and SAGE) that are monitoring the stratospheric aerosol. The satellite orbits are such that nearly global coverage is obtained. The instruments mounted in the spacecraft are sun photometers that measure solar intensity at specific wavelengths as it is moderated by atmospheric particulates and gases during each sunrise and sunset encountered by the satellites. The data obtained are ''inverted'' to yield vertical aerosol and gaseous (primarily ozone) extinction profiles with 1 km vertical resolution. Thus, latitudinal, longitudinal, and temporal variations in the aerosol layer can be evaluated. The satellite systems are being validated by a series of ground truth experiments using airborne and ground lidar, balloon-borne dustsondes, aircraft-mounted impactors, and other correlative sensors. We describe the SAM II and SAGE satellite systems, instrument characteristics, and mode of operation; outline the methodology of the experiments; and describe the ground truth experiments. We present preliminary results from these measurements

  9. Aerospace Engineering Space Mission Concept Feasibility Study: A Neptune Mission Design Example

    Science.gov (United States)

    Esper, Jaime

    2007-01-01

    This viewgraph document reviews the feasibility study of a mission to Neptune. Included are discussions of the science instruments, the design methodology, the trajectory, the spacecraft design, the alternative propulsion systems, (chemical, solar electric (SEP)), the communications systems, the power systems, the thermal system.

  10. VHR satellite imagery for humanitarian crisis management: a case study

    Science.gov (United States)

    Bitelli, Gabriele; Eleias, Magdalena; Franci, Francesca; Mandanici, Emanuele

    2017-09-01

    During the last years, remote sensing data along with GIS have been largely employed for supporting emergency management activities. In this context, the use of satellite images and derived map products has become more common also in the different phases of humanitarian crisis response. In this work very high resolution satellite imagery was processed to assess the evolution of Za'atari Refugee Camp, built in Jordan in 2012 by the UN Refugee Agency to host Syrian refugees. Multispectral satellite scenes of the Za'atari area were processed by means of object-based classifications. The main aim of the present work is the development of a semiautomated procedure for multi-temporal camp monitoring with particular reference to the dwellings detection. Whilst in the emergency mapping domain automation of feature extraction is widely investigated, in the field of humanitarian missions the information is often extracted by means of photointerpretation of the satellite data. This approach requires time for the interpretation; moreover, it is not reliable enough in complex situations, where features of interest are often small, heterogeneous and inconsistent. Therefore, the present paper discusses a methodology to obtain information for assisting humanitarian crisis management, using a semi-automatic classification approach applied to satellite imagery.

  11. A satellite study of dayside auroral conjugacy

    Directory of Open Access Journals (Sweden)

    H. B. Vo

    Full Text Available A study of dayside auroral conjugacy has been done using the cleft/boundary layer auroral particle boundaries observed by the DMSP-F7 satellite in the southern hemisphere and the global UV auroral images taken by the Viking spacecraft in the northern hemisphere. The 22 events have been studied on the basis of an internal IGRF 1985 magnetic field; it is shown that there is a displacement of up to 4° in latitude from the conjugate points with the northern aurora appearing to be located poleward of the conjugate point. No local time dependence of the north-south auroral location difference was seen. The use of a more realistic magnetic field model for tracing field lines which incorporates the dipole tilt angle and Kp index, the Tsyganenko 1987 long model plus the IGRF 1985 internal magnetic field model, appears to organize the data better. Although with this external plus internal model some tracings did not close in the opposite hemisphere, 70% of those that did indicated satisfactory conjugacy. The study shows that the degree of auroral conjugacy is dependent upon the accuracy of the magnetic field model used to trace to the conjugate point, especially in the dayside region where the field lines can either go to the dayside magnetopause near the subsolar point or sweep all the way back to the flanks of the magnetotail. Also the discrepancy in the latitude of northern and southern aurora can be partially explained by the displacement of the neutral sheet (source region of the aurora by the dipole tilt effect.

  12. A satellite study of dayside auroral conjugacy

    Directory of Open Access Journals (Sweden)

    H. B. Vo

    1995-11-01

    Full Text Available A study of dayside auroral conjugacy has been done using the cleft/boundary layer auroral particle boundaries observed by the DMSP-F7 satellite in the southern hemisphere and the global UV auroral images taken by the Viking spacecraft in the northern hemisphere. The 22 events have been studied on the basis of an internal IGRF 1985 magnetic field; it is shown that there is a displacement of up to 4° in latitude from the conjugate points with the northern aurora appearing to be located poleward of the conjugate point. No local time dependence of the north-south auroral location difference was seen. The use of a more realistic magnetic field model for tracing field lines which incorporates the dipole tilt angle and Kp index, the Tsyganenko 1987 long model plus the IGRF 1985 internal magnetic field model, appears to organize the data better. Although with this external plus internal model some tracings did not close in the opposite hemisphere, 70% of those that did indicated satisfactory conjugacy. The study shows that the degree of auroral conjugacy is dependent upon the accuracy of the magnetic field model used to trace to the conjugate point, especially in the dayside region where the field lines can either go to the dayside magnetopause near the subsolar point or sweep all the way back to the flanks of the magnetotail. Also the discrepancy in the latitude of northern and southern aurora can be partially explained by the displacement of the neutral sheet (source region of the aurora by the dipole tilt effect.

  13. PROMISE: A preliminary study of a scientific information system for MIPAS satellite experiment

    International Nuclear Information System (INIS)

    Kapetanios, E.

    1993-08-01

    A scientific information system for MIPAS satellite experiment will be presented according to its main hardware and software configuration. It will be considered as a MIPAS data processing and archiving node of the ground segment of the planned satellite mission for the remote sensing of atmospheric parameters, as well as an information system supporting the researchers in their scientific environment. In this preliminary study, the methodology of a more detailed system design has also been specified. The system consists of two logical components, an operational database for the generation, storage and management of vast amounts of MIPAS data received from the satellite, and the research and development database, which must be interfaced to the operational one, providing a more abstract and user-friendly interface for the scientific community enabling experimentation and the extraction of the information needed. (orig.) [de

  14. NASA and international studies of the Solar Probe Mission

    Science.gov (United States)

    Randolph, James E.

    1992-01-01

    A review is presented summarizing the history and current status of the studies of the Solar Probe Mission by NASA and other space agencies. The technology and scientific challenges of the mission are addressed in these studies and can be met with current instrument and technology capabilities. The specific set of experiments recommended by a scientific advisory group to the NASA study for integration into the design concept is discussed.

  15. Mission Analysis for the Don Quijote Phase-A Study

    Science.gov (United States)

    Cano, Juan L.; Sanchez, Mariano; Cornara, Stefania; Carnelli, Ian

    2007-01-01

    The Don Quijote Phase-A study is a definition study funded by ESA and devoted to the analysis of the possibilities to deflect a Near Earth Object (NEO) in the range of 300-800 m diameter. DEIMOS Space S.L. and EADS Astrium have teamed up within this study to form one of the three consortia that have analyzed these aspects for ESA. Target asteroids for the mission are 1989 ML, 2002 AT4 and Apophis. This paper presents the mission analysis activities within the consortium providing: low-thrust interplanetary rendezvous Orbiter trajectories to the target asteroids, ballistic interplanetary trajectories for the Impactor, Orbiter arrival description at the asteroids, Orbiter stable orbits characterization at the asteroid, deflection determination by means of a Radio Science Experiment (RSE) as well as the mission timelines and overall mission scenarios.

  16. Correlative studies of satellite ozone sensor measurements

    International Nuclear Information System (INIS)

    Lovill, J.E.; Ellis, J.S.

    1983-01-01

    Comparisons are made between total ozone measurements made by four satellite ozone sensors (TOMS, SBUV, TOVS and MFR). The comparisons were made during July 1979 when all sensors were operating simultaneously. The TOMS and SBUV sensors were observed to measure less total ozone than the MFR sensor, 10 and 15 Dobson units (DU) respectively. The MFR and TOMS sensors measured less ozone than the TOVS sensor, 19 an 28 DU, respectively. Latitudinal variability of the total ozone comparisons is discussed

  17. The new worlds observer: The astrophysics strategic mission concept study

    Directory of Open Access Journals (Sweden)

    Cash W.

    2011-07-01

    Full Text Available We present some results of the Astrophysics Strategic Mission Concept Study for the New Worlds Observer (NWO. We show that the use of starshades is the most effective and affordable path to mapping and understanding our neighboring planetary systems, to opening the search for life outside our solar system, while serving the needs of the greater astronomy community. A starshade-based mission can be implemented immediately with a near term program of technology demonstration.

  18. First champ mission results for gravity, magnetic and atmospheric studies

    CERN Document Server

    Lühr, Hermann; Schwintzer, Peter

    2003-01-01

    In the summer of 2000 the German geo-research satellite CHAMP was launched into orbit. Its innovative payload arrangement and the low intial orbit allow CHAMP to simultaneously collect and almost continuously analyse precise data relating to gravity and magnetic fields at low altitude. In addition to this CHAMP also measures the neutral atmosphere and ionosphere using GPS techniques. Eighteen months after the launch, CHAMP research groups from all over the world met at the Geo-Forschungs-Zentrum in Potsdam for an initial exchange of experiences and results. The main outcome of this user meeting is summarized in this volume. Apart from technical information about the mission, the book offers a comprehensive insight into the present status of CHAMP data exploitation for Earth system research and practical applications in geodesy, geophysics and meteorology.

  19. Fiscal 2000 survey report. Survey and study of constellation satellites technology; 2000 nendo chosa hokokusho. Konsutereshon eisei gijutsu ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Demands for constellation satellites were surveyed and satellite systems were studied for extracting basic technical tasks relative to constellation satellite systems and for drafting space verification plans. For a constellation satellite system to accomplish its missions, two or more satellites have to be simultaneously navigated. It is assumed that its field of application will cover earth observation, information communication, risk management, disaster prevention, and the like. With such applications taken into consideration, surveys and studies were conducted about the need and marketability of constellation satellites, need of state-level involvement, and requests for missions to be imposed on a constellation system. For plural satellites to satisfy mission requests by coordinating with each other, it will be necessary to develop basic technologies, such as navigational guidance, communications control, system autonomous management, and operation on the ground. Functions and performance that a constellation satellite system are requested to have and basic technologies to be studied and developed were extracted, and space verification plans were drafted. (NEDO)

  20. Geomagnetic field models for satellite angular motion studies

    Science.gov (United States)

    Ovchinnikov, M. Yu.; Penkov, V. I.; Roldugin, D. S.; Pichuzhkina, A. V.

    2018-03-01

    Four geomagnetic field models are discussed: IGRF, inclined, direct and simplified dipoles. Geomagnetic induction vector expressions are provided in different reference frames. Induction vector behavior is compared for different models. Models applicability for the analysis of satellite motion is studied from theoretical and engineering perspectives. Relevant satellite dynamics analysis cases using analytical and numerical techniques are provided. These cases demonstrate the benefit of a certain model for a specific dynamics study. Recommendations for models usage are summarized in the end.

  1. Advanced Russian Mission Laplace-P to Study the Planetary System of Jupiter: Scientific Goals, Objectives, Special Features and Mission Profile

    Science.gov (United States)

    Martynov, M. B.; Merkulov, P. V.; Lomakin, I. V.; Vyatlev, P. A.; Simonov, A. V.; Leun, E. V.; Barabanov, A. A.; Nasyrov, A. F.

    2017-12-01

    The advanced Russian project Laplace-P is aimed at developing and launching two scientific spacecraft (SC)— Laplace-P1 ( LP1 SC) and Laplace-P2 ( LP2 SC)—designed for remote and in-situ studies of the system of Jupiter and its moon Ganymede. The LP1 and LP2 spacecraft carry an orbiter and a lander onboard, respectively. One of the orbiter's objectives is to map the surface of Ganymede from the artificial satellite's orbit and to acquire the data for the landing site selection. The main objective of the lander is to carry out in-situ investigations of Ganymede's surface. The paper describes the scientific goals and objectives of the mission, its special features, and the LP1 and LP2 mission profiles during all of the phases—from the launch to the landing on the surface of Ganymede.

  2. Propagation of Satelite Rainfall Products uncertainties in hydrological applications : Examples in West-Africa in the framework of the Megha-Tropiques Satellite Mission

    Science.gov (United States)

    Casse, C.; Gosset, M.; Peugeot, C.; Boone, A.; Pedinotti, V.

    2013-12-01

    The use of satellite based rainfall in research or operational Hydrological application is becoming more and more frequent. This is specially true in the Tropics where ground based gauge (or radar) network are generally scarce and often degrading. Member of the GPM constellation, the new French-Indian satellite Mission Megha-Tropiques (MT) dedicated to the water and energy budget in the tropical atmosphere contributes to a better monitoring of rainfall in the inter-tropical zone. As part of this mission, research is developed on the use of MT rainfall products for hydrological research or operational application such as flood monitoring. A key issue for such applications is how to account for rainfall products biases and uncertainties, and how to propagate them in the end user models ? Another important question is how to choose the best space-time resolution for the rainfall forcing, given that both model performances and rain-product uncertainties are resolution dependent. This talk will present on going investigations and perspectives on this subject, with examples from the Megha_tropiques Ground validation sites in West Africa. The CNRM model Surfex-ISBA/TRIP has been set up to simulate the hydrological behavior of the Niger River. This modeling set up is being used to study the predictability of Niger Floods events in the city of Niamey and the performances of satellite rainfall products as forcing for such predictions. One of the interesting feature of the Niger outflow in Niamey is its double peak : a first peak attributed to 'local' rainfall falling in small to medium size basins situated in the region of Niamey, and a second peak linked to the rainfall falling in the upper par of the river, and slowly propagating through the river towards Niamey. The performances of rainfall products are found to differ between the wetter/upper part of the basin, and the local/sahelian areas. Both academic tests with artificially biased or 'perturbed' rainfield and actual

  3. Preliminary Feasibility Study of the Solar Observation Payloads for STSAT-CLASS Satellites

    Directory of Open Access Journals (Sweden)

    Yong-Jae Moon

    2004-12-01

    Full Text Available In this paper, we present preliminary feasibility studies on three types of solar observation payloads for future Korean Science and Technology Satellite (STSAT programs. The three candidates are (1 an UV imaging telescope, (2 an UV spectrograph, and (3 an X-ray spectrometer. In the case of UV imaging telescope, the most important constraint seems to be the control stability of a satellite in order to obtain a reasonably good spatial resolution. Considering that the current pointing stability estimated from the data of the Far ultraviolet Imaging Spectrograph (FIMS onboard the Korean STSAT-1, is around 1 arc minutes/sec, we think that it is hard to obtain a spatial resolution sufficient for scientific research by such an UV Imaging Telescope. For solar imaging missions, we realize that an image stabilization system, which is composed of a small guide telescope with limb sensor and a servo controller of secondary mirror, is quite essential for a very good pointing stability of about 0.1 arcsec. An UV spectrograph covering the solar full disk seems to be a good choice in that there is no risk due to poor pointing stability as well as that it can provide us with valuable UV spectral irradiance data valuable for studying their effects on the Earth's atmosphere and satellites. The heritage of the FIMS can be a great advantage of developing the UV spectrograph. Its main disadvantage is that two major missions are in operation or scheduled. Our preliminary investigations show that an X-ray spectrometer for the full disk Sun seems to be the best choice among the three candidates. The reasons are : (1 high temporal and spectral X-ray data are very essential for studying the acceleration process of energetic particles associated with solar flares, (2 we have a good heritage of X-ray detectors including a rocket-borne X-ray detector, (3 in the case of developing countries such as India and Czech, solar X-ray spectrometers were selected as their early stage

  4. Climate mission study n.10, january 2007

    International Nuclear Information System (INIS)

    Delbosc, A.; Keppler, J.H.; Leseur, A.

    2007-01-01

    This note aims to explain the evolution of the intensity of the the developed economies of the greenhouse gases emission. This study concerns only the countries called industrialized without the developing countries and those of the old east soviet bloc. In the first part the authors aim to know if the carbon intensity evolution of the economies go with convergence or divergence phenomena. The second part is more devoted to the impacts of the energetic choices on the adopted policies of the countries. Finally a particular attention is given to the characteristics of the european union countries which present a unique policy among the developed countries. (A.L.B.)

  5. Does the GPM mission improve the systematic error component in satellite rainfall estimates over TRMM? An evaluation at a pan-India scale

    Science.gov (United States)

    Beria, Harsh; Nanda, Trushnamayee; Singh Bisht, Deepak; Chatterjee, Chandranath

    2017-12-01

    The last couple of decades have seen the outburst of a number of satellite-based precipitation products with Tropical Rainfall Measuring Mission (TRMM) as the most widely used for hydrologic applications. Transition of TRMM into the Global Precipitation Measurement (GPM) promises enhanced spatio-temporal resolution along with upgrades to sensors and rainfall estimation techniques. The dependence of systematic error components in rainfall estimates of the Integrated Multi-satellitE Retrievals for GPM (IMERG), and their variation with climatology and topography, was evaluated over 86 basins in India for year 2014 and compared with the corresponding (2014) and retrospective (1998-2013) TRMM estimates. IMERG outperformed TRMM for all rainfall intensities across a majority of Indian basins, with significant improvement in low rainfall estimates showing smaller negative biases in 75 out of 86 basins. Low rainfall estimates in TRMM showed a systematic dependence on basin climatology, with significant overprediction in semi-arid basins, which gradually improved in the higher rainfall basins. Medium and high rainfall estimates of TRMM exhibited a strong dependence on basin topography, with declining skill in higher elevation basins. The systematic dependence of error components on basin climatology and topography was reduced in IMERG, especially in terms of topography. Rainfall-runoff modeling using the Variable Infiltration Capacity (VIC) model over two flood-prone basins (Mahanadi and Wainganga) revealed that improvement in rainfall estimates in IMERG did not translate into improvement in runoff simulations. More studies are required over basins in different hydroclimatic zones to evaluate the hydrologic significance of IMERG.

  6. Does the GPM mission improve the systematic error component in satellite rainfall estimates over TRMM? An evaluation at a pan-India scale

    Directory of Open Access Journals (Sweden)

    H. Beria

    2017-12-01

    Full Text Available The last couple of decades have seen the outburst of a number of satellite-based precipitation products with Tropical Rainfall Measuring Mission (TRMM as the most widely used for hydrologic applications. Transition of TRMM into the Global Precipitation Measurement (GPM promises enhanced spatio-temporal resolution along with upgrades to sensors and rainfall estimation techniques. The dependence of systematic error components in rainfall estimates of the Integrated Multi-satellitE Retrievals for GPM (IMERG, and their variation with climatology and topography, was evaluated over 86 basins in India for year 2014 and compared with the corresponding (2014 and retrospective (1998–2013 TRMM estimates. IMERG outperformed TRMM for all rainfall intensities across a majority of Indian basins, with significant improvement in low rainfall estimates showing smaller negative biases in 75 out of 86 basins. Low rainfall estimates in TRMM showed a systematic dependence on basin climatology, with significant overprediction in semi-arid basins, which gradually improved in the higher rainfall basins. Medium and high rainfall estimates of TRMM exhibited a strong dependence on basin topography, with declining skill in higher elevation basins. The systematic dependence of error components on basin climatology and topography was reduced in IMERG, especially in terms of topography. Rainfall-runoff modeling using the Variable Infiltration Capacity (VIC model over two flood-prone basins (Mahanadi and Wainganga revealed that improvement in rainfall estimates in IMERG did not translate into improvement in runoff simulations. More studies are required over basins in different hydroclimatic zones to evaluate the hydrologic significance of IMERG.

  7. MIT Project Apophis: Surface Evaulation & Tomography (SET) Mission Study for the April 2029 Earth Encounter

    Science.gov (United States)

    Binzel, R. P.; Earle, A. M.; Vanatta, M.; Miller, D. W.

    2017-12-01

    Nature is providing a once-per-thousand year opportunity to study the geophysical outcome induced on an unprecedentedly large (350 meter) asteroid making an extremely close passage by the Earth (inside the distance of geosynchronous satellites) on Friday April 13, 2029. The aircraft carrier-sized (estimated 20 million metric ton) asteroid is named Apophis. While many previous spacecraft missions have studied asteroids, none has ever had the opportunity to study "live" the outcome of planetary tidal forces on their shapes, spin states, surface geology, and internal structure. Beyond the science interest directly observing this planetary process, the Apophis encounter provides an invaluable opportunity to gain knowledge for any eventuality of a known asteroid found to be on a certain impact trajectory. MIT's Project Apophis [1] is our response to nature's generous opportunity by developing a detailed mission concept for sending a spacecraft to orbit Apophis with the objectives of surveying its surface and interior structure before, during, and after its 2029 near-Earth encounter. The Surface Evaluation & Tomography (SET) mission concept we present is designed toward accomplishing three key science objectives: (1) bulk physical characterization, (2) internal structure, and (3) long-term orbit tracking. For its first mission objective, SET will study Apophis' bulk properties, including: shape, size, mass, volume, bulk density, surface geology, and composition, rotation rate, and spin state. The second mission objective is to characterize Apophis' internal structure before and after the encounter to determine its strength and cohesion - including tidally induced changes. Finally, the third objective studies the process of thermal re-radiation and consequential Yarkovsky drift, whose results will improve orbit predictions for Apophis as well as other potentially hazardous asteroids. [1] https://eapsweb.mit.edu/mit-project-apophis

  8. Objectives and Model Payload Definition for NEO Human Mission Studies

    Science.gov (United States)

    Carnelli, I.; Galvez, A.; Carpenter, J.

    2011-10-01

    ESA has supported studies on NEO threat assessment systems and deflection concepts in the context of the General Studies Programme and in close cooperation with the directorates of Technical and Quality Management and of the Scientific Programme. This work has made it possible to identify a project for Europe to make a significant - yet realistic - contribution to the international efforts in this field: the Don Quijote NEO technology demonstration mission. This paper describes what such a small mission can do to prepare future human exploration and what is the in-situ data that can be obtained through such a project.

  9. Study of Background Rejection Systems for the IXO Mission.

    Science.gov (United States)

    Laurent, Philippe; Limousin, O.; Tatischeff, V.

    2009-01-01

    The scientific performances of the IXO mission will necessitate a very low detector background level. This will imply thorough background simulations, and efficient background rejection systems. It necessitates also a very good knowledge of the detectors to be shielded. In APC, Paris, and CEA, Saclay, we got experience on these activities by conceiving and optimising in parallel the high energy detector and the active and passive background rejection system of the Simbol-X mission. Considering that this work may be naturally extended to other X-ray missions, we have initiated with CNES a R&D project on the study of background rejection systems mainly in view the IXO project. We will detail this activity in the poster.

  10. SunRISE Mission Concept Step 2 Study Status

    Science.gov (United States)

    Alibay, F.; Kasper, J. C.; Lazio, J.; Neilsen, T. L.

    2017-12-01

    We present an update on the Sun Radio Interferometer Space Experiment (SunRISE) mission concept, which was selected for a Step 2 study as part of the Small Explorer (SMEX) Mission of Opportunity (MoO) call. SunRISE is space-based sparse array, composed of six 6U CubeSats, designed to localize the radio emission associated with coronal mass ejections (CMEs) from the Sun. Radio emission from CMEs is a direct tracer of the particle acceleration in the inner heliosphere and potential magnetic connections from the lower solar corona to the larger heliosphere. Furthermore, CME radio emission is quite strong such that only a relatively small number of antennas is required, and a small mission would make a fundamental advancement. Indeed, the state-of-the-art for tracking CME radio emission is defined by single antennas (Wind/WAVES, Stereo/SWAVES) in which the tracking is accomplished by assuming a frequency-to-density mapping. This type of Heliophysics mission would be inherently cost prohibitive in a traditional spacecraft paradigm. However, the use of CubeSats, accompanied by the miniaturization of subsystem components, enables the development of this concept at lower cost than ever before. We present the most recent updates on this mission concept, starting from the concept's performance as compared to the required science and driving technical requirements. We then focus on the SunRISE mission concept of operations, which consists of six 6U CubeSats placed in a GEO graveyard orbit for 6 months to achieve the aforementioned science goals. The spacecraft fly in a passive formation, which allows them to form an interferometer while minimizing the impact on operations complexity. We also present details of the engineering design and the key trades being performed as part of the Step 2 concept study.

  11. Equatorial hydrology studies by satellite telemetry

    International Nuclear Information System (INIS)

    Clegg, B.; Koranda, J.; Robison, W.; Holladay, G.

    1980-01-01

    We are using a geostationary satellite functioning as a transponder to collect surface environmental data to describe the fate of soil-borne radionuclides. The remote, former atomic testing grounds at the Enewetak and Bikini Atolls present a difficult environment in which to collect continuous field data. Our land-based, solar-powered microprocessor and environmental data systems remotely measure net and total solar radiation, rain, humidity, temperature, and soil-water potentials. For the past year, our water-flux model predicted wet season plant-transpiration rates nearly equal to the 6- to 7-mm/d evaporation-pan rate, which decreases to 2 to 3 mm/d for the dry season. From the microclimate data we estimated a 1:3 and 1:20 137 Cs dry-matter concentration ratio, which was later confirmed by radioisotopic analysis. This ratio exacerbates the dose to man from intake of food plants. Nephelometer measurements of airborne particulates presently indicate a minimum respiratory radiological dose

  12. Study of Microflares through SOXS Mission Rajmal Jain , Vishal ...

    Indian Academy of Sciences (India)

    Abstract. We present a study of 10 microflares observed in 4–30 keV by SOXS mission simultaneously with Hα observations made at NAOJ,. Japan during the interval between February and August 2004. The X-ray and Hα light curves showed that the lifetime of microflares varies between. 4 and 25 min. We found that the ...

  13. NOAA's Joint Polar Satellite System's (JPSS) Proving Ground and Risk Reduction (PGRR) Program - Bringing JPSS Science into Support of Key NOAA Missions!

    Science.gov (United States)

    Sjoberg, W.; McWilliams, G.

    2017-12-01

    This presentation will focus on the continuity of the NOAA Joint Polar Satellite System (JPSS) Program's Proving Ground and Risk Reduction (PGRR) and key activities of the PGRR Initiatives. The PGRR Program was established in 2012, following the launch of the Suomi National Polar Partnership (SNPP) satellite. The JPSS Program Office has used two PGRR Project Proposals to establish an effective approach to managing its science and algorithm teams in order to focus on key NOAA missions. The presenter will provide details of the Initiatives and the processes used by the initiatives that have proven so successful. Details of the new 2017 PGRR Call-for-Proposals and the status of project selections will be discussed.

  14. Propulsion Trade Studies for Spacecraft Swarm Mission Design

    Science.gov (United States)

    Dono, Andres; Plice, Laura; Mueting, Joel; Conn, Tracie; Ho, Michael

    2018-01-01

    Spacecraft swarms constitute a challenge from an orbital mechanics standpoint. Traditional mission design involves the application of methodical processes where predefined maneuvers for an individual spacecraft are planned in advance. This approach does not scale to spacecraft swarms consisting of many satellites orbiting in close proximity; non-deterministic maneuvers cannot be preplanned due to the large number of units and the uncertainties associated with their differential deployment and orbital motion. For autonomous small sat swarms in LEO, we investigate two approaches for controlling the relative motion of a swarm. The first method involves modified miniature phasing maneuvers, where maneuvers are prescribed that cancel the differential delta V of each CubeSat's deployment vector. The second method relies on artificial potential functions (APFs) to contain the spacecraft within a volumetric boundary and avoid collisions. Performance results and required delta V budgets are summarized, indicating that each method has advantages and drawbacks for particular applications. The mini phasing maneuvers are more predictable and sustainable. The APF approach provides a more responsive and distributed performance, but at considerable propellant cost. After considering current state of the art CubeSat propulsion systems, we conclude that the first approach is feasible, but the modified APF method of requires too much control authority to be enabled by current propulsion systems.

  15. Mission Operations Planning with Preferences: An Empirical Study

    Science.gov (United States)

    Bresina, John L.; Khatib, Lina; McGann, Conor

    2006-01-01

    This paper presents an empirical study of some nonexhaustive approaches to optimizing preferences within the context of constraint-based, mixed-initiative planning for mission operations. This work is motivated by the experience of deploying and operating the MAPGEN (Mixed-initiative Activity Plan GENerator) system for the Mars Exploration Rover Mission. Responsiveness to the user is one of the important requirements for MAPGEN, hence, the additional computation time needed to optimize preferences must be kept within reasonabble bounds. This was the primary motivation for studying non-exhaustive optimization approaches. The specific goals of rhe empirical study are to assess the impact on solution quality of two greedy heuristics used in MAPGEN and to assess the improvement gained by applying a linear programming optimization technique to the final solution.

  16. SeaWiFS Technical Report Series. Volume 42; Satellite Primary Productivity Data and Algorithm Development: A Science Plan for Mission to Planet Earth

    Science.gov (United States)

    Falkowski, Paul G.; Behrenfeld, Michael J.; Esaias, Wayne E.; Balch, William; Campbell, Janet W.; Iverson, Richard L.; Kiefer, Dale A.; Morel, Andre; Yoder, James A.; Hooker, Stanford B. (Editor); hide

    1998-01-01

    Two issues regarding primary productivity, as it pertains to the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Program and the National Aeronautics and Space Administration (NASA) Mission to Planet Earth (MTPE) are presented in this volume. Chapter 1 describes the development of a science plan for deriving primary production for the world ocean using satellite measurements, by the Ocean Primary Productivity Working Group (OPPWG). Chapter 2 presents discussions by the same group, of algorithm classification, algorithm parameterization and data availability, algorithm testing and validation, and the benefits of a consensus primary productivity algorithm.

  17. Probability of satellite collision

    Science.gov (United States)

    Mccarter, J. W.

    1972-01-01

    A method is presented for computing the probability of a collision between a particular artificial earth satellite and any one of the total population of earth satellites. The collision hazard incurred by the proposed modular Space Station is assessed using the technique presented. The results of a parametric study to determine what type of satellite orbits produce the greatest contribution to the total collision probability are presented. Collision probability for the Space Station is given as a function of Space Station altitude and inclination. Collision probability was also parameterized over miss distance and mission duration.

  18. Numerical modeling and remote sensing of global water management systems: Applications for land surface modeling, satellite missions, and sustainable water resources

    Science.gov (United States)

    Solander, Kurt C.

    The ability to accurately quantify water storages and fluxes in water management systems through observations or models is of increasing importance due to the expected impacts from climate change and population growth worldwide. Here, I describe three innovative techniques developed to better understand this problem. First, a model was created to represent reservoir storage and outflow with the objective of integration into a Land Surface Model (LSM) to simulate the impacts of reservoir management on the climate system. Given this goal, storage capacity represented the lone model input required that is not already available to an LSM user. Model parameterization was linked to air temperature to allow future simulations to adapt to a changing climate, making it the first such model to mimic the potential response of a reservoir operator to climate change. Second, spatial and temporal error properties of future NASA Surface Water and Ocean Topography (SWOT) satellite reservoir operations were quantified. This work invoked the use of the SWOTsim instrument simulator, which was run over a number of synthetic and actual reservoirs so the resulting error properties could be extrapolated to the global scale. The results provide eventual users of SWOT data with a blueprint of expected reservoir error properties so such characteristics can be determined a priori for a reservoir given knowledge about its topology and anticipated repeat orbit pass over its location. Finally, data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission was used in conjunction with in-situ water use records to evaluate sustainable water use at the two-digit HUC basin scale over the contiguous United States. Results indicate that the least sustainable water management region is centered in the southwest, where consumptive water use exceeded water availability by over 100% on average for some of these basins. This work represents the first attempt at evaluating sustainable

  19. Satellite Observation Systems for Polar Climate Change Studies

    Science.gov (United States)

    Comiso, Josefino C.

    2012-01-01

    The key observational tools for detecting large scale changes of various parameters in the polar regions have been satellite sensors. The sensors include passive and active satellite systems in the visible, infrared and microwave frequencies. The monitoring started with Tiros and Nimbus research satellites series in the 1970s but during the period, not much data was stored digitally because of limitations and cost of the needed storage systems. Continuous global data came about starting with the launch of ocean color, passive microwave, and thermal infrared sensors on board Nimbus-7 and Synthetic Aperture Radar, Radar Altimeter and Scatterometer on board SeaSat satellite both launched in 1978. The Nimbus-7 lasted longer than expected and provided about 9 years of useful data while SeaSat quit working after 3 months but provided very useful data that became the baseline for follow-up systems with similar capabilities. Over the years, many new sensors were launched, some from Japan Aeronautics and Space Agency (JAXA), some from the European Space Agency (ESA) and more recently, from RuSSia, China, Korea, Canada and India. For polar studies, among the most useful sensors has been the passive microwave sensor which provides day/night and almost all weather observation of the surface. The sensor provide sea surface temperature, precipitation, wind, water vapor and sea ice concentration data that have been very useful in monitoring the climate of the region. More than 30 years of such data are now available, starting with the Scanning Multichannel Microwave Radiometer (SMMR) on board the Nimbus-7, the Special Scanning Microwave/Imager (SSM/I) on board a Defense Meteorological Satellite Program (DMSP) and the Advanced Microwave Scanning Radiometer on board the EOS/ Aqua satellite. The techniques that have been developed to derive geophysical parameters from data provided by these and other sensors and associated instrumental and algorithm errors and validation techniques

  20. In situ Volcanic Plume Monitoring with small Unmanned Aerial Systems for Cal/Val of Satellite Remote Sensing Data: CARTA-UAV 2013 Mission (Invited)

    Science.gov (United States)

    Diaz, J. A.; Pieri, D. C.; Bland, G.; Fladeland, M. M.

    2013-12-01

    The development of small unmanned aerial systems (sUAS) with a variety of sensor packages, enables in situ and proximal remote sensing measurements of volcanic plumes. Using Costa Rican volcanoes as a Natural Laboratory, the University of Costa Rica as host institution, in collaboration with four NASA centers, have started an initiative to develop low-cost, field-deployable airborne platforms to perform volcanic gas & ash plume research, and in-situ volcanic monitoring in general, in conjunction with orbital assets and state-of-the-art models of plume transport and composition. Several gas sensors have been deployed into the active plume of Turrialba Volcano including a miniature mass spectrometer, and an electrochemical SO2 sensor system with temperature, pressure, relative humidity, and GPS sensors. Several different airborne platforms such as manned research aircraft, unmanned aerial vehicles, tethered balloons, as well as man-portable in-situ ground truth systems are being used for this research. Remote sensing data is also collected from the ASTER and OMI spaceborne instruments and compared with in situ data. The CARTA-UAV 2013 Mission deployment and follow up measurements successfully demonstrated a path to study and visualize gaseous volcanic emissions using mass spectrometer and gas sensor based instrumentation in harsh environment conditions to correlate in situ ground/airborne data with remote sensing satellite data for calibration and validation purposes. The deployment of such technology improves on our current capabilities to detect, analyze, monitor, model, and predict hazards presented to aircraft by volcanogenic ash clouds from active and impending volcanic eruptions.

  1. Solar power satellite offshore rectenna study

    Science.gov (United States)

    1980-01-01

    It was found that an offshore rectenna is feasible and cost competitive with land rectennas but that the type of rectenna which is suitable for offshore use is quite different from that specified in the present reference system. The result is a nonground plane design which minimizes the weight and greatly reduces the number of costly support towers. This preferred design is an antenna array consisting of individually encapsulated dipoles with reflectors supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane and icing conditions for a one time cost of 5.7 billion dollars. Subsequent units would be about 1/3 less expensive. The east coast site chosen for this study represents an extreme case of severe environmental conditions. More benign and more shallow water sites would result in lower costs. Secondary uses such as mariculture appear practical with only minor impact on the rectenna design. The potential advantages of an offshore rectenna, such as no land requirements, removal of microwave radiation from populated areas and minimal impact on the local geopolitics argue strongly that further investigation of the offshore rectenna should be vigorously pursued.

  2. Validation of Satellite Estimates (Tropical Rainfall Measuring Mission, TRMM for Rainfall Variability over the Pacific Slope and Coast of Ecuador

    Directory of Open Access Journals (Sweden)

    Bolívar Erazo

    2018-02-01

    Full Text Available A dense rain-gauge network within continental Ecuador was used to evaluate the quality of various products of rainfall data over the Pacific slope and coast of Ecuador (EPSC. A cokriging interpolation method is applied to the rain-gauge data yielding a gridded product at 5-km resolution covering the period 1965–2015. This product is compared with the Global Precipitation Climatology Centre (GPCC dataset, the Climatic Research Unit–University of East Anglia (CRU dataset, the Tropical Rainfall Measuring Mission (TRMM/TMPA 3B43 Version 7 dataset and the ERA-Interim Reanalysis. The analysis reveals that TRMM data show the most realistic features. The relative bias index (Rbias indicates that TRMM data is closer to the observations, mainly over lowlands (mean Rbias of 7% but have more limitations in reproducing the rainfall variability over the Andes (mean Rbias of −28%. The average RMSE and Rbias of 68.7 and −2.8% of TRMM are comparable with the GPCC (69.8 and 5.7% and CRU (102.3 and −2.3% products. This study also focuses on the rainfall inter-annual variability over the study region which experiences floods that have caused high economic losses during extreme El Niño events. Finally, our analysis evaluates the ability of TRMM data to reproduce rainfall events during El Niño years over the study area and the large basins of Esmeraldas and Guayas rivers. The results show that TRMM estimates report reasonable levels of heavy rainfall detection (for the extreme 1998 El Niño event over the EPSC and specifically towards the center-south of the EPSC (Guayas basin but present underestimations for the moderate El Niño of 2002–2003 event and the weak 2009–2010 event. Generally, the rainfall seasonal features, quantity and long-term climatology patterns are relatively well estimated by TRMM.

  3. Introduction to the Personal Access Satellite System Study

    Science.gov (United States)

    Sue, Miles K.

    1990-01-01

    A recent study by the National Telecommunications and Information Administration (NTIA) has concluded that the 21st century will be the age of information in which the telecommunication infrastructure will be vital to the social and economic well being of society. To meet the challenge of the coming age, JPL has been performing studies on a personal access satellite system (PASS) for the 21st century. The PASS study can be traced back to a study in which the technical feasibility and potential applications of a high frequency, low data rate satellite system were identified using small fixed terminals. Herein, the PASS concept is described along with the strawman design. Then the key challenges are identified along with possible solutions. Finally, the plan for the future is summarized from the key results.

  4. Virtual Satellite Integration Environment, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — An integrated environment for rapid design studies of small satellite missions will be developed. This environment will be designed to streamline processes at the...

  5. Earth Observatory Satellite system definition study. Report 3: Design cost trade-off studies and recommendations

    Science.gov (United States)

    1974-01-01

    An analysis of the design and cost tradeoff aspects of the Earth Observatory Satellite (EOS) development is presented. The design/cost factors that affect a series of mission/system level concepts are discussed. The subjects considered are as follows: (1) spacecraft subsystem cost tradeoffs, (2) ground system cost tradeoffs, and (3) program cost summary. Tables of data are provided to summarize the results of the analyses. Illustrations of the various spacecraft configurations are included.

  6. Antenna System for Nano-satelite Mission GOMX-3

    DEFF Research Database (Denmark)

    Tatomirescu, Alexandru; Pedersen, Gert F.; Christiansen, J.

    2016-01-01

    In this paper, we present the antenna design for a nano-satellite mission launched in September, the GOMX-3 mission. Some of the key design challenges are discussed and the chosen solutions are presented. In an effort to minimize development and manufacturing costs for future missions, this study...

  7. Study of Power Options for Jupiter and Outer Planet Missions

    Science.gov (United States)

    Landis, Geoffrey A.; Fincannon, James

    2015-01-01

    Power for missions to Jupiter and beyond presents a challenging goal for photovoltaic power systems, but NASA missions including Juno and the upcoming Europa Clipper mission have shown that it is possible to operate solar arrays at Jupiter. This work analyzes photovoltaic technologies for use in Jupiter and outer planet missions, including both conventional arrays, as well as analyzing the advantages of advanced solar cells, concentrator arrays, and thin film technologies. Index Terms - space exploration, spacecraft solar arrays, solar electric propulsion, photovoltaic cells, concentrator, Fresnel lens, Jupiter missions, outer planets.

  8. FLEX (Fluorescence Explorer mission: Observation fluorescence as a new remote sensing technique to study the global terrestrial vegetation state

    Directory of Open Access Journals (Sweden)

    J. Moreno

    2014-06-01

    Full Text Available FLEX (Fluorescence EXplorer is a candidate for the 8th ESA’s Earth Explorer mission. Is the first space mission specifically designed for the estimation of vegetation fluorescence on a global scale. The mission is proposed to fly in tandem with the future ESA´s Sentinel-3 satellite. It is foreseen that the information obtained by Sentinel-3 will be supplemented with that provided by FLORIS (Fluorescence Imaging Spectrometer onboard FLEX. FLORIS will measure the radiance between 500 and 800 nm with a bandwidth between 0.1 nm and 2 nm, providing images with a 150 km swath and 300 m pixel size. This information will allow a detailed monitoring of vegetation dynamics, by improving the methods for the estimation of classical biophysical parameters, and by introducing a new one: fluorescence. This paper presents the current status of FLEX mission in A/B1 phase and the different ongoing studies, campaigns and projects carried out in support of the FLEX mission.

  9. Satellite Power Systems (SPS) concept definition study. Volume 5: Special emphasis studies. [rectenna and solar power satellite design studies

    Science.gov (United States)

    Hanley, G. M.

    1980-01-01

    Satellite configurations based on the Satellite Power System baseline requirements were analyzed and a preferred concept selected. A satellite construction base was defined, precursor operations incident to establishment of orbital support facilities identified, and the satellite construction sequence and procedures developed. Rectenna construction requirement were also addressed. Mass flow to orbit requirements were revised and traffic models established based on construction of 60 instead of 120 satellites. Analyses were conducted to determine satellite control, resources, manufacturing, and propellant requirements. The impact of the laser beam used for space-to-Earth power transmission upon the intervening atmosphere was examined as well as the inverse effect. The significant space environments and their effects on spacecraft components were investigated to define the design and operational limits imposed by the environments on an orbit transfer vehicle. The results show that LEO altitude 300 nmi and transfer orbit duration 6 months are preferrable.

  10. Ka-band SAR interferometry studies for the SWOT mission

    Science.gov (United States)

    Fernandez, D. E.; Fu, L.; Rodriguez, E.; Hodges, R.; Brown, S.

    2008-12-01

    The primary objective of the NRC Decadal Survey recommended SWOT (Surface Water and Ocean Topography) Mission is to measure the water elevation of the global oceans, as well as terrestrial water bodies (such as rivers, lakes, reservoirs, and wetlands), to answer key scientific questions on the kinetic energy of ocean circulation, the spatial and temporal variability of the world's surface freshwater storage and discharge, and to provide societal benefits on predicting climate change, coastal zone management, flood prediction, and water resources management. The SWOT mission plans to carry the following suite of microwave instruments: a Ka-band interferometer, a dual-frequency nadir altimeter, and a multi-frequency water-vapor radiometer dedicated to measuring wet tropospheric path delay to correct the radar measurements. We are currently funded by the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP) to reduce the risk of the main technological drivers of SWOT, by addressing the following technologies: the Ka-band radar interferometric antenna design, the on-board interferometric SAR processor, and the internally calibrated high-frequency radiometer. The goal is to significantly enhance the readiness level of the new technologies required for SWOT, while laying the foundations for the next-generation missions to map water elevation for studying Earth. The first two technologies address the challenges of the Ka-band SAR interferometry, while the high- frequency radiometer addresses the requirement for small-scale wet tropospheric corrections for coastal zone applications. In this paper, we present the scientific rational, need and objectives behind these technology items currently under development.

  11. Gamma radiation in ceramic capacitors: a study for space missions

    Science.gov (United States)

    dos Santos Ferreira, Eduardo; Sarango Souza, Juliana

    2017-10-01

    We studied the real time effects of the gamma radiation in ceramic capacitors, in order to evaluate the effects of cosmic radiation on these devices. Space missions have electronic circuits with various types of devices, many studies have been done on semiconductor devices exposed to gamma radiation, but almost no studies for passive components, in particular ceramic capacitors. Commercially sold ceramic capacitors were exposed to gamma radiation, and the capacitance was measured before and after exposure. The results clearly show that the capacitance decreases with exposure to gamma radiation. We confirmed this observation in a real time capacitance measurement, obtained using a data logging system developed by us using the open source Arduino platform.

  12. Solar maximum mission

    International Nuclear Information System (INIS)

    Ryan, J.

    1981-01-01

    By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

  13. Evaluation of Temperature and Material Combinations on Several Lubricants for Use in the Geostationary Operational Environmental Satellite (GOES) Mission Filter Wheel Bearings

    Science.gov (United States)

    Jansen, Mark J.; Jones, William R., Jr.; Predmore, Roamer E.

    2001-01-01

    A bearing test apparatus was used to investigate lubricant degradation rates and elastohydrodynamic transition temperatures for several perfluoropolyether (Krytox) formulations, a pentasilahydrocarbon, and a synthetic hydrocarbon (Pennzane 2001 A) in an MPB 1219 bearing, which is used in the geostationary operational environmental satellite (GOES) mission filter wheel assembly. Test conditions were the following: 1000-hr duration, 75 C, 20 lb axial load, vacuum level less than 1 x 10(exp -6) Torr, and a 600-rpm rotational speed. Baseline tests were performed using unformulated Krytox 143AB, the heritage lubricant. Krytox additive formulations showed small reductions in degradation rate. Krytox GPL-105, a higher viscosity version, yielded the least amount of degradation products. Both the silahydrocarbon and Pennzane 2001A showed no signs of lubricant degradation and had ample amounts of free oil at test conclusion.

  14. Simobiz-Simulation Tool to Study the Impact of Small Satellites in Mobile Market

    Science.gov (United States)

    Burlacu, M.-M.; Kohlenberg, J.; Prathaban, M.

    2008-08-01

    Interest in small satellites is growing fast world- wide. Businesses, governments, universities and other organizations around the world are starting their own small satellite programs. The surveys conducted by the space agencies and universities shows a promising increase in the use of small satellites for commercial applications. More number of operators offers or plans to offer mobile phone services by satellite. With the help of cost effective small satellite, mobile operators can be able to provide the services cheaper. Hence, it is always interesting to study the effect of low cost small satellite over the mobile market. In this article, we present SmartSim (Small Satellites Mobile Market Simulator) - the new module of Simobiz business simulation game, in which we have implemented two operators, a normal satellite operator and a nanosatellite operator, with specific terminals and services. Our main focus in this work is to understand the future market of small satellite in mobile telecommunication network.

  15. The potential of satellite data to study individual wildfire events

    Science.gov (United States)

    Benali, Akli; López-Saldana, Gerardo; Russo, Ana; Sá, Ana C. L.; Pinto, Renata M. S.; Nikos, Koutsias; Owen, Price; Pereira, Jose M. C.

    2014-05-01

    Large wildfires have important social, economic and environmental impacts. In order to minimize their impacts, understand their main drivers and study their dynamics, different approaches have been used. The reconstruction of individual wildfire events is usually done by collection of field data, interviews and by implementing fire spread simulations. All these methods have clear limitations in terms of spatial and temporal coverage, accuracy, subjectivity of the collected information and lack of objective independent validation information. In this sense, remote sensing is a promising tool with the potential to provide relevant information for stakeholders and the research community, by complementing or filling gaps in existing information and providing independent accurate quantitative information. In this work we show the potential of satellite data to provide relevant information regarding the dynamics of individual large wildfire events, filling an important gap in wildfire research. We show how MODIS active-fire data, acquired up to four times per day, and satellite-derived burnt perimeters can be combined to extract relevant information wildfire events by describing the methods involved and presenting results for four regions of the world: Portugal, Greece, SE Australia and California. The information that can be retrieved encompasses the start and end date of a wildfire event and its ignition area. We perform an evaluation of the information retrieved by comparing the satellite-derived parameters with national databases, highlighting the strengths and weaknesses of both and showing how the former can complement the latter leading to more complete and accurate datasets. We also show how the spatio-temporal distribution of wildfire spread dynamics can be reconstructed using satellite-derived active-fires and how relevant descriptors can be extracted. Applying graph theory to satellite active-fire data, we define the major fire spread paths that yield

  16. NASA Earth Science Mission Control Center Enterprise Emerging Technology Study Study (MCC Technology Study)

    Science.gov (United States)

    Smith, Dan; Horan, Stephen; Royer, Don; Sullivan, Don; Moe, Karen

    2015-01-01

    This paper reports on the results of the study to identify technologies that could have a significant impact on Earth Science mission operations when looking out at the 5-15 year horizon (through 2025). The potential benefits of the new technologies will be discussed, as well as recommendations for early research and development, prototyping, or analysis for these technologies.

  17. On the progress of the nano-satellite SAR based mission TOPMEX-9 and specification of potential applications advancing the Earth Observation Programme of the Mexican Space Agency.

    Science.gov (United States)

    Ocampo-Torres, Francisco J.; Gutiérrez-Nava, Antonio; Ponce, Octavio; Vicente-Vivas, Esaú; Pacheco, Enrique

    2013-04-01

    TOPMEX-9 is put forward in this paper, advancing a mission for the Earth Observation Programme of the Mexican Space Agency, a distributed Micro-SAR concept within a Master and Slaves flight formation. International collaboration is essential and a start project is being developed between the Microwaves and Radar Institute of the German Aerospace Centre (DLR), the Mexican Space Agency (AEM). While the basic idea is making use of the transmitting component of a SAR on a microsatellite and the receiving component on a nano-satellites cluster, only a brief illustration is given here. The objective of this work is mainly to present some SAR characteristics and the most important potential applications. Special attention is given to the capabilities and limitations of SAR systems to properly detect ocean surface waves. We do take into account the nonlinear nature of the ocean surface imaging porcesses, mainly based upon the SAR and the waves characteristics, and certainly considering the K band SAR being proposed. Some other ocean applications are also overview, regarding coastal erosion-deposition estimation, as well as ship detection and monitoring. International co-operation is also addressed as an essential component of TOPMEX-9 Mission. This work represents a DOT Project (CONACYT-SRE 186144) contribution.

  18. Oceanic Weather Decision Support for Unmanned Global Hawk Science Missions into Hurricanes with Tailored Satellite Derived Products

    Science.gov (United States)

    Feltz, Wayne; Griffin, Sarah; Velden, Christopher; Zipser, Ed; Cecil, Daniel; Braun, Scott

    2017-04-01

    The purpose of this presentation is to identify in-flight hazards to high-altitude aircraft, namely the Global Hawk. The Global Hawk was used during Septembers 2012-2016 as part of two NASA funded Hurricane Sentinel-3 field campaigns to over-fly hurricanes in the Atlantic Ocean. This talk identifies the cause of severe turbulence experienced over Hurricane Emily (2005) and how a combination of NOAA funded GOES-R algorithm derived cloud top heights/tropical overshooting tops using GOES-13/SEVIRI imager radiances, and lightning information are used to identify areas of potential turbulence for near real-time navigation decision support. Several examples will demonstrate how the Global Hawk pilots remotely received and used real-time satellite derived cloud and lightning detection information to keep the aircraft safely above clouds and avoid regions of potential turbulence.

  19. A Comparative Study of Actuator Configurations for Satellite Attitude Control

    Directory of Open Access Journals (Sweden)

    Raymond Kristiansen

    2005-10-01

    Full Text Available In this paper a controllability study of different actuator configurations consisting of magnetic torquers, reaction wheels and a gravity boom is presented. The theoretical analysis is performed with use of controllability gramians, and simulation results with the different configurations are presented and compared regarding settling time and power consumption to substantiate the theoretical analysis. A reference model is also introduced to show how the power consumption can he lowered to the same magnitude as when magnetic torquers are used, without degrading the satellite response significantly.

  20. Using Satellite Data to Monitor the Impacts of CyanoHAB Events on Drinking Water: A Texas Case Study

    Science.gov (United States)

    Overview of CYAN and it's mission to support the environmental management and public use of U.S. lakes and estuaries by providing a capability of detecting and quantifying algal blooms and related water quality using satellite data records.

  1. Chagas disease study using satellite image processing: A Bolivian case

    Science.gov (United States)

    Vargas-Cuentas, Natalia I.; Roman-Gonzalez, Avid; Mantari, Alicia Alva; Muñoz, Luis AnthonyAucapuma

    2018-03-01

    Remote sensing is the technology that has enabled us to obtain information about the Earth's surface without directly contacting it. For this reason, currently, the Bolivian state has considered a list of interesting applications of remote sensing in the country, including the following: biodiversity and environment monitoring, mining and geology, epidemiology, agriculture, water resources and land use planning. The use of satellite images has become a great tool for epidemiology because with this technological advance we can determine the environment in which transmission occurs, the distribution of the disease and its evolution over time. In that context, one of the important diseases related to public health in Bolivia is Chagas disease, also known as South American Trypanosomiasis. Chagas is caused by a blood-sucking bug or Vinchuca, which causes serious intestinal and heart long term problems and affects 33.4% of the Bolivian population. This disease affects mostly humble people, so the Bolivian state invests millions of dollars to acquire medicine and distribute it for free. Due to the above reasons, the present research aims to analyze some areas of Bolivia using satellite images for developing an epidemiology study. The primary objective is to understand the environment in which the transmission of the disease happens, and the climatic conditions under which occurs, observe the behavior of the blood-sucking bug, identify in which months occur higher outbreaks, in which months the bug leaves its eggs, and under which weather conditions this happens. All this information would be contrasted with information extracted from the satellite images and data from the Ministry of Health, and the Institute of Meteorology in Bolivia. All this data will allow us to have a more integrated understanding of this disease and promote new possibilities to prevent and control it.

  2. STUDY REGARDING DIFFERENT TYPES OF AUDITOR’S MISSIONS

    Directory of Open Access Journals (Sweden)

    Daniel Botez

    2013-12-01

    Full Text Available After the involvement of the audit profession in several financial scandals, the international body of the profession, International Federation of Accountants – IFAC, has developed and published a conceptual framework and reviewed most of the reference standards in auditing to provide references regarding the responsibility of the professionals and the extent of their missions. Thus was established the use of a general term for professionals, the “practitioner”, in the context of specific missions using the “auditor”, “practitioner” or “accountant”. On the other hand, have been revised professional standards establish insurance missions and non-insurance operations, with their specific missions that do not provide insurance, including the recoding. The use of these references by audit professionals constitutes one of the “keys” to their success.

  3. Space Electron Density Gradient Studies using a 3D Embedded Reconfigurable Sounder and ESA/NASA CLUSTER Mission

    Science.gov (United States)

    Dekoulis, George

    2016-07-01

    This paper provides a direct comparison between data captured by a new embedded reconfigurable digital sounder, different ground-based ionospheric sounders spread around Europe and the ESA/NASA CLUSTER mission. The CLUSTER mission consists of four identical space probes flying in a formation that allows measurements of the electron density gradient in the local magnetic field. Both the ground-based and the spacecraft instrumentations assist in studying the motion, geometry and boundaries of the plasmasphere. The comparison results are in accordance to each other. Some slight deviations among the captured data were expected from the beginning of this investigation. These small discrepancies are reasonable and seriatim analyzed. The results of this research are significant, since the level of the plasma's ionization, which is related to the solar activity, dominates the propagation of electromagnetic waves through it. Similarly, unusually high solar activity presents serious hazards to orbiting satellites, spaceborne instrumentation, satellite communications and infrastructure located on the Earth's surface. Long-term collaborative study of the data is required to continue, in order to identify and determine the enhanced risk in advance. This would allow scientists to propose an immediate cure.

  4. Study of cloud properties using airborne and satellite measurements

    Science.gov (United States)

    Boscornea, Andreea; Stefan, Sabina; Vajaiac, Sorin Nicolae

    2014-08-01

    The present study investigates cloud microphysics properties using aircraft and satellite measurements. Cloud properties were drawn from data acquired both from in situ measurements with state of the art airborne instrumentation and from satellite products of the MODIS06 System. The used aircraft was ATMOSLAB - Airborne Laboratory for Environmental Atmospheric Research, property of the National Institute for Aerospace Research "Elie Carafoli" (INCAS), Bucharest, Romania, which is specially equipped for this kind of research. The main tool of the airborne laboratory is a Cloud, Aerosol and Precipitation Spectrometer - CAPS (30 bins, 0.51- 50 μm). The data was recorded during two flights during the winter 2013-2014, over a flat region in the south-eastern part of Romania (between Bucharest and Constanta). The analysis of cloud particle size variations and cloud liquid water content provided by CAPS can explain cloud processes, and can also indicate the extent of aerosols effects on clouds. The results, such as cloud coverage and/or cloud types, microphysical parameters of aerosols on the one side and the cloud microphysics parameters obtained from aircraft flights on the other side, was used to illustrate the importance of microphysics cloud properties for including the radiative effects of clouds in the regional climate models.

  5. TEAM SELLING AND CUSTOMER SATISFACTION IN THE MISSION CRITICAL SECTOR: A CASE STUDY OF EYP MISSION CRITICAL FACILITIES INC.

    Directory of Open Access Journals (Sweden)

    Timothy J. CRADER

    2013-11-01

    Full Text Available This study examined the relationships between selling teams (STs and customer satisfaction within the mission critical power design industry. The literature indicates that STs, which are considered a state of the art sales model, deserved further research. The SERVQUAL survey was used to measure customer satisfaction with EYP Mission Critical’s most strategic customers. The difference in customer satisfaction for customers serviced by STs and traditional sales personnel were compared. The investigation found support indicating that a ST approach had a positive relationship to increased customer satisfaction levels. Based on the results of the study, it is recommended that sales leaders within the specialized service industry consider a ST approach when formulating future revenue growth and relationship strategy.

  6. Study of Wetland Ecosystem Vegetation Using Satellite Data

    Science.gov (United States)

    Dyukarev, E. A.; Alekseeva, M. N.; Golovatskaya, E. A.

    2017-12-01

    The normalized difference vegetation index (NDVI) is used to estimate the aboveground net production (ANP) of wetland ecosystems for the key area at the South Taiga zone of West Siberia. The vegetation index and aboveground production are related by linear dependence and are specific for each wetland ecosystem. The NDVI grows with an increase in the ANP at wooded oligotrophic ecosystems. Open oligotrophic bogs and eutrophic wetlands are characterized by an opposite relation. Maps of aboveground production for wetland ecosystems are constructed for each study year and for the whole period of studies. The average aboveground production for all wetland ecosystems of the key area, which was estimated with consideration for the area they occupy and using the data of satellite measurements of the vegetation index, is 305 g C/m2/yr. The total annual carbon accumulation in aboveground wetland vegetation in the key area is 794600 t.

  7. Pre-Launch Calibration and Performance Study of the Polarcube 3u Temperature Sounding Radiometer Mission

    Science.gov (United States)

    Periasamy, L.; Gasiewski, A. J.; Sanders, B. T.; Rouw, C.; Alvarenga, G.; Gallaher, D. W.

    2016-12-01

    The positive impact of passive microwave observations of tropospheric temperature, water vapor and surface variables on short-term weather forecasts has been clearly demonstrated in recent forecast anomaly growth studies. The development of a fleet of such passive microwave sensors especially at V-band and higher frequencies in low earth orbit using 3U and 6U CubeSats could help accomplish the aforementioned objectives at low system cost and risk as well as provide for regularly updated radiometer technology. The University of Colorado's 3U CubeSat, PolarCube is intended to serve as a demonstrator for such a fleet of passive sounders and imagers. PolarCube supports MiniRad, an eight channel, double sideband 118.7503 GHz passive microwave sounder. The mission is focused primarily on sounding in Arctic and Antarctic regions with the following key remote sensing science and engineering objectives: (i) Collect coincident tropospheric temperature profiles above sea ice, open polar ocean, and partially open areas to develop joint sea ice concentration and lower tropospheric temperature mapping capabilities in clear and cloudy atmospheric conditions. This goal will be accomplished in conjunction with data from existing passive microwave sensors operating at complementary bands; and (ii) Assess the capabilities of small passive microwave satellite sensors for environmental monitoring in support of the future development of inexpensive Earth science missions. Performance data of the payload/spacecraft from pre-launch calibration will be presented. This will include- (i) characterization of the antenna sub-system comprising of an offset 3D printed feedhorn and spinning parabolic reflector and impact of the antenna efficiencies on radiometer performance, (ii) characterization of MiniRad's RF front-end and IF back-end with respect to temperature fluctuations and their impact on atmospheric temperature weighting functions and receiver sensitivity, (iii) results from roof

  8. Study 2.6 operations analysis mission characterization

    Science.gov (United States)

    Wolfe, R. R.

    1973-01-01

    An analysis of the current operations concepts of NASA and DoD is presented to determine if alternatives exist which may improve the utilization of resources. The final product is intended to show how sensitive these ground rules and design approaches are relative to the total cost of doing business. The results are comparative in nature, and assess one concept against another as opposed to establishing an absolute cost value for program requirements. An assessment of the mission characteristics is explained to clarify the intent, scope, and direction of this effort to improve the understanding of what is to be accomplished. The characterization of missions is oriented toward grouping missions which may offer potential economic benefits by reducing overall program costs. Program costs include design, development, testing, and engineering, recurring unit costs for logistic vehicles, payload costs. and direct operating costs.

  9. A Case Study of Three Satellite Technology Demonstration School Sites.

    Science.gov (United States)

    Law, Gordon

    The Satellite Technology Demonstration (STD) represented a cooperative and complex effort involving federal, regional, state and local interests and demonstrated the feasibility of media distribution by communication satellite of social services for rural audiences. As part of a comprehensive evaluation plan, the summative data base was augmented…

  10. Lamp reliability studies for improved satellite rubidium frequency standard

    Science.gov (United States)

    Frueholz, R. P.; Wun-Fogle, M.; Eckert, H. U.; Volk, C. H.; Jones, P. F.

    1982-01-01

    In response to the premature failure of Rb lamps used in Rb atomic clocks onboard NAVSTAR GPS satellites experimental and theoretical investigations into their failure mechanism were initiated. The primary goal of these studies is the development of an accelerated life test for future GPS lamps. The primary failure mechanism was identified as consumption of the lamp's Rb charge via direct interaction between Rb and the lamp's glass surface. The most effective parameters to accelerate the interaction between the Rb and the glass are felt to be RF excitation power and lamp temperature. Differential scanning calorimetry is used to monitor the consumption of Rb within a lamp as a function of operation time. This technique yielded base line Rb consumption data for GPS lamps operating under normal conditions.

  11. Earth Observatory Satellite system definition study. Report 1: Orbit/launch vehicle trade-off studies and recommendations

    Science.gov (United States)

    1974-01-01

    A summary of the constraints and requirements on the Earth Observatory Satellite (EOS-A) orbit and launch vehicle analysis is presented. The propulsion system (hydrazine) and the launch vehicle (Delta 2910) selected for EOS-A are examined. The rationale for the selection of the recommended orbital altitude of 418 nautical miles is explained. The original analysis was based on the EOS-A mission with the Thematic Mapper and the High Resolution Pointable Imager. The impact of the revised mission model is analyzed to show how the new mission model affects the previously defined propulsion system, launch vehicle, and orbit. A table is provided to show all aspects of the EOS multiple mission concepts. The subjects considered include the following: (1) mission orbit analysis, (2) spacecraft parametric performance analysis, (3) launch system performance analysis, and (4) orbits/launch vehicle selection.

  12. Life Support Filtration System Trade Study for Deep Space Missions

    Science.gov (United States)

    Agui, Juan H.; Perry, Jay L.

    2017-01-01

    The National Aeronautics and Space Administrations (NASA) technical developments for highly reliable life support systems aim to maximize the viability of long duration deep space missions. Among the life support system functions, airborne particulate matter filtration is a significant driver of launch mass because of the large geometry required to provide adequate filtration performance and because of the number of replacement filters needed to a sustain a mission. A trade analysis incorporating various launch, operational and maintenance parameters was conducted to investigate the trade-offs between the various particulate matter filtration configurations. In addition to typical launch parameters such as mass, volume and power, the amount of crew time dedicated to system maintenance becomes an increasingly crucial factor for long duration missions. The trade analysis evaluated these parameters for conventional particulate matter filtration technologies and a new multi-stage particulate matter filtration system under development by NASAs Glenn Research Center. The multi-stage filtration system features modular components that allow for physical configuration flexibility. Specifically, the filtration system components can be configured in distributed, centralized, and hybrid physical layouts that can result in considerable mass savings compared to conventional particulate matter filtration technologies. The trade analysis results are presented and implications for future transit and surface missions are discussed.

  13. Swarm: ESA's Magnetic Field Mission

    Science.gov (United States)

    Plank, G.; Floberghagen, R.; Menard, Y.; Haagmans, R.

    2013-12-01

    Swarm is the fifth Earth Explorer mission in ESA's Living Planet Programme, and is scheduled for launch in fall 2013. The objective of the Swarm mission is to provide the best-ever survey of the geomagnetic field and its temporal evolution using a constellation of three identical satellites. The mission shall deliver data that allow access to new insights into the Earth system by improved scientific understanding of the Earth's interior and near-Earth electromagnetic environment. After launch and triple satellite release at an initial altitude of about 490 km, a pair of the satellites will fly side-by-side with slowly decaying altitude, while the third satellite will be lifted to 530 km to complete the Swarm constellation. High-precision and high-resolution measurements of the strength, direction and variation of the magnetic field, complemented by precise navigation, accelerometer and electric field measurements, will provide the observations required to separate and model various sources of the geomagnetic field and near-Earth current systems. The mission science goals are to provide a unique view into Earth's core dynamics, mantle conductivity, crustal magnetisation, ionospheric and magnetospheric current systems and upper atmosphere dynamics - ranging from understanding the geodynamo to contributing to space weather. The scientific objectives and results from recent scientific studies will be presented. In addition the current status of the project, which is presently in the final stage of the development phase, will be addressed. A consortium of European scientific institutes is developing a distributed processing system to produce geophysical (Level 2) data products for the Swarm user community. The setup of the Swarm ground segment and the contents of the data products will be addressed. In case the Swarm satellites are already in orbit, a summary of the on-going mission operations activities will be given. More information on Swarm can be found at www.esa.int/esaLP/LPswarm.html.

  14. A CubeSat Asteroid Mission: Design Study and Trade-Offs

    Science.gov (United States)

    Landis, Geoffrey A.; Oleson, Steven R.; McGuire, Melissa; Hepp, Aloysius; Stegeman, James; Bur, Mike; Burke, Laura; Martini, Michael; Fittje, James E.; Kohout, Lisa; hide

    2014-01-01

    There is considerable interest in expanding the applicability of cubesat spacecraft into lightweight, low cost missions beyond Low Earth Orbit. A conceptual design was done for a 6-U cubesat for a technology demonstration to demonstrate use of electric propulsion systems on a small satellite platform. The candidate objective was a mission to be launched on the SLS test launch EM-1 to visit a Near-Earth asteroid. Both asteroid fly-by and asteroid rendezvous missions were analyzed. Propulsion systems analyzed included cold-gas thruster systems, Hall and ion thrusters, incorporating either Xenon or Iodine propellant, and an electrospray thruster. The mission takes advantage of the ability of the SLS launch to place it into an initial trajectory of C3=0. Targeting asteroids that fly close to earth minimizes the propulsion required for fly-by/rendezvous. Due to mass constraints, high specific impulse is required, and volume constraints mean the propellant density was also of great importance to the ability to achieve the required deltaV. This improves the relative usefulness of the electrospray salt, with higher propellant density. In order to minimize high pressure tanks and volatiles, the salt electrospray and iodine ion propulsion systems were the optimum designs for the fly-by and rendezvous missions respectively combined with a thruster gimbal and wheel system For the candidate fly-by mission, with a mission deltaV of about 400 m/s, the mission objectives could be accomplished with a 800s electrospray propulsion system, incorporating a propellant-less cathode and a bellows salt tank. This propulsion system is planned for demonstration on 2015 LEO and 2016 GEO DARPA flights. For the rendezvous mission, at a ?V of 2000 m/s, the mission could be accomplished with a 50W miniature ion propulsion system running iodine propellant. This propulsion system is not yet demonstrated in space. The conceptual design shows that an asteroid mission is possible using a cubesat

  15. Studies of relativistic effects with radioastron space mission

    Directory of Open Access Journals (Sweden)

    Zakharov A.F.

    2007-01-01

    Full Text Available In the review we discuss possible studies of GR phenomena such as gravitational microlensing and shadow analysis with the forthcoming RadioAstron space mission. It is well-known that gravitational lensing is a powerful tool in the investigation of the distribution of matter, including that of dark matter (DM. Typical angular distances between images and typical time scales depend on the gravitational lens masses. For the microlensing, angular distances between images or typical astrometric shifts are about 10-5 – 10-6 as1. Such an angular resolution will be reached with the space-ground VLBI interferometer, Radioastron. The basic targets for microlensing searches should be bright point-like radio sources at cosmological distances. In this case, an analysis of their variability and a reliable determination of microlensing could lead to an estimation of their cosmological mass density. Moreover, one could not exclude the possibility that non-baryonic dark matter could also form microlenses if the corresponding optical depth were high enough. It is known that in gravitationally lensed systems, the probability (the optical depth to observe microlensing is relatively high; therefore, for example, such gravitationally lensed objects, like CLASS gravitational lens B1600+434, appear the most suitable to detect astrometric microlensing, since features of photometric microlensing have been detected in these objects. However, to directly resolve these images and to directly detect the apparent motion of the knots, the Radioastron sensitivity would have to be improved, since the estimated flux density is below the sensitivity threshold, alternatively, they may be observed by increasing the integration time, assuming that a radio source has a typical core - jet structure and microlensing phenomena are caused by the superluminal apparent motions of knots. In the case of a confirmation (or a disproval of claims about microlensing in grav­itational lens

  16. Satellite-borne study of seismic phenomena by low frequency magnetic field observations

    Science.gov (United States)

    Schwingenschuh, Konrad; Magnes, Werner; Xuhui, Shen; Wang, Jindong; Pollinger, Andreas; Hagen, Christian; Prattes, Gustav; Eichelberger, Hans-Ulrich; Wolbang, Daniel; Boudjada, Mohammed Y.; Besser, Bruno P.; Rozhnoi, Alexander A.; Zhang, Tielong

    2015-04-01

    A combined scalar-vector magnetic field experiment will be flown on the upcoming CSES mission (China Seismo-Electromagnetic Satellite). Magnetic field data from DC to 30 Hz will be measured with an accuracy of about 10 pT. A fluxgate instrument will provide the 3 magnetic field components and a new type of an optically pumped magnetometer [see Pollinger, 2010] will measure the magnitude of the ambient magnetic field. The satellite will operate in a Sun synchronous polar orbit at an altitude of about 500 km and with an inclination of 97°. We present a model of magnetic field fluctuations in the upper ionosphere based on previous satellite observations and on a model of the lithospheric-atmospheric-ionospheric coupling. Pollinger et al., CDSM-a new scalar magnetometer, EGU General Assembly 2010

  17. New vision solar system exploration missions study: Analysis of the use of biomodal space nuclear power systems to support outer solar system exploration missions. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-08

    This report presents the results of an analysis of the capability of nuclear bimodal systems to perform outer solar system exploration missions. Missions of interest include orbiter mission s to Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. An initial technology baseline consisting of a NEBA 10 kWe, 1000 N thrust, 850 s, 1500 kg bimodal system was selected, and its performance examined against a data base for trajectories to outer solar system planetary destinations to select optimal direct and gravity assisted trajectories for study. A conceptual design for a common bimodal spacecraft capable of performing missions to all the planetary destinations was developed and made the basis of end to end mission designs for orbiter missions to Jupiter, Saturn, and Neptune. Concepts for microspacecraft capable of probing Jupiter`s atmosphere and exploring Titan were also developed. All mission designs considered use the Atlas 2AS for launch. It is shown that the bimodal nuclear power and propulsion system offers many attractive option for planetary missions, including both conventional planetary missions in which all instruments are carried by a single primary orbiting spacecraft, and unconventional missions in which the primary spacecraft acts as a carrier, relay, and mother ship for a fleet of micro spacecraft deployed at the planetary destination.

  18. Mission X: Train Like an Astronaut Pilot Study

    Science.gov (United States)

    Lloyd, Charles W.; Olivotto, C.; Boese, A.; Spiero, F.; Galoforo, G.; Niihori, M.

    2011-01-01

    Mission X: Train Like an Astronaut is an international educational challenge focusing on fitness and nutrition as we encourage students to "train like an astronaut." Teams of students (aged 8-12) learn principles of healthy eating and exercise, compete for points by finishing training modules, and get excited about their future as "fit explorers." The 18 core exercises (targeting strength, endurance, coordination, balance, spatial awareness, and more) involve the same types of skills that astronauts learn in their training and use in spaceflight. This first-of-its-kind cooperative outreach program has allowed 14 space agencies and various partner institutions to work together to address quality health/fitness education, challenge students to be more physically active, increase awareness of the importance of lifelong health and fitness, teach students how fitness plays a vital role in human performance for exploration, and inspire and motivate students to pursue careers in STEM fields. The project was initiated in 2009 in response to a request by the International Space Life Sciences Working Group. USA, Netherlands, Italy, France, Germany, Austria, Colombia, Spain, and United Kingdom hosted teams for the pilot this past spring, and Japan held a modified version of the challenge. Several more agencies provided input into the preparations. Competing on 131 teams, more than 3700 students from 40 cities worldwide participated in the first round of Mission X. OUTCOMES AND BEST PRACTICES Members of the Mission X core team will highlight the outcomes of this international educational outreach pilot project, show video highlights of the challenge, provide the working group s initial assessment of the project and discuss the future potential of the effort. The team will also discuss ideas and best practices for international partnership in education outreach efforts from various agency perspectives and experiences

  19. Hematology and immunology studies - The second manned Skylab mission

    Science.gov (United States)

    Kimzey, S. L.; Johnson, P. C.; Ritzman, S. E.; Mengel, C. E.

    1976-01-01

    The hematologic and immunologic functions of the Skylab 3 astronauts were monitored during the preflight, inflight, and postflight phases of the mission. Plasma protein profiles showed high consistency in all phases. A transient suppression of lymphocyte responsiveness was observed postflight. A reduction in the circulating blood volume due to drops in both the plasma volume and red cell mass was found. The loss of red cell mass is most likely a suppressed erythrypoiesis. The functional integrity of the circulating red cells did not appear to be compromised in the course of flight.

  20. A Study on Fuel Estimation Algorithms for a Geostationary Communication & Broadcasting Satellite

    Directory of Open Access Journals (Sweden)

    Jong Won Eun

    2000-12-01

    Full Text Available It has been developed to calculate fuel budget for a geostationary communication and broadcasting satellite. It is quite essential that the pre-launch fuel budget estimation must account for the deterministic transfer and drift orbit maneuver requirements. After on-station, the calculation of satellite lifetime should be based on the estimation of remaining fuel and assessment of actual performance. These estimations step from the proper algorithms to produce the prediction of satellite lifetime. This paper concentrates on the fuel estimation method that was studied for calculation of the propellant budget by using the given algorithms. Applications of this method are discussed for a communication and broadcasting satellite.

  1. Study of Remote Globular Cluster Satellites of M87

    Science.gov (United States)

    Sahai, Arushi; Shao, Andrew; Toloba, Elisa; Guhathakurta, Puragra; Peng, Eric W.; Zhang, Hao

    2017-01-01

    We present a sample of “orphan” globular clusters (GCs) with previously unknown parent galaxies, which we determine to be remote satellites of M87, a massive elliptical galaxy at the center of the Virgo Cluster of Galaxies. Because GCs were formed in the early universe along with their original parent galaxies, which were cannibalized by massive galaxies such as M87, they share similar age and chemical properties. In this study, we first confirm that M87 is the adoptive parent galaxy of our orphan GCs using photometric and spectroscopic data to analyze spatial and velocity distributions. Next, we increase the signal-to-noise ratio of our samples’ spectra through a process known as coaddition. We utilize spectroscopic absorption lines to determine the age and metallicity of our orphan GCs through comparison to stellar population synthesis models, which we then relate to the GCs’ original parent galaxies using a mass-metallicity relation. Our finding that remote GCs of M87 likely developed in galaxies with ~1010 solar masses implies that M87’s outer halo is formed of relatively massive galaxies, serving as important parameters for developing theories about the formation and evolution of massive galaxies.This research was funded in part by NASA/STScI and the National Science Foundation. Most of this work was carried out by high school students working under the auspices of the Science Internship Program at UC Santa Cruz.

  2. Reference Mission Version 3.0 Addendum to the Human Exploration of Mars: The Reference Mission of the NASA Mars Exploration Study Team. Addendum; 3.0

    Science.gov (United States)

    Drake, Bret G. (Editor)

    1998-01-01

    This Addendum to the Mars Reference Mission was developed as a companion document to the NASA Special Publication 6107, "Human Exploration of Mars: The Reference Mission of the NASA Mars Exploration Study Team." It summarizes changes and updates to the Mars Reference Missions that were developed by the Exploration Office since the final draft of SP 6107 was printed in early 1999. The Reference Mission is a tool used by the exploration community to compare and evaluate approaches to mission and system concepts that could be used for human missions to Mars. It is intended to identify and clarify system drivers, significant sources of cost, performance, risk, and schedule variation. Several alternative scenarios, employing different technical approaches to solving mission and technology challenges, are discussed in this Addendum. Comparing alternative approaches provides the basis for continual improvement to technology investment plan and a general understanding of future human missions to Mars. The Addendum represents a snapshot of work in progress in support of planning for future human exploration missions through May 1998.

  3. CMBPol Mission Concept Study: Probing Inflation with CMB Polarization

    CERN Document Server

    Baumann, Daniel; Adshead, Peter; Amblard, Alexandre; Ashoorioon, Amjad; Bartolo, Nicola; Bean, Rachel; Beltran, Maria; de Bernardis, Francesco; Bird, Simeon; Chen, Xingang; Chung, Daniel Jun Hun; Colombo, Loris; Cooray, Asantha R.; Creminelli, Paolo; Dodelson, Scott; Dunkley, Joanna; Dvorkin, Cora; Easther, Richard; Finelli, Fabio; Flauger, Raphael; Hertzberg, Mark P.; Jones-Smith, Katherine; Kachru, Shamit; Kadota, Kenji; Khoury, Justin; Kinney, William H.; Komatsu, Eiichiro; Krauss, Lawrence M.; Lesgourgues, Julien; Liddle, Andrew R.; Liguori, Michele; Lim, Eugene A.; Linde, Andrei D.; Matarrese, Sabino; Mathur, Harsh; McAllister, Liam; Melchiorri, Alessandro; Nicolis, Alberto; Pagano, Luca; Peiris, Hiranya V.; Peloso, Marco; Pogosian, Levon; Pierpaoli, Elena; Riotto, Antonio; Seljak, Uros; Senatore, Leonardo; Shandera, Sarah E.; Silverstein, Eva; Smith, Tristan; Vaudrevange, Pascal M.; Verde, Licia; Wandelt, Ben; Wands, David; Watson, Scott; Wyman, Mark; Yadav, Amit; Valkenburg, Wessel; Zaldarriaga, Matias

    2009-01-01

    We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to differentiate various inflationary mechanisms. In particular, a detection of primordial B-mode polarization would demonstrate that inflation occurred at a very high energy scale, and that the inflaton traversed a super-Planckian distance in field space. We explain how such a detection or constraint would illuminate aspects of physics at the Planck scale. Moreover, CMB measurements can constrain the scale-dependence and non-Gaussianity of the primordial fluctuations and limit the possibility of a significant isocurvature contribution. Each such limit provides crucial information on the underlying inflationary dynamics. Finally, we quantify these considerations by presenting forecasts for the sensitivities of a future satellite experiment to the inflationary parameters.

  4. The 30/20 GHz communications satellite trunking network study

    Science.gov (United States)

    Kolb, W.

    1981-01-01

    Alternative transmission media for a CONUS-wide trunking network in the years 1990 and 2000 are examined. The alternative technologies comprised fiber optic cable, conventional C- and Ku-band satellites, and 30/20 GHz satellites. Three levels of implementation were considered - a 10-city network, a 20-city network, and a 40-city network. The cities selected were the major metropolitan areas with the greatest communications demand. All intercity voice, data, and video traffic carried more than 40 miles was included in the analysis. In the optimized network, traffic transmitted less than 500 miles was found to be better served by fiber optic cable in 1990. By the year 2000, the crossover point would be down to 200 miles, assuming availability of 30/20 GHz satellites.

  5. Satellite monitoring of remote volcanoes improves study efforts in Alaska

    Science.gov (United States)

    Dean, K.; Servilla, M.; Roach, A.; Foster, B.; Engle, K.

    Satellite monitoring of remote volcanoes is greatly benefitting the Alaska Volcano Observatory (AVO), and last year's eruption of the Okmok Volcano in the Aleutian Islands is a good case in point. The facility was able to issue and refine warnings of the eruption and related activity quickly, something that could not have been done using conventional seismic surveillance techniques, since seismometers have not been installed at these locations.AVO monitors about 100 active volcanoes in the North Pacific (NOPAC) region, but only a handful are observed by costly and logistically complex conventional means. The region is remote and vast, about 5000 × 2500 km, extending from Alaska west to the Kamchatka Peninsula in Russia (Figure 1). Warnings are transmitted to local communities and airlines that might be endangered by eruptions. More than 70,000 passenger and cargo flights fly over the region annually, and airborne volcanic ash is a threat to them. Many remote eruptions have been detected shortly after the initial magmatic activity using satellite data, and eruption clouds have been tracked across air traffic routes. Within minutes after eruptions are detected, information is relayed to government agencies, private companies, and the general public using telephone, fax, and e-mail. Monitoring of volcanoes using satellite image data involves direct reception, real-time monitoring, and data analysis. Two satellite data receiving stations, located at the Geophysical Institute, University of Alaska Fairbanks (UAF), are capable of receiving data from the advanced very high resolution radiometer (AVHRR) on National Oceanic and Atmospheric Administration (NOAA) polar orbiting satellites and from synthetic aperture radar (SAR) equipped satellites.

  6. Educational Television Via Satellite: Studies of Antecedents and Projects, Preliminary Plan. Volume One.

    Science.gov (United States)

    Comision Nacional de Investigaciones Espaciales, Buenos Aires (Argentina).

    A proposed satellite-aided educational television (ETV) system for Argentina is described in this Spanish-language report. The requirements and advantages of such a system are discussed, and some other studies of satellite-aided ETV are summarized. International and legal considerations, and problems of integrating existing Argentine TV stations…

  7. The European Union Training Mission in Mali: A case study

    Directory of Open Access Journals (Sweden)

    Dicke Rachel

    2014-10-01

    Full Text Available For several years, the European Union (EU has been increasing its international presence and moving into the role of a global security actor. To support the goal of greater crisis management capabilities, European security integration (ESI has been deepening. This article therefore examines an Ell operation - the European Union Training Mission in Mali (EUTM Mali - with the aim of gauging the success of the EU's efforts at ESI. To determine the success of EUTM Mali and thus of ESI, three propositions are examined: if EUTM Mali is a security operation showing successful security integration, there will be evidence of (i broad participation, (ii financial burden-sharing and (iii the successful incorporation of troops and equipment. The first and third propositions are supported whereas the second does not receive as much support. Overall, EUTM Mali shows considerable success and bodes well for further ESI.

  8. Dramatic and long-term lake level changes in the Qinghai-Tibet Plateau from Cryosat-2 altimeter: validation and augmentation by results from repeat altimeter missions and satellite imagery

    Science.gov (United States)

    Hwang, Cheinway; Huang, YongRuei; Cheng, Ys; Shen, WenBin; Pan, Yuanjin

    2017-04-01

    The mean elevation of the Qinghai-Tibet Plateau (QTP) exceeds 4000 m. Lake levels in the QTP are less affected by human activities than elsewhere, and may better reflect the state of contemporary climate change. Here ground-based lake level measurements are rare. Repeat altimeter missions, particularly those from the TOPEX and ERS series of altimetry, have provided long-term lake level observations in the QTP, but their large cross-track distances allow only few lakes to be monitored. In contrast, the Cryosat-2 altimeter, equipped with the new sensor SIRAL (interferometric/ synthetic aperture radar altimeter), provides a much better ranging accuracy and a finer spatial coverage than these repeated missions, and can detect water level changes over a large number of lakes in the QTP. In this study, Cryosat-2 data are used to determine lake level changes over 75˚E-100˚E and 28˚N-37.5˚N, where Cryosat-2 covers 60 lakes and SARAL/ AltiKa covers 32 lakes from 2013 to 2016. Over a lake, Cryosat-2 in different cycles can pass through different spots of the lake, making the numbers of observations non-uniform and requiring corrections for lake slopes. Four cases are investigated to cope with these situations: (1) neglecting inconsistency in data volume and lake slopes (2) considering data volume, (3) considering lake slopes only, and (4) considering both data volume and lake slopes. The CRYOSAT-2 result is then compared with the result from the SARAL to determine the best case. Because Cryosat-2 is available from 2010 to 2016, Jason-2 data are used to fill gaps between the time series of Cryosat-2 and ICESat (2003-2009) to obtain >10 years of lake level series. The Cryosat-2 result shows dramatic lake level rises in Lakes Kusai, Zhuoaihu and Salt in 2011 caused by floods. Landsat satellite imagery assists the determination and interpretation of such rises.

  9. Feasibility study of modern airships, phase 1. Volume 1: Summary and mission analysis (tasks 2 and 4)

    Science.gov (United States)

    Bloetscher, F.

    1975-01-01

    The histroy, potential mission application, and designs of lighter-than-air (LTA) vehicles are researched and evaluated. Missions are identified to which airship vehicles are potentially suited. Results of the mission analysis are combined with the findings of a parametric analysis to formulate the mission/vehicle combinations recommended for further study. Current transportation systems are surveyed and potential areas of competition are identified as well as potential missions resulting from limitations of these systems. Potential areas of military usage are included.

  10. Human Assisted Robotic Vehicle Studies - A conceptual end-to-end mission architecture

    Science.gov (United States)

    Lehner, B. A. E.; Mazzotta, D. G.; Teeney, L.; Spina, F.; Filosa, A.; Pou, A. Canals; Schlechten, J.; Campbell, S.; Soriano, P. López

    2017-11-01

    With current space exploration roadmaps indicating the Moon as a proving ground on the way to human exploration of Mars, it is clear that human-robotic partnerships will play a key role for successful future human space missions. This paper details a conceptual end-to-end architecture for an exploration mission in cis-lunar space with a focus on human-robot interactions, called Human Assisted Robotic Vehicle Studies (HARVeSt). HARVeSt will build on knowledge of plant growth in space gained from experiments on-board the ISS and test the first growth of plants on the Moon. A planned deep space habitat will be utilised as the base of operations for human-robotic elements of the mission. The mission will serve as a technology demonstrator not only for autonomous tele-operations in cis-lunar space but also for key enabling technologies for future human surface missions. The successful approach of the ISS will be built on in this mission with international cooperation. Mission assets such as a modular rover will allow for an extendable mission and to scout and prepare the area for the start of an international Moon Village.

  11. A coordinated two-satellite study of energetic electron precipitation events

    International Nuclear Information System (INIS)

    Imhof, W.L.; Nakano, G.H.; Gaines, E.E.; Reagan, J.B.

    1975-01-01

    A new technique for studying the spatial/temporal variations of energetic electron precipitation events is investigated. Data are presented in which precipitating electrons were measured simultaneously on two coordinated polar-orbiting satellites and the bremsstrahlung produced by the electrons precipitating into the atmosphere was observed from one of the satellites. Two electron spectrometers measuring the intensities and energy spectra of electrons of >130 keV were located on the oriented satellite 1971-089A (altitude, approx. =800 km), whereas a single similar spectrometer measuring electrons of >160 keV was located on the spinning low-altitude (approx.750 km) satellite 1972-076B. The X rays of >50 keV were measured with a 50-cm 3 germanium spectrometer placed on the 1972-076B satellite. With the coordinated data a study is made of events in which large fluctuations were observed in the precipitating energetic electron intensities. In the examples presented the satellite X ray data alone demonstrate that the spatially integrated electron influx was constant in time, and when the X ray data are combined with the direct electron measurements from the two satellites, the resulting data suggest that the major features in the flux profiles were primarily spatial in nature. The combination of X ray and electron measurements from two satellites is shown to provide an important method for studying and attempting to resolve spatial and temporal effects

  12. Study of frontal weather system using satellite images

    International Nuclear Information System (INIS)

    Qureshi, J.; Ershad, S.

    2005-01-01

    Pakistan which is situated in the south Asian sub continent, has a peculiar climatological position. It is one of the few countries in the world, which undergo a complete transformation from summer to winter season. However this project only pertains to the winter weather conditions in Pakistan. During winter, the land masses cool off rapidly as compared to the seas and so high pressure cells are developed over land causing, weak anti-cyclonic circulation over the country. In between these cells of anti-cyclonic flow of wind, there are zones of convergence, which offer a good breeding place for low-pressure waves. The low-pressure waves are similar to the extra tropical depressions and approach and approach Pakistan from west. From the same reason these are locally called the western Disturbances. Consequently the focus of study is on the extra tropical cyclones which originate along the boundary between polar continental and tropical or polar maritime and tropical maritime air masses. The extra tropical cyclones (also called western disturbances and westerly waves.) which are embedded in westerly flow of air move across north of Pakistan are usually originate from the Mediterranean sea. These systems consist of two types of fronts i.e. warm and cold fronts. In fact these systems can be traced right from the Atlantic Ocean and Mediterranean Sea. The location of frontal weather is generally associated with the surrounding synoptic situation, geographical position of the westerly wave, location of subtropical jet stream, steering wind level etc. although the satellite imageries are quite helpful for forecasting the frontal weather over our region however the weather charts (both surface and upper air ) and jet maps are also very helpful for this purpose

  13. The Smithsonian Earth Physics Satellite (SEPS) definition study, volumes 1 through 4

    Science.gov (United States)

    1971-01-01

    A limited Phase B study was undertaken to determine the merit and feasibility of launching a proposed earth physics satellite with Apollo-type hardware. The study revealed that it would be feasible to launch this satellite using a S-IB stage, a S-IVB with restart capability, an instrument unit, a SLA for the satellite shroud, and a nose cone (AS-204 configuration). A definition of the proposed satellite is provided, which is specifically designed to satisfy the fundamental requirement of providing an orbiting benchmark of maximum accuracy. The satellite is a completely passive, solid 3628-kg sphere of 38.1-cm radius and very high mass-to-area ratio (7980 kg sq mi). In the suggested orbit of 55 degrees inclination, 3720 km altitude, and low eccentricity, the orbital lifetime is extremely long, so many decades of operation can be expected.

  14. The OICETS mission

    Science.gov (United States)

    Jono, Takashi; Arai, Katsuyoshi

    2017-11-01

    The Optical Inter-orbit Communications Engineering Test Satellite (OICETS) was successfully launched on 23th August 2005 and thrown into a circular orbit at the altitude of 610 km. The main mission is to demonstrate the free-space inter satellite laser communications with the cooperation of the Advanced Relay and Technology Mission (ARTEMIS) geostationary satellite developed by the European Space Agency. This paper presents the overview of the OICETS and laser terminal, a history of international cooperation between Japan Aerospace Exploration Agency (JAXA) and ESA and typical results of the inter-orbit laser communication experiment carried out with ARTEMIS.

  15. Study and Developement of Compact Permanent Magnet Hall Thrusters for Future Brazillian Space Missions

    Science.gov (United States)

    Ferreira, Jose Leonardo; Martins, Alexandre; Cerda, Rodrigo

    2016-07-01

    The Plasma Physics Laboratory of UnB has been developing a Permanent Magnet Hall Thruster (PHALL) for the UNIESPAÇO program, part of the Space Activities Program conducted by AEB- The Brazillian Space Agency since 2004. Electric propulsion is now a very successful method for primary and secondary propulsion systems. It is essential for several existing geostationary satellite station keeping systems and for deep space long duration solar system missions, where the thrusting system can be designed to be used on orbit transfer maneuvering and/or for satellite attitude control in long term space missions. Applications of compact versions of Permanent Magnet Hall Thrusters on future brazillian space missions are needed and foreseen for the coming years beginning with the use of small divergent cusp field (DCFH) Hall Thrusters type on CUBESATS ( 5-10 kg , 1W-5 W power consumption) and on Micro satellites ( 50- 100 kg, 10W-100W). Brazillian (AEB) and German (DLR) space agencies and research institutions are developing a new rocket dedicated to small satellite launching. The VLM- Microsatellite Launch Vehicle. The development of PHALL compact versions can also be important for the recently proposed SBG system, a future brazillian geostationary satellite system that is already been developed by an international consortium of brazillian and foreign space industries. The exploration of small bodies in the Solar System with spacecraft has been done by several countries with increasing frequency in these past twenty five years. Since their historical beginning on the sixties, most of the Solar System missions were based on gravity assisted trajectories very much depended on planet orbit positioning relative to the Sun and the Earth. The consequence was always the narrowing of the mission launch window. Today, the need for Solar System icy bodies in situ exploration requires less dependence on gravity assisted maneuvering and new high precision low thrust navigation methods

  16. Mission definition study for Stanford relativity satellite. Volume 2: Engineering flight test program

    Science.gov (United States)

    1971-01-01

    The need is examined for orbital flight tests of gyroscope, dewar, and other components, in order to reduce the technical and financial risk in performing the relativity experiment. A program is described that would generate engineering data to permit prediction of final performance. Two flight tests are recommended. The first flight would test a dewar smaller than that required for the final flight, but of size and form sufficient to allow extrapolation to the final design. The second flight would use the same dewar design to carry a set of three gyroscopes, which would be evaluated for spinup and drift characteristics for a period of a month or more. A proportional gas control system using boiloff helium gas from the dewar, and having the ability to prevent sloshing of liquid helium, would also be tested.

  17. Study on the Mission, Roles, and Structure of the Missile Defense Agency (MDA)

    National Research Council Canada - National Science Library

    Welch, Larry D; Briggs, David L; Bleach, R. D; Canavan, G. H; Clark-Sestak, S. L; Constantine, R. W; Cook, C. W; Fries, M. S; Frost, D. E; Graham, D. R; Keane, D. J; Kramer, S. D; Major, P. L; Primmerman, C. A; Ruddy, J. M; Schneiter, G. R; Seng, J. M; Stein, R. M; Weiner, S. D; Williams, J. D

    2008-01-01

    ...) was tasked by the Department of Defense to carry out an independent study to examine and make recommendations with respect to the long-term missions, roles, and structure of the Missile Defense Agency (MDA...

  18. Management approach recommendations. Earth Observatory Satellite system definition study (EOS)

    Science.gov (United States)

    1974-01-01

    Management analyses and tradeoffs were performed to determine the most cost effective management approach for the Earth Observatory Satellite (EOS) Phase C/D. The basic objectives of the management approach are identified. Some of the subjects considered are as follows: (1) contract startup phase, (2) project management control system, (3) configuration management, (4) quality control and reliability engineering requirements, and (5) the parts procurement program.

  19. Satellite Power Systems (SPS) concept definition study, exhibit C. Volume 2, part 1: System engineering

    Science.gov (United States)

    Hanley, G. M.

    1979-01-01

    Volume 2, Part 1, of a seven volume report is presented. Part 1 encompasses Satellite Power Systems (SPS) systems engineering aspects and is divided into three sections. The first section presents descriptions of the various candidate concepts considered and conclusions and recommendations for a preferred concept. The second section presents a summary of results of the various trade studies and analysis conducted during the course of the study. The third section describes the Photovoltaic Satellite Based Satellite Power System (SPS) Point Design as it was defined through studies performed during the period January 1977 through March 1979.

  20. Photometric and Spectral Study of the Saturnian Satellites

    Science.gov (United States)

    Newman, Sarah F.

    2005-01-01

    Photometric and spectra analysis of data from the Cassini Visual and Infrared Mapping Spectrometer (VIMS) has yielded intriguing findings regarding the surface properties of several of the icy Saturnian satellites. Spectral cubes were obtained of these satellites with a wavelength distribution in the IR far more extensive than from any previous observations. Disk-integrated solar phase curves were constructed in several key IR wavelengths that are indicative of key properties of the surface of the body, such as macroscopic roughness, fluffiness (or the porosity of the surface), global albedo and scattering properties of surface particles. Polynomial fits to these phase curves indicate a linear albedo trend of the curvature of the phase functions. Rotational phase functions from Enceladus were found to exhibit a double-peaked sinusoidal curve, which shows larger amplitudes for bands corresponding to water ice and a linear amplitude-albedo trend. These functions indicate regions on the surface of the satellite of more recent geologic activity. In addition, recent images of Enceladus show tectonic features and an absence of impact craters on Southern latitudes which could be indicative of a younger surface. Investigations into the properties of these features using VIMS are underway.

  1. Asteroid Redirect Crewed Mission Space Suit and EVA System Architecture Trade Study

    Science.gov (United States)

    Bowie, Jonathan T.; Blanco, Raul A.; Watson, Richard D.; Kelly, Cody; Buffington, Jesse; Sipila, Stephanie A.

    2014-01-01

    This paper discusses the Asteroid Redirect Crewed Mission (ARCM) space suit and Extravehicular Activity (EVA) architecture trade study and the current state of the work to mature the requirements and products to the mission concept review level. The mission requirements and the resulting concept of operations will be discussed. A historical context will be presented as to present the similarities and differences from previous NASA missions. That will set the stage for the trade study where all options for both pressure garment and life support were considered. The rationale for the architecture decisions will then be presented. Since the trade study did identity risks, the subsequent tests and analyses that mitigated the risks will be discussed. Lastly, the current state of the effort will be provided.

  2. Reusing Information Management Services for Recommended Decadal Study Missions to Facilitate Aerosol and Cloud Studies

    Science.gov (United States)

    Kempler, Steve; Alcott, Gary; Lynnes, Chris; Leptoukh, Greg; Vollmer, Bruce; Berrick, Steve

    2008-01-01

    NASA Earth Sciences Division (ESD) has made great investments in the development and maintenance of data management systems and information technologies, to maximize the use of NASA generated Earth science data. With information management system infrastructure in place, mature and operational, very small delta costs are required to fully support data archival, processing, and data support services required by the recommended Decadal Study missions. This presentation describes the services and capabilities of the Goddard Space Flight Center (GSFC) Earth Sciences Data and Information Services Center (GES DISC) and the reusability for these future missions. The GES DISC has developed a series of modular, reusable data management components currently in use. They include data archive and distribution (Simple, Scalable, Script-based, Science [S4] Product Archive aka S4PA), data processing (S4 Processor for Measurements aka S4PM), data search (Mirador), data browse, visualization, and analysis (Giovanni), and data mining services. Information management system components are based on atmospheric scientist inputs. Large development and maintenance cost savings can be realized through their reuse in future missions.

  3. Upper atmosphere research satellite program. [to study the chemistry energetics, and dynamics

    Science.gov (United States)

    Huntress, W. T., Jr.

    1978-01-01

    A satellite program to conduct research on the chemistry, energetics, and dynamics of the upper atmosphere was developed. The scientific goals of the Upper Atmospheric Research Program, the program requirements, and the approach toward meeting those requirements are outlined. An initial series of two overlapping spacecraft missions is described. Both spacecraft are launched and recovered by the STS, one in the winter of 1983 at a 56 deg inclination, and the other a year later at a 70 deg inclination. The duration of each mission is 18 months, and each carries instruments to make global measurements of the temperature, winds, composition, irradation, and radiance in the stratosphere, mesosphere, and lower thermosphere between the tropopause and 120 km altitude. The program requires a dedicated ground-based data system and a science team organization that leads to a strong interaction between the experiments and theory. The program includes supportive observations from other platforms such as rockets, balloons, and the Spacelab.

  4. VLBI Observations of Geostationary Satellites

    Science.gov (United States)

    Artz, T.; Nothnagel, A.; La Porta, L.

    2013-08-01

    For a consistent realization of a Global Geodetic Observing System (GGOS), a proper tie between the individual global reference systems used in the analysis of space-geodetic observations is a prerequisite. For instance, the link between the terrestrial, the celestial and the dynamic reference system of artificial Earth orbiters may be realized by Very Long O Baseline Interferometry (VLBI) observations of one or several satellites. In the preparation phase for a dedicated satellite mission, one option to realize this is using a geostationary (GEO) satellite emitting a radio signal in X-Band and/or S-Band and, thus, imitating a quasar. In this way, the GEO satellite can be observed by VLBI together with nearby quasars and the GEO orbit can, thus, be determined in a celestial reference frame. If the GEO satellite is, e.g., also equipped with a GNSS-type transmitter, a further tie between GNSS and VLBI may be realized. In this paper, a concept for the generation of a radio signal is shown. Furthermore, simulation studies for estimating the GEO position are presented with a GEO satellite included in the VLBI schedule. VLBI group delay observations are then simulated for the quasars as well as for the GEO satellite. The analysis of the simulated observations shows that constant orbit changes are adequately absorbed by estimated orbit parameters. Furthermore, the post-fit residuals are comparable to those from real VLBI sessions.

  5. 25 years of satellite beacon studies in Japan

    Science.gov (United States)

    Sinno, K.

    The occurrence of ionospheric scintillation exhibits behavior similar to both that of TEC fluctuations and night time ionospheric spread-F. The scintillations are also noted to vary in the same fashion diurnally and seasonally, having a principal maximum at about midnight during the summer. These characteristics also apply to the 1.7 GHz scintillation detected by the ETS-II and GMS satellites. Attention is presently given to the scintillation's frequency dependence, the development of severe scintillation events, and the enhancement of midlatitude scintillation due to field-aligned irregularities.

  6. Chartering Launchers for Small Satellites

    Science.gov (United States)

    Hernandez, Daniel

    The question of how to launch small satellites has been solved over the years by the larger launchers offering small satellites the possibility of piggy-backing. Specific fixtures have been developed and commercialized: Arianespace developed the ASAP interface, the USAF studied ESPA, NASA has promoted Shuttle launch possibilities, Russian authorities and companies have been able to find solutions with many different launchers... It is fair to say that most launcher suppliers have worked hard and finally often been able to find solutions to launch most small satellites into orbit. It is also true, however, that most of these small satellites were technology demonstration missions capable of accepting a wide range of orbit and launch characteristics: orbit altitude and inclination, launch date, etc. In some cases the small satellite missions required a well-defined type of orbit and have therefore been obliged to hire a small launcher on which they were the prime passenger. In our paper we would like to propose an additional solution to all these possibilities: launchers could plan well in advance (for example about 3 years), trips to precisely defined orbits to allow potential passengers to organize themselves and be ready on the D-Day. On the scheduled date the chartered launcher goes to the stated orbit while on another date, another chartered launcher goes to another orbit. The idea is to organize departures for space like trains or airplanes leaving on known schedules for known destinations.

  7. Moon Search Algorithms for NASA's Dawn Mission to Asteroid Vesta

    Science.gov (United States)

    Memarsadeghi, Nargess; Mcfadden, Lucy A.; Skillman, David R.; McLean, Brian; Mutchler, Max; Carsenty, Uri; Palmer, Eric E.

    2012-01-01

    A moon or natural satellite is a celestial body that orbits a planetary body such as a planet, dwarf planet, or an asteroid. Scientists seek understanding the origin and evolution of our solar system by studying moons of these bodies. Additionally, searches for satellites of planetary bodies can be important to protect the safety of a spacecraft as it approaches or orbits a planetary body. If a satellite of a celestial body is found, the mass of that body can also be calculated once its orbit is determined. Ensuring the Dawn spacecraft's safety on its mission to the asteroid Vesta primarily motivated the work of Dawn's Satellite Working Group (SWG) in summer of 2011. Dawn mission scientists and engineers utilized various computational tools and techniques for Vesta's satellite search. The objectives of this paper are to 1) introduce the natural satellite search problem, 2) present the computational challenges, approaches, and tools used when addressing this problem, and 3) describe applications of various image processing and computational algorithms for performing satellite searches to the electronic imaging and computer science community. Furthermore, we hope that this communication would enable Dawn mission scientists to improve their satellite search algorithms and tools and be better prepared for performing the same investigation in 2015, when the spacecraft is scheduled to approach and orbit the dwarf planet Ceres.

  8. Planning a pharmacy-led medical mission trip, part 4: an exploratory study of student experiences.

    Science.gov (United States)

    Brown, Dana A; Fairclough, Jamie L; Ferrill, Mary J

    2012-09-01

    At the Gregory School of Pharmacy (GSOP), pharmacy students routinely participate in domestic and international medical mission trips. Participation can be for academic credit as part of final-year Advanced Pharmacy Practice Experiences (APPEs) or as required community service hours. These mission experiences could potentially result in both professional and personal transformations for participating students. To evaluate data collected from GSOP pharmacy students regarding their experiences on the medical mission field in 2011 and how that participation has impacted the students professionally and personally. GSOP students participating in an international or domestic medical mission trip in the summer of 2011 were asked to voluntarily complete pre- and posttrip surveys. Of the 68 final-year APPE students and student volunteers who participated in a summer 2011 GSOP medical mission trip, 36 (53%) completed pre- and posttrip surveys. The mission trips significantly impacted students' beliefs regarding better preparation to care for the medical needs of patients, identification of others' needs, understanding team dynamics, perceptions about the value of patient care, and comfort level with the provision of medical and pharmaceutical care in a foreign country. However, there were no statistically significant improvements in students' perceptions of their ability to care for the emotional needs of patients, the importance of team unity, and their level of respect for team members; their ability to lead or participate in future trips; and their belief that participating preceptors and faculty serve as effective role models of servant leaders. Based on the findings from this exploratory study, participation in a domestic or international medical mission trip as a student volunteer or APPE student appears to have a positive impact on some of the beliefs and perceptions of GSOP students. By continuing to follow these particular students and similar cohorts of students in

  9. Geochemistry study of orientation made in the Uranio mission context

    International Nuclear Information System (INIS)

    1982-01-01

    The objective of the geochemical study or guidance study, is to select the three main parameters of strategic a geochemical prospection: place election for samples extraction, king of material to sample, the average density of sampling. Also throughout the tours, complementary studies can take place in order to improve the chosen techniques initially. Inspiring by results obtained by Alain Lambert to us by the end of 1981 in diverse tactics done in known indications, we have come to a preliminary study days 7 and 8 of January of 1982 in the South Long Hill region. During the campaign of strategic prospection, two complementary studies were realised: one in the region of Yerba Sola and another one in Paso Severino from the 6 to the 9 of October of 1982

  10. A study of artificial satellite resonance orbits due to lunisolar perturbations

    International Nuclear Information System (INIS)

    Hughes, S.

    1978-01-01

    A study of artificial satellite resonance orbits due to lunisolar perturbations is given. Particular emphasis is placed on the following aspects: the classification of resonance orbits according to their commensurability condition; the form of the commensurability condition when expressed in terms of the orbital elements of a satellite; the predominant resonant terms for each commensurability condition; and criteria which determine the existence or non-existence of a particular commensurability condition. (author)

  11. Two satellite study of substorm expansion near geosynchronous orbit

    Directory of Open Access Journals (Sweden)

    Ø. Holter

    2004-12-01

    Full Text Available During several time intervals in 1979–1980 the satellites GEOS-2 and SCATHA were situated relatively close on the nightside of the Earth at geosynchronous distances. Several substorm events were identified during these periods. The event considered in this paper was recorded on 22 May 1979, when the satellites were separated by less than 30min in local time around 21:00 LT. The observed 45 to 60 s delay of magnetic signatures observed at the two s/c indicates a westward expansion of ~7.7°/min. At the two s/c, the magnetic signatures are, in particular for the azimuthal magnetic field components, quite different. At GEOS-2, being close to the magnetic equator, the dominant feature is a dipolarization with a weak field-aligned current signature corresponding to a symmetric current which cancels at the equator. On SCATHA, however, being close to the current sheet boundary, the azimuthal magnetic field indicates a strong field-aligned Birkeland current structure. On both s/c the first indication of an approaching substorm was an increase in the high energy ion flux followed by a reduction in the flux intensity of energetic electrons and a further tailward stretching of the magnetic field, starting ~2min before the onset of the magnetic field dipolarization. The tailward stretching, the observed variations of the magnetic field components, and the subsequent dipolarization are interpreted in terms of an azimuthally tilted field-aligned current system passing the s/c on the tailward side from east to west. The westward expansion and dipolarization observed at the two s/c are consistent with the propagation of a Rayleigh-Taylor type instability. The increased radial ion flux corresponds to the ExB-drift due to the substorm associated electric field.

    Key words. Magnetospheric physics (storms and substorms; plasma waves and instabilities; current systems

  12. GHRSST Level 2P Global Subskin Sea Surface Temperature from TRMM Microwave Imager (TMI) onboard Tropical Rainfall Measurement Mission (TRMM) satellite (GDS versions 1 and 2)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — GDS2 Version -The Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) is a well calibrated passive microwave radiometer, similar to the Special Sensor...

  13. Experimental study of linear magnetic dichroism in photoionization satellite transitions of atomic rubidium

    International Nuclear Information System (INIS)

    Jaenkaelae, K.; Alagia, M.; Feyer, V.; Richter, R.; Prince, K. C.

    2011-01-01

    Laser orientation in the initial state has been used to study the properties of satellite transitions in inner-shell photoionization of rubidium atoms. The linear magnetic dichroism in the angular distribution (LMDAD) has been utilized to probe the continuum waves of orbital angular momentum conserving monopole, and angular momentum changing conjugate satellites, accompanying the 4p ionization of atomic Rb. We show experimentally that LMDAD of both types of satellite transitions is nonzero and that LMDAD of monopole satellites, measured as a function of photon energy, mimics the LMDAD of direct photoionization, whereas the LMDAD of conjugate transitions deviates drastically from that trend. The results indicate that conjugate transitions cannot be described theoretically without explicit inclusion of electron-electron interaction. The present data can thus be used as a very precise test of current models for photoionization.

  14. The Simbox Experiment with Arabidopsis Thaliana Cell Cultures: Hardware-Tests and First Resutls from the German-Chinese satellite Mission Shenzhou 8

    Science.gov (United States)

    Fengler, Svenja; Neef, Maren; Ecke, Margret; Hampp, Ruediger

    2013-02-01

    The Simbox experiment was the first joint German-Chinese space project. In this context Arabidopsis thaliana cell cultures were exposed to microgravity for a 17-day period. To carry out a successful space mission, diverse hardware tests were performed in advance. Due to the limited oxygen supply inside the hardware units, cells were fixed after 5 days under microgravity conditions. As a control, samples were exposed in an on-board 1g reference centrifuge. To investigate the space effect, a ground-based study was performed with the same hardware and identical experimental procedures. As we were able to obtain high quality RNA from the RNAlater quenched samples, we used the Affymetrix Arabidopsis genome array for a transcriptome analysis. Our experiment aimed at the identification of plant genes that were differentially expressed after long-term exposure to microgravity. Pair-wise comparison of flight samples with 1g controls revealed the largest differences between space 1g and ground 1g controls.

  15. The Zeus Mission Study — An application of automated collaborative design

    Science.gov (United States)

    Doyotte, Romain; Love, Stanley G.; Peterson, Craig E.

    1999-11-01

    The purpose of the Zeus Mission Study was threefold. As an element of a graduate course in spacecraft system engineering, its purpose was primarily educational — to allow the students to apply their knowledge in a real mission study. The second purpose was to investigate the feasibility of applying advanced technology (the power antenna and solar electric propulsion concepts) to a challenging mission. Finally, the study allowed evaluation of the benefits of using quality-oriented techniques (Quality Function Deployment (QFD) and Taguchi Methods) for a mission study. To encourage innovation, several constraints were placed on the study from the onset. While the primary goal was to place at least one lander on Europa, the additional constraint of no nuclear power sources posed an additional challenge, particularly when coupled with the mass constraints imposed by using a Delta II class launch vehicle. In spite of these limitations, the team was able to develop a mission and spacecraft design capable of carrying three simple, lightweight, yet capable landers. The science return will more than adequately meet the science goals established QFD was used to determine the optimal choice of instrumentation. The lander design was selected from several competing lander concepts, including rovers. The carrier design was largely dictated by the needs of the propulsion system required to support the mission, although the development of a Project Trades Model (PTM) in software allowed for rapid recalculation of key system parameters as changes were made. Finally, Taguchi Methods (Design of Experiments) were used in conjunction with the PTM allowing for some limited optimization of design features.

  16. Studies of outer planet satellites, Mercury and Uranus

    Science.gov (United States)

    Mckinnon, William B.; Schenk, Paul M.

    1987-01-01

    Arguments were made, based on geometry, for both an impact and an internal origin for the ancient, partially preserved furrow system of Ganymede. It was concluded that furrows were not concentric, but could be impact related if multiringed structures on icy satellites are initially noncircular. The geometry of the Valhalla ring structure on Callisto was examined in order to assess the circularity of an unmodified ring system. The Ganymede furrow system was remapped to make use of improvements in coordinate control. The least-squares center of curvature for all furrows in the Marius and Galileao Regio is -20.7, and 179.2 degrees. Furrows in Marius and Galileo Regio are reasonably concentric, and are much more circular than previously estimated. The perceived present nonalignment of the assumed originally concentric furrows were used to argue for large-scale lateral motion of dark terrain blocks in Ganymede's crust, presumably in association with bright terrain formation., The overall alignment of furrows as well as the inherent scatter in centers of curvature from subregions of Galileo and Marius do not support this hypothesis.

  17. Wide Field Infra-Red Survey Telescope (WFIRST) 2.4-Meter Mission Study

    Science.gov (United States)

    Content, D.; Aaron, K.; Alplanalp, L.; Anderson, K.; Capps, R.; Chang, Z.; Dooley, J.; Egerman, R.; Goullioud, R.; Klein, D.; hide

    2013-01-01

    The most recent study of the Wide Field Infrared Survey Telescope (WFIRST) mission is based on reuse of an existing 2.4m telescope. This study was commissioned by NASA to examine the potential science return and cost effectiveness of WFIRST by using this significantly larger aperture telescope. We review the science program envisioned by the WFIRST 2012-2013 Science Definition Team (SDT), an overview of the mission concept, and the telescope design and status. Comparisons against the previous 1.3m and reduced cost 1.1m WFIRST design concepts are discussed. A significant departure from past point designs is the option for serviceability and the geostationary orbit location which enables servicing and replacement instrument insertion later during mission life. Other papers at this conference provide more in depth discussion of the wide field instrument and the optional exoplanet imaging coronagraph instrument.

  18. Comparative study of FDMA, TDMA and hybrid 30/20 GHz satellite communications systems for small users

    Science.gov (United States)

    Berk, G.; Jean, P. N.; Rotholz, E.

    1982-01-01

    This study compares several satellite uplink and downlink accessing schemes for a Customer Premises Service. Four conceptual system designs are presented: Satellite-Routed FDMA, Frequency-Routed TDMA, Satellite-Switched TDMA, and Processor-Routed TDMA, operating in the 30/20 GHz band. The designs are compared on the basis of estimated satellite weight, power consumption, and cost. The system capacities are analyzed for a fixed multibeam coverage of CONUS. Analysis shows that the system capacity is limited by the available satellite resources and by the terminal size and cost.

  19. The Hydrosphere State (Hydros) Satellite Mission: An Earth System Pathfinder for Global Mapping of Soil Moisture and Land Freeze/Thaw

    Science.gov (United States)

    Entekhabi, D.; Njoku, E. G.; Spencer, M.; Kim, Y.; Smith, J.; McDonald, K. C.; vanZyl, J.; Houser, P.; Dorion, T.; Koster, R.; hide

    2004-01-01

    The Hydrosphere State Mission (Hydros) is a pathfinder mission in the National Aeronautics and Space Administration (NASA) Earth System Science Pathfinder Program (ESSP). The objective of the mission is to provide exploratory global measurements of the earth's soil moisture at 10-km resolution with two- to three-days revisit and land-surface freeze/thaw conditions at 3-km resolution with one- to two-days revisit. The mission builds on the heritage of ground-based and airborne passive and active low-frequency microwave measurements that have demonstrated and validated the effectiveness of the measurements and associated algorithms for estimating the amount and phase (frozen or thawed) of surface soil moisture. The mission data will enable advances in weather and climate prediction and in mapping processes that link the water, energy, and carbon cycles. The Hydros instrument is a combined radar and radiometer system operating at 1.26 GHz (with VV, HH, and HV polarizations) and 1.41 GHz (with H, V, and U polarizations), respectively. The radar and the radiometer share the aperture of a 6-m antenna with a look-angle of 39 with respect to nadir. The lightweight deployable mesh antenna is rotated at 14.6 rpm to provide a constant look-angle scan across a swath width of 1000 km. The wide swath provides global coverage that meet the revisit requirements. The radiometer measurements allow retrieval of soil moisture in diverse (nonforested) landscapes with a resolution of 40 km. The radar measurements allow the retrieval of soil moisture at relatively high resolution (3 km). The mission includes combined radar/radiometer data products that will use the synergy of the two sensors to deliver enhanced-quality 10-km resolution soil moisture estimates. In this paper, the science requirements and their traceability to the instrument design are outlined. A review of the underlying measurement physics and key instrument performance parameters are also presented.

  20. Landsat Data Continuity Mission

    Science.gov (United States)

    ,

    2012-01-01

    The Landsat Data Continuity Mission (LDCM) is a partnership formed between the National Aeronautics and Space Administration (NASA) and the U.S. Geological Survey (USGS) to place the next Landsat satellite in orbit in January 2013. The Landsat era that began in 1972 will become a nearly 41-year global land record with the successful launch and operation of the LDCM. The LDCM will continue the acquisition, archiving, and distribution of multispectral imagery affording global, synoptic, and repetitive coverage of the Earth's land surfaces at a scale where natural and human-induced changes can be detected, differentiated, characterized, and monitored over time. The mission objectives of the LDCM are to (1) collect and archive medium resolution (30-meter spatial resolution) multispectral image data affording seasonal coverage of the global landmasses for a period of no less than 5 years; (2) ensure that LDCM data are sufficiently consistent with data from the earlier Landsat missions in terms of acquisition geometry, calibration, coverage characteristics, spectral characteristics, output product quality, and data availability to permit studies of landcover and land-use change over time; and (3) distribute LDCM data products to the general public on a nondiscriminatory basis at no cost to the user.

  1. Advanced mobile satellite communications using COMETS satellite in MM-wave and Ka-band

    Science.gov (United States)

    Ohmori, Shingo; Isobe, Shunkichi; Takeuchi, Makoto; Naito, Hideyuki

    1993-01-01

    Early in the 21st century, the demand for personal communications using mobile, hand-held, and VSAT terminals will rapidly increase. In a future system, many different types of services should be provided with one-hop connection. The Communications Research Laboratory (CRL) has studied a future advanced mobile satellite communications system using millimeter wave and Ka band. In 1990, CRL started the Communications and Broadcasting Engineering Test Satellite (COMETS) project. The satellite has been developed in conjunction with NASDA and will be launched in 1997. This paper describes the COMETS payload configuration and the experimental system for the advanced mobile communications mission.

  2. SmallSats, Iodine Propulsion Technology, Applications to Low-Cost Lunar Missions, and the Iodine Satellite (iSAT) Project

    Science.gov (United States)

    Dankanich, John W.

    2014-01-01

    Closing Remarks: ?(1) SmallSats hold significant potential for future low cost high value missions; (2) Propulsion remains a key limiting capability for SmallSats that Iodine can address: High ISP * Density for volume constrained spacecraft; Indefinite quiescence, unpressurized and non-hazardous as a secondary payload; (3) Iodine enables MicroSat and SmallSat maneuverability: Enables transfer into high value orbits, constellation deployment and deorbit; (4) Iodine may enable a new class of planetary and exploration class missions: Enables GTO launched secondary spacecraft to transit to the moon, asteroids, and other interplanetary destinations for approximately 150 million dollars full life cycle cost including the launch; (5) ESPA based OTVs are also volume constrained and a shift from xenon to iodine can significantly increase the transfer vehicle change in volume capability including transfers from GTO to a range of Lunar Orbits; (6) The iSAT project is a fast pace high value iodine Hall technology demonstration mission: Partnership with NASA GRC and NASA MSFC with industry partner - Busek; (7) The iSAT mission is an approved project with PDR in November of 2014 and is targeting a flight opportunity in FY17.

  3. New Approach to Concept Feasibility and Design Studies for Astrophysics Missions

    Science.gov (United States)

    Deutsch, M. J.; McLaughlin, W.; Nichols, J.

    1998-01-01

    JPL has assembled a team of multidisciplinary experts with corporate knowledge of space mission and instrument development. The advanced Concept Design Team, known as Team X, provides interactive design trades including cost as a design parameter, and advanced visualization for pre-Phase A Studies.

  4. Study of LEO-SAT microwave link for broad-band mobile satellite communication system

    Science.gov (United States)

    Fujise, Masayuki; Chujo, Wataru; Chiba, Isamu; Furuhama, Yoji; Kawabata, Kazuaki; Konishi, Yoshihiko

    1993-01-01

    In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented.

  5. The Himalia Satellite Group: A Case Study on the Dynamical Self-spreading of Families of Irregular Satellites and Asteroids

    Science.gov (United States)

    Li, Daohai; Christou, Apostolos A.

    2015-11-01

    Many of the outer planets' irregular satellites are grouped into families, thought to originate from collisional fragmentation (Nesvorný et al 2004, AJ). Interestingly, families associated with the largest irregulars are either more dispersed than expected (e.g. J6 Himalia; Nesvorný et al 2003, AJ), or do not exist at all (e.g. S9 Phoebe; Ćuk et al 2003, DDA meeting #34). Christou (2005, Icarus) found that gravitational scattering by Himalia of its own group could explain the large velocity dispersion found by Nesvorný et al (2003, AJ). At the same time, Christou identified a new type of dynamical mechanism that intermittently locks the node of the satellite J10 Lysithea to that of Himalia. The same mechanism, but due to Ceres, was recently found to operate within the Hoffmeister family, dispersing its members and allowing an estimate of its age (Novaković et al 2015, ApJ).Here we revisit the issue of family self-dispersion, aiming to better understand it by studying its effects on the Himalia group. For this we utilise (a) intensive test particle simulations on a larger scale than those by Christou (2005, Icarus) (b) a semi-analytical treatment of the new resonance based on the secular theory of coorbital motion by Namouni (1999, Icarus). This has allowed us to obtain firmer constraints on the rate of dispersion over time and on how the resonance affects the long-term evolution of the orbital elements. A principal result of this work is that particles near the resonance evolve differently than those away from it. During the meeting, we will present a new estimate of the family’s age as well as an analysis of the resonant structure and how it affects Himalia family members. We will also discuss the broader implications for the long-term evolution of orbital concentrations of small bodies in the solar system.Astronomical research at the Armagh Observatory is funded by the Northern Ireland Department of Culture, Arts and Leisure (DCAL).

  6. ESA CAMELOT study: Challenges in future operational missions for GMES atmospheric monitoring, sentinel 4 and 5

    Science.gov (United States)

    Levelt, P.; Veefkind, P.

    2009-04-01

    Dedicated atmospheric chemistry observations from space have been made for over 30 years now, starting with the SBUV and TOMS measurements of the ozone layer. Since then huge progress has been made, improving the accuracy of the measurements, extending the amount of constituents, and by sensing not only the stratosphere, but the last five to ten years also the troposphere. The potential to operational monitor the atmosphere, following the meteorological community, came within reach. At the same time, the importance for society of regular operational environmental measurements, related to the ozone layer, air quality and climate change, became apparent, amongst others resulting in the EU initiative Global Monitoring for Environment and Security (GMES) In order to prepare the operational missions in the context of the GMES, ESA took the initiative to further study the user requirements for the Sentinel 4 and 5 (precursor) missions. The Sentinel 4 and 5 (precursor) missions are dedicated operational missions to monitor the atmospheric composition in the 2013-2020 timeframe and onward. The user requirements for the sentinel missions focus on monitoring the atmosphere from an environmental point of view (ozone layer, air quality and climate). ESA's CAMELOT (Composition of the Atmospheric Mission concEpts and SentineL Observation Techniques) study is the follow-on study to ESA's CAPACITY study finished in 2005. The general objective of the CAMELOT study is to further contribute to the definition of the air quality and climate protocol monitoring parts of the GMES Sentinel 4 and 5 missions. Key issues in the CAMELOT study are: • trade-offs between different observation strategies (spectral ranges, polarisation, direction etc) for aerosols and several trace gases • a quantitative assessment of the requirements for spatio-temporal sampling taking into account the contamination of nadir-viewing observations by cloud • optimising several orbit scenario's (leo, inclined

  7. Magnetospheric ULF wave studies in the frame of Swarm mission: new advanced tools for automated detection of pulsations in magnetic and electric field observations

    Science.gov (United States)

    Balasis, Georgios; Daglis, Ioannis A.; Papadimitriou, Constantinos; Georgiou, Marina; Giamini, Sigiava A.; Sandberg, Ingmar; Haagmans, Roger

    2014-05-01

    The rekindling of the interest in space science in the last 15 years has led to many successful satellite missions in the Earth's magnetosphere and topside ionosphere, which were able to provide the scientific community with high-quality data on the magnetic and electric fields surrounding our planet. This data pool will be further enriched by the measurements of ESA's Swarm mission, a constellation of three satellites in different polar orbits, flying at altitudes from 400 to 550 km, which was launched on the 22nd of November 2013. Aiming at the best scientific exploitation of this corpus of accumulated data, we have developed a set of analysis tools that can cope with measurements of various spacecraft, at various regions of the magnetosphere and in the topside ionosphere. Our algorithms are based on a combination of wavelet spectral methods and artificial neural network techniques and are suited for the detection of waves and wave-like disturbances as well as the extraction of several physical parameters. Our recent work demonstrates the applicability of our developed analysis tools, both for individual case studies and statistical analysis of ultra low frequency (ULF) waves. We provide evidence for a rare simultaneous observation of a ULF wave event in the Earth's magnetosphere, topside ionosphere and surface: we have found a specific time interval during the Halloween 2003 magnetic storm, when the Cluster and CHAMP spacecraft were in good local time (LT) conjunction, and have examined the ULF wave activity in the Pc3 (22-100 mHz), Pc4 (7-22 mHz) and Pc5 (1-7 mHz) bands using data from the Geotail, Cluster and CHAMP missions, as well as the CARISMA, GIMA and IMAGE magnetometer networks. Our study shows that the same wave event, characterized by increased activity in the high end of the Pc3 band, was simultaneously observed by all three satellite missions and by certain stations of ground networks. This observation provides a strong argument in favour of the

  8. Experimental study on the precise orbit determination of the BeiDou navigation satellite system.

    Science.gov (United States)

    He, Lina; Ge, Maorong; Wang, Jiexian; Wickert, Jens; Schuh, Harald

    2013-03-01

    The regional service of the Chinese BeiDou satellite navigation system is now in operation with a constellation including five Geostationary Earth Orbit satellites (GEO), five Inclined Geosynchronous Orbit (IGSO) satellites and four Medium Earth Orbit (MEO) satellites. Besides the standard positioning service with positioning accuracy of about 10 m, both precise relative positioning and precise point positioning are already demonstrated. As is well known, precise orbit and clock determination is essential in enhancing precise positioning services. To improve the satellite orbits of the BeiDou regional system, we concentrate on the impact of the tracking geometry and the involvement of MEOs, and on the effect of integer ambiguity resolution as well. About seven weeks of data collected at the BeiDou Experimental Test Service (BETS) network is employed in this experimental study. Several tracking scenarios are defined, various processing schemata are designed and carried out; and then, the estimates are compared and analyzed in detail. The results show that GEO orbits, especially the along-track component, can be significantly improved by extending the tracking network in China along longitude direction, whereas IGSOs gain more improvement if the tracking network extends in latitude. The involvement of MEOs and ambiguity-fixing also make the orbits better.

  9. Second-generation mobile satellite system. A conceptual design and trade-off study

    Science.gov (United States)

    Sue, M. K.; Park, Y. H.

    1985-01-01

    In recent years, interest has grown in the mobile satellite (MSAT) system, a satellite-based communications system capable of providing integrated voice and data services to a large number of users. To explore the potential of a commercial mobile satellite system (MSS) beyond the horizon of the first generation, using technologies of the 1990's and to assist MSAT-X in directing its efforts, a conceptual design has been performed for a second-generation system to be launched around the mid-1990's. The design goal is to maximize the number of satellite channels and/or minimize the overall life-cycle cost, subject to the constraint of utilizing a commercial satellite bus with minimum modifications. To provide an optimal design, a series of trade-offs are performed, including antenna sizing, feed configurations, and interference analysis. Interference is a serious problem for MSAT and often an overlapping feed design is required to reduce interbeam interference. The trade-off studies will show that a simple non-overlapping feed is sufficient for the second-generation system, thus avoiding the need for the complicated beam-forming network that is associated with the overlapping feed designs. In addition, a system that operates at L-band, an alternative frequency band that is being considered by some for possible MSAT applications, is also presented.

  10. Prospects of the ICESat-2 Laser Altimetry Mission for Savanna Ecosystem Structural Studies Based on Airborne Simulation Data

    Science.gov (United States)

    Gwenzi, David; Lefsky, Michael A.; Suchdeo, Vijay P.; Harding, David J.

    2016-01-01

    The next planned spaceborne lidar mission is the Ice, Cloud and land Elevation Satellite 2 (ICESat-2), which will use the Advanced Topographic Laser Altimeter System (ATLAS) sensor, a photon counting technique. To pre-validate the capability of this mission for studying three dimensional vegetation structure in savannas, we assessed the potential of the measurement approach to estimate canopy height in an oak savanna landscape. We used data from the Multiple Altimeter Beam Experimental Lidar (MABEL), an airborne photon counting lidar sensor developed by NASA's Goddard Space Flight Center. ATLAS-like data was generated using the MATLAS simulator, which adjusts MABEL data's detected number of signal and noise photons to that expected from the ATLAS instrument. Transects flown over the Tejon ranch conservancy in Kern County, California, USA were used for this work. For each transect we chose to use data from the near infrared channel that had the highest number of photons. We segmented each transect into 50 m, 25 m and 14 m long blocks and aggregated the photons in each block into a histogram based on their elevation values. We then used an automated algorithm to identify cut off points where the cumulative density of photons from the highest elevation indicates the presence of the canopy top and likewise where such cumulative density from the lowest elevation indicates the mean terrain elevation. MABEL derived height metrics were moderately correlated to discrete return lidar (DRL) derived height metrics r(sub 2) and RMSE values ranging from 0.60 to 0.73 and 2.9 m to 4.4 m respectively) but MATLAS simulation resulted in more modest correlations with DRL indices r(sub 2) ranging from 0.5 to 0.64 and RMSE from 3.6 m to 4.6 m). Simulations also indicated that the expected number of signal photons from ATLAS will be substantially lower, a situation that reduces canopy height estimation precision especially in areas of low density vegetation cover. On the basis of the

  11. A case study of GWE satellite data impact on GLA assimilation analyses of two ocean cyclones

    Science.gov (United States)

    Gallimore, R. G.; Johnson, D. R.

    1986-01-01

    The effects of the Global Weather Experiment (GWE) data obtained on January 18-20, 1979 on Goddard Laboratory for Atmospheres assimilation analyses of simultaneous cyclones in the western Pacific and Atlantic oceans are examined. The ability of satellite data within assimilation models to determine the baroclinic structures of developing extratropical cyclones is evaluated. The impact of the satellite data on the amplitude and phase of the temperature structure within the storm domain, potential energy, and baroclinic growth rate is studied. The GWE data are compared with Data Systems Test results. It is noted that it is necessary to characterize satellite effects on the baroclinic structure of cyclone waves which degrade numerical weather predictions of cyclogenesis.

  12. Evaluating Satellite Products for Precipitation Estimation in Mountain Regions: A Case Study for Nepal

    Directory of Open Access Journals (Sweden)

    Tarendra Lakhankar

    2013-08-01

    Full Text Available Precipitation in mountain regions is often highly variable and poorly observed, limiting abilities to manage water resource challenges. Here, we evaluate remote sensing and ground station-based gridded precipitation products over Nepal against weather station precipitation observations on a monthly timescale. We find that the Tropical Rainfall Measuring Mission (TRMM 3B-43 precipitation product exhibits little mean bias and reasonable skill in giving precipitation over Nepal. Compared to station observations, the TRMM precipitation product showed an overall Nash-Sutcliffe efficiency of 0.49, which is similar to the skill of the gridded station-based product Asian Precipitation-Highly Resolved Observational Data Integration Towards Evaluation of Water Resources (APHRODITE. The other satellite precipitation products considered (Global Satellite Mapping of Precipitation (GSMaP, the Climate Prediction Center Morphing technique (CMORPH, Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS were less skillful, as judged by Nash-Sutcliffe efficiency, and, on average, substantially underestimated precipitation compared to station observations, despite their, in some cases, higher nominal spatial resolution compared to TRMM. None of the products fully captured the dependence of mean precipitation on elevation seen in the station observations. Overall, the TRMM product is promising for use in water resources applications.

  13. The FODA-TDMA satellite access scheme - Presentation, study of the system, and results

    Science.gov (United States)

    Celandroni, Nedo; Ferro, Erina

    1991-12-01

    A description is given of FODA-TDMA, a satellite access scheme designed for mixed traffic. The study of the system is presented and the choice of some parameters is justified. A simplified analytic solution is found, describing the steady-state behavior of the system. Some results of the simulation tests for an already existing hardware environment are also presented for the channel speeds of 2 and 8 Mb/s, considering both the stationary and the transient cases. The results of the experimentation at 2 Mb/s on the satellite Eutelsat-F2 are also presented and compared with the results of the simulation.

  14. Semi-analytical study of the rotational motion stability of artificial satellites using quaternions

    International Nuclear Information System (INIS)

    Dos Santos, Josué C; Zanardi, Maria Cecília; Matos, Nicholas

    2013-01-01

    This study at aims performing the stability analysis of the rotational motion to artificial satellites using quaternions to describe the satellite attitude (orientation on the space). In the system of rotational motion equations, which is composed by four kinematic equations of the quaternions and by the three Euler equations in terms of the rotational spin components. The influence of the gravity gradient and the direct solar radiation pressure torques have been considered. Equilibrium points were obtained through numerical simulations using the softwares Matlab and Octave, which are then analyzed by the Routh-Hurwitz Stability Criterion

  15. Study and modeling of the most energetic Active Galactic Nuclei with the Fermi satellite

    International Nuclear Information System (INIS)

    Sanchez, D.

    2010-06-01

    The Fermi satellite was launched in June 2008. The onboard LAT detector is dedicated to the study of galactic and extra-galactic gamma sources with an energy comprised between 200 MeV and 300 GeV. 1451 sources have been detected in less than 11 months. This document is divided into 6 chapters: 1) gamma astronomy, 2) the Fermi satellite, 3) the active galactic nuclei (NAG), 4) the observation of several blazars (PKS-2155-304 and PG-1553+113) and its simulation, 5) the observation of PKS-2155-304 with both RXTE and Fermi, and 6) conclusion

  16. Advanced mobile satellite communications system using Ka and MM-wave bands in Japan's R and D satellite project

    Science.gov (United States)

    Isobe, Shunkichi; Ohmori, Shingo; Hamamoto, Naokazu; Yamamoto, Minoru

    1991-01-01

    Communications Research Laboratory (CRL) studied an advanced mobile satellite communications system using Ka and millimeter-wave bands in the R&D Satellite project. The project started in 1990 and the satellite will be launched in 1997. On-board multi-beam interconnecting is one of basic functions to realize one-hop connection among Very Small Aperture Terminals (VSATs), mobile, and hand-held terminals in future mobile satellite communications system. An Intermediate Frequency (IF) filter bank and regenerative transponder are suitable for this function. The transponder configuration of an advanced mobile communications mission of the R&D Satellite for experiment is shown. High power transmitters of Ka and millimeter-wave bands, a 3x3 IF filter band and Single Channel Per Carrier/Time Division Multiplexing (SCPC/TDM) regenerative MODEMS, which will be boarded on the R&D Satellite, are being developed for the purpose of studying the feasibility of advanced mobile communications system.

  17. Highly Enhanced Risk Management Emergency Satellite

    DEFF Research Database (Denmark)

    Dalmeir, Michael; Gataullin, Yunir; Indrajit, Agung

    HERMES (Highly Enhanced Risk Management Emergency Satellite) is potential European satellite mission for global flood management, being implemented by Technical University Munich and European Space Agency. With its main instrument - a reliable and precise Synthetic Aperture Radar (SAR) antenna...

  18. Direct Imaging of Stellar Surfaces: Results from the Stellar Imager (SI) Vision Mission Study

    Science.gov (United States)

    Carpenter, Kenneth; Schrijver, Carolus; Karovska, Margarita

    2006-01-01

    The Stellar Imager (SI) is a UV-Optical, Space-Based Interferometer designed to enable 0.1 milli-arcsecond (mas) spectral imaging of stellar surfaces and stellar interiors (via asteroseismology) and of the Universe in general. SI is identified as a "Flagship and Landmark Discovery Mission'' in the 2005 Sun Solar System Connection (SSSC) Roadmap and as a candidate for a "Pathways to Life Observatory'' in the Exploration of the Universe Division (EUD) Roadmap (May, 2005). The ultra-sharp images of the Stellar Imager will revolutionize our view of many dynamic astrophysical processes: The 0.1 mas resolution of this deep-space telescope will transform point sources into extended sources, and snapshots into evolving views. SI's science focuses on the role of magnetism in the Universe, particularly on magnetic activity on the surfaces of stars like the Sun. SI's prime goal is to enable long-term forecasting of solar activity and the space weather that it drives in support of the Living With a Star program in the Exploration Era. SI will also revolutionize our understanding of the formation of planetary systems, of the habitability and climatology of distant planets, and of many magneto-hydrodynamically controlled processes in the Universe. In this paper we will discuss the results of the SI Vision Mission Study, elaborating on the science goals of the SI Mission and a mission architecture that could meet those goals.

  19. High spectral resolution studies of gamma ray bursts on new missions

    International Nuclear Information System (INIS)

    Desai, U. D.; Acuna, M. H.; Cline, T. L.; Dennis, B. R.; Orwig, L. E.; Trombka, J. I.; Starr, R. D.

    1996-01-01

    Two new missions will be launched in 1996 and 1997, each carrying X-ray and gamma ray detectors capable of high spectral resolution at room temperature. The Argentine Satelite de Aplicaciones Cientificas (SAC-B) and the Small Spacecraft Technology Initiative (SSTI) Clark missions will each carry several arrays of X-ray detectors primarily intended for the study of solar flares and gamma-ray bursts. Arrays of small (1 cm 2 ) cadmium zinc telluride (CZT) units will provide x-ray measurements in the 10 to 80 keV range with an energy resolution of ≅6 keV. Arrays of both silicon avalanche photodiodes (APD) and P-intrinsic-N (PIN) photodiodes (for the SAC-B mission only) will provide energy coverage from 2-25 keV with ≅1 keV resolution. For SAC-B, higher energy spectral data covering the 30-300 keV energy range will be provided by CsI(Tl) scintillators coupled to silicon APDs, resulting in similar resolution but greater simplicity relative to conventional CsI/PMT systems. Because of problems with the Pegasus launch vehicle, the launch of SAC-B has been delayed until 1997. The launch of the SSTI Clark mission is scheduled for June 1996

  20. Beacon satellite studies and modelling of total electron contents of the ionosphere

    International Nuclear Information System (INIS)

    Tyagi, T.R.

    1990-01-01

    An attempt is made to highlight some of the beacon satellite studies, particularly those relating to total electron content (TEC) and scintillations, with special attention to Indian subcontinent observations. The modelling of TEC is described. The scope of new experiments for specific problem is indicated. (author). 78 refs., 12 figs

  1. Solar power satellite system definition study. Volume 7, phase 1: SPS and rectenna systems analyses

    Science.gov (United States)

    1979-01-01

    A systems definition study of the solar power satellite systems is presented. The design and power distribution of the rectenna system is discussed. The communication subsystem and thermal control characteristics are described and a failure analysis performed on the systems is reported.

  2. Analysis of high resolution satellite digital data for land use studies ...

    African Journals Online (AJOL)

    High-resolution satellite data can give vital information about land cover, which can lead to better interpretation and classification of land resources. This study examined the relationship between Systeme Probatoire d'Observation de la Terre (SPOT) digital data and land use types in the derived savanna ecosystem of ...

  3. The Swarm End-to-End mission simulator study: A demonstration of separating the various contributions to Earth's magnetic field using synthetic data

    DEFF Research Database (Denmark)

    Olsen, Nils; Haagmans, R.; Sabaka, T.J.

    2006-01-01

    Swarm, a satellite constellation to measure Earth's magnetic field with unpreceded accuracy, has been selected by ESA for launch in 2009. The mission will provide the best ever survey of the geomagnetic field and its temporal evolution, in order to gain new insights into the Earth system...... to the science objectives of Swarm. In order to be able to use realistic parameters of the Earth's environment, the mission simulation starts at January 1, 1997 and lasts until re-entry of the lower satellites five years later. Synthetic magnetic field values were generated for all relevant contributions...

  4. A Mission Concept to Study Multigenerational Mammalian Reproduction in Partial Gravity

    Science.gov (United States)

    Rodgers, Erica M.; Simon, Matthew A.; Chai, Patrick R.; Neilan, James H.; Stillwagen, Fred H.; Williams, Phillip A.; Lewis, Weston

    2016-01-01

    A team at NASA Langley Research Center conducted a study during which a conceptual space mission was designed. In this study, rodents are used as human analogs to gather biological and systems data in a relevant environment applicable to future settlements on Mars. The mission concept uniquely addresses the combined effects of long-durations (one-year or greater), autonomous and robotic operations, and biological responses to partial gravity with an emphasis on reproduction. The objectives of this study were to 1) understand challenges associated with designing an artificial gravity habitat that supports the reproduction and maturation of a large animal colony, 2) identify mission architectures and operational concepts to transport and maintain such a facility, and 3) identify fundamental science considerations for mammalian reproduction studies to inform vehicle design. A model demonstration unit was developed to visualize and test certain design concepts that resulted from these considerations. Three versions of this demonstration unit were built over the course of the study, each taking into account lessons learned from the previous version. This paper presents the updated baseline mission and spacecraft design concepts to achieve these objectives, with a specific emphasis on updates since publication in previous works. Analyses of the integrated system trades among the elements which make up the conceptual vehicle are described to address overall feasibility and identify potential integrated design opportunities. The latest iteration of the habitat robotics design and a conceptual design example for autonomous care of crew and systems are also presented. Finally, the conclusion of this conceptual design study, necessary future analyses to enable such a facility, and comments upon other applications of a similar exploration-focused research facilities are addressed.

  5. Global Food Security Index Studies and Satellite Information

    Science.gov (United States)

    Medina, T. A.; Ganti-Agrawal, S.; Joshi, D.; Lakhankar, T.

    2017-12-01

    Food yield is equal to the total crop harvest per unit cultivated area. During the elapsed time of germination and frequent harvesting, both human and climate related effects determine a country's' contribution towards global food security. Each country across the globe's annual income per capita was collected to then determine nine countries for further studies. For a location to be chosen, its income per capita needed to be considered poor, uprising or wealthy. Both physical land cover and regional climate helped categorize potential parameters thought to be studied. Once selected, Normalized Difference Vegetation Index (NDVI) data was collected for Ethiopia, Liberia, Indonesia, United States, Norway, Russia, Kuwait and Saudi Arabia over the recent 16 years for approximately every 16 days starting from early in the year 2000. Software languages such as Geographic Information System (GIS), MatLab and Excel were used to determine how population size, income and deforestation directly determines agricultural yields. Because of high maintenance requirements for large harvests when forest areas are cleared, they often have a reduction in soil quality, requiring fertilizer use to produce sufficient crop yields. Total area and vegetation index of each country is to be studied, to determine crop and deforestation percentages. To determine how deforestation impacts future income and crop yield predictions of each country studied. By using NDVI results a parameter is to be potentially found that will help define an index, to create an equation that will determine a country's annual income and ability to provide for their families and themselves.

  6. Female leaders in an international evangelical mission organisation: an empirical study of Youth With A Mission in Germany

    Directory of Open Access Journals (Sweden)

    F.A.S. Hornstra-Fuchs

    2010-07-01

    Full Text Available Evangelicals are frequently perceived as conservative, for instance in their perspective on women. There is indeed a widespread evangelical hierarchical or complementarian theological view which objects to women in church leadership. There is, however, a growing egalitarian counter position, sometimes also referred to as “evangelical feminism”, which supports female leadership. This article concentrates on the international missionary organisation Youth With A Mission (YWAM, which clearly endorses female leaders in formal statements. In YWAM Germany, however, women are under-represented in leadership positions. The article seeks to explain this under-representation, especially in terms of the role played by Scripture. By means of interviews with leaders in YWAM Germany, possible answers were explored. Surprisingly, for an evangelical organisation, the interpretation of Scripture proved not to be a significant factor. Factors that do play a role are church background, the lack of female role models, lower self-confidence of women, family responsibilities, and the role of incumbent leadership. The latter appears to be the most crucial factor, since the incumbent leaders, who mostly are men, select and appoint new leaders. It is likely that in this they are influenced by stereotypical conceptions of the leader as male and are inclined to appoint leaders similar to themselves.

  7. Phased mission analysis of maintained systems: a study in reliability risk analysis

    International Nuclear Information System (INIS)

    Terpstra, K.

    1984-01-01

    The present study develops a general theory that treats the probability of occurrence of each branch of an event tree and that takes correctly into account the dependencies between systems; incorporates within the general theory the solution of the problem of phased mission analysis. It also includes the general model components, that may or may not be repairable, with general lifetime and repairtime distribution, i.e. in the model repairable systems should be taken into account. Finally a computer program is developed that is based on this general theory, i.e. a computer program that is able to perform fully the probabilistic calculations of a risk analysis and that can handle in a correct way phased mission analysis of repairable systems. The theory is applied to a boiling water reactor accident. (Auth.)

  8. An Object Model for Integrating Diverse Remote Sensing Satellite Sensors: A Case Study of Union Operation

    Directory of Open Access Journals (Sweden)

    Chuli Hu

    2014-01-01

    Full Text Available In the Earth Observation sensor web environment, the rapid, accurate, and unified discovery of diverse remote sensing satellite sensors, and their association to yield an integrated solution for a comprehensive response to specific emergency tasks pose considerable challenges. In this study, we propose a remote sensing satellite sensor object model, based on the object-oriented paradigm and the Open Geospatial Consortium Sensor Model Language. The proposed model comprises a set of sensor resource objects. Each object consists of identification, state of resource attribute, and resource method. We implement the proposed attribute state description by applying it to different remote sensors. A real application, involving the observation of floods at the Yangtze River in China, is undertaken. Results indicate that the sensor inquirer can accurately discover qualified satellite sensors in an accurate and unified manner. By implementing the proposed union operation among the retrieved sensors, the inquirer can further determine how the selected sensors can collaboratively complete a specific observation requirement. Therefore, the proposed model provides a reliable foundation for sharing and integrating multiple remote sensing satellite sensors and their observations.

  9. Improved Satellite-based Photosysnthetically Active Radiation (PAR) for Air Quality Studies

    Science.gov (United States)

    Pour Biazar, A.; McNider, R. T.; Cohan, D. S.; White, A.; Zhang, R.; Dornblaser, B.; Doty, K.; Wu, Y.; Estes, M. J.

    2015-12-01

    One of the challenges in understanding the air quality over forested regions has been the uncertainties in estimating the biogenic hydrocarbon emissions. Biogenic volatile organic compounds, BVOCs, play a critical role in atmospheric chemistry, particularly in ozone and particulate matter (PM) formation. In southeastern United States, BVOCs (mostly as isoprene) are the dominant summertime source of reactive hydrocarbon. Despite significant efforts in improving BVOC estimates, the errors in emission inventories remain a concern. Since BVOC emissions are particularly sensitive to the available photosynthetically active radiation (PAR), model errors in PAR result in large errors in emission estimates. Thus, utilization of satellite observations to estimate PAR can help in reducing emission uncertainties. Satellite-based PAR estimates rely on the technique used to derive insolation from satellite visible brightness measurements. In this study we evaluate several insolation products against surface pyranometer observations and offer a bias correction to generate a more accurate PAR product. The improved PAR product is then used in biogenic emission estimates. The improved biogenic emission estimates are compared to the emission inventories over Texas and used in air quality simulation over the period of August-September 2013 (NASA's Discover-AQ field campaign). A series of sensitivity simulations will be performed and evaluated against Discover-AQ observations to test the impact of satellite-derived PAR on air quality simulations.

  10. Study of the Nevada Test Site using Landsat satellite imagery

    International Nuclear Information System (INIS)

    Zimmerman, P.D.

    1993-07-01

    In the period covered by the purchase order CSIS has obtained one Landsat image and determined that two images previously supplied to the principal investigator under a subcontract with George Washington University were inherently defective. We have negotiated with EOSAT over the reprocessing of those scenes and anticipate final delivery within the next few weeks. A critical early purchase during the subcontract period was of an EXABYTE tape drive, Adaptec SCSI interface, and the appropriate software with which to read Landsat images at CSIS. This gives us the capability of reading and manipulating imagery in house without reliance on outside services which have not proven satisfactory. In addition to obtaining imagery for the study, we have also performed considerable analytic work on the newly and previously purchased images. A technique developed under an earlier subcontract for identifying underground nuclear tests at Pahute Mesa has been significantly refined, and similar techniques were applied to the summit of Rainier Mesa and to the Yucca Flats area. An entirely new technique for enhancing the spectral signatures of different regions of NTS was recently developed, and appears to have great promise of success

  11. Research from the NASA Twins Study and Omics in Support of Mars Missions

    Science.gov (United States)

    Kundrot, C.; Shelhamer, M.; Scott, G.

    2015-01-01

    The NASA Twins Study, NASA's first foray into integrated omic studies in humans, illustrates how an integrated omics approach can be brought to bear on the challenges to human health and performance on a Mars mission. The NASA Twins Study involves US Astronaut Scott Kelly and his identical twin brother, Mark Kelly, a retired US Astronaut. No other opportunity to study a twin pair for a prolonged period with one subject in space and one on the ground is available for the foreseeable future. A team of 10 principal investigators are conducting the Twins Study, examining a very broad range of biological functions including the genome, epigenome, transcriptome, proteome, metabolome, gut microbiome, immunological response to vaccinations, indicators of atherosclerosis, physiological fluid shifts, and cognition. A novel aspect of the study is the integrated study of molecular, physiological, cognitive, and microbiological properties. Major sample and data collection from both subjects for this study began approximately six months before Scott Kelly's one year mission on the ISS, continue while Scott Kelly is in flight and will conclude approximately six months after his return to Earth. Mark Kelly will remain on Earth during this study, in a lifestyle unconstrained by this study, thereby providing a measure of normal variation in the properties being studied. An overview of initial results and the future plans will be described as well as the technological and ethical issues raised for spaceflight studies involving omics.

  12. Resumes of the Bird mission

    Science.gov (United States)

    Lorenz, E.; Borwald, W.; Briess, K.; Kayal, H.; Schneller, M.; Wuensten, Herbert

    2004-11-01

    The DLR micro satellite BIRD (Bi-spectral Infra Red Detection) was piggy- back launched with the Indian Polar Satellite Launch Vehicle PSLV-C3 into a 570 km circular sun-synchronous orbit on 22 October 2001. The BIRD mission, fully funded by the DLR, answers topical technological and scientific questions related to the operation of a compact infra- red push-broom sensor system on board of a micro satellite and demonstrates new spacecraft bus technologies. BIRD mission control is conducted by DLR / GSOC in Oberpfaffenhofen. Commanding, data reception and data processing is performed via ground stations in Weilheim and Neustrelitz (Germany). The BIRD mission is a demonstrator for small satellite projects dedicated to the hazard detection and monitoring. In the year 2003 BIRD has been used in the ESA project FUEGOSAT to demonstrate the utilisation of innovative space technologies for fire risk management.

  13. Evolving earth-based and in-situ satellite network architectures for Mars communications and navigation support

    Science.gov (United States)

    Hastrup, Rolf; Weinberg, Aaron; McOmber, Robert

    1991-09-01

    Results of on-going studies to develop navigation/telecommunications network concepts to support future robotic and human missions to Mars are presented. The performance and connectivity improvements provided by the relay network will permit use of simpler, lower performance, and less costly telecom subsystems for the in-situ mission exploration elements. Orbiting relay satellites can serve as effective navigation aids by supporting earth-based tracking as well as providing Mars-centered radiometric data for mission elements approaching, in orbit, or on the surface of Mars. The relay satellite orbits may be selected to optimize navigation aid support and communication coverage for specific mission sets.

  14. Cognitive demand of human sensorimotor performance during an extended space mission: a dual-task study.

    Science.gov (United States)

    Bock, Otmar; Weigelt, Cornelia; Bloomberg, Jacob J

    2010-09-01

    Two previous single-case studies found that the dual-task costs of manual tracking plus memory search increased during a space mission, and concluded that sensorimotor deficits during spaceflight may be related to cognitive overload. Since dual-task costs were insensitive to the difficulty of memory search, the authors argued that the overload may reflect stress-related problems of multitasking, rather than a scarcity of specific cognitive resources. Here we expand the available database and compare different types of concurrent task. Three subjects were repeatedly tested before, during, and after an extended mission on the International Space Station (ISS). They performed an unstable tracking task and four reaction-time tasks, both separately and concurrently. Inflight data could only be obtained during later parts of the mission. The tracking error increased from pre- to in flight by a factor of about 2, both under single- and dual-task conditions. The dual-task costs with a reaction-time task requiring rhythm production was 2.4 times higher than with a reaction-time task requiring visuo-spatial transformations, and 8 times higher than with a regular choice reaction-time task. Long-term sensorimotor deficits during spaceflight may reflect not only stress, but also a scarcity of resources related to complex motor programming; possibly those resources are tied up by sensorimotor adaptation to the space environment.

  15. MISSION-ORIENTED SENSOR ARRAYS AND UAVs – A CASE STUDY ON ENVIRONMENTAL MONITORING

    Directory of Open Access Journals (Sweden)

    N. M. Figueira

    2015-08-01

    Full Text Available This paper presents a new concept of UAV mission design in geomatics, applied to the generation of thematic maps for a multitude of civilian and military applications. We discuss the architecture of Mission-Oriented Sensors Arrays (MOSA, proposed in Figueira et Al. (2013, aimed at splitting and decoupling the mission-oriented part of the system (non safety-critical hardware and software from the aircraft control systems (safety-critical. As a case study, we present an environmental monitoring application for the automatic generation of thematic maps to track gunshot activity in conservation areas. The MOSA modeled for this application integrates information from a thermal camera and an on-the-ground microphone array. The use of microphone arrays technology is of particular interest in this paper. These arrays allow estimation of the direction-of-arrival (DOA of the incoming sound waves. Information about events of interest is obtained by the fusion of the data provided by the microphone array, captured by the UAV, fused with information from the termal image processing. Preliminary results show the feasibility of the on-the-ground sound processing array and the simulation of the main processing module, to be embedded into an UAV in a future work. The main contributions of this paper are the proposed MOSA system, including concepts, models and architecture.

  16. A Venus/Saturn Mission Study: 45deg Sphere-Cone Rigid Aeroshells and Ballistic Entries

    Science.gov (United States)

    Prabhu, Dinesh K.; Allen, Gary A.; Cappuccio, Gelsomina

    2012-01-01

    The present study considers ballistic entries into the atmospheres of Saturn and Venus using a 45deg sphere-cone rigid aeroshell (a legacy shape that has been successfully used in the Pioneer Venus and Galileo missions). For a number of entry mass and diameter combinations (i.e., various entries ballistic coefficients), entry velocities, and heading angles, the trajectory space in terms of entry flight path angles between skip out and -30deg is explored with a 3DOF trajectory code, TRAJ. Assuming that the thermal protection material of choice is carbon phenolic of flight heritage, the entry flight path angle space is constrained a posteriori by the mechanical and thermal performance parameters of the material. For mechanical performance, a 200 g limit is place on the peak deceleration load and 10 bar is assumed as the spallation pressure threshold for the legacy material. It is shown that both constraints cannot be active simultaneously. For thermal performance, a minimum margined heat flux threshold of 2.5 kW/sq cm is assumed for the heritage material. Using these constraints, viable entry flight path angle corridors are determined. Analysis of the results also hints at the existence of a "critical" ballistic coefficient beyond which the steepest possible entries are determined by the spallation pressure threshold. The results are verified against known performance of the various probes used in the Galileo and Pioneer Venus missions. It is hoped that the results presented here will serve as a baseline in the development of a new class of ablative materials for Venus and Saturn missions being considered in a future New Frontiers class of NASA missions.

  17. Towards Automatic Classification of Exoplanet-Transit-Like Signals: A Case Study on Kepler Mission Data

    Science.gov (United States)

    Valizadegan, Hamed; Martin, Rodney; McCauliff, Sean D.; Jenkins, Jon Michael; Catanzarite, Joseph; Oza, Nikunj C.

    2015-08-01

    Building new catalogues of planetary candidates, astrophysical false alarms, and non-transiting phenomena is a challenging task that currently requires a reviewing team of astrophysicists and astronomers. These scientists need to examine more than 100 diagnostic metrics and associated graphics for each candidate exoplanet-transit-like signal to classify it into one of the three classes. Considering that the NASA Explorer Program's TESS mission and ESA's PLATO mission survey even a larger area of space, the classification of their transit-like signals is more time-consuming for human agents and a bottleneck to successfully construct the new catalogues in a timely manner. This encourages building automatic classification tools that can quickly and reliably classify the new signal data from these missions. The standard tool for building automatic classification systems is the supervised machine learning that requires a large set of highly accurate labeled examples in order to build an effective classifier. This requirement cannot be easily met for classifying transit-like signals because not only are existing labeled signals very limited, but also the current labels may not be reliable (because the labeling process is a subjective task). Our experiments with using different supervised classifiers to categorize transit-like signals verifies that the labeled signals are not rich enough to provide the classifier with enough power to generalize well beyond the observed cases (e.g. to unseen or test signals). That motivated us to utilize a new category of learning techniques, so-called semi-supervised learning, that combines the label information from the costly labeled signals, and distribution information from the cheaply available unlabeled signals in order to construct more effective classifiers. Our study on the Kepler Mission data shows that semi-supervised learning can significantly improve the result of multiple base classifiers (e.g. Support Vector Machines, Ada

  18. NASA Satellite Observations: A Unique Asset for the Study of the Environment and Implications for Public Health

    Science.gov (United States)

    Estes Sue M.

    2010-01-01

    This slide presentation highlights how satellite observation systems are assets for studying the environment in relation to public health. It includes information on current and future satellite observation systems, NASA's public health and safety research, surveillance projects, and NASA's public health partners.

  19. Asteroid Redirect Crewed Mission Space Suit and EVA System Architecture Trade Study

    Science.gov (United States)

    Blanco, Raul A.; Bowie, Jonathan T.; Watson, Richard D.; Sipila, Stephanie A.

    2014-01-01

    The Asteroid Redirect Crewed Mission (ARCM) requires a Launch/Entry/Abort (LEA) suit capability and short duration Extra Vehicular Activity (EVA) capability for Orion. The EVAs will involve a two-person crew for approximately four hours. Currently, two EVAs are planned with one contingency EVA in reserve. Providing this EVA capability is very challenging due to system level constraints and a new and unknown environment. The goal of the EVA architecture for ARCM is one that builds upon previously developed technologies and lessons learned, and that accomplishes the ARCM mission while providing a stepping stone to future missions and destinations. The primary system level constraints are to 1) minimize system mass and volume and 2) minimize the interfacing impacts to the baseline Orion design. In order to minimize the interfacing impacts and to not perturb the baseline Orion schedule, the concept of adding "kits" to the baseline system is proposed. These kits consist of: an EVA kit (converts LEA suit to EVA suit), EVA Servicing and Recharge Kit (provides suit consumables), the EVA Tools, Translation Aids & Sample Container Kit (the tools and mobility aids to complete the tasks), the EVA Communications Kit (interface between the EVA radio and the MPCV), and the Cabin Repress Kit (represses the MPCV between EVAs). This paper will focus on the trade space, analysis, and testing regarding the space suit (pressure garment and life support system). Historical approaches and lessons learned from all past EVA operations were researched. Previous and current, successfully operated EVA hardware and high technology readiness level (TRL) hardware were evaluated, and a trade study was conducted for all possible pressure garment and life support options. Testing and analysis was conducted and a recommended EVA system architecture was proposed. Pressure garment options that were considered for this mission include the currently in-use ISS EVA Mobility Unit (EMU), all variations of

  20. Chemical and Biological Substances Decontamination Study for Mars Missions and Terrestrial Applications

    Science.gov (United States)

    Pottage, Thomas; Walker, James; Bennett, Allan; Vrublevskis, John; Hovland, Scott

    This study, funded by the European Space Agency (ESA) and undertaken by the Health Protec-tion Agency, UK supported by Systems Engineering and Assessment Ltd., was devised to select suitable current decontamination technologies for development for future manned missions to the Moon and Mars. There is a requirement to decontaminate the habitat module due to the concerns about astronaut ill health, microbial deterioration of materials and potential forward contamination in the case of Mars. In the case of the MIR space station, biodeterioration of components and materials occurred, and dangerous levels of airborne microorganisms were detected during air sampling procedures which lead to the introduction of microbial exposure limits (as MORD SSP 50260) to ensure the health of the crew. COSPAR planetary protection guidelines highlight the need to reduce any potential forward or backwards contamination issues that may occur through the use of Extra Vehicular Activity (EVA) suits whilst on Mars. Decontamination of the suit exterior must be completed before any EVA activity on Mars, whilst a further decontamination cycle must be completed after entry to the airlock following EVA. Technologies and techniques have also been investigated for the microbial reduction of the interior surfaces of the EVA suit to stop biodeterioration of the materials and protect the user from pathogenic microbe accumulation. The first work package reviewed the systems description and requirements as detailed in the statement of work. The requirements were broken down into 12 further requirement sections, where they were updated and expanded, resulted in Technical Note (TN) 1 which was then used as the base document for WP2 and WP3. WP2 investigated the current technologies available for the decontamination of the habitat module interior on missions of up to 6 months and missions that have durations of greater than 6 months. A comprehensive review was carried out for the different methods that

  1. A satellite born charged particles telescope for the study of cosmic ray nuclei

    Energy Technology Data Exchange (ETDEWEB)

    De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy)]|[INFN, Rome (Italy); Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy); Bellotti, R.; Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy)

    1995-09-01

    The description of the high energy particle telescope NINA for the study of cosmic ray nuclei is presented. The instrument will be installed on board of the Resource 01 satellite and will fly on a polar orbit at 690 Km. The telescope consists on a pile of 16 detecting planes each of them is composed by two silicon strip detectors with perpendicular strips and has a total area of 60x60mm{sup 2}. The experiment goals are the study of cosmic ray protons and nuclei in the energy range 12-100 MeV/amu. It will be sensitive to the anomalous component and will also make the observation of the large solar flare events and geophysical phenomena as well. This experiment is the first step of the program RIM whose goal is the satellite study of anti particles in primary cosmic rays.

  2. User requirements and user acceptance of current and next-generation satellite mission and sensor complement, oriented toward the monitoring of water resources

    Science.gov (United States)

    Castruccio, P. A.; Loats, H. L., Jr.; Fowler, T. R.; Robinson, P.

    1975-01-01

    Principal water resources users were surveyed to determine the applicability of remotely sensed data to their present and future requirements. Analysis of responses was used to assess the levels of adequacy of LANDSAT 1 and 2 in fulfilling hydrological functions, and to derive systems specifications for future water resources-oriented remote sensing satellite systems. The analysis indicates that water resources applications for all but the very large users require: (1) resolutions on the order of 15 meters, (2) a number of radiometric levels of the same order as currently used in LANDSAT 1 (64), (3) a number of spectral bands not in excess of those used in LANDSAT 1, and (4) a repetition frequency on the order of 2 weeks. The users had little feel for the value of new sensors (thermal IR, passive and active microwaves). What is needed in this area is to achieve specific demonstrations of the utility of these sensors and submit the results to the users to evince their judgement.

  3. PFERD Mission: Pluto Flyby Exploration/Research Design

    Science.gov (United States)

    Lemke, Gary; Zayed, Husni; Herring, Jason; Fuehne, Doug; Sutton, Kevin; Sharkey, Mike

    1990-01-01

    The Pluto Flyby Exploration/Research Design (PFERD) mission will consist of a flyby spacecraft to Pluto and its satellite, Charon. The mission lifetime is expected to be 18 years. The Titan 4 with a Centaur upper stage will be utilized to launch the craft into the transfer orbit. The proposal was divided into six main subsystems: (1) scientific instrumentation; (2) command, communications, and control: (3) altitude and articulation control; (4) power and propulsion; (5) structures and thermal control; and (6) mission management and costing. Tradeoff studies were performed to optimize all factors of design, including survivability, performance, cost, and weight. Problems encountered in the design are also presented.

  4. Solar power satellite rectenna design study: Directional receiving elements and parallel-series combining analysis

    Science.gov (United States)

    Gutmann, R. J.; Borrego, J. M.

    1978-01-01

    Rectenna conversion efficiencies (RF to dc) approximating 85 percent were demonstrated on a small scale, clearly indicating the feasibility and potential of efficiency of microwave power to dc. The overall cost estimates of the solar power satellite indicate that the baseline rectenna subsystem will be between 25 to 40 percent of the system cost. The directional receiving elements and element extensions were studied, along with power combining evaluation and evaluation extensions.

  5. Assimilating satellite soil moisture into rainfall-runoff modelling: towards a systematic study

    Science.gov (United States)

    Massari, Christian; Tarpanelli, Angelica; Brocca, Luca; Moramarco, Tommaso

    2015-04-01

    Soil moisture is the main factor for the repartition of the mass and energy fluxes between the land surface and the atmosphere thus playing a fundamental role in the hydrological cycle. Indeed, soil moisture represents the initial condition of rainfall-runoff modelling that determines the flood response of a catchment. Different initial soil moisture conditions can discriminate between catastrophic and minor effects of a given rainfall event. Therefore, improving the estimation of initial soil moisture conditions will reduce uncertainties in early warning flood forecasting models addressing the mitigation of flood hazard. In recent years, satellite soil moisture products have become available with fine spatial-temporal resolution and a good accuracy. Therefore, a number of studies have been published in which the impact of the assimilation of satellite soil moisture data into rainfall-runoff modelling is investigated. Unfortunately, data assimilation involves a series of assumptions and choices that significantly affect the final result. Given a satellite soil moisture observation, a rainfall-runoff model and a data assimilation technique, an improvement or a deterioration of discharge predictions can be obtained depending on the choices made in the data assimilation procedure. Consequently, large discrepancies have been obtained in the studies published so far likely due to the differences in the implementation of the data assimilation technique. On this basis, a comprehensive and robust procedure for the assimilation of satellite soil moisture data into rainfall-runoff modelling is developed here and applied to six subcatchment of the Upper Tiber River Basin for which high-quality hydrometeorological hourly observations are available in the period 1989-2013. The satellite soil moisture product used in this study is obtained from the Advanced SCATterometer (ASCAT) onboard Metop-A satellite and it is available since 2007. The MISDc ("Modello Idrologico Semi

  6. The concentration principle applied to spaceborne solar arrays. AGORA mission: Studies synthesis

    Science.gov (United States)

    Laget, R.

    1986-01-01

    Studies that led to selection of the distributed 25 kW SARA LOUVRE concept for the solar cell generator to be flown on the AGORA asteroid mission, and the major characteristics of such a spaceborne solar array are summarized. In the SARA LOUVRE concept, a parabolic cross section reflector concentrates incident light over the rear face of the identical, preceding reflector dish. The whole set of reflectors is pivotally commanded, thus compensating the effects of depointing. Geometric concentration factor is 10. End of life power level at 2.5 AU is 4.5 kW.

  7. Solar Electric Propulsion (SEP) Systems for SMD Mission Needs. Technology Infusion Study.

    Science.gov (United States)

    Anderson, David

    2014-01-01

    Two presentations for SBAG and OPAG meetings: 1) Solar Electric Propulsion Systems for SMD Missions, and 2) Technology Infusion Study - Draft Findings Recommendation Small Bodies Assessment Group (SBAG) meeting is January 9th in Washington D.C., and the Outer Planets Assessment Group (OPAG) meeting is January 23-14 in Tucson, AZ. NASA sponsors these assessment groups, through the NRC, for the science community to assess and provide advice. These talks are to provide a status of 2 NASA activities, and to seek feedback from the respective science communities.

  8. Satellite-Enhanced Regional Downscaling for Applied Studies: Extreme Precipitation Events in Southeastern South America

    Science.gov (United States)

    Nunes, A.; Gomes, G.; Ivanov, V. Y.

    2016-12-01

    Frequently found in southeastern South America during the warm season from October through May, strong and localized precipitation maxima are usually associated with the presence of mesoscale convective complexes (MCCs) travelling across the region. Flashfloods and landslides can be caused by these extremes in precipitation, with damages to the local communities. Heavily populated, southeastern South America hosts many agricultural activities and hydroelectric production. It encompasses one of the most important river basins in South America, the La Plata River Basin. Therefore, insufficient precipitation is equally prejudicial to the region socio-economic activities. MCCs are originated in the warm season of many regions of the world, however South American MCCs are related to the most severe thunderstorms, and have significantly contributed to the precipitation regime. We used the hourly outputs of Satellite-enhanced Regional Downscaling for Applied Studies (SRDAS), developed at the Federal University of Rio de Janeiro in Brazil, in the analysis of the dynamics and physical characteristics of MCCs in South America. SRDAS is the 25-km resolution downscaling of a global reanalysis available from January 1998 through December 2010. The Regional Spectral Model is the SRDAS atmospheric component and assimilates satellite-based precipitation estimates from the NOAA/Climate Prediction Center MORPHing technique global precipitation analyses. In this study, the SRDAS atmospheric and land-surface variables, global reanalysis products, infrared satellite imagery, and the physical retrievals from the Atmospheric Infrared Sounder (AIRS), on board of the NASA's Aqua satellite, were used in the evaluation of the MCCs developed in southeastern South America from 2008 and 2010. Low-level circulations and vertical profiles were analyzed together to establish the relevance of the moisture transport in connection with the upper-troposphere dynamics to the development of those MCCs.

  9. Cyber security with radio frequency interferences mitigation study for satellite systems

    Science.gov (United States)

    Wang, Gang; Wei, Sixiao; Chen, Genshe; Tian, Xin; Shen, Dan; Pham, Khanh; Nguyen, Tien M.; Blasch, Erik

    2016-05-01

    Satellite systems including the Global Navigation Satellite System (GNSS) and the satellite communications (SATCOM) system provide great convenience and utility to human life including emergency response, wide area efficient communications, and effective transportation. Elements of satellite systems incorporate technologies such as navigation with the global positioning system (GPS), satellite digital video broadcasting, and information transmission with a very small aperture terminal (VSAT), etc. The satellite systems importance is growing in prominence with end users' requirement for globally high data rate transmissions; the cost reduction of launching satellites; development of smaller sized satellites including cubesat, nanosat, picosat, and femtosat; and integrating internet services with satellite networks. However, with the promising benefits, challenges remain to fully develop secure and robust satellite systems with pervasive computing and communications. In this paper, we investigate both cyber security and radio frequency (RF) interferences mitigation for satellite systems, and demonstrate that they are not isolated. The action space for both cyber security and RF interferences are firstly summarized for satellite systems, based on which the mitigation schemes for both cyber security and RF interferences are given. A multi-layered satellite systems structure is provided with cross-layer design considering multi-path routing and channel coding, to provide great security and diversity gains for secure and robust satellite systems.

  10. Pentecostal mission spirituality: a study of the classical Pentecostal Churches in Ghana

    Directory of Open Access Journals (Sweden)

    White, Peter

    2016-03-01

    Full Text Available Mission is not just about proclaiming the gospel - it encompasses spiritual preparation of those involved in both mission activity and in converted souls. This approach is what is termed as mission spirituality in this article. Mission spirituality is the means by which churches and individual believers participate in the mission of God, through the way they live in and by the Holy Spirit, in order to know the will of God regarding what He is doing in their context and to follow His example. In view of the importance of mission spirituality in missionary activities of the church, this article explores the mission spirituality of the classical Pentecostal churches in Ghana (The church of Pentecost, Christ Apostolic Church International, The Apostolic Church Ghana and the Assemblies of God.

  11. Evaluating a satellite-based seasonal evapotranspiration product and identifying its relationship with other satellite-derived products and crop yield: A case study for Ethiopia

    Science.gov (United States)

    Tadesse, Tsegaye; Senay, Gabriel B.; Berhan, Getachew; Regassa, Teshome; Beyene, Shimelis

    2015-08-01

    Satellite-derived evapotranspiration anomalies and normalized difference vegetation index (NDVI) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data are currently used for African agricultural drought monitoring and food security status assessment. In this study, a process to evaluate satellite-derived evapotranspiration (ETa) products with a geospatial statistical exploratory technique that uses NDVI, satellite-derived rainfall estimate (RFE), and crop yield data has been developed. The main goal of this study was to evaluate the ETa using the NDVI and RFE, and identify a relationship between the ETa and Ethiopia's cereal crop (i.e., teff, sorghum, corn/maize, barley, and wheat) yields during the main rainy season. Since crop production is one of the main factors affecting food security, the evaluation of remote sensing-based seasonal ETa was done to identify the appropriateness of this tool as a proxy for monitoring vegetation condition in drought vulnerable and food insecure areas to support decision makers. The results of this study showed that the comparison between seasonal ETa and RFE produced strong correlation (R2 > 0.99) for all 41 crop growing zones in Ethiopia. The results of the spatial regression analyses of seasonal ETa and NDVI using Ordinary Least Squares and Geographically Weighted Regression showed relatively weak yearly spatial relationships (R2 products have a good predictive potential for these 31 identified zones in Ethiopia. Decision makers may potentially use ETa products for monitoring cereal crop yields and early warning of food insecurity during drought years for these identified zones.

  12. Particulate matter concentration mapping from MODIS satellite data: a Vietnamese case study

    International Nuclear Information System (INIS)

    Nguyen, Thanh T N; Bui, Hung Q; Pham, Ha V; Luu, Hung V; Man, Chuc D; Pham, Hai N; Le, Ha T; Nguyen, Thuy T

    2015-01-01

    Particulate Matter (PM) pollution is one of the most important air quality concerns in Vietnam. In this study, we integrate ground-based measurements, meteorological and satellite data to map temporal PM concentrations at a 10 × 10 km grid for the entire of Vietnam. We specifically used MODIS Aqua and Terra data and developed statistically-significant regression models to map and extend the ground-based PM concentrations. We validated our models over diverse geographic provinces i.e., North East, Red River Delta, North Central Coast and South Central Coast in Vietnam. Validation suggested good results for satellite-derived PM 2.5 data compared to ground-based PM 2.5 (n = 285, r 2  = 0.411, RMSE = 20.299 μg m −3 and RE = 39.789%). Further, validation of satellite-derived PM 2.5 on two independent datasets for North East and South Central Coast suggested similar results (n = 40, r 2  = 0.455, RMSE = 21.512 μg m −3 , RE = 45.236% and n = 45, r 2  = 0.444, RMSE = 8.551 μg m −3 , RE = 46.446% respectively). Also, our satellite-derived PM 2.5 maps were able to replicate seasonal and spatial trends of ground-based measurements in four different regions. Our results highlight the potential use of MODIS datasets for PM estimation at a regional scale in Vietnam. However, model limitation in capturing maximal or minimal PM 2.5 peaks needs further investigations on ground data, atmospheric conditions and physical aspects. (letter)

  13. Particulate matter concentration mapping from MODIS satellite data: a Vietnamese case study

    Science.gov (United States)

    Nguyen, Thanh T. N.; Bui, Hung Q.; Pham, Ha V.; Luu, Hung V.; Man, Chuc D.; Pham, Hai N.; Le, Ha T.; Nguyen, Thuy T.

    2015-09-01

    Particulate Matter (PM) pollution is one of the most important air quality concerns in Vietnam. In this study, we integrate ground-based measurements, meteorological and satellite data to map temporal PM concentrations at a 10 × 10 km grid for the entire of Vietnam. We specifically used MODIS Aqua and Terra data and developed statistically-significant regression models to map and extend the ground-based PM concentrations. We validated our models over diverse geographic provinces i.e., North East, Red River Delta, North Central Coast and South Central Coast in Vietnam. Validation suggested good results for satellite-derived PM2.5 data compared to ground-based PM2.5 (n = 285, r2 = 0.411, RMSE = 20.299 μg m-3 and RE = 39.789%). Further, validation of satellite-derived PM2.5 on two independent datasets for North East and South Central Coast suggested similar results (n = 40, r2 = 0.455, RMSE = 21.512 μg m-3, RE = 45.236% and n = 45, r2 = 0.444, RMSE = 8.551 μg m-3, RE = 46.446% respectively). Also, our satellite-derived PM2.5 maps were able to replicate seasonal and spatial trends of ground-based measurements in four different regions. Our results highlight the potential use of MODIS datasets for PM estimation at a regional scale in Vietnam. However, model limitation in capturing maximal or minimal PM2.5 peaks needs further investigations on ground data, atmospheric conditions and physical aspects.

  14. A Study on Satellite Diagnostic Expert Systems Using Case-Based Approach

    Directory of Open Access Journals (Sweden)

    Young-Tack Park

    1997-06-01

    Full Text Available Many research works are on going to monitor and diagnose diverse malfunctions of satellite systems as the complexity and number of satellites increase. Currently, many works on monitoring and diagnosis are carried out by human experts but there are needs to automate much of the routine works of them. Hence, it is necessary to study on using expert systems which can assist human experts routine work by doing automatically, thereby allow human experts devote their expertise more critical and important areas of monitoring and diagnosis. In this paper, we are employing artificial intelligence techniques to model human experts' knowledge and inference the constructed knowledge. Especially, case-based approaches are used to construct a knowledge base to model human expert capabilities which use previous typical exemplars. We have designed and implemented a prototype case-based system for diagnosing satellite malfunctions using cases. Our system remembers typical failure cases and diagnoses a current malfunction by indexing the case base. Diverse methods are used to build a more user friendly interface which allows human experts can build a knowledge base in as easy way.

  15. Design and Fabrication of DebriSat - A Representative LEO Satellite for Improvements to Standard Satellite Breakup Models

    Science.gov (United States)

    Clark, S.; Dietrich, A.; Fitz-Coy, N.; Weremeyer, M.; Liou, J.-C.

    2012-01-01

    This paper discusses the design and fabrication of DebriSat, a 50 kg satellite developed to be representative of a modern low Earth orbit satellite in terms of its components, materials used, and fabrication procedures. DebriSat will be the target of a future hypervelocity impact experiment to determine the physical characteristics of debris generated after an on-orbit collision of a modern LEO satellite. The major ground-based satellite impact experiment used by DoD and NASA in their development of satellite breakup models was SOCIT, conducted in 1992. The target used for that experiment was a Navy transit satellite (40 cm, 35 kg) fabricated in the 1960's. Modern satellites are very different in materials and construction techniques than those built 40 years ago. Therefore, there is a need to conduct a similar experiment using a modern target satellite to improve the fidelity of the satellite breakup models. To ensure that DebriSat is truly representative of typical LEO missions, a comprehensive study of historical LEO satellite designs and missions within the past 15 years for satellites ranging from 1 kg to 5000 kg was conducted. This study identified modern trends in hardware, material, and construction practices utilized in recent LEO missions. Although DebriSat is an engineering model, specific attention is placed on the quality, type, and quantity of the materials used in its fabrication to ensure the integrity of the outcome. With the exception of software, all other aspects of the satellite s design, fabrication, and assembly integration and testing will be as rigorous as that of an actual flight vehicle. For example, to simulate survivability of launch loads, DebriSat will be subjected to a vibration test. As well, the satellite will undergo thermal vacuum tests to verify that the components and overall systems meet typical environmental standards. Proper assembly and integration techniques will involve comprehensive joint analysis, including the precise

  16. Near-term hybrid vehicle program, phase 1. Appendix A: Mission analysis and performance specification studies report

    Science.gov (United States)

    1979-01-01

    Results of a study leading to the preliminary design of a five passenger hybrid vehicle utilizing two energy sources (electricity and gasoline/diesel fuel) to minimize petroleum usage on a fleet basis are presented. The study methodology is described. Vehicle characterizations, the mission description, characterization, and impact on potential sales, and the rationale for the selection of the reference internal combustion engine vehicle are presented. Conclusions and recommendations of the mission analysis and performance specification report are included.

  17. Smaller Satellite Operations Near Geostationary Orbit

    Science.gov (United States)

    2007-09-01

    of that study when a purely mathematical approach is not possible or too cumbersome to emphasize a point clearly. I will approach 7 the...components that are specifically designed to be utilized in CubeSats. Pumpkin Incorporated and Clyde Space are leading developers of COTS equipment...year mission life. From a purely hypothetical approach, assume the high interest targets were operating over Asia, with a number of satellites

  18. Atmospheric Entry Studies for Venus Missions: 45 deg Sphere-Cone Rigid Aeroshells and Ballistic Entries

    Science.gov (United States)

    Prabu, Dinesh K.; Allen, Gary A., Jr.; Cappuccio, Gelsomina; Spilker, Thomas R.; Hwang, Helen H.; Moses, Robert W.

    2013-01-01

    The present study considers ballistic entries into the atmosphere of Venus using a 45deg sphere-cone rigid aeroshell, a legacy shape that has been used successfully in the past in the Pioneer Venus Multiprobe Mission. For a number of entry mass and capsule diameter combinations (i.e., various ballistic coefficients) and entry velocities, the trajectory space in terms of entry flight path angles between skip out and -30 is explored with a 3DOF trajectory code, TRAJ. Assuming that the thermal protection material of choice is carbon phenolic of flight heritage, the entry flight path angle space is constrained a posteriori by the mechanical and thermal performance parameters of the material. For mechanical performance, a 200 g limit is placed on the peak deceleration load and 10 bar is assumed as the limit for heritage carbon-phenolic material. It is shown that both constraints cannot be active simultaneously. For thermal performance, a heat flux 2.5 kW/sq cm is utilized as a threshold below which the heritage carbon phenolic is considered mass inefficient. Using these constraints, viable entry flight path angle corridors are determined. Analysis of the results also hints at the existence of a range of "critical" ballistic coefficients beyond which the steepest possible entries are determined by the pressure limit of 10 bar. The results are verified against known performance of the various probes used in the Pioneer Venus mission. It is anticipated that the results presented here will serve as a baseline in the development of a new class of ablative materials for future Venus missions.

  19. Concept definition study for recovery of tumbling satellites. Volume 2: Supporting research and technology report

    Science.gov (United States)

    Cable, D. A.; Derocher, W. L., Jr.; Cathcart, J. A.; Keeley, M. G.; Madayev, L.; Nguyen, T. K.; Preese, J. R.

    1986-01-01

    A number of areas of research and laboratory experiments were identified which could lead to development of a cost efficient remote, disable satellite recovery system. Estimates were planned of disabled satellite motion. A concept is defined as a Tumbling Satellite Recovery kit which includes a modular system, composed of a number of subsystem mechanisms that can be readily integrated into varying combinations. This would enable the user to quickly configure a tailored remote, disabled satellite recovery kit to meet a broad spectrum of potential scenarios. The capability was determined of U.S. Earth based satellite tracking facilities to adequately determine the orientation and motion rates of disabled satellites.

  20. Climate mission study n.10, january 2007; Mission climat note d'etude n. 10, janvier 2007

    Energy Technology Data Exchange (ETDEWEB)

    Delbosc, A.; Keppler, J.H.; Leseur, A

    2007-07-01

    This note aims to explain the evolution of the intensity of the the developed economies of the greenhouse gases emission. This study concerns only the countries called industrialized without the developing countries and those of the old east soviet bloc. In the first part the authors aim to know if the carbon intensity evolution of the economies go with convergence or divergence phenomena. The second part is more devoted to the impacts of the energetic choices on the adopted policies of the countries. Finally a particular attention is given to the characteristics of the european union countries which present a unique policy among the developed countries. (A.L.B.)

  1. Gas mission; Mission gaz

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This preliminary report analyses the desirable evolutions of gas transport tariffing and examines some questions relative to the opening of competition on the French gas market. The report is made of two documents: a synthesis of the previous report with some recommendations about the tariffing of gas transport, about the modalities of network access to third parties, and about the dissociation between transport and trade book-keeping activities. The second document is the progress report about the opening of the French gas market. The first part presents the European problem of competition in the gas supply and its consequences on the opening and operation of the French gas market. The second part presents some partial syntheses about each topic of the mission letter of the Ministry of Economics, Finances and Industry: future evolution of network access tariffs, critical analysis of contractual documents for gas transport and delivery, examination of auxiliary services linked with the access to the network (modulation, balancing, conversion), consideration about the processing of network congestions and denied accesses, analysis of the metering dissociation between the integrated activities of gas operators. Some documents are attached in appendixes: the mission letter from July 9, 2001, the detailed analysis of the new temporary tariffs of GdF and CFM, the offer of methane terminals access to third parties, the compatibility of a nodal tariffing with the presence of three transport operators (GdF, CFM and GSO), the contract-type for GdF supply, and the contract-type for GdF connection. (J.S.)

  2. Mission Climate study note n.8, april 2006; Mission climat note d'etude n. 8, avril 2006

    Energy Technology Data Exchange (ETDEWEB)

    Dufour, C.; Leseur, A

    2006-07-01

    In order to reduce the emissions, in the framework of the Kyoto protocol, the European Union implemented a market of CO{sub 2} emission quotas, which began in January 2005. The study of the first National Plans of quotas allocation in Europe shows the necessity of the homogenization some allocation rules. This note presents in a first part the evaluation one year after the beginning of the market, in a second part the geographical and sectoral repartition of the quotas, in a third part the allocation methods and the main principles applied differently in function of the countries. The last part is devoted to the transition between the phase I and phase II and the banking. (A.L.B.)

  3. Monitoring soil wetness variations by means of satellite passive microwave observations: the HYDROPTIMET study cases

    Directory of Open Access Journals (Sweden)

    T. Lacava

    2005-01-01

    Full Text Available Soil moisture is an important component of the hydrological cycle. In the framework of modern flood warning systems, the knowledge of soil moisture is crucial, due to the influence on the soil response in terms of infiltration-runoff. Precipitation-runoff processes, in fact, are related to catchment's hydrological conditions before the precipitation. Thus, an estimation of these conditions is of significant importance to improve the reliability of flood warning systems. Combining such information with other weather-related satellite products (i.e. rain rate estimation might represent a useful exercise in order to improve our capability to handle (and possibly mitigate or prevent hydro-geological hazards. Remote sensing, in the last few years, has supported several techniques for soil moisture/wetness monitoring. Most of the satellite-based techniques use microwave data, thanks to the all-weather and all-time capability of these data, as well as to their high sensitivity to water content in the soil. On the other hand, microwave data are unfortunately highly affected by the presence of surface roughness or vegetation coverage within the instantaneous satellite field of view (IFOV. Those problems, consequently, strongly limit the efficiency and the reliability of traditional satellite techniques. Recently, using data coming from AMSU (Advanced Microwave Sounding Unit, flying aboard NOAA (National Oceanic and Atmospheric Administration satellites, a new methodology for soil wetness estimation has been proposed. The proposed index, called Soil Wetness Variation Index (SWVI, developed by a multi-temporal analysis of AMSU records, seems able to reduce the problems related to vegetation and/or roughness effects. Such an approach has been tested, with promising results, on the analysis of some flooding events which occurred in Europe in the past. In this study, results achieved for the HYDROPTIMET test cases will be analysed and discussed in detail

  4. IntroductionThe Cluster mission

    Directory of Open Access Journals (Sweden)

    M. Fehringer

    Full Text Available The Cluster mission, ESA’s first cornerstone project, together with the SOHO mission, dating back to the first proposals in 1982, was finally launched in the summer of 2000. On 16 July and 9 August, respectively, two Russian Soyuz rockets blasted off from the Russian cosmodrome in Baikonour to deliver two Cluster spacecraft, each into their proper orbit. By the end of August 2000, the four Cluster satellites had reached their final tetrahedral constellation. The commissioning of 44 instruments, both individually and as an ensemble of complementary tools, was completed five months later to ensure the optimal use of their combined observational potential. On 1 February 2001, the mission was declared operational. The main goal of the Cluster mission is to study the small-scale plasma structures in three dimensions in key plasma regions, such as the solar wind, bow shock, magnetopause, polar cusps, magnetotail and the auroral zones. With its unique capabilities of three-dimensional spatial resolution, Cluster plays a major role in the International Solar Terrestrial Program (ISTP, where Cluster and the Solar and Heliospheric Observatory (SOHO are the European contributions. Cluster’s payload consists of state-of-the-art plasma instrumentation to measure electric and magnetic fields from the quasi-static up to high frequencies, and electron and ion distribution functions from energies of nearly 0 eV to a few MeV. The science operations are coordinated by the Joint Science Operations Centre (JSOC, at the Rutherford Appleton Laboratory (UK, and implemented by the European Space Operations Centre (ESOC, in Darmstadt, Germany. A network of eight national data centres has been set up for raw data processing, for the production of physical parameters, and their distribution to end users all over the world. The latest information on the Cluster mission can be found at http://sci.esa.int/cluster/.

  5. IntroductionThe Cluster mission

    Directory of Open Access Journals (Sweden)

    C. P. Escoubet

    2001-09-01

    Full Text Available The Cluster mission, ESA’s first cornerstone project, together with the SOHO mission, dating back to the first proposals in 1982, was finally launched in the summer of 2000. On 16 July and 9 August, respectively, two Russian Soyuz rockets blasted off from the Russian cosmodrome in Baikonour to deliver two Cluster spacecraft, each into their proper orbit. By the end of August 2000, the four Cluster satellites had reached their final tetrahedral constellation. The commissioning of 44 instruments, both individually and as an ensemble of complementary tools, was completed five months later to ensure the optimal use of their combined observational potential. On 1 February 2001, the mission was declared operational. The main goal of the Cluster mission is to study the small-scale plasma structures in three dimensions in key plasma regions, such as the solar wind, bow shock, magnetopause, polar cusps, magnetotail and the auroral zones. With its unique capabilities of three-dimensional spatial resolution, Cluster plays a major role in the International Solar Terrestrial Program (ISTP, where Cluster and the Solar and Heliospheric Observatory (SOHO are the European contributions. Cluster’s payload consists of state-of-the-art plasma instrumentation to measure electric and magnetic fields from the quasi-static up to high frequencies, and electron and ion distribution functions from energies of nearly 0 eV to a few MeV. The science operations are coordinated by the Joint Science Operations Centre (JSOC, at the Rutherford Appleton Laboratory (UK, and implemented by the European Space Operations Centre (ESOC, in Darmstadt, Germany. A network of eight national data centres has been set up for raw data processing, for the production of physical parameters, and their distribution to end users all over the world. The latest information on the Cluster mission can be found at http://sci.esa.int/cluster/.

  6. Preliminary study of the charged particle radiaton for th satellite power system

    International Nuclear Information System (INIS)

    Stassinopoulos, E.G.

    1978-01-01

    A preliminary radiation study was performed for the SPS project in order to determine the energetic charged particle environment for the three major phases of an SPS mission: the low earth orbit (LEO), the transfer ellipse (TE), and the synchronous geostationary trajectory (GEO). For that purpose, extensive calculations were performed and a large data base was generated, processeed, and analyzed. The external (surface incident) charged particle intensities, predicted for the SPS in each mission phase, were determined by orbital flux integration from the latest environment models. Magnetic field definitions for the three trajectories were obtained from a current field model. Spatial and temporal variations or conditions were considered and accounted for, where possible. Limited shielding and dose evaluations were performed for a simple geometry. The results of this analysis are presented in tabular and graphical form

  7. Study of the crater deformation of the CODELCO/Andina mine using the satellite and ground data

    Science.gov (United States)

    Caverlotti-Silva, M. A.; Arellano-Baeza, A. A.

    2011-12-01

    The correct monitoring of the subsidence of the craters related to the underground mine exploitation is one of the most important endeavors of the satellite remote sensing. The ASTER and LANDSAT satellite images have been used to study the deformation of the crater of the CODELCO/Andina mine, Valparaiso Region, Chile. The high-resolution satellite images were used to detect changes in the lineament patterns related to the subsidence. These results were compared with the ground deformation extracted from the GPS and topography station networks. It was found that sudden changes in the lineament patterns appear when the ground deformation overcomes a definite threshold.

  8. Study and optimisation of the high energy detector in Cd(Zn)Te of the Simbol-X space mission for X and gamma astronomy

    International Nuclear Information System (INIS)

    Meuris, A.

    2009-09-01

    Stars in final phases of evolution are sites of highest energetic phenomena of the Universe. The understanding of their mechanisms is based on the observation of the X and gamma rays from the sources. The Simbol-X French-Italian project is a novel concept of telescope with two satellites flying in formation. This space mission combines upgraded optics from X-ray telescopes with detection Systems from gamma-ray telescopes. CEA Saclay involved in major space missions for gamma astronomy is in charge of the definition and the design of the High Energy Detector (HED) of Simbol-X to cover the spectral range from 8 to 80 keV. Two generations of micro-cameras called Caliste have been designed, fabricated and tested. They integrate cadmium telluride (CdTe) crystals and optimised front-end electronics named Idef-X. The hybridization technique enables to put them side by side as a mosaic to achieve for the first time a CdTe detection plane with fine spatial resolution (600 μm) and arbitrarily large surface. By setting up test benches and leading test campaigns, I was involved in the fabrication of Caliste prototypes and I assessed temporal, spatial and spectral resolutions. At the conclusion of experiments and simulations, I propose a detector type, operating conditions and digital processing on board the spacecraft to optimise HED performance. The best detector candidate is CdTe Schottky, well suited to high resolution spectroscopy; however, it suffers from lost in stability during biasing. Beyond Simbol-X mission, I studied theoretically and experimentally this kind of detector to build an updated model that can apply to other projects of gamma spectroscopy and imaging. (author)

  9. Working hours, sleep, salivary cortisol, fatigue and neuro-behavior during Mars analog mission: five crews study.

    Science.gov (United States)

    Rai, Balwant; Foing, Bernard H; Kaur, Jasdeep

    2012-05-16

    The buoyancy of humans in exploring extreme space environments has been established during missions to the moon. Long duration missions like mission to Mars however, requires humans to adapt to systemic and complex environments beyond the human body's capacity. Astronauts will encounter both physiological and psychological extremes during this trip. Very few studies are conducted on effect of long duration work and sleepiness on cognitive performance. So, this study was planned to find out effects of leadership responsibility, sleepiness and long duration working hours on cognitive performance. The 30 members (leadership: normal; 10:20) were selected from MDRS crews (Mars Desert Research Station, USA). Neurobehavioral test performance, self-ratings of fatigue and sleepiness, and salivary cortisol levels were evaluated during first day, mid and end day of mission. The leadership group did not show any signs of reduced test performance, even in elevated fatigue and sleepiness. The leadership group had faster reaction times on end of mission as compared to first and after 7 day of mission. Salivary cortisol levels were significantly higher in leadership group as compared to normal group. The results suggest that long duration work and sleepiness does not affect the cognitive performance of crew member. Further study is required while taking into account all factors and large sample size to prove this fact. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Metamorphic Testing Integer Overflow Faults of Mission Critical Program: A Case Study

    Directory of Open Access Journals (Sweden)

    Zhanwei Hui

    2013-01-01

    Full Text Available For mission critical programs, integer overflow is one of the most dangerous faults. Different testing methods provide several effective ways to detect the defect. However, it is hard to validate the testing outputs, because the oracle of testing is not always available or too expensive to get, unless the program throws an exception obviously. In the present study, the authors conduct a case study, where the authors apply a metamorphic testing (MT method to detect the integer overflow defect and alleviate the oracle problem in testing critical program of Traffic Collision Avoidance System (TCAS. Experimental results show that, in revealing typical integer mutations, compared with traditional safety property testing method, MT with a novel symbolic metamorphic relation is more effective than the traditional method in some cases.

  11. The YORP effect on the GOES 8 and GOES 10 satellites: A case study

    Science.gov (United States)

    Albuja, Antonella A.; Scheeres, Daniel J.; Cognion, Rita L.; Ryan, William; Ryan, Eileen V.

    2018-01-01

    The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is a proposed explanation for the observed rotation behavior of inactive satellites in Earth orbit. This paper further explores the YORP effect for highly asymmetric inactive satellites. Satellite models are developed to represent the GOES 8 and GOES 10 satellites, both of which are currently inactive in geosynchronous Earth orbit (GEO). A simple satellite model for the GOES 8 satellite is used to analyze the short period variations of the angular velocity and obliquity as a result of the YORP effect. A more complex model for the rotational dynamics of the GOES 8 and GOES 10 satellites are developed to probe their sensitivity and to match observed spin periods and states of these satellites. The simulated rotation periods are compared to observations for both satellites. The comparison between YORP theory and observed rotation rates for both satellites show that the YORP effect could be the cause for the observed rotational behavior. The YORP model also predicts a novel state for the GOES 8 satellite, namely that it could periodically fall into a tumbling rotation state. Recent observations of this satellite are consistent with this prediction.

  12. A Study on the Potential Applications of Satellite Data in Air Quality Monitoring and Forecasting

    Science.gov (United States)

    Li, Can; Hsu, N. Christina; Tsay, Si-Chee

    2011-01-01

    In this study we explore the potential applications of MODIS (Moderate Resolution Imaging Spectroradiometer) -like satellite sensors in air quality research for some Asian regions. The MODIS aerosol optical thickness (AOT), NCEP global reanalysis meteorological data, and daily surface PM(sub 10) concentrations over China and Thailand from 2001 to 2009 were analyzed using simple and multiple regression models. The AOT-PM(sub 10) correlation demonstrates substantial seasonal and regional difference, likely reflecting variations in aerosol composition and atmospheric conditions, Meteorological factors, particularly relative humidity, were found to influence the AOT-PM(sub 10) relationship. Their inclusion in regression models leads to more accurate assessment of PM(sub 10) from space borne observations. We further introduced a simple method for employing the satellite data to empirically forecast surface particulate pollution, In general, AOT from the previous day (day 0) is used as a predicator variable, along with the forecasted meteorology for the following day (day 1), to predict the PM(sub 10) level for day 1. The contribution of regional transport is represented by backward trajectories combined with AOT. This method was evaluated through PM(sub 10) hindcasts for 2008-2009, using ohservations from 2005 to 2007 as a training data set to obtain model coefficients. For five big Chinese cities, over 50% of the hindcasts have percentage error less than or equal to 30%. Similar performance was achieved for cities in northern Thailand. The MODIS AOT data are responsible for at least part of the demonstrated forecasting skill. This method can be easily adapted for other regions, but is probably most useful for those having sparse ground monitoring networks or no access to sophisticated deterministic models. We also highlight several existing issues, including some inherent to a regression-based approach as exemplified by a case study for Beijing, Further studies will be

  13. Exploitation of satellite optical and SAR data for public work studies

    Science.gov (United States)

    Ioannidis, Charalabos; Soile, Sofia; Stamos, Athanassios; Vassilaki, Dimitra; Maltezos, Evangelos; Verykokou, Styliani

    2015-06-01

    This paper studies the use of high resolution satellite optical and SAR images for 1:5,000 mapping production, which is essential for public work and environmental impact assessment studies. The images were used for the extraction of DEMs and their "fit for purpose" use was investigated, through the examination of parameters like accuracy, reliability and performance of morphological features. Orthoimages from satellite optical images using the produced DEMs with or without breaklines were produced. An application was developed on Antiparos island, a Greek island with irregular terrain. The data includes: (a) a triplet of Pleiades (1A, tri-stereo) satellite images, with a resolution of 0.5m, (b) a TanDEM-X Intermediate DEM, a preliminary version of the forthcoming TanDEM-X global DEM, and (c) an accurate DEM produced from the Greek National Cadastre & Mapping Agency S.A. was used as the reference DEM. The georeferencing of the optical images was computed using GCPs which were measured with GNSS. DEMs were extracted using all the possible combinations of the images triplet using automated image matching without any filtering or editing and were evaluated using the reference DEM. The combination of images which yielded the best DEM was then used to manually editing 3D points and collecting breaklines in order to produce a better DEM, which was also evaluated using various statistical measures and geo-morphological features. Orthoimages were created and evaluated using DEMs from optical and SAR data. A discussion about the use of the computed mapping products for the various stages of the public work studies is included.

  14. Experimental study of electronic electrostatic waves detected in the terrestrial magnetosphere by the satellite GEOS 2

    International Nuclear Information System (INIS)

    Canu, P.

    1982-09-01

    After reviewing the general characteristics of electrostator waves a brief resume is given of the observations made up to the present moment. The GEOS satellite and the ''wave'' experiment are described, as well as the method and results of the statistical study of the strong electrostatic wave observed. Creating mechanisms of diffuse auroras are discussed. In a later chapter a new method of using the relaxation probe is presented as well as the results it gives on the mode of propagation of waves in the neighbourhood of the FUH frequency [fr

  15. Study of high-resolution satellite geoid and gravity anomaly data over the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Majumdar, T. J.; Krishna, K.S.; Chatterjee, S.; Bhattacharya, R.; Michael, L.

    research vessels. Solid line shows location of the profile along which interpreted seismic results and var i- ous products of satellite gravity data are shown in Fi gure 4. RESEARCH COMMUNICATIONS CURRENT SCIENCE, VOL. 90, NO. 2 , 25 JANUARY 2006... depth le v els. Location o f the profile is shown with solid line in Figure 3. of the Bay of Bengal can be reasonably co n sidered in mapping the structural features of the region. Thereby the results can be used to study the tectonics...

  16. Synergy of Satellite-Surface Observations for Studying the Properties of Absorbing Aerosols in Asia

    Science.gov (United States)

    Tsay, Si-Chee

    2010-01-01

    Through interaction with clouds and alteration of the Earth's radiation budget, atmospheric aerosols significantly influence our weather and climate. Monsoon rainfalls, for example, sustain the livelihood of more than half of the world's population. Thus, understanding the mechanism that drives the water cycle and freshwater distribution is high-lighted as one of the major near-term goals in NASA's Earth Science Enterprise Strategy. Every cloud droplet/ice-crystal that serves as an essential element in portraying water cycle and distributing freshwater contains atmospheric aerosols at its core. In addition, the spatial and temporal variability of atmospheric aerosol properties is complex due to their dynamic nature. In fact, the predictability of the tropical climate system is much reduced during the boreal spring, which is associated with the peak season of biomass burning activities and regional/long-range transport of dust aerosols. Therefore, to accurately assess the impact of absorbing aerosols on regional-to-global climate requires not only modeling efforts but also continuous observations from satellites, aircraft, networks of ground-based instruments and dedicated field experiments. Since 1997 NASA has been successfully launching a series of satellites the Earth Observing System - to intensively study, and gain a better understanding of, the Earth as an integrated system. Through participation in many satellite remote-sensing/retrieval and validation projects over the years, we have gradually developed and refined the SMART (Surface-sensing Measurements for Atmospheric Radiative Transfer) and COMMIT (Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile observatories, a suite of surface remote sensing and in-situ instruments that proved to be vital in providing high temporal measurements, which complement the satellite observations. In this talk, we will present SMART-COMMIT which has played key roles, serving as network or supersite

  17. Landsat Data Continuity Mission - Launch Fever

    Science.gov (United States)

    Irons, James R.; Loveland, Thomas R.; Markham, Brian L.; Masek, Jeffrey G.; Cook, Bruce; Dwyer, John L.

    2012-01-01

    The year 2013 will be an exciting period for those that study the Earth land surface from space, particularly those that observe and characterize land cover, land use, and the change of cover and use over time. Two new satellite observatories will be launched next year that will enhance capabilities for observing the global land surface. The United States plans to launch the Landsat Data Continuity Mission (LDCM) in January. That event will be followed later in the year by the European Space Agency (ESA) launch of the first Sentinel 2 satellite. Considered together, the two satellites will increase the frequency of opportunities for viewing the land surface at a scale where human impact and influence can be differentiated from natural change. Data from the two satellites will provide images for similar spectral bands and for comparable spatial resolutions with rigorous attention to calibration that will facilitate cross comparisons. This presentation will provide an overview of the LDCM satellite system and report its readiness for the January launch.

  18. Infrared Astronomical Satellite (IRAS) Catalogs and Atlases. Explanatory Supplement

    Science.gov (United States)

    Beichman, C. A. (Editor); Neugebauer, G. (Editor); Habing, H. J. (Editor); Clegg, P. E. (Editor); Chester, T. J. (Editor)

    1985-01-01

    The Infrared Astronomical Satellite (IRAS) mission is described. An overview of the mission, a description of the satellite and its telescope system, and a discussion of the mission design, requirements, and inflight modifications are given. Data reduction, flight tests, flux reconstruction and calibration, data processing, and the formats of the IRAS catalogs and atlases are also considered.

  19. Potential and limitations of multidecadal satellite soil moisture observations for selected climate model evaluation studies

    Directory of Open Access Journals (Sweden)

    A. Loew

    2013-09-01

    Full Text Available Soil moisture is an essential climate variable (ECV of major importance for land–atmosphere interactions and global hydrology. An appropriate representation of soil moisture dynamics in global climate models is therefore important. Recently, a first multidecadal, observation-based soil moisture dataset has become available that provides information on soil moisture dynamics from satellite observations (ECVSM, essential climate variable soil moisture. The present study investigates the potential and limitations of this new dataset for several applications in climate model evaluation. We compare soil moisture data from satellite observations, reanalysis and simulations from a state-of-the-art land surface model and analyze relationships between soil moisture and precipitation anomalies in the different dataset. Other potential applications like model parameter optimization or model initialization are not investigated in the present study. In a detailed regional study, we show that ECVSM is capable to capture well the interannual and intraannual soil moisture and precipitation dynamics in the Sahelian region. Current deficits of the new dataset are critically discussed and summarized at the end of the paper to provide guidance for an appropriate usage of the ECVSM dataset for climate studies.

  20. Analysing Regional Land Surface Temperature Changes by Satellite Data, a Case Study of Zonguldak, Turkey

    Science.gov (United States)

    Sekertekin, A.; Kutoglu, S.; Kaya, S.; Marangoz, A. M.

    2014-12-01

    In recent years, climate change is one of the most important problems that the ecological system of the world has been encountering. Global warming and climate change have been studied frequently by all disciplines all over the world and Geomatics Engineering also contributes to such studies by means of remote sensing, global positioning system etc. Monitoring Land Surface Temperature (LST) via remote sensing satellites is one of the most important contributions to climatology. LST is an important parameter governing the energy balance on the Earth and there are lots of algorithms to obtain LST by remote sensing techniques. The most commonly used algorithms are split-window algorithm, temperature/emissivity separation method, mono-window algorithm and single channel method. Generally three algorithms are used to obtain LST by using Landsat 5 TM data. These algorithms are radiative transfer equation method, single channel method and mono-window algorithm. Radiative transfer equation method is not applicable because during the satellite pass, atmospheric parameters must be measured in-situ. In this research, mono window algorithm was implemented to Landsat 5 TM image. Besides, meteorological data such as humidity and temperature are used in the algorithm. Acquisition date of the image is 28.08.2011 and our study area is Zonguldak, Turkey. High resolution images are used to investigate the relationships between LST and land cover type. As a result of these analyses, area with vegetation cover has approximately 5 ºC lower temperature than the city center and arid land. Because different surface properties like reinforced concrete construction, green zones and sandbank are all together in city center, LST differs about 10 ºC in the city center. The temperature around some places in thermal power plant region Çatalağzı, is about 5 ºC higher than city center. Sandbank and agricultural areas have highest temperature because of land cover structure. Thanks to this

  1. A Comparative Study on Satellite- and Model-Based Crop Phenology in West Africa

    Directory of Open Access Journals (Sweden)

    Elodie Vintrou

    2014-02-01

    Full Text Available Crop phenology is essential for evaluating crop production in the food insecure regions of West Africa. The aim of the paper is to study whether satellite observation of plant phenology are consistent with ground knowledge of crop cycles as expressed in agro-simulations. We used phenological variables from a MODIS Land Cover Dynamics (MCD12Q2 product and examined whether they reproduced the spatio-temporal variability of crop phenological stages in Southern Mali. Furthermore, a validated cereal crop growth model for this region, SARRA-H (System for Regional Analysis of Agro-Climatic Risks, provided precise agronomic information. Remotely-sensed green-up, maturity, senescence and dormancy MODIS dates were extracted for areas previously identified as crops and were compared with simulated leaf area indices (LAI temporal profiles generated using the SARRA-H crop model, which considered the main cropping practices. We studied both spatial (eight sites throughout South Mali during 2007 and temporal (two sites from 2002 to 2008 differences between simulated crop cycles and determined how the differences were indicated in satellite-derived phenometrics. The spatial comparison of the phenological indicator observations and simulations showed mainly that (i the satellite-derived start-of-season (SOS was detected approximately 30 days before the model-derived SOS; and (ii the satellite-derived end-of-season (EOS was typically detected 40 days after the model-derived EOS. Studying the inter-annual difference, we verified that the mean bias was globally consistent for different climatic conditions. Therefore, the land cover dynamics derived from the MODIS time series can reproduce the spatial and temporal variability of different start-of-season and end-of-season crop species. In particular, we recommend simultaneously using start-of-season phenometrics with crop models for yield forecasting to complement commonly used climate data and provide a better

  2. Scientific Satellites

    Science.gov (United States)

    1967-01-01

    noise signal level exceeds 10 times the normal background. EXPERIMENTS FOR SATELLITE ASTRONOMY 615 ANTENNA MONOPOLE -., PREAMPLFE = BANDPASS-FILTER...OUTPUT TO AND DETECTOR TELEMETRYCHANNELS (18) CALIBRATION NOISE MATRIX CLOCK NOISE SOURCE ’ON’ SOURCE COMMAND F ROM PROGRAMERP ANTENNA MONOPOLE FIGURE 13...Animal Tempera- ture Sensing for Studying the Effect of Prolonged Orbital Flight on the Circadian Rhythms of Pocket Mice . Unmanned Spacecraft Meeting

  3. Quantifying offshore wind resources from satellite wind maps: Study area the North Sea

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Barthelmie, Rebecca Jane; Christiansen, Merete B.

    2006-01-01

    Offshore wind resources are quantified from satellite synthetic aperture radar (SAR) and satellite scatterometer observations at local and regional scale respectively at the Horns Rev site in Denmark. The method for wind resource estimation from satellite observations interfaces with the wind atlas...... of the Horns Rev wind farm is quantified from satellite SAR images and compared with state-of-the-art wake model results with good agreement. It is a unique method using satellite observations to quantify the spatial extent of the wake behind large offshore wind farms. Copyright © 2006 John Wiley & Sons, Ltd....... analysis and application program (WAsP). An estimate of the wind resource at the new project site at Horns Rev is given based on satellite SAR observations. The comparison of offshore satellite scatterometer winds, global model data and in situ data shows good agreement. Furthermore, the wake effect...

  4. Space station needs, attributes and architectural options study. Volume 3: Mission requirements

    Science.gov (United States)

    1983-04-01

    User missions that are enabled or enhanced by a manned space station are identified. The mission capability requirements imposed on the space station by these users are delineated. The accommodation facilities, equipment, and functional requirements necessary to achieve these capabilities are identified, and the economic, performance, and social benefits which accrue from the space station are defined.

  5. Observational Cosmology with the Planck satellite: extraction of the astrophysical signal from raw data of HFI instrument and study of the impact of cosmic rays

    International Nuclear Information System (INIS)

    Girard, D.

    2010-01-01

    Cosmology is a very old science. It's goal is to describe the Universe at large scales. The standard model of cosmology is an inflation-CDM Big-Bang model. It is based on General Relativity. The cosmic microwave background is one of the three pillars of this model, with the expansion of the Universe and the primordial nucleosynthesis. It is the oldest detectable radiation in the Universe. The study of its temperature and polarisation anisotropies allow us to access direct information about the content and the geometry of the primordial Universe. The Planck satellite, launched on May 14 of 2009, represents the third generation of satellite missions which study the cosmic microwave background. The exceptional sensitivity of its instruments, High Frequency Instrument and Low Frequency Instrument, will allow us to constrain very strongly the cosmological models describing the early Universe, particularly the inflationary period, and to measure the cosmological parameters which describe the evolution of the Universe with an accuracy down to the percent. To reach these ambitious scientific objectives, each systematic instrumental effect has to be severely controlled and corrected by the data analysis. The effect of cosmic rays interacting with the bolometers of HFI, which is one of the most important effects, and which differs significatively from predictions, is corrected during the time ordered data analysis. The detailed understanding of this phenomenon and its modeling are necessary to correct it and to reach an optimal effective sensitivity. They will permit to take this effect into account in the conception of the future instruments detectors. This thesis proposes a first part focused on cosmology, a second part describing the Planck satellite, the HFI instrument and particularly its detectors and a third part dedicated to the HFI instrument data analysis. I concentrate on time ordered data analysis and on the corrections of instrumental systematic effects. Then I

  6. [The mission].

    Science.gov (United States)

    Ruiz Moreno, J; Blanch Mon, A

    2000-01-01

    After having made a historical review of the concept of mission statement, of evaluating its importance (See Part I), of describing the bases to create a mission statement from a strategic perspective and of analyzing the advantages of this concept, probably more important as a business policy (See Parts I and II), the authors proceed to analyze the mission statement in health organizations. Due to the fact that a mission statement is lacking in the majority of health organizations, the strategy of health organizations are not exactly favored; as a consequence, neither are its competitive advantage nor the development of its essential competencies. After presenting a series of mission statements corresponding to Anglo-Saxon health organizations, the authors highlight two mission statements corresponding to our social context. The article finishes by suggesting an adequate sequence for developing a mission statement in those health organizations having a strategic sense.

  7. A Conceptual Design for a Small Deployer Satellite

    Science.gov (United States)

    Zumbo, S.

    2002-01-01

    In the last few years, the space scientific and industrial communities have demonstrated a renewed interest for small missions based on new categories of space platforms: micro &nano satellites. The cost reduction w.r.t. larger satellite missions, the shorter time from concept to launch, the risk distribution and the possibility to use this kind of bus both for stand-alone projects and as complementary to larger programs, are key factors that make this new kind of technology suitable for a wide range of space related activities. In particular it is now possible to conceive new mission philosophy implying the realisation of micro satellite constellations, with S/C flying in close formation to form a network of distributed sensors either for near-real time telecommunication or Earth remote sensing and disaster monitoring systems or physics and astronomical researches for Earth-Sun dynamics and high energy radiation studies. At the same time micro satellite are becoming important test- beds for new technologies that will eventually be used on larger missions, with relevant spin-offs potentialities towards other industrial fields. The foreseen social and economical direct benefits, the reduced mission costs and the possibility even for a small skilled team to manage all the project, represent very attractive arguments for universities and research institutes to invest funds and human resources to get first order technical and theoretical skills in the field of micro satellite design, with important influences on the training programs of motivated students that are directly involved in all the project's phases. In consideration of these space market important new trends and of the academic benefits that could be guaranteed by undertaking a micro satellite mission project, basing on its long space activities heritage, University of Rome "La Sapienza" - Aerospace and Astronautics Department, with the support of the Italian Space Agency, Alenia Spazio and of important

  8. The NASA Earth Science Program and Small Satellites

    Science.gov (United States)

    Neeck, Steven P.

    2015-01-01

    Earth's changing environment impacts every aspect of life on our planet and climate change has profound implications on society. Studying Earth as a single complex system is essential to understanding the causes and consequences of climate change and other global environmental concerns. NASA's Earth Science Division (ESD) shapes an interdisciplinary view of Earth, exploring interactions among the atmosphere, oceans, ice sheets, land surface interior, and life itself. This enables scientists to measure global and climate changes and to inform decisions by Government, other organizations, and people in the United States and around the world. The data collected and results generated are accessible to other agencies and organizations to improve the products and services they provide, including air quality indices, disaster prediction and response, agricultural yield projections, and aviation safety. ESD's Flight Program provides the spacebased observing systems and supporting infrastructure for mission operations and scientific data processing and distribution that support NASA's Earth science research and modeling activities. The Flight Program currently has 21 operating Earth observing space missions, including the recently launched Global Precipitation Measurement (GPM) mission, the Orbiting Carbon Observatory-2 (OCO-2), the Soil Moisture Active Passive (SMAP) mission, and the International Space Station (ISS) RapidSCAT and Cloud-Aerosol Transport System (CATS) instruments. The ESD has 22 more missions and instruments planned for launch over the next decade. These include first and second tier missions from the 2007 Earth Science Decadal Survey, Climate Continuity missions to assure availability of key climate data sets, and small-sized competitively selected orbital missions and instrument missions of opportunity belonging to the Earth Venture (EV) Program. Small satellites (500 kg or less) are critical contributors to these current and future satellite missions

  9. Satellite-based laser windsounder

    International Nuclear Information System (INIS)

    Schultz, J.F.; Czuchlewski, S.J.; Quick, C.R.

    1997-01-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project''s primary objective is to determine the technical feasibility of using satellite-based laser wind sensing systems for detailed study of winds, aerosols, and particulates around and downstream of suspected proliferation facilities. Extensive interactions with the relevant operational organization resulted in enthusiastic support and useful guidance with respect to measurement requirements and priorities. Four candidate wind sensing techniques were evaluated, and the incoherent Doppler technique was selected. A small satellite concept design study was completed to identify the technical issues inherent in a proof-of-concept small satellite mission. Use of a Mach-Zehnder interferometer instead of a Fabry-Perot would significantly simplify the optical train and could reduce weight, and possibly power, requirements with no loss of performance. A breadboard Mach-Zehnder interferometer-based system has been built to verify these predictions. Detailed plans were made for resolving other issues through construction and testing of a ground-based lidar system in collaboration with the University of Wisconsin, and through numerical lidar wind data assimilation studies

  10. The esa earth explorer land surface processes and interactions mission

    Science.gov (United States)

    Labandibar, Jean-Yves; Jubineau, Franck; Silvestrin, Pierluigi; Del Bello, Umberto

    2017-11-01

    The European Space Agency (ESA) is defining candidate missions for Earth Observation. In the class of the Earth Explorer missions, dedicated to research and pre-operational demonstration, the Land Surface Processes and Interactions Mission (LSPIM) will acquire the accurate quantitative measurements needed to improve our understanding of the nature and evolution of biosphere-atmosphere interactions and to contribute significantly to a solution of the scaling problems for energy, water and carbon fluxes at the Earth's surface. The mission is intended to provide detailed observations of the surface of the Earth and to collect data related to ecosystem processes and radiation balance. It is also intended to address a range of issues important for environmental monitoring, renewable resources assessment and climate models. The mission involves a dedicated maneuvering satellite which provides multi-directional observations for systematic measurement of Land Surface BRDF (BiDirectional Reflectance Distribution Function) of selected sites on Earth. The satellite carries an optical payload : PRISM (Processes Research by an Imaging Space Mission), a multispectral imager providing reasonably high spatial resolution images (50 m over 50 km swath) in the whole optical spectral domain (from 450 nm to 2.35 μm with a resolution close to 10 nm, and two thermal bands from 8.1 to 9.1 μm). This paper presents the results of the Phase A study awarded by ESA, led by ALCATEL Space Industries and concerning the design of LSPIM.

  11. SPICE for ESA Planetary Missions: geometry and visualization support to studies, operations and data analysis within your reach

    Science.gov (United States)

    Costa, Marc

    2018-05-01

    JUICE is a mission chosen in the framework of the Cosmic Vision 2015-2024 program of the SRE. JUICE will survey the Jovian system with a special focus on the three Galilean Moons. Currently the mission is under study activities during its Definition Phase. For this period the future mission scenarios are being studied by the Science Working Team (SWT). The Mission Analysis and Payload Support (MAPPS) and the Solar System Science Operations Laboratory (SOLab) tools are being used to provide active support to the SWT in synergy with other operational tools used in the Department in order to evaluate the feasibility of those scenarios. This contribution will outline the capabilities, synergies as well as use cases of the mentioned tools focusing on the support provided to JUICEís study phase on the study of its critical operational scenarios and the early developments of its Science Ground Segment demonstrating the added value that such a tool provides to planetary science missions.

  12. Biomass estimation with high resolution satellite images: A case study of Quercus rotundifolia

    Science.gov (United States)

    Sousa, Adélia M. O.; Gonçalves, Ana Cristina; Mesquita, Paulo; Marques da Silva, José R.

    2015-03-01

    Forest biomass has had a growing importance in the world economy as a global strategic reserve, due to applications in bioenergy, bioproduct development and issues related to reducing greenhouse gas emissions. Current techniques used for forest inventory are usually time consuming and expensive. Thus, there is an urgent need to develop reliable, low cost methods that can be used for forest biomass estimation and monitoring. This study uses new techniques to process high spatial resolution satellite images (0.70 m) in order to assess and monitor forest biomass. Multi-resolution segmentation method and object oriented classification are used to obtain the area of tree canopy horizontal projection for Quercus rotundifolia. Forest inventory allows for calculation of tree and canopy horizontal projection and biomass, the latter with allometric functions. The two data sets are used to develop linear functions to assess above ground biomass, with crown horizontal projection as an independent variable. The functions for the cumulative values, both for inventory and satellite data, for a prediction error equal or smaller than the Portuguese national forest inventory (7%), correspond to stand areas of 0.5 ha, which include most of the Q.rotundifolia stands.

  13. Autoionization study of the Argon 2p satellites excited near the argon 2s threshold

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Glans, P.; Hemmers, O. [Univ. of Nevada, Las Vegas, NV (United States)] [and others

    1997-04-01

    The dynamics of near-threshold photoionization is a complex phenomenon in which the many-electron character of the wavefunctions plays an important role. According to generalized time-independent resonant scattering theory, the transition matrix element from an initial state to a final state is the summation of the amplitudes of direct photoionization and an indirect term in which intermediate states are involved and the resonant behavior is embedded. Studies of the interference effects of intermediate states have been explored in the cases where the direct term is negligible. In the present work, electron time-of-flight spectra of the Ar 2p satellites were measured at two angles (magic and 0{degrees}) in the dipole plane with the exciting photon energy tuned in the vicinity of the Ar 2s threshold. For excitation far below or above the 2s threshold, the 2p satellites spectrum is dominated by 3p to np shakeup contributions upon the ionization of a 2p electron.

  14. Autoionization study of the Argon 2p satellites excited near the argon 2s threshold

    International Nuclear Information System (INIS)

    Wang, H.; Glans, P.; Hemmers, O.

    1997-01-01

    The dynamics of near-threshold photoionization is a complex phenomenon in which the many-electron character of the wavefunctions plays an important role. According to generalized time-independent resonant scattering theory, the transition matrix element from an initial state to a final state is the summation of the amplitudes of direct photoionization and an indirect term in which intermediate states are involved and the resonant behavior is embedded. Studies of the interference effects of intermediate states have been explored in the cases where the direct term is negligible. In the present work, electron time-of-flight spectra of the Ar 2p satellites were measured at two angles (magic and 0 degrees) in the dipole plane with the exciting photon energy tuned in the vicinity of the Ar 2s threshold. For excitation far below or above the 2s threshold, the 2p satellites spectrum is dominated by 3p to np shakeup contributions upon the ionization of a 2p electron

  15. High energy universe – Satellite missions

    Indian Academy of Sciences (India)

    hydrogen and helium are fully ionized. Heavier ... one solar mass is completely converted into energy in one second, say by thermonuclear fusion. ... The big puzzle, however, is the production of a nonthermal spectrum from an explosion.

  16. Centralized mission planning and scheduling system for the Landsat Data Continuity Mission

    Science.gov (United States)

    Kavelaars, Alicia; Barnoy, Assaf M.; Gregory, Shawna; Garcia, Gonzalo; Talon, Cesar; Greer, Gregory; Williams, Jason; Dulski, Vicki

    2014-01-01

    Satellites in Low Earth Orbit provide missions with closer range for studying aspects such as geography and topography, but often require efficient utilization of space and ground assets. Optimizing schedules for these satellites amounts to a complex planning puzzle since it requires operators to face issues such as discontinuous ground contacts, limited onboard memory storage, constrained downlink margin, and shared ground antenna resources. To solve this issue for the Landsat Data Continuity Mission (LDCM, Landsat 8), all the scheduling exchanges for science data request, ground/space station contact, and spacecraft maintenance and control will be coordinated through a centralized Mission Planning and Scheduling (MPS) engine, based upon GMV’s scheduling system flexplan9 . The synchronization between all operational functions must be strictly maintained to ensure efficient mission utilization of ground and spacecraft activities while working within the bounds of the space and ground resources, such as Solid State Recorder (SSR) and available antennas. This paper outlines the functionalities that the centralized planning and scheduling system has in its operational control and management of the Landsat 8 spacecraft.

  17. Ocean Surface Topography Mission (OSTM) /Jason-3: Orbital Information, 2015- (NODC Accession 0122598)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Jason-3 is the fourth mission in U.S.-European series of satellite missions that measure the height of the ocean surface. Scheduled to launch in 2015, the mission...

  18. Ocean Surface Topography Mission (OSTM) /Jason-3: Telemetry, 2015- (NODC Accession 0122599)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Jason-3 is the fourth mission in U.S.-European series of satellite missions that measure the height of the ocean surface. Scheduled to launch in 2015, the mission...

  19. Ocean Surface Topography Mission (OSTM) /Jason-3: Auxiliary Files, 2015- (NODC Accession 0122597)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Jason-3 is the fourth mission in U.S.-European series of satellite missions that measure the height of the ocean surface. Scheduled to launch in 2015, the mission...

  20. Ocean Surface Topography Mission (OSTM) /Jason-3: Ancillary Files, 2015- (NCEI Accession 0122596)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Jason-3 is the fourth mission in U.S.-European series of satellite missions that measure the height of the ocean surface. Scheduled to launch in 2015, the mission...

  1. A Study on the Tracking and Position Predictions of Artificial Satellite (II

    Directory of Open Access Journals (Sweden)

    Pil-Ho Park

    1991-06-01

    Full Text Available We developed a software system called IODS (ISSA Orbit Determination System, which can predict the orbit of arbitrary artificial satellite using the numerical method. For evaluating the orbit prediction accuracy of IODS, the orbital data predicted for the meteorological satellite NOAA-11 and the stationary satellite INTELSAT-V are intercompared with those tracked at the Central Bureau of Meteorology and the Kum-San Satellites Communication Station. And the Perturbation affecting the orbit of these artificial satellites are quantitatively analyzed. The orbital variation and the eclipse phenomina due to the earth shadow are analyzed for a hypothetical geostationary satellite called KORSAT-1 which is assumed to be located in longitude 110°E.

  2. [Myanmar mission].

    Science.gov (United States)

    Alfandari, B; Persichetti, P; Pelissier, P; Martin, D; Baudet, J

    2004-06-01

    The authors report the accomplishment of humanitarian missions in plastic surgery performed by a small team in town practice in Yangon, about their 3 years experience in Myanmar with 300 consultations and 120 surgery cases. They underline the interest of this type of mission and provide us their reflexion about team training, the type of relation with the country where the mission is conducted and the type of right team.

  3. A Study on Fuel Estimation Algorithms for a Geostationary Communication & Broadcasting Satellite

    OpenAIRE

    Jong Won Eun

    2000-01-01

    It has been developed to calculate fuel budget for a geostationary communication and broadcasting satellite. It is quite essential that the pre-launch fuel budget estimation must account for the deterministic transfer and drift orbit maneuver requirements. After on-station, the calculation of satellite lifetime should be based on the estimation of remaining fuel and assessment of actual performance. These estimations step from the proper algorithms to produce the prediction of satellite lifet...

  4. SAC-C mission, an example of international cooperation

    Science.gov (United States)

    Colomb, F.; Alonso, C.; Hofmann, C.; Nollmann, I.

    In comp liance with the objectives established in the National Space Program, Argentina in Space 1997-2008 ((Plan Espacial Nacional, Argentina en el Espacio 1997-2008), the National Commission on Space Activities (Comisión Nacional de Actividades Espaciales - CONAE) undertook the design, construction, and launching of the SAC-C satellite in close collaboration with NASA. The purpose of this Mission is to carry out observations of interest both for the USA and Argentina, thus contributing effectively to NASA's Earth Science Program and to CONAE's National Space Program. The SAC-C is an international Earth observing satellite mission conceived as a partnership between CONAE and NASA, with additional support in instrumentation and satellite development from the Danish DSRI, the Italian ASI, the French CNES and the Brazilian INPE. A Delta II rocket successfully launched it on November 21st, 2000, from Vandenberg AFB, California, USA. Ten instruments on board the SAC-C perform different studies related to the ground and sea ecosystems, the atmosphere and the geomagnetic field. There are also technological experiments for determination of the satellite attitude and velocity as well as for the studies of the influence of space radiation on advanced electronic components . The inclusion of SAC-C in the AM Constellation, jointly with NASA satellites Landsat 7, EO 1 and Terra, is another example of important international cooperation which synergies the output of any single Mission. The Constellation has been working since March 2001 as a single mission and several cooperative activities have been undertaken including several jointly sponsored technical workshops and collaborative spacecraft navigation experiments. A flight campaign of the NASA AVIRIS instrument was performed in Argentine during January and February 2001, for calibration of SAC-C and EO 1 cameras and the development of joint scientific works. In Cordoba Space Center a jointly operated ground GPS reference

  5. Planning, Implementation, and Scientific Goals of the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) Field Missions

    Science.gov (United States)

    Toon, Owen B.; Maring, Hal; Dibb, Jack; Ferrare, Richard A.; Jacob, Daniel J.; Jensen, Eric J.; Luo, Z. Johnny; Mace, Gerald G.; Pan, Laura L.; Pfister, Leonhard; hide

    2016-01-01

    The Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) field mission based at Ellington Field, Texas, during August and September 2013 employed the most comprehensive airborne payload to date to investigate atmospheric composition over North America. The NASA ER-2, DC-8, and SPEC Inc. Learjet flew 57 science flights from the surface to 20 km. The ER-2 employed seven remote sensing instruments as a satellite surrogate and eight in situ instruments. The DC-8 employed 23 in situ and five remote sensing instruments for radiation, chemistry, and microphysics. The Learjet used 11 instruments to explore cloud microphysics. SEAC4RS launched numerous balloons, augmented Aerosol RObotic NETwork, and collaborated with many existing ground measurement sites. Flights investigating convection included close coordination of all three aircraft. Coordinated DC-8 and ER-2 flights investigated the optical properties of aerosols, the influence of aerosols on clouds, and the performance of new instruments for satellite measurements of clouds and aerosols. ER-2 sorties sampled stratospheric injections of water vapor and other chemicals by local and distant convection. DC-8 flights studied seasonally evolving chemistry in the Southeastern U.S., atmospheric chemistry with lower emissions of NOx and SO2 than in previous decades, isoprene chemistry under high and low NOx conditions at different locations, organic aerosols, air pollution near Houston and in petroleum fields, smoke from wildfires in western forests and from agricultural fires in the Mississippi Valley, and the ways in which the chemistry in the boundary layer and the upper troposphere were influenced by vertical transport in convective clouds.

  6. The behaviour of satellite cells in response to exercise: what have we learned from human studies?

    DEFF Research Database (Denmark)

    Kadi, Fawzi; Olsen, Steen Schytte

    2005-01-01

    Understanding the complex role played by satellite cells in the adaptive response to exercise in human skeletal muscle has just begun. The development of reliable markers for the identification of satellite cell status (quiescence/activation/proliferation) is an important step towards the underst......Understanding the complex role played by satellite cells in the adaptive response to exercise in human skeletal muscle has just begun. The development of reliable markers for the identification of satellite cell status (quiescence/activation/proliferation) is an important step towards...

  7. The Italian contribution to the CSES satellite

    Science.gov (United States)

    Conti, Livio

    2016-04-01

    We present the Italian contribution to the CSES (China Seismo-Electromagnetic Satellite) mission. The CSES satellite aims at investigating electromagnetic field, plasma and particles in the near-Earth environment in order to study in particular seismic precursors, particles fluxes (from Van Allen belts, cosmic rays, solar wind, etc.), anthropogenic electromagnetic pollution and more in general the atmosphere-ionosphere-magnetosphere coupling mechanisms that can affect the climate changes. The launch of CSES - the first of a series of several satellite missions - is scheduled by the end of 2016. The CSES satellite has been financed by the CNSA (China National Space Agency) and developed by CEA (China Earthquake Administration) together with several Chinese research institutes and private companies such as the DFH (that has developed the CAST2000 satellite platform). Italy participates to the CSES satellite mission with the LIMADOU project funded by ASI (Italian Space Agency) in collaboration with the Universities of Roma Tor Vergata, Uninettuno, Trento, Bologna and Perugia, as well as the INFN (Italian National Institute of Nuclear Physics), INGV (Italian National Institute of Geophysics and Volcanology) and INAF-IAPS (Italian National Institute of Astrophysics and Planetology). Many analyses have shown that satellite observations of electromagnetic fields, plasma parameters and particle fluxes in low Earth orbit may be useful in order to study the existence of electromagnetic emissions associated with the occurrence of earthquakes of medium and high magnitude. Although the earthquakes forecasting is not possible today, it is certainly a major challenge - and perhaps even a duty - for science in the near future. The claims that the reported anomalies (of electromagnetic, plasma and particle parameters) are seismic precursors are still intensely debated and analyses for confirming claimed correlations are still lacking. In fact, ionospheric currents, plasma

  8. Mars ISRU for Production of Mission Critical Consumables - Options, Recent Studies, and Current State of the Art

    Science.gov (United States)

    Sanders, G. B.; Paz, A.; Oryshchyn, L.; Araghi, K.; Muscatello, A.; Linne, D.; Kleinhenz, J.; Peters, T.

    2015-01-01

    In 1978, a ground breaking paper titled, "Feasibility of Rocket Propellant Production on Mars" by Ash, Dowler, and Varsi discussed how ascent propellants could be manufactured on the Mars surface from carbon dioxide collected from the atmosphere to reduce launch mass. Since then, the concept of making mission critical consumables such as propellants, fuel cell reactants, and life support consumables from local resources, commonly known as In-Situ Resource Utilization (ISRU), for robotic and human missions to Mars has been studied many times. In the late 1990's, NASA initiated a series of Mars Human Design Reference Missions (DRMs), the first of which was released in 1997. These studies primarily focused on evaluating the impact of making propellants on Mars for crew ascent to Mars orbit, but creating large caches of life support consumables (water & oxygen) as a backup for regenerative life support systems for long-duration surface stays (>500 days) was also considered in Mars DRM 3.0. Until science data from the Mars Odyssey orbiter and subsequent robotic missions revealed that water may be widely accessable across the surface of Mars, prior Mars ISRU studies were limited to processing Mars atmospheric resources (carbon dioxide, nitrogen, argon, oxygen, and water vapor). In December 2007, NASA completed the Mars Human Design Reference Architecture (DRA) 5.0 study which considered water on Mars as a potential resource for the first time in a human mission architecture. While knowledge of both water resources on Mars and the hardware required to excavate and extract the water were very preliminary, the study concluded that a significant reduction in mass and significant enhancements to the mission architecture were possible if Mars water resources were utilized. Two subsequent Mars ISRU studies aimed at reexamining ISRU technologies, processing options, and advancements in the state-of-the-art since 2007 and to better understand the volume and packaging associated

  9. Stilwell’s North Burma campaign: a case study in multinational mission command

    Science.gov (United States)

    2017-05-25

    senior leaders to communicate how they envision the Army operating in 2025 and beyond.28 During the fall of 2015, Perkins told an audience at the US...Mission to China, 140-41; 192. 48 Romanus and Sunderland, Stillwellʼs Mission to China, 213. 22 medical reception of Chinese soldiers. Dr. Seagrave... reception for NRA soldiers after the First Burma Campaign. He repeated the process when he assigned the hospital unit to Maingkwan to conduct medical

  10. The X-Ray Surveyor Mission Concept Study: Forging the Path to NASA Astrophysics 2020 Decadal Survey Prioritization

    Science.gov (United States)

    Gaskin, Jessica; Ozel, Feryal; Vikhlinin, Alexey

    2016-01-01

    The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.

  11. The X-Ray Surveyor mission concept study: forging the path to NASA astrophysics 2020 decadal survey prioritization

    Science.gov (United States)

    Gaskin, Jessica; Özel, Feryal; Vikhlinin, Alexey

    2016-07-01

    The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.

  12. Using Satellite Imagery to Monitor the Major Lakes; Case Study Lake Hamun

    Science.gov (United States)

    Norouzi, H.; Islam, R.; Bah, A.; AghaKouchak, A.

    2015-12-01

    Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes would provide invaluable information for policy-makers and local people. As part of a comprehensive study, we aim to monitor the land-cover/ land-use changes in the world's major lakes using satellite observations. As a case study, Hamun Lake which is a pluvial Lake, also known as shallow Lake, located on the south-east of Iran and adjacent to Afghanistan, and Pakistan borders is investigated. The Lake is the main source of resources (agriculture, fishing and hunting) for the people around it and politically important in the region since it is shared among three different countries. The purpose of the research is to find the Lake's area from 1972 to 2015 and to see if any drought or water resources management has affected the lake. Analyzing satellites imagery from Landsat shows that the area of the Lake changes seasonally and intra-annually. Significant seasonal effects are found in 1975,1977, 1987, 1993, 1996, 1998, 2000, 2009 and 2011, as well as, substantial amount of shallow water is found throughout the years. The precipitation records as well as drought historical records are studied for the lake's basin. Meteorological studies suggest that the drought, decrease of rainfalls in the province and the improper management of the Lake have caused environmental, economic and geographical consequences. The results reveal that lake has experienced at least two prolong dryings since 1972 which drought cannot solely be blamed as main forcing factor.Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes

  13. An Organizational Culture Study of Missouri State University Faculty/Staff in Relation to the University's Public Affair Mission

    Science.gov (United States)

    Weaver, Marissa LeClaire

    2012-01-01

    The purpose of the study was to address a problem of practice of the public affairs mission through the perceptions of faculty and staff members at Missouri State University of the University's organizational culture. The design included a phenomenological study with a set of organizational culture procedural questions related to the perceptions…

  14. NASA CYGNSS Tropical Cyclone Mission

    Science.gov (United States)

    Ruf, Chris; Atlas, Robert; Majumdar, Sharan; Ettammal, Suhas; Waliser, Duane

    2017-04-01

    The NASA Cyclone Global Navigation Satellite System (CYGNSS) mission consists of a constellation of eight microsatellites that were launched into low-Earth orbit on 15 December 2016. Each observatory carries a four-channel bistatic scatterometer receiver to measure near surface wind speed over the ocean. The transmitter half of the scatterometer is the constellation of GPS satellites. CYGNSS is designed to address the inadequacy in observations of the inner core of tropical cyclones (TCs) that result from two causes: 1) much of the TC inner core is obscured from conventional remote sensing instruments by intense precipitation in the eye wall and inner rain bands; and 2) the rapidly evolving (genesis and intensification) stages of the TC life cycle are poorly sampled in time by conventional polar-orbiting, wide-swath surface wind imagers. The retrieval of wind speed by CYGNSS in the presence of heavy precipitation is possible due to the long operating wavelength used by GPS (19 cm), at which scattering and attenuation by rain are negligible. Improved temporal sampling by CYGNSS is possible due to the use of eight spacecraft with 4 scatterometer channels on each one. Median and mean revisit times everywhere in the tropics are 3 and 7 hours, respectively. Wind speed referenced to 10m height above the ocean surface is retrieved from CYGNSS measurements of bistatic radar cross section in a manner roughly analogous to that of conventional ocean wind scatterometers. The technique has been demonstrated previously from space by the UK-DMC and UK-TDS missions. Wind speed is retrieved with 25 km spatial resolution and an uncertainty of 2 m/s at low wind speeds and 10% at wind speeds above 20 m/s. Extensive simulation studies conducted prior to launch indicate that there will be a significant positive impact on TC forecast skill for both track and intensity with CYGNSS measurements assimilated into HWRF numerical forecasts. Simulations of CYGNSS spatial and temporal sampling

  15. Pentecostals and the pulpit: A case study of the Apostolic Faith Mission of South Africa

    Directory of Open Access Journals (Sweden)

    Marius Nel

    2018-04-01

    Full Text Available In general, early Pentecostals did not use any pulpits in their halls in order to underline their emphasis that each believer is a prophet and priest equipped by the Holy Spirit with gifts for the edification of other members of the assembly. All participated in the worship service by way of praying, prophesying, witnessing and bringing a message from God. From the 1940s, Pentecostals in their desire to be acceptable in their communities formed an alliance with evangelicals, accepted their hermeneutical viewpoint and built traditional churches in accordance with the Protestant tradition. From the 1980s, the pulpit started disappearing from the front of Pentecostal churches. This is explained in terms of new alliances that Pentecostals made with neo-Pentecostalist churches and a new hermeneutical viewpoint. The hypothesis of the article is that the Pentecostal stance towards the pulpit was determined by its hermeneutical perspectives. It is described by way of a comparative literature study and applied to a specific case study, the Apostolic Faith Mission of South Africa.

  16. Cosmic ray investigation for the Voyager missions; energetic particle studies in the outer heliosphere - and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Stone, E C; Vogt, R E [California Inst. of Tech., Pasadena (USA); McDonald, F B; Teegarden, B J; Trainor, J H [National Aeronautics and Space Administration, Greenbelt, Md. (USA). Goddard Space Flight Center; Jokipii, J R [Arizona Univ., Tucson (USA); Webber, W R [New Hampshire Univ., Durham (USA)

    1977-12-01

    A cosmic-ray detector system (CRS) has been developed for the Voyager mission which will measure the energy spectrum of electrons from approximately 3-110 MeV and the energy spectra and elemental comparison of all cosmic-ray nuclei from hydrogen through iron over an energy range from approximately 1-500 MeV.nuc. Isotopes of hydrogen through sulfur will be resolved from approximately 2-75 MeV/nuc. Studies with CRS data will provide information on the energy content, origin and acceleration process, life history, and dynamics of cosmic rays in the galaxy, and contribute to an understanding of the nucleosynthesis of elements in the cosmic-ray sources. Particular emphasis will be placed on low-energy phenomena that are expected to exist in interstellar space and are known to be present in the outer Solar System. This investigation will also add to our understanding of the transport of cosmic rays, Jovian electrons, and low-energy interplanetary particles over an extended region of interplanetary space. A major contribution to these areas of study will be the measurement of three-dimensional streaming patterns of nuclei from H through Fe and electrons over an extended energy range, with a precision that will allow determination of anisotropies down to 1%. The required combination of charge resolution, reliability and redundance has been achieved with systems consisting entirely of solid-state charged-particle detectors.

  17. Nanosatellite missions - the future

    Science.gov (United States)

    Koudelka, O.; Kuschnig, R.; Wenger, M.; Romano, P.

    2017-09-01

    In the beginning, nanosatellite projects were focused on educational aspects. In the meantime, the technology matured and now allows to test, demonstrate and validate new systems, operational procedures and services in space at low cost and within much shorter timescales than traditional space endeavors. The number of spacecraft developed and launched has been increasing exponentially in the last years. The constellation of BRITE nanosatellites is demonstrating impressively that demanding scientific requirements can be met with small, low-cost satellites. Industry and space agencies are now embracing small satellite technology. Particularly in the USA, companies have been established to provide commercial services based on CubeSats. The approach is in general different from traditional space projects with their strict product/quality assurance and documentation requirements. The paper gives an overview of nanosatellite missions in different areas of application. Based on lessons learnt from the BRITE mission and recent developments at TU Graz (in particular the implementation of the OPS-SAT nanosatellite for ESA), enhanced technical possibilities for a future astronomy mission after BRITE will be discussed. Powerful on-board computers will allow on-board data pre-processing. A state-of-the-art telemetry system with high data rates would facilitate interference-free operations and increase science data return.

  18. Cibola flight experiment satellite

    Science.gov (United States)

    Davies, P.; Liddle, Doug; Paffett, John; Sweeting, Martin; Curiel, A.; Sun, Wei; Eves, Stuart

    2004-11-01

    In order to achieve an "economy of scale" with respect to payload capacity the major trend in telecommunications satellites is for larger and larger platforms. With these large platforms the level of integration between platform and payload is increasing leading to longer delivery schedules. The typical lifecycle for procurement of these large telecommunications satellites is now 3-6 years depending on the level of non-recurring engineering needed. Surrey Satellite Technology Ltd (SSTL) has designed a low-cost platform aimed at telecommunications and navigation applications. SSTL's Geostationary Minisatellite Platform (GMP) is a new entrant addressing the lower end of the market with payloads up to 250kg requiring less than 1.5 kW power. The British National Space Centre through the MOSAIC Small Satellite Initiative supported the development of GMP. The main design goals for GMP are low-cost for the complete mission including launch and operations and a platform allowing flexible payload accommodation. GMP is specifically designed to allow rapid development and deployment with schedules typically between 1 and 2 years from contract signature to flight readiness. GMP achieves these aims by a modular design where the level of integration between the platform and payload is low. The modular design decomposes the satellite into three major components - the propulsion bay, the avionics bay and the payload module. Both the propulsion and avionics bays are reusable, largely unchanged, and independent of the payload configuration. Such a design means that SSTL or a 3rd party manufacturer can manufacture the payload in parallel to the platform with integration taking place quite late in the schedule. In July 2003 SSTL signed a contract for ESA's first Galileo navigation satellite known as GSTBV2/A. The satellite is based on GMP and ESA plan to launch it into a MEO orbit late in 2005. The second flight of GMP is likely to be in 2006 carrying a geostationary payload

  19. Experimental study of the helicopter-mobile radioelectrical channel and possible extension to the satellite-mobile channel

    Science.gov (United States)

    Blanchetiere-Ciarletti, V.; Sylvain, M.; Lemenn, P.

    1994-07-01

    The use of satellite seems to be an answer to the radioelectrical covering problem for the mobile communications, particularly in the low populated areas. Frequency bands at 1.5 and 2.5 GHz have been dedicated to these future services. Satellite-mobile links will be much more affected by propagation phenomena than the existing links between satellites and fixed stations. The reasons for that are twofold: The probable use of LEO (Low-Earth-Orbit) satellites instead of GEO; such satellites will have to be received at relatively low elevation to limit their number; the use of mobile communication terminals with small and non directive antennas that must work in various environments instead of terrestrian stations located at carefully chosen places and equipped with large diameter paraboloids. These propagation phenomena mainly consist in the fading of the signal level (shadowing of the link), and a frequency selective fading due to multipath propagation. The experience run by C.R.P.E. is aimed at a better understanding of the satellite-mobile propagation channel at fixed frequency as well as on a large band. In this paper, we discuss preliminary results from a series of propagation measurements performed (by lack of any experimental satellite) on an experimental radio link at 1.45 GHz on a of 20 MHz bandwidth between a helicopter flying at a height of 2 km and a mobile receiver. The whole experiment has been run in a rural environment in Brittany (France). In a first part, we illustrate the quality of the data collected during the experiment on a typical case study and give a possible physical interpretation of the observed phenomena. Then we present statistical results concerning the various characteristics (attenuation and delay spreads) of the propagation channel. Finally, we discuss the problem of using a helicopter (flying at a height of 2 km) as a substitute for a satellite at about 1000 km and try to estimate to what extent it is possible to use the data

  20. Enterprise Level Status and Control of Multi-Satellite Operations

    Data.gov (United States)

    National Aeronautics and Space Administration — Single-satellite mission operation centers are used for nearly all Goddard Space Flight Center (GSFC) mission ground data systems, with a focus on localized data...

  1. Psychological characteristics of Swedish mandatory enlisted soldiers volunteering and not volunteering for international missions: an exploratory study.

    Science.gov (United States)

    Rydstedt, Leif W; Osterberg, Johan

    2013-04-01

    The purpose of this study was to assess personality traits, psychological fitness, and hardiness among conscript soldiers volunteering for international missions (n = 146), by comparing them with conscripts from the same year class and unit who did not apply for international missions (n = 275). The sample consisted of all mandatory enlisted soldiers assigned to a supply and maintenance regiment. There were no demographic differences between the groups. The volunteers reported greater stress tolerance, concern for others, extraversion, and self-confidence than the non-volunteers. There were no differences between the groups in orderliness, temper instability, or independence. Volunteers repeatedly reported greater psychological fitness for military missions and greater hardiness over the period of military service compared to the non-volunteers.

  2. Study of Sea Surface Temperatures changes due to tropical cyclone fanoos in the southwest Bay of Bengal using satellite and argo observations

    Science.gov (United States)

    Krishna Kailasam, Muni

    Sea surface temperature (SST) plays an important role in the studies of global climate system and as a boundary condition for operational numerical forecasts. Estimation of SST has tra-ditionally been performed with satellite based sensors operating in the infrared (IR) portion of the electromagnetic spectrum, where the ocean emissivity is close to unity. The National Oceanic and Atmospheric Administration (NOAA) satellite series, the GOES Imagers on the Geostationary Operational Environmental Satellites, the Along Track Scanning Radiometer (ATSR) on the European Remote Sensing satellites and the Moderate Resolution Imaging Spectroradiometer (MODIS) on the NASA EOS platform are successful examples of IR sen-sors currently used for operational SST retrievals. Significant progress in SST retrieval from remote sensing data came with the introduction of a new low-frequency channel (10.7 GHz) on microwave (MW) sensors. The anthropogenic effects over a period of time resulted in increase of infrared absorbers such as greenhouse gases and absorbing aerosol would produce increase of both daytime maximum and nighttime minimum temperatures. In contrast, the increases of visible reflectors such as sulfate aerosols and low cloud amount would result in a decrease of the daytime maximum temperature. Solar radiation, wind stress and vertical mixing are known to be the three major factors impacting the SST seasonal variations. In the present study, impact of absorbing aerosols on the sea surface temperature (SST) over Bay of Bengal (BoB) region was investigated. Increased aerosol loading over BoB was observed due to advection of aerosols from continental region consisting of absorbing particles primarily from dust and biomass burning. This increased loading over BoB resulted in reduction of surface reaching solar radiation. Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) de-rived SST over BoB showed negative correlation with OMI-Aerosol Index (AI) (R = 0.87) and

  3. Nanosar-case study of synthetic aperture radar for nano-satellites

    NARCIS (Netherlands)

    Engelen, S.; Oever, M. van den; Mahapatra, P.; Sundaramoorthy, P.; Gill, E.; Meijer, R.J.; Verhoeven, C.

    2012-01-01

    Nano-satellites have a cost advantage due to their low mass and usage of commercial-off-the-shelf technologies. However, the low mass also restricts the functionality of a nano-satellite's payload. Typically, this would imply instruments with very low to low resolution and accuracy, essentially

  4. Satellite altimetry and GRACE gravimetry for studies of annual water storage variations in Bangladesh

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Berry, P.; Freeman, J.

    2008-01-01

    Four different data sources have been compared with respect to observations of the annual water storage variations in the region of Bangladesh. Data from satellite altimeters and river gauges estimates the variation in surface water storage in the major rivers of Bangladesh. The GRACE satellites ...

  5. A European satellite-derived UV climatology available for impact studies

    International Nuclear Information System (INIS)

    Verdebout, J.

    2004-01-01

    This paper presents a satellite-derived climatology of the surface UV radiation, intended to support impact studies on the environment and human health. As of today, the dataset covers the period from 1 January 1984 to 31 August 2003, with daily dose maps covering Europe with a spatial resolution of 0.05 deg.. A comparison between the modelled erythemal daily dose and measurements in Ispra yields an r.m.s value with a relative difference of 29% and a bias of 3%. The seemingly large dispersion is, however, due to a restricted number of days for which the relative difference is very high. The climatological dataset documents systematic patterns in the geographical distribution of the surface UV radiation due to cloudiness, altitude and snow. It also shows a large year-to-year variability in monthly doses of up to ±50% in spring and ±30% in summer. (authors)

  6. Critical review of Ames Life Science participation in Spacelab Mission Development Test 3: The SMD 3 management study

    Science.gov (United States)

    Helmreich, R.; Wilhelm, J.; Tanner, T. A.; Sieber, J. E.; Burgenbauch, S.

    1978-01-01

    A management study was conducted to specify activities and problems encountered during the development of procedures for documentation and crew training on experiments, as well as during the design, integration, and delivery of a life sciences experiment payload to Johnson Space Center for a 7 day simulation of a Spacelab mission. Conclusions and recommendations to project management for current and future Ames' life sciences projects are included. Broader issues relevant to the conduct of future scientific missions under the constraints imposed by the environment of space are also addressed.

  7. Atmospheric Entry Studies for Venus Missions: 45 Sphere-Cone Rigid Aeroshells and Ballistic Entries

    Science.gov (United States)

    Prabhu, Dinesh K.; Spilker, Thomas R.; Allen, Gary A., Jr.; Hwang, Helen H.; Cappuccio, Gelsomina; Moses, Robert W.

    2013-01-01

    The present study considers direct ballistic entries into the atmosphere of Venus using a 45deg sphere-cone rigid aeroshell, a legacy shape that has been used successfully in the past in the Pioneer Venus Multiprobe Mission. For a number of entry mass and heatshield diameter combinations (i.e., various ballistic coefficients) and entry velocities, the trajectory space in terms of entry flight path angles between skip out and -30deg is explored with a 3DoF trajectory code, TRAJ. From these trajectories, the viable entry flight path angle space is determined through the use of mechanical and thermal performance limits on the thermal protection material and science payload; the thermal protection material of choice is entry-grade carbon phenolic, for which a material thermal response model is available. For mechanical performance, a 200 g limit is placed on the peak deceleration load experienced by the science instruments, and 10 bar is assumed as the pressure limit for entry-grade carbon-phenolic material. For thermal performance, inflection points in the total heat load distribution are used as cut off criteria. Analysis of the results shows the existence of a range of critical ballistic coefficients beyond which the steepest possible entries are determined by the pressure limit of the material rather than the deceleration load limit.

  8. A feasibility study and mission analysis for the Hybrid Plume Plasma Rocket

    Science.gov (United States)

    Sullivan, Daniel J.; Micci, Michael M.

    1990-01-01

    The Hybrid Plume Plasma Rocket (HPPR) is a high power electric propulsion concept which is being developed at the MIT Plasma Fusion Center. This paper presents a theoretical overview of the concept as well as the results and conclusions of an independent study which has been conducted to identify and categorize those technologies which require significant development before the HPPR can be considered a viable electric propulsion device. It has been determined that the technologies which require the most development are high power radio-frequency and microwave generation for space applications and the associated power processing units, low mass superconducting magnets, a reliable, long duration, multi-megawatt space nuclear power source, and long term storage of liquid hydrogen propellant. In addition to this, a mission analysis of a one-way transfer from low earth orbit (LEO) to Mars indicates that a constant acceleration thrust profile, which can be obtained using the HPPR, results in faster trip times and greater payload capacities than those afforded by more conventional constant thrust profiles.

  9. The contribution of the ARIEL space mission to the study of planetary formation

    Science.gov (United States)

    Turrini, D.; Miguel, Y.; Zingales, T.; Piccialli, A.; Helled, R.; Vazan, A.; Oliva, F.; Sindoni, G.; Panić, O.; Leconte, J.; Min, M.; Pirani, S.; Selsis, F.; Coudé du Foresto, V.; Mura, A.; Wolkenberg, P.

    2018-01-01

    The study of extrasolar planets and of the Solar System provides complementary pieces of the mosaic represented by the process of planetary formation. Exoplanets are essential to fully grasp the huge diversity of outcomes that planetary formation and the subsequent evolution of the planetary systems can produce. The orbital and basic physical data we currently possess for the bulk of the exoplanetary population, however, do not provide enough information to break the intrinsic degeneracy of their histories, as different evolutionary tracks can result in the same final configurations. The lessons learned from the Solar System indicate us that the solution to this problem lies in the information contained in the composition of planets. The goal of the Atmospheric Remote-Sensing Infrared Exoplanet Large-survey (ARIEL), one of the three candidates as ESA M4 space mission, is to observe a large and diversified population of transiting planets around a range of host star types to collect information on their atmospheric composition. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres, which should show minimal condensation and sequestration of high-Z materials and thus reveal their bulk composition across all main cosmochemical elements. In this work we will review the most outstanding open questions concerning the way planets form and the mechanisms that contribute to create habitable environments that the compositional information gathered by ARIEL will allow to tackle.

  10. The Study of the Electron Enhancements during Garuda-1 Satellite anomaly

    Science.gov (United States)

    Neflia, Neflia

    Garuda-1 Satellite is one of Indonesian geostationary satellite. On April 5, 2005 Garuda-1 experienced power loss. According to space weather condition, This anomaly could be caused by the enhancement of electron during the day of anomaly and geomagnetic activity. The electron enhancement during quite solar activity have been associated with solar wind speed and IMF. For this study I will use solar wind speed, IMF , AE, Kp, Dst and Plasma Flow Pressure. The result of this study show that before the electron fluxes exceed 1000 pfu on April 5 at 13 UT, solar wind plasma speed exceed 500 km/s from April 4 at 16 UT until April 6 at 21 UT, with maximum speed, 646 km/s, occur on April 5 at 9 UT. AE index also increase from April 4 at 16 UT until April 6 at 09 UT, with maximum AE, 1024 nT, occur on April 5 at 18 and 21 UT. From April 4 at 14 UT until April 5 at 7 UT, Bz index directed southward, with minimum Bz, -8.8 nT, occur at April 5 at 1 UT. Kp index also increase from April 4 at 16 UT until April 6 at 09 UT, with maximum Kp, 7, occur on April 5 at 0-3 UT. Dst decrease from April 4 at 21 UT until April 6 at 09 UT, with minimum Dst occur on April 5 at 5-6 UT. The plasma flow pressure increase from April4 at 18 UT until April 5 at 3 UT, with maximum pressure, 6.9 nPa, occur on April 4 at 21 UT. This result indicate that plasma condition was disturbed which started with geomagnetic subtorm in the Auroral region before electron flux increase.

  11. Studying Vegetation Salinity: From the Field View to a Satellite-Based Perspective

    Directory of Open Access Journals (Sweden)

    Rachel Lugassi

    2017-02-01

    Full Text Available Salinization of irrigated lands in the semi-arid Jezreel Valley, Northern Israel results in soil-structure deterioration and crop damage. We formulated a generic rule for estimating salinity of different vegetation types by studying the relationship between Cl/Na and different spectral slopes in the visible–near infrared–shortwave infrared (VIS–NIR–SWIR spectral range using both field measurements and satellite imagery (Sentinel-2. For the field study, the slope-based model was integrated with conventional partial least squares (PLS analyses. Differences in 14 spectral ranges, indicating changes in salinity levels, were identified across the VIS–NIR–SWIR region (350–2500 nm. Next, two different models were run using PLS regression: (i using spectral slope data across these ranges; and (ii using preprocessed spectral reflectance. The best model for predicting Cl content was based on continuum removal reflectance (R2 = 0.84. Satisfactory correlations were obtained using the slope-based PLS model (R2 = 0.77 for Cl and R2 = 0.63 for Na. Thus, salinity contents in fresh plants could be estimated, despite masking of some spectral regions by water absorbance. Finally, we estimated the most sensitive spectral channels for monitoring vegetation salinity from a satellite perspective. We evaluated the recently available Sentinel-2 imagery’s ability to distinguish variability in vegetation salinity levels. The best estimate of a Sentinel-2-based vegetation salinity index was generated based on a ratio between calculated slopes: the 490–665 nm and 705–1610 nm. This index was denoted as the Sentinel-2-based vegetation salinity index (SVSI (band 4 − band 2/(band 5 + band 11.

  12. Cadastral Resurvey using High Resolution Satellite Ortho Image - challenges: A case study in Odisha, India

    Science.gov (United States)

    Parida, P. K.; Sanabada, M. K.; Tripathi, S.

    2014-11-01

    Advancements in satellite sensor technology enabling capturing of geometrically accurate images of earth's surface coupled with DGPS/ETS and GIS technology holds the capability of large scale mapping of land resources at cadastral level. High Resolution Satellite Images depict field bunds distinctly. Thus plot parcels are to be delineated from cloud free ortho-images and obscured/difficult areas are to be surveyed using DGPS and ETS. The vector datasets thus derived through RS/DGPS/ETS survey are to be integrated in GIS environment to generate the base cadastral vector datasets for further settlement/title confirmation activities. The objective of this paper is to illustrate the efficacy of a hybrid methodology employed in Pitambarpur Sasana village under Digapahandi Tahasil of Ganjam district, as a pilot project, particularly in Odisha scenario where the land parcel size is very small. One of the significant observations of the study is matching of Cadastral map area i.e. 315.454 Acres, the image map area i.e. 314.887 Acres and RoR area i.e. 313.815 Acre. It was revealed that 79 % of plots derived by high-tech survey method show acceptable level of accuracy despite the fact that the mode of area measurement by ground and automated method has significant variability. The variations are more in case of Government lands, Temple/Trust lands, Common Property Resources and plots near to river/nalas etc. The study indicates that the adopted technology can be extended to other districts and cadastral resurvey and updating work can be done for larger areas of the country using this methodology.

  13. Using Multi-Scale Modeling Systems and Satellite Data to Study the Precipitation Processes

    Science.gov (United States)

    Tao, Wei-Kuo; Chern, J.; Lamg, S.; Matsui, T.; Shen, B.; Zeng, X.; Shi, R.

    2011-01-01

    In recent years, exponentially increasing computer power has extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 km2 in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale model can be run in grid size similar to cloud resolving model through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (l) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, the recent developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling system to study the precipitating systems and hurricanes/typhoons will be presented. The high-resolution spatial and temporal visualization will be utilized to show the evolution of precipitation processes. Also how to

  14. Evaluating a satellite-based seasonal evapotranspiration product and identifying its relationship with other satellite-derived products and crop yield: A case study for Ethiopia

    Science.gov (United States)

    Tadesse, Tsegaye; Senay, Gabriel B.; Berhan, Getachew; Regassa, Teshome; Beyene, Shimelis

    2015-01-01

    Satellite-derived evapotranspiration anomalies and normalized difference vegetation index (NDVI) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data are currently used for African agricultural drought monitoring and food security status assessment. In this study, a process to evaluate satellite-derived evapotranspiration (ETa) products with a geospatial statistical exploratory technique that uses NDVI, satellite-derived rainfall estimate (RFE), and crop yield data has been developed. The main goal of this study was to evaluate the ETa using the NDVI and RFE, and identify a relationship between the ETa and Ethiopia’s cereal crop (i.e., teff, sorghum, corn/maize, barley, and wheat) yields during the main rainy season. Since crop production is one of the main factors affecting food security, the evaluation of remote sensing-based seasonal ETa was done to identify the appropriateness of this tool as a proxy for monitoring vegetation condition in drought vulnerable and food insecure areas to support decision makers. The results of this study showed that the comparison between seasonal ETa and RFE produced strong correlation (R2 > 0.99) for all 41 crop growing zones in Ethiopia. The results of the spatial regression analyses of seasonal ETa and NDVI using Ordinary Least Squares and Geographically Weighted Regression showed relatively weak yearly spatial relationships (R2 < 0.7) for all cropping zones. However, for each individual crop zones, the correlation between NDVI and ETa ranged between 0.3 and 0.84 for about 44% of the cropping zones. Similarly, for each individual crop zones, the correlation (R2) between the seasonal ETa anomaly and de-trended cereal crop yield was between 0.4 and 0.82 for 76% (31 out of 41) of the crop growing zones. The preliminary results indicated that the ETa products have a good predictive potential for these 31 identified zones in Ethiopia. Decision makers may potentially use ETa products for monitoring cereal

  15. GRACE Status at Mission End

    Science.gov (United States)

    Tapley, B. D.; Flechtner, F. M.; Watkins, M. M.; Bettadpur, S. V.

    2017-12-01

    The twin satellites of the Gravity Recovery and Climate Experiment (GRACE) were launched on March 17, 2002 and have operated for nearly 16 years. The mission objectives are to observe the spatial and temporal variations of the Earth's mass through its effects on the gravity field at the GRACE satellite altitude. The mass changes observed are related to both the changes within the solid earth and the change within and between the Erath system components. A significant cause of the time varying mass is water motion and the GRACE mission has provided a continuous decade long measurement sequence which characterizes the seasonal cycle of mass transport between the oceans, land, cryosphere and atmosphere; its inter-annual variability; and the climate driven secular, or long period, mass transport signals. The fifth reanalysis on the mission data set, the RL05 data, were released in mid-2013. With the planned launch of GRACE Follow-On in early 2018, plans are underway for a reanalysis that will be consistent with the GRACE FO processing standards. The mission is entering the final phases of its operation life with mission end expected to occur in early 2018. The current mission operations strategy emphasizes extending the mission lifetime to obtain an overlap with the GRACE FO. This presentation will review the mission status and the projections for mission lifetime, describe the current operations philosophy and its impact on the science data, discuss the issues related to achieving the GRACE and GRACE FO connection and discuss issues related to science data products during this phase of the mission period.

  16. Iodine Satellite

    Science.gov (United States)

    Kamhawi, Hani; Dankanich, John; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Iodine Satellite (iSat) spacecraft will be the first CubeSat to demonstrate high change in velocity from a primary propulsion system by using Hall thruster technology and iodine as a propellant. The mission will demonstrate CubeSat maneuverability, including plane change, altitude change and change in its closest approach to Earth to ensure atmospheric reentry in less than 90 days. The mission is planned for launch in fall 2017. Hall thruster technology is a type of electric propulsion. Electric propulsion uses electricity, typically from solar panels, to accelerate the propellant. Electric propulsion can accelerate propellant to 10 times higher velocities than traditional chemical propulsion systems, which significantly increases fuel efficiency. To enable the success of the propulsion subsystem, iSat will also demonstrate power management and thermal control capabilities well beyond the current state-of-the-art for spacecraft of its size. This technology is a viable primary propulsion system that can be used on small satellites ranging from about 22 pounds (10 kilograms) to more than 1,000 pounds (450 kilograms). iSat's fuel efficiency is ten times greater and its propulsion per volume is 100 times greater than current cold-gas systems and three times better than the same system operating on xenon. iSat's iodine propulsion system consists of a 200 watt (W) Hall thruster, a cathode, a tank to store solid iodine, a power processing unit (PPU) and the feed system to supply the iodine. This propulsion system is based on a 200 W Hall thruster developed by Busek Co. Inc., which was previously flown using xenon as the propellant. Several improvements have been made to the original system to include a compact PPU, targeting greater than 80 percent reduction in mass and volume of conventional PPU designs. The cathode technology is planned to enable heaterless cathode conditioning, significantly increasing total system efficiency. The feed system has been designed to

  17. Comparative Study of Optical and RF Communication Systems for a Mars Mission - Part II. Unified Value Metrics

    Science.gov (United States)

    Hemmati, H.; Layland, J.; Lesh, J.; Wilson, K.; Sue, M.; Rascoe, D.; Lansing, F.; Wilhelm, M.; Harcke, L.; Chen, C.; hide

    1997-01-01

    In this Par-II report of the Advanced Communications Benefits study, two critical metrics for comparing the benefits of utilizing X-band, Ka-band and Optical frequencies for supporting generic classes of Martian exploration missions have been evaluated.

  18. Task and work performance on Skylab missions 2, 3, and 4: Time and motion study: Experiment M151

    Science.gov (United States)

    Kubis, J. F.; Mclaughlin, E. J.; Jackson, J. M.; Rusnak, R.; Mcbride, G. H.; Saxon, S. V.

    1977-01-01

    Human task performance was evaluated under weightlessness conditions during long duration space flight in order to study the characteristics of the adaptation function. Results show that despite pronounced variability in training schedules and in initial reaction to the Skylab environment, in-flight task performance was relatively equivalent among Skylab crews, and behavioral performance continued to improve from beginning to end of all missions.

  19. The Ballerina experiment on the Romer mission

    DEFF Research Database (Denmark)

    Brandt, Søren Kristian

    2001-01-01

    The Romer mission has recently been approved as the next mission within the Danish Small Satellite Program. The scientific payload will consist of two separate experiments, the MONS and the Ballerina payloads. The primary objective of Ballerina is to provide accurate, real-time positions relayed...

  20. Lunar Exploration Missions Since 2006

    Science.gov (United States)

    Lawrence, S. J. (Editor); Gaddis, L. R.; Joy, K. H.; Petro, N. E.

    2017-01-01

    The announcement of the Vision for Space Exploration in 2004 sparked a resurgence in lunar missions worldwide. Since the publication of the first "New Views of the Moon" volume, as of 2017 there have been 11 science-focused missions to the Moon. Each of these missions explored different aspects of the Moon's geology, environment, and resource potential. The results from this flotilla of missions have revolutionized lunar science, and resulted in a profoundly new emerging understanding of the Moon. The New Views of the Moon II initiative itself, which is designed to engage the large and vibrant lunar science community to integrate the results of these missions into new consensus viewpoints, is a direct outcome of this impressive array of missions. The "Lunar Exploration Missions Since 2006" chapter will "set the stage" for the rest of the volume, introducing the planetary community at large to the diverse array of missions that have explored the Moon in the last decade. Content: This chapter will encompass the following missions: Kaguya; ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon’s Interaction with the Sun); Chang’e-1; Chandrayaan-1; Moon Impact Probe; Lunar Reconnaissance Orbiter (LRO); Lunar Crater Observation Sensing Satellite (LCROSS); Chang’e-2; Gravity Recovery and Interior Laboratory (GRAIL); Lunar Atmosphere and Dust Environment Explorer (LADEE); Chang’e-3.

  1. Saturn satellites

    International Nuclear Information System (INIS)

    Ruskol, E.L.

    1981-01-01

    The characteristics of the Saturn satellites are discussed. The satellites close to Saturn - Janus, Mimas, Enceladus, Tethys, Dione and Rhea - rotate along the circular orbits. High reflectivity is attributed to them, and the density of the satellites is 1 g/cm 3 . Titan is one of the biggest Saturn satellites. Titan has atmosphere many times more powerful than that of Mars. The Titan atmosphere is a peculiar medium with a unique methane and hydrogen distribution in the whole Solar system. The external satellites - Hyperion, Japetus and Phoebe - are poorly investigated. Neither satellite substance density, nor their composition are known. The experimental data on the Saturn rings obtained on the ''Pioneer-11'' and ''Voyager-1'' satellites are presented [ru

  2. The determinations of remote sensing satellite data delivery service quality: A positivistic case study in Chinese context

    Science.gov (United States)

    Jin, Jiahua; Yan, Xiangbin; Tan, Qiaoqiao; Li, Yijun

    2014-03-01

    With the development of remote sensing technology, remote-sensing satellite has been widely used in many aspects of national construction. Big data with different standards and massive users with different needs, make the satellite data delivery service to be a complex giant system. How to deliver remote-sensing satellite data efficiently and effectively is a big challenge. Based on customer service theory, this paper proposes a hierarchy conceptual model for examining the determinations of remote-sensing satellite data delivery service quality in the Chinese context. Three main dimensions: service expectation, service perception and service environment, and 8 sub-dimensions are included in the model. Large amount of first-hand data on the remote-sensing satellite data delivery service have been obtained through field research, semi-structured questionnaire and focused interview. A positivist case study is conducted to validate and develop the proposed model, as well as to investigate the service status and related influence mechanisms. Findings from the analysis demonstrate the explanatory validity of the model, and provide potentially helpful insights for future practice.

  3. The determinations of remote sensing satellite data delivery service quality: A positivistic case study in Chinese context

    International Nuclear Information System (INIS)

    Jin, Jiahua; Yan, Xiangbin; Tan, Qiaoqiao; Li, Yijun

    2014-01-01

    With the development of remote sensing technology, remote-sensing satellite has been widely used in many aspects of national construction. Big data with different standards and massive users with different needs, make the satellite data delivery service to be a complex giant system. How to deliver remote-sensing satellite data efficiently and effectively is a big challenge. Based on customer service theory, this paper proposes a hierarchy conceptual model for examining the determinations of remote-sensing satellite data delivery service quality in the Chinese context. Three main dimensions: service expectation, service perception and service environment, and 8 sub-dimensions are included in the model. Large amount of first-hand data on the remote-sensing satellite data delivery service have been obtained through field research, semi-structured questionnaire and focused interview. A positivist case study is conducted to validate and develop the proposed model, as well as to investigate the service status and related influence mechanisms. Findings from the analysis demonstrate the explanatory validity of the model, and provide potentially helpful insights for future practice

  4. Interplanetary Trajectory Design for the Asteroid Robotic Redirect Mission Alternate Approach Trade Study

    Science.gov (United States)

    Merrill, Raymond Gabriel; Qu, Min; Vavrina, Matthew A.; Englander, Jacob A.; Jones, Christopher A.

    2014-01-01

    This paper presents mission performance analysis methods and results for the Asteroid Robotic Redirect Mission (ARRM) option to capture a free standing boulder on the surface of a 100 m or larger NEA. It details the optimization and design of heliocentric low-thrust trajectories to asteroid targets for the ARRM solar electric propulsion spacecraft. Extensive searches were conducted to determine asteroid targets with large pick-up mass potential and potential observation opportunities. Interplanetary trajectory approximations were developed in method based tools for Itokawa, Bennu, 1999 JU3, and 2008 EV5 and were validated by end-to-end integrated trajectories.

  5. IUS/TUG orbital operations and mission support study. Volume 4: Project planning data

    Science.gov (United States)

    1975-01-01

    Planning data are presented for the development phases of interim upper stage (IUS) and tug systems. Major project planning requirements, major event schedules, milestones, system development and operations process networks, and relevant support research and technology requirements are included. Topics discussed include: IUS flight software; tug flight software; IUS/tug ground control center facilities, personnel, data systems, software, and equipment; IUS mission events; tug mission events; tug/spacecraft rendezvous and docking; tug/orbiter operations interface, and IUS/orbiter operations interface.

  6. Mission to Planet Earth

    Science.gov (United States)

    Tilford, Shelby G.; Asrar, Ghassem; Backlund, Peter W.

    1994-01-01

    Mission to Planet Earth (MTPE) is NASA's concept for an international science program to produce the understanding needed to predict changes in the Earth's environment. NASA and its interagency and international partners will place satellites carrying advanced sensors in strategic Earth orbits to gather multidisciplinary data. A sophisticated data system will process and archive an unprecedented amount of information about the Earth and how it works as a system. Increased understanding of the Earth system is a basic human responsibility, a prerequisite to informed management of the planet's resources and to the preservation of the global environment.

  7. Mission to Planet Earth

    International Nuclear Information System (INIS)

    Wilson, G.S.; Backlund, P.W.

    1992-01-01

    Mission to Planet Earth (MTPE) is NASA's concept for an international science program to produce the understanding needed to predict changes in the earth's environment. NASA and its interagency and international partners will place satellites carrying advanced sensors in strategic earth orbits to gather multidisciplinary data. A sophisticated data system will process and archive an unprecedented amount of information about the earth and how it works as a system. Increased understanding of the earth system is a basic human responsibility, a prerequisite to informed management of the planet's resources and to the preservation of the global environment. 8 refs

  8. Radiation shielding aspects for long manned mission to space - Criteria, survey study and preliminary model

    International Nuclear Information System (INIS)

    Sztejnberg, M.; Xiao, S.; Satvat, N.; Limon, F.; Hopkins, J.; Jevremovic, T.; T. Jevremovic)

    2006-01-01

    The prospect of manned space missions out side Earth's or bit is limited by the travel time and shielding against cosmic radiation. The chemical rockets currently used in the space program have no hope of propelling a manned vehicle to a far away location such as Mars due to the enormous mass of fuel that would be required. The specific energy available from nuclear fuel is a factor of 106 higher than chemical fuel; it is there fore obvious that nuclear power production in space is a must. On the other hand, recent considerations to send a man to the Moon for a long stay would require a stable, secured, and safe source of energy (there is hardly anything beyond nuclear power that would provide a useful and reliably safe sustainable supply of energy). National Aeronautics and Space Administration (NASA) anticipates that the mass of a shielding material required for long travel to Mars is the next major design driver. In 2006 NASA identified a need to assess and evaluate potential gaps in existing knowledge and understanding of the level and types of radiation critical to astronauts' health during the long travel to Mars and to start a comprehensive study related to the shielding design of a spacecraft finding the conditions for the mitigation of radiation components contributing to the doses beyond accepted limits. In order to reduce the overall space craft mass, NASA is looking for the novel, multi-purpose and multi-functional materials that will provide effective shielding of the crew and electronics on board. The Laboratory for Neutronics and Geometry Computation in the School of Nuclear Engineering at Purdue University led by Prof. Tatjana Jevremovic began in 2004 the analytical evaluations of different lightweight materials. The preliminary results of the design survey study are presented in this paper. (author)

  9. Radiation shielding aspects for long manned mission to space: Criteria, survey study, and preliminary model

    Directory of Open Access Journals (Sweden)

    Sztejnberg Manuel

    2006-01-01

    Full Text Available The prospect of manned space missions outside Earth's orbit is limited by the travel time and shielding against cosmic radiation. The chemical rockets currently used in the space program have no hope of propelling a manned vehicle to a far away location such as Mars due to the enormous mass of fuel that would be required. The specific energy available from nuclear fuel is a factor of 106 higher than chemical fuel; it is therefore obvious that nuclear power production in space is a must. On the other hand, recent considerations to send a man to the Moon for a long stay would require a stable, secured and safe source of energy (there is hardly anything beyond nuclear power that would provide a useful and reliably safe sustainable supply of energy. National Aeronautics and Space Administration (NASA anticipates that the mass of a shielding material required for long travel to Mars is the next major design driver. In 2006 NASA identified a need to assess and evaluate potential gaps in existing knowledge and understanding of the level and types of radiation critical to astronauts' health during the long travel to Mars and to start a comprehensive study related to the shielding design of a spacecraft finding the conditions for the mitigation of radiation components contributing to the doses beyond accepted limits. In order to reduce the overall space craft mass, NASA is looking for the novel, multi-purpose and multi-functional materials that will provide effective shielding of the crew and electronics on board. The Laboratory for Neutronics and Geometry Computation in the School of Nuclear Engineering at Purdue University led by Prof. Tatjana Jevremović began in 2004 the analytical evaluations of different lightweight materials. The preliminary results of the design survey study are presented in this paper.

  10. MIOSAT Mission Scenario and Design

    Science.gov (United States)

    Agostara, C.; Dionisio, C.; Sgroi, G.; di Salvo, A.

    2008-08-01

    MIOSAT ("Mssione Ottica su microSATellite") is a low-cost technological / scientific microsatellite mission for Earth Observation, funded by Italian Space Agency (ASI) and managed by a Group Agreement between Rheinmetall Italia - B.U. Spazio - Contraves as leader and Carlo Gavazzi Space as satellite manufacturer. Several others Italians Companies, SME and Universities are involved in the development team with crucial roles. MIOSAT is a microsatellite weighting around 120 kg and placed in a 525 km altitude sun-synchronuos circular LEO orbit. The microsatellite embarks three innovative optical payloads: Sagnac multi spectral radiometer (IFAC-CNR), Mach Zehender spectrometer (IMM-CNR), high resolution pancromatic camera (Selex Galileo). In addition three technological experiments will be tested in-flight. The first one is an heat pipe based on Marangoni effect with high efficiency. The second is a high accuracy Sun Sensor using COTS components and the last is a GNSS SW receiver that utilizes a Leon2 processor. Finally a new generation of 28% efficiency solar cells will be adopted for the power generation. The platform is highly agile and can tilt along and cross flight direction. The pointing accuracy is in the order of 0,1° for each axe. The pointing determination during images acquisition is <0,02° for the axis normal to the boresight and 0,04° for the boresight. This paper deals with MIOSAT mission scenario and definition, highlighting trade-offs for mission implementation. MIOSAT mission design has been constrained from challenging requirements in terms of satellite mass, mission lifetime, instrument performance, that have implied the utilization of satellite agility capability to improve instruments performance in terms of S/N and resolution. The instruments provide complementary measurements that can be combined in effective ways to exploit new applications in the fields of atmosphere composition analysis, Earth emissions, antropic phenomena, etc. The Mission

  11. The THEMIS Mission

    CERN Document Server

    Burch, J. L

    2009-01-01

    The THEMIS mission aims to determine the trigger and large-scale evolution of substorms by employing five identical micro-satellites which line up along the Earth's magnetotail to track the motion of particles, plasma, and waves from one point to another and for the first time, resolve space-time ambiguities in key regions of the magnetosphere on a global scale. The primary goal of THEMIS is to elucidate which magnetotail process is responsible for substorm onset at the region where substorm auroras map: (i) local disruption of the plasma sheet current (current disruption) or (ii) the interaction of the current sheet with the rapid influx of plasma emanating from reconnection. The probes also traverse the radiation belts and the dayside magnetosphere, allowing THEMIS to address additional baseline objectives. This volume describes the mission, the instrumentation, and the data derived from them.

  12. Study to forecast and determine characteristics of world satellite communications market

    Science.gov (United States)

    Filep, R. T.; Schnapf, A.; Fordyce, S. W.

    1983-01-01

    The world commercial communications satellite market during the spring and summer of 1983 was examined and characteristics and forecasts of the market extending to the year 2000 were developed. Past, present and planned satellites were documented in relation to frequencies, procurement and launch dates, costs, transponders, and prime contractor. Characteristics of the market are outlined for the periods 1965 - 1985, 1986 - 1989, and 1990 - 2000. Market share forecasts, discussions of potential competitors in various world markets, and profiles of major communication satellite manufacturing and user countries are documented.

  13. Large Observatory for x-ray Timing (LOFT-P): a Probe-class mission concept study

    Science.gov (United States)

    Wilson-Hodge, Colleen A.; Ray, Paul S.; Chakrabarty, Deepto; Feroci, Marco; Alvarez, Laura; Baysinger, Michael; Becker, Chris; Bozzo, Enrico; Brandt, Soren; Carson, Billy; Chapman, Jack; Dominguez, Alexandra; Fabisinski, Leo; Gangl, Bert; Garcia, Jay; Griffith, Christopher; Hernanz, Margarita; Hickman, Robert; Hopkins, Randall; Hui, Michelle; Ingram, Luster; Jenke, Peter; Korpela, Seppo; Maccarone, Tom; Michalska, Malgorzata; Pohl, Martin; Santangelo, Andrea; Schanne, Stephane; Schnell, Andrew; Stella, Luigi; van der Klis, Michiel; Watts, Anna; Winter, Berend; Zane, Silvia

    2016-07-01

    LOFT-P is a mission concept for a NASA Astrophysics Probe-Class (matter? What are the effects of strong gravity on matter spiraling into black holes? It would be optimized for sub-millisecond timing of bright Galactic X-ray sources including X-ray bursters, black hole binaries, and magnetars to study phenomena at the natural timescales of neutron star surfaces and black hole event horizons and to measure mass and spin of black holes. These measurements are synergistic to imaging and high-resolution spectroscopy instruments, addressing much smaller distance scales than are possible without very long baseline X-ray interferometry, and using complementary techniques to address the geometry and dynamics of emission regions. LOFT-P would have an effective area of >6 m2, > 10x that of the highly successful Rossi X-ray Timing Explorer (RXTE). A sky monitor (2-50 keV) acts as a trigger for pointed observations, providing high duty cycle, high time resolution monitoring of the X-ray sky with 20 times the sensitivity of the RXTE All-Sky Monitor, enabling multi-wavelength and multimessenger studies. A probe-class mission concept would employ lightweight collimator technology and large-area solid-state detectors, segmented into pixels or strips, technologies which have been recently greatly advanced during the ESA M3 Phase A study of LOFT. Given the large community interested in LOFT (>800 supporters*, the scientific productivity of this mission is expected to be very high, similar to or greater than RXTE ( 2000 refereed publications). We describe the results of a study, recently completed by the MSFC Advanced Concepts Office, that demonstrates that such a mission is feasible within a NASA probe-class mission budget.

  14. Hipparcos: mission accomplished

    Science.gov (United States)

    1993-08-01

    During the last few months of its life, as the high radiation environment to which the satellite was exposed took its toll on the on-board system, Hipparcos was operated with only two of the three gyroscopes normally required for such a satellite, following an ambitious redesign of the on-board and on-ground systems. Plans were in hand to operate the satellite without gyroscopes at all, and the first such "gyro- less" data had been acquired, when communication failure with the on-board computers on 24 June 1993 put an end to the relentless flow of 24000 bits of data that have been sent down from the satellite each second, since launch. Further attempts to continue operations proved unsuccessful, and after a short series of sub-systems tests, operations were terminated four years and a week after launch. An enormous wealth of scientific data was gathered by Hipparcos. Even though data analysis by the scientific teams involved in the programme is not yet completed, it is clear that the mission has been an overwhelming success. "The ESA advisory bodies took a calculated risk in selecting this complex but fundamental programme" said Dr. Roger Bonnet, ESA's Director of Science, "and we are delighted to have been able to bring it to a highly successful conclusion, and to have contributed unique information that will take a prominent place in the history and development of astrophysics". Extremely accurate positions of more than one hundred thousand stars, precise distance measurements (in most cases for the first time), and accurate determinations of the stars' velocity through space have been derived. The resulting HIPPARCOS Star Catalogue, expected to be completed in 1996, will be of unprecedented accuracy, achieving results some 10-100 times more accurate than those routinely determined from ground-based astronomical observatories. A further star catalogue, the Thyco Star Catalogue of more than a million stars, is being compiled from additional data accumulated by the

  15. In Situ Biological Contamination Studies of the Moon: Implications for Future Planetary Protection and Life Detection Missions

    Science.gov (United States)

    Glavin, Daniel P.; Dworkin, Jason P.; Lupisella, Mark; Kminek, Gerhard; Rummel, John D.

    2010-01-01

    NASA and ESA have outlined visions for solar system exploration that will include a series of lunar robotic precursor missions to prepare for, and support a human return to the Moon, and future human exploration of Mars and other destinations. One of the guiding principles for exploration is to pursue compelling scientific questions about the origin and evolution of life. The search for life on objects such as Mars will require that all spacecraft and instrumentation be sufficiently cleaned and sterilized prior to launch to ensure that the scientific integrity of extraterrestrial samples is not jeopardized by terrestrial organic contamination. Under the Committee on Space Research's (COSPAR's) current planetary protection policy for the Moon, no sterilization procedures are required for outbound lunar spacecraft, nor is there yet a planetary protection category for human missions. Future in situ investigations of a variety of locations on the Moon by highly sensitive instruments designed to search for biologically derived organic compounds would help assess the contamination of the Moon by lunar spacecraft. These studies could also provide valuable "ground truth" data for Mars sample return missions and help define planetary protection requirements for future Mars bound spacecraft carrying life detection experiments. In addition, studies of the impact of terrestrial contamination of the lunar surface by the Apollo astronauts could provide valuable data to help refine future Mars surface exploration plans for a human mission to Mars.

  16. Adapting an existing visualization application for browser-based deployment: A case study from the Tropical Rainfall Measuring Mission

    Science.gov (United States)

    Kelley, Owen A.

    2013-02-01

    THOR, the Tool for High-resolution Observation Review, is a data viewer for the Tropical Rainfall Measuring Mission (TRMM) and the upcoming Global Precipitation Measurement (GPM) mission. THOR began as a desktop application, but now it can be accessed with a web browser, making THOR one of the first online tools for visualizing TRMM satellite data (http://pps.gsfc.nasa.gov/thor). In this effort, the reuse of the existing visualization code was maximized and the complexity of new code was minimized by avoiding unnecessary functionality, frameworks, or libraries. The simplicity of this approach makes it potentially attractive to researchers wishing to adapt their visualization applications for online deployment. To enable THOR to run within a web browser, three new pieces of code are written. First, the graphical user interface (GUI) of the desktop application is translated into HTML, JavaScript, and CSS. Second, a simple communication mechanism is developed over HTTP. Third, a virtual GUI is created on the server that interfaces with the image-generating routines of the existing desktop application so that these routines do not need to be modified for online use. While the basic functionality of THOR is now available online, prototyping is ongoing for enhanced 3D imaging and other aspects of both THOR Desktop and THOR Online. Because TRMM data products are complex and periodically reprocessed with improved algorithms, having a tool such as THOR is important to analysts at the Precipitation Processing System where the algorithms are tested and the products generated, stored, and distributed. Researchers also have found THOR useful for taking a first look at individual files before writing their own software to perform specialized calculations and analyses.

  17. Forest fires detection in Indonesia using satellite Himawari-8 (case study: Sumatera and Kalimantan on august-october 2015)

    Science.gov (United States)

    Fatkhuroyan; Wati, Trinah; Panjaitan, Andersen

    2017-01-01

    Forest fires in Indonesia are serious problem affecting widely in material losses, health and environment. Himawari-8 as one of meteorological satellites with high resolution 0,5 km x 0,5 km can be used for forest fire monitoring and detection. Combination between 3, 4 and 6 channels using Sataid (Satellite Animation and Interactive Diagnosis) software will visualize forest fire in the study site. Monitoring which used Himawari-8 data on August, September and October 2015 can detect the distribution of smoke and the extents of forest fire in Sumatera and Kalimantan. The result showed the extent of forest fire can be identified for anticipation in the next step.

  18. Recent progress in biomass burning research: a perspective from analyses of satellite data and model studies. (Invited)

    Science.gov (United States)

    Logan, J. A.

    2010-12-01

    Significant progress has been made in using satellite data to provide bottom-up constraints on biomass burning (BB) emissions. However, inverse studies with CO satellite data imply that tropical emissions are underestimated by current inventories, while model simulations of the ARCTAS period imply that the FLAMBE estimates of extratropical emissions are significantly overestimated. Injection heights of emissions from BB have been quantified recently using MISR data, and these data provide some constraints on 1-d plume models. I will discuss recent results in these areas, highlighting future research needs.

  19. Supernova / Acceleration Probe: A Satellite Experiment to Study the Nature of the Dark Energy

    Energy Technology Data Exchange (ETDEWEB)

    Aldering, G; Althouse, W; Amanullah, R; Annis, J; Astier, P; Baltay, C; Barrelet, E; Basa, S; Bebek, C; Bergstrom, L; Bernstein, G; Bester, M; Bigelow, B; Blandford, R; Bohlin, R; Bonissent, A; Bower, C; Brown, M; Campbell, M; Carithers, W; Commins, E; Craig, W; Day, C; DeJongh, F; Deustua, S; Diehl, T; Dodelson, S; Ealet, A; Ellis, R; Emmet, W; Fouchez, D; Frieman, J; Fruchter, A; Gerdes, D; Gladney, L; Goldhaber, G; Goobar, A; Groom, D; Heetderks, H; Hoff, M; Holland, S; Huffer, M; Hui, L; Huterer, D; Jain, B; Jelinsky, P; Karcher, A; Kent, S; Kahn, S; Kim, A; Kolbe, W; Krieger, B; Kushner, G; Kuznetsova, N; Lafever, R; Lamoureux, J; Lampton, M; Fevre, OL; Levi, M; Limon, P; Lin, H; Linder, E; Loken, S; Lorenzon, W; Malina, R; Marriner, J; Marshall, P; Massey, R; Mazure, A; McKay, T; McKee, S; Miquel, R; Morgan, N; Mortsell, E; Mostek, N; Mufson, S; Musser, J; Nugent, P; Oluseyi, H; Pain, R; Palaio, N; Pankow, D; Peoples, J; Perlmutter, S; Prieto, E; Rabinowitz, D; Refregier, A; Rhodes, J; Roe, N; Rusin, D; Scarpine, V; Schubnell, M; Sholl, M; Smadja, G; Smith, RM; Smoot, G; Snyder, J; Spadafora, A; Stebbins, A; Stoughton, C; Szymkowiak, A; Tarle, G; Taylor, K; Tilquin, A; Tomasch, A; Tucker, D; Vincent, D; Lippe, HVD; Walder, J-P; Wang, G; Wester, W

    2004-05-12

    The Supernova / Acceleration Probe (SNAP) is a proposed space-based experiment designed to study the dark energy and alternative explanations of the acceleration of the Universe's expansion by performing a series of complementary systematics-controlled measurements. We describe a self-consistent reference mission design for building a Type Ia supernova Hubble diagram and for performing a wide-area weak gravitational lensing study. A 2-m wide-field telescope feeds a focal plane consisting of a 0.7 square-degree imager tiled with equal areas of optical CCDs and near infrared sensors, and a high-efficiency low-resolution integral field spectrograph. The SNAP mission will obtain high-signal-to-noise calibrated light-curves and spectra for several thousand supernovae at redshifts between z=0.1 and 1.7. A wide-field survey covering one thousand square degrees resolves ~100 galaxies per square arcminute. If we assume we live in a cosmological-constant-dominated Universe, the matter density, dark energy density, and flatness of space can all be measured with SNAP supernova and weak-lensing measurements to a systematics-limited accuracy of 1%. For a flat universe, the density-to-pressure ratio of dark energy can be similarly measured to 5% for the present value w0 and ~0.1 for the time variation w'. The large survey area, depth, spatial resolution, time-sampling, and nine-band optical to NIR photometry will support additional independent and/or complementary dark-energy measurement approaches as well as a broad range of auxiliary science programs.

  20. Preliminary design of an asteroid hopping mission

    Science.gov (United States)

    Scheppa, Michael D.

    In 2010, NASA announced that its new vision is to support private space launch operations. It is anticipated that this new direction will create the need for new and innovative ideas that push the current boundaries of space exploration and contain the promise of substantial gain, both in research and capital. The purpose of the study is to plan and estimate the feasibility of a mission to visit a number of near Earth asteroids (NEAs). The mission would take place before the end of the 21st century, and would only use commercially available technology. Throughout the mission design process, while holding astronaut safety paramount, it was the goal to maximize the return while keeping the cost to a minimum. A mission of the nature would appeal to the private space industry because it could be easily adapted and set into motion. The mission design was divided into three main parts; mission timeline, vehicle design and power sources, with emphasis on nuclear and solar electric power, were investigated. The timeline and associated trajectories were initially selected using a numerical estimation and then optimized using Satellite Tool Kit (STK) 9.s's Design Explorer Optimizer [1]. Next, the spacecraft was design using commercially available parts that would support the mission requirements. The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) was and instrumental piece in maximizing the number of NEAs visited. Once the spacecraft was designed, acceptable power supply options were investigated. The VASIMR VX-200 requires 200 kilowatts of power to maintain thrust. This creates the need for a substantial power supply that consists of either a nuclear reactor of massive solar arrays. STK 9.1's Design Explorer Optimizer was able to create a mission time line that allowed for the exploration of seven NEAs in under two years, while keeping the total mission DeltaV under 71 kilometers per second. Based on these initial findings, it is determined that a mission of this

  1. Virtual Satellite Integration Environment, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Advatech Pacific proposes to develop a Virtual Satellite Integration Environment (VSIE) for the NASA Ames Mission Design Center. The VSIE introduces into NASA...

  2. Future Satellite Gravimetry and Earth Dynamics

    CERN Document Server

    Flury, Jakob

    2005-01-01

    Currently, a first generation of dedicated satellite missions for the precise mapping of the Earth’s gravity field is in orbit (CHAMP, GRACE, and soon GOCE). The gravity data from these satellite missions provide us with very new information on the dynamics of planet Earth. In particular, on the mass distribution in the Earth’s interior, the entire water cycle (ocean circulation, ice mass balance, continental water masses, and atmosphere), and on changes in the mass distribution. The results are fascinating, but still rough with respect to spatial and temporal resolution. Technical progress in satellite-to-satellite tracking and in gravity gradiometry will allow more detailed results in the future. In this special issue, Earth scientists develop visions of future applications based on follow-on high-precision satellite gravimetry missions.

  3. A Study of Background Conditions for Sphinx—The Satellite-Borne Gamma-Ray Burst Polarimeter

    Directory of Open Access Journals (Sweden)

    Fei Xie

    2018-04-01

    Full Text Available SPHiNX is a proposed satellite-borne gamma-ray burst polarimeter operating in the energy range 50–500 keV. The mission aims to probe the fundamental mechanism responsible for gamma-ray burst prompt emission through polarisation measurements. Optimising the signal-to-background ratio for SPHiNX is an important task during the design phase. The Geant4 Monte Carlo toolkit is used in this work. From the simulation, the total background outside the South Atlantic Anomaly (SAA is about 323 counts/s, which is dominated by the cosmic X-ray background and albedo gamma rays, which contribute ∼60% and ∼35% of the total background, respectively. The background from albedo neutrons and primary and secondary cosmic rays is negligible. The delayed background induced by the SAA-trapped protons is about 190 counts/s when SPHiNX operates in orbit for one year. The resulting total background level of ∼513 counts/s allows the polarisation of ∼50 GRBs with minimum detectable polarisation less than 30% to be determined during the two-year mission lifetime.

  4. Performance metrics for the assessment of satellite data products: an ocean color case study

    Science.gov (United States)

    Performance assessment of ocean color satellite data has generally relied on statistical metrics chosen for their common usage and the rationale for selecting certain metrics is infrequently explained. Commonly reported statistics based on mean squared errors, such as the coeffic...

  5. Satellite and ship studies of phytoplankton along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Goes, J.I.; Gomes, H.; Kumar, A; Gouveia, A; Devassy, V.P.; Parulekar, A; Rao, L.V.G.

    AidEd. by a sequence of chlorophyll images from the Coastal Zone Color Scanner on board the Nimbus-7 satellite and extensive shipboard observations, a descriptive analysis of the factors influencing the distribution and production of phytoplankton...

  6. ''Meteor'' radio/television satellites for study of earth's natural resources

    Energy Technology Data Exchange (ETDEWEB)

    Selivanov, A S; Tuchin, Yu M

    1981-01-01

    Two types of wide sweep multi-zonal scanning devices are included in the Meteor units, including radio-transmitting, and memory units. Data is transmitted within the wave range assigned to meteorologic earth satellites.

  7. Reconstructing Global-scale Ionospheric Outflow With a Satellite Constellation

    Science.gov (United States)

    Liemohn, M. W.; Welling, D. T.; Jahn, J. M.; Valek, P. W.; Elliott, H. A.; Ilie, R.; Khazanov, G. V.; Glocer, A.; Ganushkina, N. Y.; Zou, S.

    2017-12-01

    The question of how many satellites it would take to accurately map the spatial distribution of ionospheric outflow is addressed in this study. Given an outflow spatial map, this image is then reconstructed from a limited number virtual satellite pass extractions from the original values. An assessment is conducted of the goodness of fit as a function of number of satellites in the reconstruction, placement of the satellite trajectories relative to the polar cap and auroral oval, season and universal time (i.e., dipole tilt relative to the Sun), geomagnetic activity level, and interpolation technique. It is found that the accuracy of the reconstructions increases sharply from one to a few satellites, but then improves only marginally with additional spacecraft beyond 4. Increased dwell time of the satellite trajectories in the auroral zone improves the reconstruction, therefore a high-but-not-exactly-polar orbit is most effective for this task. Local time coverage is also an important factor, shifting the auroral zone to different locations relative to the virtual satellite orbit paths. The expansion and contraction of the polar cap and auroral zone with geomagnetic activity influences the coverage of the key outflow regions, with different optimal orbit configurations for each level of activity. Finally, it is found that reconstructing each magnetic latitude band individually produces a better fit to the original image than 2-D image reconstruction method (e.g., triangulation). A high-latitude, high-altitude constellation mission concept is presented that achieves acceptably accurate outflow reconstructions.

  8. Model-Based Systems Engineering for Capturing Mission Architecture System Processes with an Application Case Study - Orion Flight Test 1

    Science.gov (United States)

    Bonanne, Kevin H.

    2011-01-01

    Model-based Systems Engineering (MBSE) is an emerging methodology that can be leveraged to enhance many system development processes. MBSE allows for the centralization of an architecture description that would otherwise be stored in various locations and formats, thus simplifying communication among the project stakeholders, inducing commonality in representation, and expediting report generation. This paper outlines the MBSE approach taken to capture the processes of two different, but related, architectures by employing the Systems Modeling Language (SysML) as a standard for architecture description and the modeling tool MagicDraw. The overarching goal of this study was to demonstrate the effectiveness of MBSE as a means of capturing and designing a mission systems architecture. The first portion of the project focused on capturing the necessary system engineering activities that occur when designing, developing, and deploying a mission systems architecture for a space mission. The second part applies activities from the first to an application problem - the system engineering of the Orion Flight Test 1 (OFT-1) End-to-End Information System (EEIS). By modeling the activities required to create a space mission architecture and then implementing those activities in an application problem, the utility of MBSE as an approach to systems engineering can be demonstrated.

  9. CHEOPS: A transit photometry mission for ESA's small mission programme

    Directory of Open Access Journals (Sweden)

    Queloz D.

    2013-04-01

    Full Text Available Ground based radial velocity (RV searches continue to discover exoplanets below Neptune mass down to Earth mass. Furthermore, ground based transit searches now reach milli-mag photometric precision and can discover Neptune size planets around bright stars. These searches will find exoplanets around bright stars anywhere on the sky, their discoveries representing prime science targets for further study due to the proximity and brightness of their host stars. A mission for transit follow-up measurements of these prime targets is currently lacking. The first ESA S-class mission CHEOPS (CHaracterizing ExoPlanet Satellite will fill this gap. It will perform ultra-high precision photometric monitoring of selected bright target stars almost anywhere on the sky with sufficient precision to detect Earth sized transits. It will be able to detect transits of RV-planets by photometric monitoring if the geometric configuration results in a transit. For Hot Neptunes discovered from the ground, CHEOPS will be able to improve the transit light curve so that the radius can be determined precisely. Because of the host stars' brightness, high precision RV measurements will be possible for all targets. All planets observed in transit by CHEOPS will be validated and their masses will be known. This will provide valuable data for constraining the mass-radius relation of exoplanets, especially in the Neptune-mass regime. During the planned 3.5 year mission, about 500 targets will be observed. There will be 20% of open time available for the community to develop new science programmes.

  10. Qualification study of LiF flight crystals for the objective crystal spectrometer on the SPECTRUM-X-GAMMA satellite

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Rasmussen, I.; Schnopper, Herbert W.

    1992-01-01

    The Objective Crystal Spectrometer (OXS) on the SPECTRUM-X-GAMMA satellite will carry these types of natural crystals LiF(220), Ge(111) and RAP(001). They will be used to study, among others, the H- and the He-like emission from the cosmically important elements Fe, S, Ar and O. More than 300 Li...

  11. Assessing the Impact of Earth Radiation Pressure Acceleration on Low-Earth Orbit Satellites

    Science.gov (United States)

    Vielberg, Kristin; Forootan, Ehsan; Lück, Christina; Kusche, Jürgen; Börger, Klaus

    2017-04-01

    The orbits of satellites are influenced by several external forces. The main non-gravitational forces besides thermospheric drag, acting on the surface of satellites, are accelerations due to the Earth and Solar Radiation Pres- sure (SRP and ERP, respectively). The sun radiates visible and infrared light reaching the satellite directly, which causes the SRP. Earth also emits and reflects the sunlight back into space, where it acts on satellites. This is known as ERP acceleration. The influence of ERP increases with decreasing distance to the Earth, and for low-earth orbit (LEO) satellites ERP must be taken into account in orbit and gravity computations. Estimating acceler- ations requires knowledge about energy emitted from the Earth, which can be derived from satellite remote sensing data, and also by considering the shape and surface material of a satellite. In this sensitivity study, we assess ERP accelerations based on different input albedo and emission fields and their modelling for the satellite missions Challenging Mini-Satellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE). As input fields, monthly 1°x1° products of Clouds and the Earth's Radiant En- ergy System (CERES), L3 are considered. Albedo and emission models are generated as latitude-dependent, as well as in terms of spherical harmonics. The impact of different albedo and emission models as well as the macro model and the altitude of satellites on ERP accelerations will be discussed.

  12. Jupiter Icy Moons Explorer (JUICE) : Science Objectives, Mission and Instruments (abstract)

    NARCIS (Netherlands)

    Gurvits, L.; Plaut, J.J.; Barabash, S.; Bruzzone, L.; Dougherty, M.; Erd, C.; Fletcher, L.; Gladstone, R.; Grasset, O.; Hartogh, P.; Hussmann, H.; Iess, L.; Jaumann, R.; Langevin, Y.; Palumbo, P.; Piccioni, G.; Titov, D.; Wahlund, J.E.

    2014-01-01

    The JUpiter ICy Moons Explorer (JUICE) is a European Space Agency mission that will fly by and observe the Galilean satellites Europa, Ganymede and Callisto, characterize the Jovian system in a lengthy Jupiter-orbit phase, and ultimately orbit Ganymede for in-depth studies of habitability, evolution

  13. Constellations of Next Generation Gravity Missions: Simulations regarding optimal orbits and mitigation of aliasing errors

    Science.gov (United States)

    Hauk, M.; Pail, R.; Gruber, T.; Purkhauser, A.

    2017-12-01

    The CHAMP and GRACE missions have demonstrated the tremendous potential for observing mass changes in the Earth system from space. In order to fulfil future user needs a monitoring of mass distribution and mass transport with higher spatial and temporal resolution is required. This can be achieved by a Bender-type Next Generation Gravity Mission (NGGM) consisting of a constellation of satellite pairs flying in (near-)polar and inclined orbits, respectively. For these satellite pairs the observation concept of the GRACE Follow-on mission with a laser-based low-low satellite-to-satellite tracking (ll-SST) system and more precise accelerometers and state-of-the-art star trackers is adopted. By choosing optimal orbit constellations for these satellite pairs high frequency mass variations will be observable and temporal aliasing errors from under-sampling will not be the limiting factor anymore. As part of the European Space Agency (ESA) study "ADDCON" (ADDitional CONstellation and Scientific Analysis Studies of the Next Generation Gravity Mission) a variety of mission design parameters for such constellations are investigated by full numerical simulations. These simulations aim at investigating the impact of several orbit design choices and at the mitigation of aliasing errors in the gravity field retrieval by co-parametrization for various constellations of Bender-type NGGMs. Choices for orbit design parameters such as altitude profiles during mission lifetime, length of retrieval period, value of sub-cycles and choice of prograde versus retrograde orbits are investigated as well. Results of these simulations are presented and optimal constellations for NGGM's are identified. Finally, a short outlook towards new geophysical applications like a near real time service for hydrology is given.

  14. Centriolar satellites

    DEFF Research Database (Denmark)

    Tollenaere, Maxim A X; Mailand, Niels; Bekker-Jensen, Simon

    2015-01-01

    Centriolar satellites are small, microscopically visible granules that cluster around centrosomes. These structures, which contain numerous proteins directly involved in centrosome maintenance, ciliogenesis, and neurogenesis, have traditionally been viewed as vehicles for protein trafficking...... highlight newly discovered regulatory mechanisms targeting centriolar satellites and their functional status, and we discuss how defects in centriolar satellite components are intimately linked to a wide spectrum of human diseases....

  15. Damage assessment of mission essential buildings based on simulation studies of low yield explosives

    Science.gov (United States)

    Allen, Thomas G. L.

    2006-04-01

    There has been a lack of investigations related to low yield explosives instigated by terrorist on small but high occupancy buildings. Also, mitigating the threat of terrorist attacks against high occupancy buildings with network equipment essential to the mission of an organization is a challenging task. At the same time, it is difficult to predict how, why, and when terrorists may attack theses assets. Many factors must be considered in creating a safe building environment. Although it is possible that the dominant threat mode may change in the future, bombings have historically been a favorite tactic of terrorists. Ingredients for homemade bombs are easily obtained on the open market, as are the techniques for making bombs. Bombings are easy and quick to execute. This paper discusses the problems with and provides insights of experience gained in analyzing small scale explosions on older military base buildings. In this study, we examine the placement of various bombs on buildings using the shock wave simulation code CTH and examine the damage effects on the interior of the building, particularly the damage that is incurred on a computer center. These simulation experiments provide data on the effectiveness of a building's security and an understanding of the phenomenology of shocks as they propagate through rooms and corridors. It's purpose is to motivate researchers to take the seriousness of small yield explosives on moderately sized buildings. Visualizations from this analysis are used to understand the complex flow of the air blasts around corridors and hallways. Finally, we make suggestions for improving the mitigation of such terrorist attacks. The intent of this study is not to provide breakthrough technology, but to provide a tool and a means for analyzing the material hardness of a building and to eventually provide the incentive for more security. The information mentioned in this paper is public domain information and easily available via the

  16. Real time deforestation detection using ann and satellite images the Amazon rainforest study case

    CERN Document Server

    Nunes Kehl, Thiago; Roberto Veronez, Maurício; Cesar Cazella, Silvio

    2015-01-01

    The foremost aim of the present study was the development of a tool to detect daily deforestation in the Amazon rainforest, using satellite images from the MODIS/TERRA sensor and Artificial Neural Networks. The developed tool provides parameterization of the configuration for the neural network training to enable us to select the best neural architecture to address the problem. The tool makes use of confusion matrices to determine the degree of success of the network. A spectrum-temporal analysis of the study area was done on 57 images from May 20 to July 15, 2003 using the trained neural network. The analysis enabled verification of quality of the implemented neural network classification and also aided in understanding the dynamics of deforestation in the Amazon rainforest, thereby highlighting the vast potential of neural networks for image classification. However, the complex task of detection of predatory actions at the beginning, i.e., generation of consistent alarms, instead of false alarms has not bee...

  17. Optimization of Instrument Requirements for NASAs GEO-CAPE Coastal Mission Concept Based On Sensor Capability And Cost Studies

    Science.gov (United States)

    Mannino, Antonio

    2015-01-01

    NASA's GEOstationary Coastal and Air Pollution Events (GEOCAPE) mission concept recommended by the U.S. National Research Council (2007) focuses on measurements of atmospheric trace gases and aerosols and aquatic coastal ecology and biogeochemistry from geostationary orbit (35,786 km altitude). GEO-CAPE is currently in pre-formulation (pre- Phase) A with no established launch date. NASA continues to support science and engineering studies to reduce mission risk. Instrument design lab (IDL) studies were commissioned in 2014 to design and cost two implementations for geostationary ocean color instruments (1) Wide-Angle Spectrometer (WAS) and (2) Filter Radiometer (FR) and (3) a cost scaling study to compare the costs for implementing different science performance requirements.

  18. Initial Assessment of Cyclone Global Navigation Satellite System (CYGNSS) Observations

    Science.gov (United States)

    McKague, D. S.; Ruf, C. S.

    2017-12-01

    The NASA Cyclone Global Navigation Satellite System (CYNSS) mission provides high temporal resolution observations of cyclones from a constellation of eight low-Earth orbiting satellites. Using the relatively new technique of Global Navigation Satellite System reflectometry (GNSS-R), all-weather observations are possible, penetrating even deep convection within hurricane eye walls. The compact nature of the GNSS-R receivers permits the use of small satellites, which in turn enables the launch of a constellation of satellites from a single launch vehicle. Launched in December of 2016, the eight CYGNSS satellites provide 25 km resolution observations of mean square slope (surface roughness) and surface winds with a 2.8 hour median revisit time from 38 S to 38 N degrees latitude. In addition to the calibration and validation of CYGNSS sea state observations, the CYGNSS science team is assessing the ability of the mission to provide estimates of cyclone size, intensity, and integrated kinetic energy. With its all-weather ability and high temporal resolution, the CYGNSS mission will add significantly to our ability to monitor cyclone genesis and intensification and will significantly reduce uncertainties in our ability to estimate cyclone intensity, a key variable in predicting its destructive potential. Members of the CYGNSS Science Team are also assessing the assimilation of CYGNSS data into hurricane forecast models to determine the impact of the data on forecast skill, using the data to study extra-tropical cyclones, and looking at connections between tropical cyclones and global scale weather, including the global hydrologic cycle. This presentation will focus on the assessment of early on-orbit observations of cyclones with respect to these various applications.

  19. Regionalization Study of Satellite based Hydrological Model (SHM) in Hydrologically Homogeneous River Basins of India

    Science.gov (United States)

    Kumari, Babita; Paul, Pranesh Kumar; Singh, Rajendra; Mishra, Ashok; Gupta, Praveen Kumar; Singh, Raghvendra P.

    2017-04-01

    A new semi-distributed conceptual hydrological model, namely Satellite based Hydrological Model (SHM), has been developed under 'PRACRITI-2' program of Space Application Centre (SAC), Ahmedabad for sustainable water resources management of India by using data from Indian Remote Sensing satellites. Entire India is divided into 5km x 5km grid cells and properties at the center of the cells are assumed to represent the property of the cells. SHM contains five modules namely surface water, forest, snow, groundwater and routing. Two empirical equations (SCS-CN and Hargreaves) and water balance method have been used in the surface water module; the forest module is based on the calculations of water balancing & dynamics of subsurface. 2-D Boussinesq equation is used for groundwater modelling which is solved using implicit finite-difference. The routing module follows a distributed routing approach which requires flow path and network with the key point of travel time estimation. The aim of this study is to evaluate the performance of SHM using regionalization technique which also checks the usefulness of a model in data scarce condition or for ungauged basins. However, homogeneity analysis is pre-requisite to regionalization. Similarity index (Φ) and hierarchical agglomerative cluster analysis are adopted to test the homogeneity in terms of physical attributes of three basins namely Brahmani (39,033 km km^2)), Baitarani (10,982 km km^2)) and Kangsabati (9,660 km km^2)) with respect to Subarnarekha (29,196 km km^2)) basin. The results of both homogeneity analysis show that Brahmani basin is the most homogeneous with respect to Subarnarekha river basin in terms of physical characteristics (land use land cover classes, soiltype and elevation). The calibration and validation of model parameters of Brahmani basin is in progress which are to be transferred into the SHM set up of Subarnarekha basin and results are to be compared with the results of calibrated and validated

  20. Several thoughts for using new satellite remote sensing and global modeling for aerosol and cloud climate studies

    Science.gov (United States)

    Nakajima, Teruyuki; Hashimoto, Makiko; Takenaka, Hideaki; Goto, Daisuke; Oikawa, Eiji; Suzuki, Kentaroh; Uchida, Junya; Dai, Tie; Shi, Chong

    2017-04-01

    The rapid growth of satellite remote sensing technologies in the last two decades widened the utility of satellite data for understanding climate impacts of aerosols and clouds. The climate modeling community also has received the benefit of the earth observation and nowadays closed-collaboration of the two communities make us possible to challenge various applications for societal problems, such as for global warming and global-scale air pollution and others. I like to give several thoughts of new algorithm developments, model use of satellite data for climate impact studies and societal applications related with aerosols and clouds. Important issues are 1) Better aerosol detection and solar energy application using expanded observation ability of the third generation geostationary satellites, i.e. Himawari-8, GOES-R and future MTG, 2) Various observation functions by directional, polarimetric, and high resolution near-UV band by MISR, POLDER&PARASOL, GOSAT/CAI and future GOSAT2/CAI2, 3) Various applications of general purpose-imagers, MODIS, VIIRS and future GCOM-C/SGLI, and 4) Climate studies of aerosol and cloud stratification and convection with active and passive sensors, especially climate impact of BC aerosols using CLOUDSAT&CALIPSO and future Earth Explorer/EarthCARE.

  1. Asteroid Redirect Crewed Mission Space Suit and EVA System Architecture Trade Study

    Science.gov (United States)

    Bowie, Jonathan; Buffington, Jesse; Hood, Drew; Kelly, Cody; Naids, Adam; Watson, Richard; Blanco, Raul; Sipila, Stephanie

    2014-01-01

    The Asteroid Redirect Crewed Mission (ARCM) requires a Launch/Entry/Abort (LEA) suit capability and short duration Extra Vehicular Activity (EVA) capability from the Orion spacecraft. For this mission, the pressure garment selected for both functions is the Modified Advanced Crew Escape Suit (MACES) with EVA enhancements and the life support option that was selected is the Exploration Portable Life Support System (PLSS) currently under development for Advanced Exploration Systems (AES). The proposed architecture meets the ARCM constraints, but much more work is required to determine the details of the suit upgrades, the integration with the PLSS, and the tools and equipment necessary to accomplish the mission. This work has continued over the last year to better define the operations and hardware maturation of these systems. EVA simulations were completed in the Neutral Buoyancy Lab (NBL) and interfacing options were prototyped and analyzed with testing planned for late 2014. This paper discusses the work done over the last year on the MACES enhancements, the use of tools while using the suit, and the integration of the PLSS with the MACES.

  2. Preface to the Special Issue on "Geophysical and Climate Change Studies in Tibet, Xinjiang, and Siberia (TibXS from Satellite Geodesy"

    Directory of Open Access Journals (Sweden)

    Cheinway Hwang

    2013-01-01

    Full Text Available This special issue publishes papers on recent results in geophysical and climate change studies over Tibet, Xinjiang and Siberia (TibXS based upon some of the key sensors used in satellite geodesy, including satellite gravimetric sensors (GRACE and GOCE, satellite altimeters (TOPEX, Jason-1 and -2, and ENVISAT, and Global Positioning System satellites. Results from ground- and airborne-based geodetic observations, notably those based on airborne gravimeter, superconducting gravimeter (SG and seismometers are also included in the special issue. In all, 22 papers were submitted for this special issue; 17 papers were accepted.

  3. Results from Navigator GPS Flight Testing for the Magnetospheric MultiScale Mission

    Science.gov (United States)

    Lulich, Tyler D.; Bamford, William A.; Wintermitz, Luke M. B.; Price, Samuel R.

    2012-01-01

    The recent delivery of the first Goddard Space Flight Center (GSFC) Navigator Global Positioning System (GPS) receivers to the Magnetospheric MultiScale (MMS) mission spacecraft is a high water mark crowning a decade of research and development in high-altitude space-based GPS. Preceding MMS delivery, the engineering team had developed receivers to support multiple missions and mission studies, such as Low Earth Orbit (LEO) navigation for the Global Precipitation Mission (GPM), above the constellation navigation for the Geostationary Operational Environmental Satellite (GOES) proof-of-concept studies, cis-Lunar navigation with rapid re-acquisition during re-entry for the Orion Project and an orbital demonstration on the Space Shuttle during the Hubble Servicing Mission (HSM-4).

  4. A Correlated Study of the Response of a Satellite to Acoustic Radiation Using Statistical Energy Analysis and Acoustic Test Data

    International Nuclear Information System (INIS)

    CAP, JEROME S.; TRACEY, BRIAN

    1999-01-01

    Aerospace payloads, such as satellites, are subjected to vibroacoustic excitation during launch. Sandia's MTI satellite has recently been certified to this environment using a combination of base input random vibration and reverberant acoustic noise. The initial choices for the acoustic and random vibration test specifications were obtained from the launch vehicle Interface Control Document (ICD). In order to tailor the random vibration levels for the laboratory certification testing, it was necessary to determine whether vibration energy was flowing across the launch vehicle interface from the satellite to the launch vehicle or the other direction. For frequencies below 120 Hz this issue was addressed using response limiting techniques based on results from the Coupled Loads Analysis (CLA). However, since the CLA Finite Element Analysis FEA model was only correlated for frequencies below 120 Hz, Statistical Energy Analysis (SEA) was considered to be a better choice for predicting the direction of the energy flow for frequencies above 120 Hz. The existing SEA model of the launch vehicle had been developed using the VibroAcoustic Payload Environment Prediction System (VAPEPS) computer code[1]. Therefore, the satellite would have to be modeled using VAPEPS as well. As is the case for any computational model, the confidence in its predictive capability increases if one can correlate a sample prediction against experimental data. Fortunately, Sandia had the ideal data set for correlating an SEA model of the MTI satellite--the measured response of a realistic assembly to a reverberant acoustic test that was performed during MTI's qualification test series. The first part of this paper will briefly describe the VAPEPS modeling effort and present the results of the correlation study for the VAPEPS model. The second part of this paper will present the results from a study that used a commercial SEA software package[2] to study the effects of in-plane modes and to evaluate

  5. A Study on the Use of Commercial Satellite Imagery for Monitoring of Yongbyon Nuclear Activities

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Hyun; Kim, Min Soo [Korea Institute of Nuclear Nonproliferation and Control Daejeon (Korea, Republic of)

    2014-10-15

    It is particularly useful for the areas that are hard to access, such as the DPRK. On April 2009, North Korea expelled IAEA inspectors and USA disabling team at Yongbyon. Since then, there is not much left except for satellite imagery analysis. In this paper, we focused on the growing role and importance of commercial satellite imagery analysis for detecting and identifying nuclear activities at Yongbyon. For this, we examined monitoring capability of commercial satellite imagery status of commercial satellite imagery analysis to monitor the Yongbyon nuclear site. And we suggested several recommendations for enhancing the monitoring and analyzing capability. Current commercial satellite imagery has proven effective in monitoring for Yongbyon nuclear activities, especially change detection including the new construction activities. But identification and technical analysis of the operation status is still limited. In case of North Korea, operation status of 5 MWe reactor should be clearly identified to assess its plutonium production capability and to set up the negotiation strategy. To enhance the monitoring capability, we need much more thermal infrared imagery and radar imagery.

  6. The Mothership Mission Architecture

    Science.gov (United States)

    Ernst, S. M.; DiCorcia, J. D.; Bonin, G.; Gump, D.; Lewis, J. S.; Foulds, C.; Faber, D.

    2015-12-01

    The Mothership is considered to be a dedicated deep space carrier spacecraft. It is currently being developed by Deep Space Industries (DSI) as a mission concept that enables a broad participation in the scientific exploration of small bodies - the Mothership mission architecture. A Mothership shall deliver third-party nano-sats, experiments and instruments to Near Earth Asteroids (NEOs), comets or moons. The Mothership service includes delivery of nano-sats, communication to Earth and visuals of the asteroid surface and surrounding area. The Mothership is designed to carry about 10 nano-sats, based upon a variation of the Cubesat standard, with some flexibility on the specific geometry. The Deep Space Nano-Sat reference design is a 14.5 cm cube, which accommodates the same volume as a traditional 3U CubeSat. To reduce cost, Mothership is designed as a secondary payload aboard launches to GTO. DSI is offering slots for nano-sats to individual customers. This enables organizations with relatively low operating budgets to closely examine an asteroid with highly specialized sensors of their own choosing and carry out experiments in the proximity of or on the surface of an asteroid, while the nano-sats can be built or commissioned by a variety of smaller institutions, companies, or agencies. While the overall Mothership mission will have a financial volume somewhere between a European Space Agencies' (ESA) S- and M-class mission for instance, it can be funded through a number of small and individual funding sources and programs, hence avoiding the processes associated with traditional space exploration missions. DSI has been able to identify a significant interest in the planetary science and nano-satellite communities.

  7. The Earth Observing System Terra Mission

    Science.gov (United States)

    Kaufman, Yoram J.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Langley's remarkable solar and lunar spectra collected from Mt. Whitney inspired Arrhenius to develop the first quantitative climate model in 1896. After the launch in Dec. 16 1999, NASA's Earth Observing AM Satellite (EOS-Terra) will repeat Langley's experiment, but for the entire planet, thus pioneering a wide array of calibrated spectral observations from space of the Earth System. Conceived in response to real environmental problems, EOS-Terra, in conjunction with other international satellite efforts, will fill a major gap in current efforts by providing quantitative global data sets with a resolution better than 1 km on the physical, chemical and biological elements of the earth system. Thus, like Langley's data, EOS-Terra can revolutionize climate research by inspiring a new generation of climate system models and enable us to assess the human impact on the environment. In the talk I shall review the historical perspective of the Terra mission and the key new elements of the mission. We expect to have first images that demonstrate the most innovative capability from EOS Terra 5 instruments: MODIS - 1.37 micron cirrus cloud channel; 250m daily coverage for clouds and vegetation change; 7 solar channels for land and aerosol studies; new fire channels; Chlorophyll fluorescence; MISR - first 9 multi angle views of clouds and vegetation; MOPITT - first global CO maps and C114 maps; ASTER - Thermal channels for geological studies with 15-90 m resolution.

  8. Solar Radiation and Climate Experiment (SORCE) Satellite

    Science.gov (United States)

    2003-01-01

    This is a close-up of the NASA-sponsored Solar Radiation and Climate Experiment (SORCE) Satellite. The SORCE mission, launched aboard a Pegasus rocket January 25, 2003, will provide state of the art measurements of incoming x-ray, ultraviolet, visible, near-infrared, and total solar radiation. Critical to studies of the Sun and its effect on our Earth system and mankind, SORCE will provide measurements that specifically address long-term climate change, natural variability and enhanced climate prediction, and atmospheric ozone and UV-B radiation. Orbiting around the Earth accumulating solar data, SORCE measures the Sun's output with the use of state-of-the-art radiometers, spectrometers, photodiodes, detectors, and bolo meters engineered into instruments mounted on a satellite observatory. SORCE is carrying 4 instruments: The Total Irradiance Monitor (TIM); the Solar Stellar Irradiance Comparison Experiment (SOLSTICE); the Spectral Irradiance Monitor (SIM); and the XUV Photometer System (XPS).

  9. New Space at Airbus Defence & Space to facilitate science missions

    Science.gov (United States)

    Boithias, Helene; Benchetrit, Thierry

    2016-10-01

    In addition to Airbus legacy activities, where Airbus satellites usually enable challenging science missions such as Venus Express, Mars Express, Rosetta with an historic landing on a comet, Bepi Colombo mission to Mercury and JUICE to orbit around Jupiter moon Ganymede, Swarm studying the Earth magnetic field, Goce to measure the Earth gravitational field and Cryosat to monitor the Earth polar ice, Airbus is now developing a new approach to facilitate next generation missions.After more than 25 years of collaboration with the scientists on space missions, Airbus has demonstrated its capacity to implement highly demanding missions implying a deep understanding of the science mission requirements and their intrinsic constraints such as- a very fierce competition between the scientific communities,- the pursuit of high maturity for the science instrument in order to be selected,- the very strict institutional budget limiting the number of operational missions.As a matter of fact, the combination of these constraints may lead to the cancellation of valuable missions.Based on that and inspired by the New Space trend, Airbus is developing an highly accessible concept called HYPE.The objective of HYPE is to make access to Space much more simple, affordable and efficient.With a standardized approach, the scientist books only the capacities he needs among the resources available on-board, as the HYPE satellites can host a large range of payloads from 1kg up to 60kg.At prices significantly more affordable than those of comparable dedicated satellite, HYPE is by far a very cost-efficient way of bringing science missions to life.After the launch, the scientist enjoys a plug-and-play access to two-way communications with his instrument through a secure high-speed portal available online 24/7.Everything else is taken care of by Airbus: launch services and the associated risk, reliable power supply, setting up and operating the communication channels, respect of space law

  10. UV Spectrophotometry of the Galilean Satellites, Saturnian Satellites & Selected Asteroids

    Science.gov (United States)

    Nelson, Robert M.

    We propose a series of ultraviolet spectral observations of solid surfaces of selected solar system objects, specifically the Galilean satellites of Jupiter, several atmosphereless satellites of Saturn, and the asteroids, 5 Astraea, 18 Melpomene, 532 Herculina, 68 Leto, 31 Euphmsyne, 80 Sappho, 3 Juno, and 39 Laetitia. Historically such spectral observations have allowed for the Identification of spectrally active solid state materials on planetary surfaces. Furthermore, because the rotational properties are known for all the objects proposed for study, this technique will provide a longitude map of such materials on the objects' surfaces. The study of asteroid surface mineralogy is an important method of constraining solar system formation models. The asteroid spectra we have previously acquired with IUE have created unique subdivisions within the existent asteroid types. The new spectra will provide more sophisticated mineralogical characterizations of asteroid surface materials. Our other accomplishments with IUE include mapping of the distribution of condensed S02 on Io, identification of a longitudinal asymmetry on Europa associated with magnetospheric particle bombardment of the surface, and establishing the ultraviolet geometric albedo variation as a function of longitude for all the Galilean satellites. Because Io is the most volcanically active body In the solar system, and short tern variations in selected regions of the Jovian magnetosphere are known to occur, it is important to periodically check for temporal variations in the spectra of the Galilean satellites that may be due to variations n Io tectonic/volcanic activity, or magnetosphere changes. These proposed UV observations are critical to the design and operation of several instruments on Project Galileo, NASA's Jupiter Orbiter and Probe Mission. Spectra of Iapetus, Rhea and Dione have been acquired during the previous year; however, only at orbital locations near elongation. In addition, the dark

  11. NASA CYGNSS Mission Overview

    Science.gov (United States)

    Ruf, C. S.; Balasubramaniam, R.; Gleason, S.; McKague, D. S.; O'Brien, A.

    2017-12-01

    The CYGNSS constellation of eight satellites was successfully launched on 15 December 2016 into a low inclination (tropical) Earth orbit. Each satellite carries a four-channel bi-static radar receiver that measures GPS signals scattered by the ocean, from which ocean surface roughness, near surface wind speed, and air-sea latent heat flux are estimated. The measurements are unique in several respects, most notably in their ability to penetrate through all levels of precipitation, made possible by the low frequency at which GPS operates, and in the frequent sampling of tropical cyclone intensification and of the diurnal cycle of winds, made possible by the large number of satellites. Engineering commissioning of the constellation was successfully completed in March 2017 and the mission is currently in the early phase of science operations. Level 2 science data products have been developed for near surface (10 m referenced) ocean wind speed, ocean surface roughness (mean square slope) and latent heat flux. Level 3 gridded versions of the L2 products have also been developed. A set of Level 4 products have also been developed specifically for direct tropical cyclone overpasses. These include the storm intensity (peak sustained winds) and size (radius of maximum winds), its extent (34, 50 and 64 knot wind radii), and its integrated kinetic energy. Assimilation of CYGNSS L2 wind speed data into the HWRF hurricane weather prediction model has also been developed. An overview and the current status of the mission will be presented, together with highlights of early on-orbit performance and scientific results.

  12. Flood modelling with global precipitation measurement (GPM) satellite rainfall data: a case study of Dehradun, Uttarakhand, India

    Science.gov (United States)

    Sai Krishna, V. V.; Dikshit, Anil Kumar; Pandey, Kamal

    2016-05-01

    Urban expansion, water bodies and climate change are inextricably linked with each other. The macro and micro level climate changes are leading to extreme precipitation events which have severe consequences on flooding in urban areas. Flood simulations shall be helpful in demarcation of flooded areas and effective flood planning and preparedness. The temporal availability of satellite rainfall data at varying spatial scale of 0.10 to 0.50 is helpful in near real time flood simulations. The present research aims at analysing stream flow and runoff to monitor flood condition using satellite rainfall data in a hydrologic model. The satellite rainfall data used in the research was NASA's Integrated Multi-satellite Retrievals for Global Precipitation Measurement (IMERG), which is available at 30 minutes temporal resolution. Landsat data was used for mapping the water bodies in the study area. Land use land cover (LULC) data was prepared using Landsat 8 data with maximum likelihood technique that was provided as an input to the HEC-HMS hydrological model. The research was applied to one of the urbanized cities of India, viz. Dehradun, which is the capital of Uttarakhand State. The research helped in identifying the flood vulnerability at the basin level on the basis of the runoff and various socio economic parameters using multi criteria analysis.

  13. Implementation Options for the PROPEL Electrodynamic Tether Demonstration Mission

    Science.gov (United States)

    Bilen, Sven G.; Johnson, C. Les; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael; Stone, Nobie

    2014-01-01

    The PROPEL ("Propulsion using Electrodynamics") flight demonstration mission concept will demonstrate the use of an electrodynamic tether (EDT) for generating thrust, which will allow the propulsion system to overcome the limitations of the rocket equation. The mission concept has been developed by a team of government, industry, and academia partners led by NASA Marshall Space Flight Center (MSFC). PROPEL is being designed for versatility of the EDT system with multiple end users in mind and to be flexible with respect to platform. Previously, we reported on a comprehensive mission design for PROPEL with a mission duration of six months or longer with multiple mission goals including demonstration of significant boost, deboost, inclination change, and drag make-up activities. To explore a range of possible configurations, primarily driven by cost considerations, other mission concept designs have been pursued. In partnership with the NASA's Office of Chief Technologist (OCT) Game Changing Program, NASA MSFC Leadership, and the MSFC Advanced Concepts Office, a mission concept design was developed for a near-term EDT propulsion flight validation mission. The Electrodynamic Tether Propulsion Study (ETPS) defined an EDT propulsion system capable of very large delta-V for use on future missions developed by NASA, DoD, and commercial customers. To demonstrate the feasibility of an ETPS, the study focused on a space demonstration mission concept design with configuration of a pair of tethered satellite busses, one of which is the Japanese H-II Transfer Vehicle (HTV). The HTV would fly its standard ISS resupply mission. When resupply mission is complete, the ISS reconfigures and releases the HTV to perform the EDT experiment at safe orbital altitudes below the ISS. Though the focus of this particular mission concept design addresses a scenario involving the HTV or a similar vehicle, the propulsion system's capability is relevant to a number of applications, as noted above

  14. Satellite Communications

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Satellite Communications. Arthur C Clarke wrote a seminal paper in 1945 in wireless world. Use three satellites in geo-synchronous orbit to enable intercontinental communications. System could be realised in '50 to 100 years'

  15. A statistical study of high-altitude electric fields measured on the Viking satellite

    International Nuclear Information System (INIS)

    Lindqvist, P.A.; Marklund, G.T.

    1990-01-01

    Characteristics of high-altitude data from the Viking electric field instrument are presented in a statistical study based on 109 Viking orbits. The study is focused in particular on the signatures of and relationships between various parameters measured by the electric field instrument, such as the parallel and transverse (to B) components of the electric field instrument, such as electric field variability. A major goal of the Viking mission was to investigate the occurrence and properties of parallel electric fields and their role in the auroral acceleration process. The results in this paper on the altitude distribution of the electric field variability confirm earlier findings on the distribution of small-scale electric fields and indicate the presence of parallel fields up to about 11,000 km altitude. The directly measured parallel electric field is also investigated in some detail. It is in general directed upward with an average value of 1 mV/m, but depends on, for example, altitude and plasma density. Possible sources of error in the measurement of the parallel field are also considered and accounted for

  16. Erosion, Transportation, and Deposition on Outer Solar System Satellites: Landform Evolution Modeling Studies

    Science.gov (United States)

    Moore, Jeffrey Morgan; Howard, Alan D.; Schenk, Paul M.

    2013-01-01

    Mass movement and landform degradation reduces topographic relief by moving surface materials to a lower gravitational potential. In addition to the obvious role of gravity, abrasive mechanical erosion plays a role, often in combination with the lowering of cohesion, which allows disaggregation of the relief-forming material. The identification of specific landform types associated with mass movement and landform degradation provides information about local sediment particle size and abundance and transportation processes. Generally, mass movements can be classified in terms of the particle sizes of the transported material and the speed the material moved during transport. Most degradation on outer planet satellites appears consistent with sliding or slumping, impact erosion, and regolith evolution. Some satellites, such as Callisto and perhaps Hyperion and Iapetus, have an appearance that implies that some additional process is at work, most likely sublimation-driven landform modification and mass wasting. A variant on this process is thermally driven frost segregation as seen on all three icy Galilean satellites and perhaps elsewhere. Titan is unique among outer planet satellites in that Aeolian and fluvial processes also operate to erode, transport, and deposit material. We will evaluate the sequence and extent of various landform-modifying erosional and volatile redistribution processes that have shaped these icy satellites using a 3-D model that simulates the following surface and subsurface processes: 1) sublimation and re-condensation of volatiles; 2) development of refractory lag deposits; 3) disaggregation and downward sloughing of surficial material; 4) radiative heating/cooling of the surface (including reflection, emission, and shadowing by other surface elements); 5) thermal diffusion; and 6) vapor diffusion. The model will provide explicit simulations of landform development and thusly predicts the topographic and volatile evolution of the surface

  17. The satellite situation center

    International Nuclear Information System (INIS)

    Teague, M.J.; Sawyer, D.M.; Vette, J.I.

    1982-01-01

    Considerations related to the early planning for the International Magnetospheric Study (IMS) took into account the desirability of an establishment of specific entities for generating and disseminating coordination information for both retrospective and predictive periods. The organizations established include the IMS/Satellite Situation Center (IMS/SSC) operated by NASA. The activities of the SSC are related to the preparation of reports on predicted and actually achieved satellite positions, the response to inquiries, the compilation of information on satellite experiments, and the issue of periodic status summaries. Attention is given to high-altitude satellite services, other correlative satellite services, non-IMS activities of the SSC, a summary of the SSC request activity, and post-IMS and future activities

  18. Radiation shielding aspects for long manned mission to space: Criteria, survey study, and preliminary model

    OpenAIRE

    Sztejnberg Manuel; Xiao Shanjie; Satvat Nader; Limón Felisa; Hopkins John; Jevremović Tatjana

    2006-01-01

    The prospect of manned space missions outside Earth's orbit is limited by the travel time and shielding against cosmic radiation. The chemical rockets currently used in the space program have no hope of propelling a manned vehicle to a far away location such as Mars due to the enormous mass of fuel that would be required. The specific energy available from nuclear fuel is a factor of 106 higher than chemical fuel; it is therefore obvious that nuclear power production in space is a must. On th...

  19. Case study of mission-critical smart grid remedial action schemes via Ethernet

    Energy Technology Data Exchange (ETDEWEB)

    Dolezilek, David

    2010-09-15

    At Southern California Edison (SCE), RAS systems are implemented to mitigate thermal overloads and system instability upon the loss of one or more transmission lines. RAS automatic protection eliminates expensive alternative measures, including reconductoring transmission lines, building new lines, and/or adding new transformers. SCE has demonstrated successful use of IEC 61850 GOOSE messages over distances up to 460 miles to collect analysis and arming data and transfer status and control indications. This paper explains methods to perform mission-critical RAS and other smart grid actions via nondeterministic bandwidth sharing Ethernet being promoted to move smart grid information.

  20. Exploring Frameworks to Integrate Globalization, Mission, and Higher Education: Case Study Inquiry at Two Higher Education Institutions in the Pacific Northwest

    Science.gov (United States)

    Gustafson, Jacqueline N.

    2011-01-01

    The purpose of this study was to explore the merits of three conceptual frameworks that emerged from a synthesis of literature related to globalization, mission, and higher education. The first framework, higher education and mission, included three frames: important, not important, and emergent. The second framework, globalization and higher…

  1. The Swarm Satellite Constellation Application and Research Facility (SCARF) and Swarm data products

    DEFF Research Database (Denmark)

    Olsen, Nils; Friis-Christensen, Eigil; Floberghagen, R.

    2013-01-01

    Swarm, a three-satellite constellation to study the dynamics of the Earth's magnetic field and its interactions with the Earth system, is expected to be launched in late 2013. The objective of the Swarm mission is to provide the best ever survey of the geomagnetic field and its temporal evolution...

  2. ESA Swarm Mission - Level 1b Products

    Science.gov (United States)

    Tøffner-Clausen, Lars; Floberghagen, Rune; Mecozzi, Riccardo; Menard, Yvon

    2014-05-01

    Swarm, a three-satellite constellation to study the dynamics of the Earth's magnetic field and its interactions with the Earth system, has been launched in November 2013. The objective of the Swarm mission is to provide the best ever survey of the geomagnetic field and its temporal evolution, which will bring new insights into the Earth system by improving our understanding of the Earth's interior and environment. The Level 1b Products of the Swarm mission contain time-series of the quality screened, calibrated, corrected, and fully geo-localized measurements of the magnetic field intensity, the magnetic field vector (provided in both instrument and Earth-fixed frames), the plasma density, temperature, and velocity. Additionally, quality screened and pre-calibrated measurements of the nongravitational accelerations are provided. Geo-localization is performed by 24- channel GPS receivers and by means of unique, three head Advanced Stellar Compasses for high-precision satellite attitude information. The Swarm Level 1b data will be provided in daily products separately for each of the three Swarm spacecrafts. This poster will present detailed lists of the contents of the Swarm Level 1b Products and brief descriptions of the processing algorithms used in the generation of these data.

  3. A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions

    Science.gov (United States)

    Reid, Concha; Bennett, William

    2009-01-01

    NASA's Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair lunar lander and the Extravehicular Activities (EVA) advanced lunar surface spacesuit. These customers require safe, reliable energy storage systems with extremely high specific energy as compared to today's state-of-the-art batteries. Based on customer requirements, the specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery level at 0 degrees Celsius (degrees Celcius) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation over 0 to 30 degrees C, and 200 cycles are targeted. The team, consisting of members from NASA Glenn Research Center, Johnson Space Center, and Jet Propulsion laboratory, surveyed the literature, compiled information on recent materials developments, and consulted with other battery experts in the community to identify advanced battery materials that might be capable of achieving the desired results with further development. A variety of electrode materials were considered, including layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. lithium-sulfur systems were also considered. Hypothetical cell constructs that combined compatible anode and cathode materials with suitable electrolytes, separators, current collectors, headers, and cell enclosures were modeled. While some of these advanced materials are projected to obtain the desired electrical performance, there are risks that also factored into the decision making process. The risks include uncertainties due to issues such as safety of a system containing some of these materials, ease of scaling-up of large batches of raw materials, adaptability of the materials to processing using established

  4. Status of the JEM-EUSO mission and studies of the instrument's performance

    Energy Technology Data Exchange (ETDEWEB)

    Bertaina, M. [University of Torino and INFN, Torino (Italy)

    2013-06-15

    The JEM-EUSO mission explores the origin of the extreme energy cosmic rays (EECRs) above 50 EeV through the observations of their arrival directions and energies. It is designed to open a new particle astronomy channel. This super-wide-field (60 degrees) telescope with a diameter of about 2.5m looks down from space onto the night sky to detect near UV photons (290–430nm, both fluorescent and Cherenkov emissions) produced by EECR-induced giant air showers. The arrival direction map with more than five hundred events will tell us the origin of the EECRs and allow us to identify the nearest EECR sources with known astronomical objects, and to be examined in other astronomical channels. This is likely to lead to an understanding of the acceleration mechanisms perhaps producing discoveries in astrophysics and/or fundamental physics. The comparison of the energy spectra among the spatially resolved individual sources will help to clarify the acceleration and emission mechanisms, and also finally confirm the Greisen-Zatsepin-Kuz'min process for the validation of Lorentz invariance up to γ∼10{sup 11}. Neutral components (neutrinos and gamma rays) can be detected as well, if their fluxes are high enough. The JEM-EUSO mission is planned to be launched by a H2B rocket and transferred to ISS by H2 Transfer Vehicle (HTV). It will be attached to the Exposed Facility external experiment platform of Kibo.

  5. Calling Taikong a strategy report and study of China's future space science missions

    CERN Document Server

    Wu, Ji

    2017-01-01

    This book describes the status quo of space science in China, details the scientific questions to be addressed by the Chinese space science community in 2016-2030, and proposes key strategic goals, space science programs and missions, the roadmap and implementation approaches. Further, it explores the supporting technologies needed and provides an outlook of space science beyond the year 2030. “Taikong” means “outer space” in Chinese, and space science is one of the most important areas China plans to develop in the near future. This book is authored by Ji Wu, a leader of China's space science program, together with National Space Science Center, Chinese Academy of Sciences, a leading institute responsible for planning and managing most of China’s space science missions. It also embodies the viewpoints shared by many space scientists and experts on future space science development. Through this book, general readers and researchers alike will gain essential insights into the current developments an...

  6. Cassini Solstice Mission Maneuver Experience: Year Two

    Science.gov (United States)

    Arrieta, Juan; Ballard, Christopher G.; Hahn, Yungsun

    2012-01-01

    The Cassini Spacecraft was launched in October 1997 on a mission to observe Saturn and its moons; it entered orbit around Saturn in July 2004 for a nominal four-year Prime Mission, later augmented by two extensions: the Equinox Mission, from July 2008 through September 2010, and the Solstice Mission, from October 2010 through September 2017. This paper provides an overview of the maneuver activities from August 2011 through June 2012 which include the design of 38 Orbit Trim Maneuvers--OTM-288 through OTM-326-- for attaining 14 natural satellite encounters: seven with Titan, six with Enceladus, and one with Dione.

  7. Instructional Television: A Comparative Study of Satellites and Other Delivery Systems. Final Report.

    Science.gov (United States)

    Syracuse Univ. Research Corp., NY. Educational Policy Research Center.

    This report summarizes the results of a two year investigation into the feasibility of using telecommunications satellites for educational purposes compared with the use of other delivery systems. Different systems emerge as preferable depending upon such circumstances as topography, number, and geographic distribution of participants, and the…

  8. Radiation properties of moving constellations of (nano) satellites: A complexity study

    NARCIS (Netherlands)

    Bruinsma, Wessel P.; Hes, Robin P.; Bosma, Sjoerd; Lager, Ioan E.; Bentum, Marinus Jan

    2016-01-01

    The (computational) complexity involved by beamforming in moving constellations of (nano) satellites is investigated by means of illustrative numerical experiments. While the number of radiators in such three-dimensional (3D) array antennas is not large, evaluating their radiation patterns entails

  9. Customer premise service study for 30/20 GHz satellite system

    Science.gov (United States)

    Milton, R. T.; Ross, D. P.; Harcar, A. R.; Freedenberg, P.; Schoen, D.

    1983-01-01

    Satellite systems in which the space segment operates in the 30/20 GHz frequency band are defined and compared as to their potential for providing various types of communications services to customer premises and the economic and technical feasibility of doing so. Technical tasks performed include: market postulation, definition of the ground segment, definition of the space segment, definition of the integrated satellite system, service costs for satellite systems, sensitivity analysis, and critical technology. Based on an analysis of market data, a sufficiently large market for services is projected so as to make the system economically viable. A large market, and hence a high capacity satellite system, is found to be necessary to minimize service costs, i.e., economy of scale is found to hold. The wide bandwidth expected to be available in the 30/20 GHz band, along with frequency reuse which further increases the effective system bandwidth, makes possible the high capacity system. Extensive ground networking is required in most systems to both connect users into the system and to interconnect Earth stations to provide spatial diversity. Earth station spatial diversity is found to be a cost effective means of compensating the large fading encountered in the 30/20 GHz operating band.

  10. Study on networking issues of medium earth orbit satellite communications systems

    Science.gov (United States)

    Araki, Noriyuki; Shinonaga, Hideyuki; Ito, Yasuhiko

    1993-01-01

    Two networking issues of communications systems with medium earth orbit (MEO) satellites, namely network architectures and location determination and registration methods for hand-held terminals, are investigated in this paper. For network architecture, five candidate architectures are considered and evaluated in terms of signaling traffic. For location determination and registration, two methods are discussed and evaluated.

  11. Study and optimisation of the high energy detector in Cd(Zn)Te of the Simbol-X space mission for X and gamma astronomy; Etude et optimisation du plan de detection de haute energie en Cd(Zn)Te pour la mission spatiale d'observation astronomie X et gamma SIMBOL-X

    Energy Technology Data Exchange (ETDEWEB)

    Meuris, A.

    2009-09-15

    Stars in final phases of evolution are sites of highest energetic phenomena of the Universe. The understanding of their mechanisms is based on the observation of the X and gamma rays from the sources. The Simbol-X French-Italian project is a novel concept of telescope with two satellites flying in formation. This space mission combines upgraded optics from X-ray telescopes with detection Systems from gamma-ray telescopes. CEA Saclay involved in major space missions for gamma astronomy is in charge of the definition and the design of the High Energy Detector (HED) of Simbol-X to cover the spectral range from 8 to 80 keV. Two generations of micro-cameras called Caliste have been designed, fabricated and tested. They integrate cadmium telluride (CdTe) crystals and optimised front-end electronics named Idef-X. The hybridization technique enables to put them side by side as a mosaic to achieve for the first time a CdTe detection plane with fine spatial resolution (600 {mu}m) and arbitrarily large surface. By setting up test benches and leading test campaigns, I was involved in the fabrication of Caliste prototypes and I assessed temporal, spatial and spectral resolutions. At the conclusion of experiments and simulations, I propose a detector type, operating conditions and digital processing on board the spacecraft to optimise HED performance. The best detector candidate is CdTe Schottky, well suited to high resolution spectroscopy; however, it suffers from lost in stability during biasing. Beyond Simbol-X mission, I studied theoretically and experimentally this kind of detector to build an updated model that can apply to other projects of gamma spectroscopy and imaging. (author)

  12. A DEEP STUDY OF THE DWARF SATELLITES ANDROMEDA XXVIII AND ANDROMEDA XXIX

    International Nuclear Information System (INIS)

    Slater, Colin T.; Bell, Eric F.; Martin, Nicolas F.; Tollerud, Erik J.; Ho, Nhung

    2015-01-01

    We present the results of a deep study of the isolated dwarf galaxies Andromeda XXVIII and Andromeda XXIX with Gemini/GMOS and Keck/DEIMOS. Both galaxies are shown to host old, metal-poor stellar populations with no detectable recent star formation, conclusively identifying both of them as dwarf spheroidal galaxies (dSphs). And XXVIII exhibits a complex horizontal branch morphology, which is suggestive of metallicity enrichment and thus an extended period of star formation in the past. Decomposing the horizontal branch into blue (metal-poor, assumed to be older) and red (relatively more metal-rich, assumed to be younger) populations shows that the metal-rich are also more spatially concentrated in the center of the galaxy. We use spectroscopic measurements of the calcium triplet, combined with the improved precision of the Gemini photometry, to measure the metallicity of the galaxies, confirming the metallicity spread and showing that they both lie on the luminosity–metallicity relation for dwarf satellites. Taken together, the galaxies exhibit largely typical properties for dSphs despite their significant distances from M31. These dwarfs thus place particularly significant constraints on models of dSph formation involving environmental processes such as tidal or ram pressure stripping. Such models must be able to completely transform the two galaxies into dSphs in no more than two pericentric passages around M31, while maintaining a significant stellar population gradient. Reproducing these features is a prime requirement for models of dSph formation to demonstrate not just the plausibility of environmental transformation but the capability of accurately recreating real dSphs

  13. A multi-satellite study of accelerated ionospheric ion beams above the polar cap

    Directory of Open Access Journals (Sweden)

    R. Maggiolo

    2006-07-01

    Full Text Available This paper presents a study of nearly field-aligned outflowing ion beams observed on the Cluster satellites over the polar cap. Data are taken at geocentric radial distances of the order of 5–9 RE. The distinction is made between ion beams originating from the polar cusp/cleft and beams accelerated almost along the magnetic field line passing by the spacecraft. Polar cusp beams are characterized by nearly field-aligned proton and oxygen ions with an energy ratio EO+ / EH+, of the order of 3 to 4, due to the ion energy repartition inside the source and to the latitudinal extension of the source. Rapid variations in the outflowing ion energy are linked with pulses/modifications of the convection electric field. Cluster data allow one to show that these perturbations of the convection velocity and the associated ion structures propagate at the convection velocity. In contrast, polar cap local ion beams are characterized by field-aligned proton and oxygen ions with similar energies. These beams show the typical inverted V structures usually observed in the auroral zone and are associated with a quasi-static converging electric field indicative of a field-aligned electric field. The field-aligned potential drop fits well the ion energy profile. The simultaneous observation of precipitating electrons and upflowing ions of similar energies at the Cluster orbit indicates that the spacecraft are crossing the mid-altitude part of the acceleration region. In the polar cap, the parallel electric field can thus extend to altitudes higher than 5 Earth radii. A detailed analysis of the distribution functions shows that the ions are heated during their parallel acceleration and that energy is exchanged between H+ and O+. Furthermore, intense electrostatic waves are observed simultaneously. These observations could be due to an ion-ion two-stream instability.

  14. The HORUS Observatory - A Next Generation 2.4m UV-Optical Mission To Study Planetary, Stellar And Galactic Formation

    Science.gov (United States)

    Scowen, Paul A.; SDT, HORUS

    2013-01-01

    The High-ORbit Ultraviolet-visible Satellite (HORUS) is a 2.4-meter class UV-optical space telescope that will conduct a comprehensive and systematic study of the astrophysical processes and environments relevant for the births and life cycles of stars and their planetary systems, to investigate and understand the range of environments, feedback mechanisms, and other factors that most affect the outcome of the star and planet formation process. To do so, HORUS will provide 100 times greater imaging effici