WorldWideScience

Sample records for earth orbit space

  1. Orbital Dynamics of Low-Earth Orbit Laser-Propelled Space Vehicles

    International Nuclear Information System (INIS)

    Yamakawa, Hiroshi; Funaki, Ikkoh; Komurasaki, Kimiya

    2008-01-01

    Trajectories applicable to laser-propelled space vehicles with a laser station in low-Earth orbit are investigated. Laser vehicles are initially located in the vicinity of the Earth-orbiting laser station in low-earth orbit at an altitude of several hundreds kilometers, and are accelerated by laser beaming from the laser station. The laser-propelled vehicles start from low-earth orbit and finally escape from the Earth gravity well, enabling interplanetary trajectories and planetary exploration

  2. The problem of space nuclear power sources collisions with artificial space objects in near-earth orbits

    International Nuclear Information System (INIS)

    Gafarov, A.A.

    1993-01-01

    Practically all space objects with onboard nuclear power sources stay in earth satellite orbits with an orbital lifetime long enough to reduce their radioactivity to levels presenting no danger for the Earth population. One of the reasons for orbit lifetime reduction can be collisions with other space objects in near-earth orbits. The possible consequence of collisions can be partial, or even complete, destruction of the spacecraft with an onboard nuclear power source; as well as delivery of additional impulse both to the spacecraft and its fragments. It is shown that collisions in orbit do not cause increase of radiation hazard for the Earth population if there is aerodynamic breakup of nuclear power sources into fragments of safe sizes during atmospheric reentry

  3. Thermal and orbital analysis of Earth monitoring Sun-synchronous space experiments

    Science.gov (United States)

    Killough, Brian D.

    1990-01-01

    The fundamentals of an Earth monitoring Sun-synchronous orbit are presented. A Sun-synchronous Orbit Analysis Program (SOAP) was developed to calculate orbital parameters for an entire year. The output from this program provides the required input data for the TRASYS thermal radiation computer code, which in turn computes the infrared, solar and Earth albedo heat fluxes incident on a space experiment. Direct incident heat fluxes can be used as input to a generalized thermal analyzer program to size radiators and predict instrument operating temperatures. The SOAP computer code and its application to the thermal analysis methodology presented, should prove useful to the thermal engineer during the design phases of Earth monitoring Sun-synchronous space experiments.

  4. Specialized Finite Set Statistics (FISST)-Based Estimation Methods to Enhance Space Situational Awareness in Medium Earth Orbit (MEO) and Geostationary Earth Orbit (GEO)

    Science.gov (United States)

    2016-08-17

    Specialized Finite Set Statistics (FISST)-based Estimation Methods to Enhance Space Situational Awareness in Medium Earth Orbit (MEO) and Geostationary...terms of specialized Geostationary Earth Orbit (GEO) elements to estimate the state of resident space objects in the geostationary regime. Justification...AFRL-RV-PS- AFRL-RV-PS- TR-2016-0114 TR-2016-0114 SPECIALIZED FINITE SET STATISTICS (FISST)- BASED ESTIMATION METHODS TO ENHANCE SPACE SITUATIONAL

  5. Using The Global Positioning System For Earth Orbiter and Deep Space Network

    Science.gov (United States)

    Lichten, Stephen M.; Haines, Bruce J.; Young, Lawrence E.; Dunn, Charles; Srinivasan, Jeff; Sweeney, Dennis; Nandi, Sumita; Spitzmesser, Don

    1994-01-01

    The Global Positioning System (GPS) can play a major role in supporting orbit and trajectory determination for spacecraft in a wide range of applications, including low-Earth, high-earth, and even deep space (interplanetary) tracking.

  6. Space tourism: from earth orbit to the moon

    Science.gov (United States)

    Collins, P.

    Travel to and from the lunar surface has been known to be feasible since it was first achieved 34 years ago. Since that time there has been enormous progress in related engineering fields such as rocket propulsion, materials and avionics, and about 1 billion has been spent on lunar science and engineering research. Consequently there are no fundamental technical problems facing the development of lunar tourism - only business and investment problems. The outstanding problem is to reduce the cost of launch to low Earth orbit. Recently there has been major progress towards overturning the myth that launch costs are high because of physical limits. Several "X Prize" competitor vehicles currently in test-flight are expected to be able to perform sub-orbital flights at approximately 1/1,000 of the cost of Alan Shepard's similar flight in 1961. This activity could have started 30 years ago if space agencies had had economic rather than political objectives. A further encouraging factor is that the demand for space tourism seems potentially limitless. Starting with sub-orbital flights and growing through orbital activities, travel to the Moon will offer further unique attractions. In every human culture there is immense interest in the Moon arising from millennia of myths. In addition, bird-like flying sports, first described by Robert Heinlein, will become another powerful demand factor. Roundtrips of 1 to 2 weeks are very convenient for travel companies; and the radiation environment will permit visitors several days of surface activity without significant health risks. The paper also discusses economic aspects of lunar tourism, including the benefits it will have for those on Earth. Lunar economic development based on tourism will have much in common with economic development on Earth based on tourism: starting from the fact that many people spontaneously wish to visit popular places, companies in the tourism industry invest to sell a growing range of services to ever

  7. Supporting a Deep Space Gateway with Free-Return Earth-Moon Periodic Orbits

    Science.gov (United States)

    Genova, A. L.; Dunham, D. W.; Hardgrove, C.

    2018-02-01

    Earth-Moon periodic orbits travel between the Earth and Moon via free-return circumlunar segments and can host a station that can provide architecture support to other nodes near the Moon and Mars while enabling science return from cislunar space.

  8. Space radiation dosimetry in low-Earth orbit and beyond

    International Nuclear Information System (INIS)

    Benton, E.R.; Benton, E.V.

    2001-01-01

    Space radiation dosimetry presents one of the greatest challenges in the discipline of radiation protection. This is a result of both the highly complex nature of the radiation fields encountered in low-Earth orbit (LEO) and interplanetary space and of the constraints imposed by spaceflight on instrument design. This paper reviews the sources and composition of the space radiation environment in LEO as well as beyond the Earth's magnetosphere. A review of much of the dosimetric data that have been gathered over the last four decades of human space flight is presented. The different factors affecting the radiation exposures of astronauts and cosmonauts aboard the International Space Station (ISS) are emphasized. Measurements made aboard the Mir Orbital Station have highlighted the importance of both secondary particle production within the structure of spacecraft and the effect of shielding on both crew dose and dose equivalent. Roughly half the dose on ISS is expected to come from trapped protons and half from galactic cosmic rays (GCRs). The dearth of neutron measurements aboard LEO spacecraft and the difficulty inherent in making such measurements have led to large uncertainties in estimates of the neutron contribution to total dose equivalent. Except for a limited number of measurements made aboard the Apollo lunar missions, no crew dosimetry has been conducted beyond the Earth's magnetosphere. At the present time we are forced to rely on model-based estimates of crew dose and dose equivalent when planning for interplanetary missions, such as a mission to Mars. While space crews in LEO are unlikely to exceed the exposure limits recommended by such groups as the NCRP, dose equivalents of the same order as the recommended limits are likely over the course of a human mission to Mars

  9. Using the Global Positioning System for Earth Orbiter and Deep Space Tracking

    Science.gov (United States)

    Lichten, Stephen M.

    1994-01-01

    The Global Positioning System (GPS) can play a major role in supporting orbit and trajectory determination for spacecraft in a wide range of applications, including low-Earth, high-Earth, and even deep space (interplanetary) tracking. This paper summarizes recent results demonstrating these unique and far-ranging applications of GPS.

  10. Earth observation from the manned low Earth orbit platforms

    Science.gov (United States)

    Guo, Huadong; Dou, Changyong; Zhang, Xiaodong; Han, Chunming; Yue, Xijuan

    2016-05-01

    The manned low Earth orbit platforms (MLEOPs), e.g., the U.S. and Russia's human space vehicles, the International Space Station (ISS) and Chinese Tiangong-1 experimental space laboratory not only provide laboratories for scientific experiments in a wide range of disciplines, but also serve as exceptional platforms for remote observation of the Earth, astronomical objects and space environment. As the early orbiting platforms, the MLEOPs provide humans with revolutionary accessibility to the regions on Earth never seen before. Earth observation from MLEOPs began in early 1960s, as a part of manned space flight programs, and will continue with the ISS and upcoming Chinese Space Station. Through a series of flight missions, various and a large amount of Earth observing datasets have been acquired using handheld cameras by crewmembers as well as automated sophisticated sensors onboard these space vehicles. Utilizing these datasets many researches have been conducted, demonstrating the importance and uniqueness of studying Earth from a vantage point of MLEOPs. For example, the first, near-global scale digital elevation model (DEM) was developed from data obtained during the shuttle radar topography mission (SRTM). This review intends to provide an overview of Earth observations from MLEOPs and present applications conducted by the datasets collected by these missions. As the ISS is the most typical representative of MLEOPs, an introduction to it, including orbital characteristics, payload accommodations, and current and proposed sensors, is emphasized. The advantages and challenges of Earth observation from MLEOPs, using the ISS as an example, is also addressed. At last, a conclusive note is drawn.

  11. The Lunar Space Tug: A sustainable bridge between low Earth orbits and the Cislunar Habitat

    Science.gov (United States)

    Mammarella, M.; Paissoni, C. A.; Viola, N.; Denaro, A.; Gargioli, E.; Massobrio, F.

    2017-09-01

    The International Space Station is the first space human outpost and over the last 15 years, it has represented a peculiar environment where science, technology and human innovation converge together in a unique microgravity and space research laboratory. With the International Space Station entering the second part of its life and its operations running steadily at nominal pace, the global space community is starting planning how the human exploration could move further, beyond Low-Earth-Orbit. According to the Global Exploration Roadmap, the Moon represents the next feasible path-way for advances in human exploration towards the nal goal, Mars. Based on the experience of the ISS, one of the most widespread ideas is to develop a Cislunar Station in preparation of long duration missions in a deep space environment. Cislunar space is de ned as the area of deep space under the influence of Earth-Moon system, including a set of special orbits, e.g. Earth-Moon Libration points and Lunar Retrograde Orbit. This habitat represents a suitable environment for demonstrating and testing technologies and capabilities in deep space. In order to achieve this goal, there are several crucial systems and technologies, in particular related to transportation and launch systems. The Orion Multi-Purpose Crew Vehicle is a reusable transportation capsule designed to provide crew transportation in deep space missions, whereas NASA is developing the Space Launch System, the most powerful rocket ever built, which could provide the necessary heavy-lift launch capability to support the same kind of missions. These innovations would allow quite-fast transfers from Earth to the Cislunar Station and vice versa, both for manned and unmanned missions. However, taking into account the whole Concept of Operations for both the growth and sustainability of the Cislunar Space Station, the Lunar Space Tug can be considered as an additional, new and fundamental element for the mission architecture. The

  12. Low earth orbit environmental effects on the space station photovoltaic power generation systems

    International Nuclear Information System (INIS)

    Nahra, H.K.

    1977-01-01

    A summary of the Low Earth Orbital Environment, its impact on the photovoltaic power systems of the space station and the solutions implemented to resolve the environmental concerns or issues are described. Low Earth Orbital Environment (LEO) presents several concerns to the photovoltaic power systems of the space station. These concerns include atomic oxygen interaction with the polymeric substrate of the solar arrays, ionized environment effects on the array operating voltage, the effects of the meteoroids and debris impacts and penetration through the different layers of the solar cells and their circuits, and the high energy particle and radiation effects on the overall solar array performance. Potential solutions to some of the degrading environmental interactions that will provide the photovoltaic power system of the space station with the desired life are also summarized

  13. Space Tourism: Orbital Debris Considerations

    Science.gov (United States)

    Mahmoudian, N.; Shajiee, S.; Moghani, T.; Bahrami, M.

    2002-01-01

    Space activities after a phase of research and development, political competition and national prestige have entered an era of real commercialization. Remote sensing, earth observation, and communication are among the areas in which this growing industry is facing competition and declining government money. A project like International Space Station, which draws from public money, has not only opened a window of real multinational cooperation, but also changed space travel from a mere fantasy into a real world activity. Besides research activities for sending man to moon and Mars and other outer planets, space travel has attracted a considerable attention in recent years in the form of space tourism. Four countries from space fairing nations are actively involved in the development of space tourism. Even, nations which are either in early stages of space technology development or just beginning their space activities, have high ambitions in this area. This is worth noting considering their limited resources. At present, trips to space are available, but limited and expensive. To move beyond this point to generally available trips to orbit and week long stays in LEO, in orbital hotels, some of the required basic transportations, living requirements, and technological developments required for long stay in orbit are already underway. For tourism to develop to a real everyday business, not only the price has to come down to meaningful levels, but also safety considerations should be fully developed to attract travelers' trust. A serious hazard to space activities in general and space tourism in particular is space debris in earth orbit. Orbiting debris are man-made objects left over by space operations, hazardous to space missions. Since the higher density of debris population occurs in low earth orbit, which is also the same orbit of interest to space tourism, a careful attention should be paid to the effect of debris on tourism activities. In this study, after a

  14. The International Space Station: A Low-Earth Orbit (LEO) Test Bed for Advancements in Space and Environmental Medicine

    Science.gov (United States)

    Ruttley, Tara M.; Robinson, Julie A.

    2010-01-01

    Ground-based space analog projects such as the NASA Extreme Environment Mission Operations (NEEMO) can be valuable test beds for evaluation of experimental design and hardware feasibility before actually being implemented on orbit. The International Space Station (ISS) is an closed-system laboratory that orbits 240 miles above the Earth, and is the ultimate extreme environment. Its inhabitants spend hours performing research that spans from fluid physics to human physiology, yielding results that have implications for Earth-based improvements in medicine and health, as well as those that will help facilitate the mitigation of risks to the human body associated with exploration-class space missions. ISS health and medical experiments focus on pre-flight and in-flight prevention, in-flight treatment, and postflight recovery of health problems associated with space flight. Such experiments include those on enhanced medical monitoring, bone and muscle loss prevention, cardiovascular health, immunology, radiation and behavior. Lessons learned from ISS experiments may not only be applicable to other extreme environments that face similar capability limitations, but also serve to enhance standards of care for everyday use on Earth.

  15. Space station orbit maintenance

    Science.gov (United States)

    Kaplan, D. I.; Jones, R. M.

    1983-01-01

    The orbit maintenance problem is examined for two low-earth-orbiting space station concepts - the large, manned Space Operations Center (SOC) and the smaller, unmanned Science and Applications Space Platform (SASP). Atmospheric drag forces are calculated, and circular orbit altitudes are selected to assure a 90 day decay period in the event of catastrophic propulsion system failure. Several thrusting strategies for orbit maintenance are discussed. Various chemical and electric propulsion systems for orbit maintenance are compared on the basis of propellant resupply requirements, power requirements, Shuttle launch costs, and technology readiness.

  16. Space environment effects on polymers in low earth orbit

    International Nuclear Information System (INIS)

    Grossman, E.; Gouzman, I.

    2003-01-01

    Polymers are widely used in space vehicles and systems as structural materials, thermal blankets, thermal control coatings, conformal coatings, adhesives, lubricants, etc. The low earth orbit (LEO) space environment includes hazards such as atomic oxygen, UV radiation, ionizing radiation (electrons, protons), high vacuum, plasma, micrometeoroids and debris, as well as severe temperature cycles. Exposure of polymers and composites to the space environment may result in different detrimental effects via modification of their chemical, electrical, thermal, optical and mechanical properties as well as surface erosion. The high vacuum induces material outgassing (e.g. low-molecular weight residues, plasticizers and additives) and consequent contamination of nearby surfaces. The present work reviews the LEO space environment constituents and their interactions with polymers. Examples of degradation of materials exposed in ground simulation facilities are presented. The issues discussed include the erosion mechanisms of polymers, formation of contaminants and their interaction with the space environment, and protection of materials from the harsh space environment

  17. Spatial analysis of galactic cosmic ray particles in low earth orbit/near equator orbit using SPENVIS

    International Nuclear Information System (INIS)

    Suparta, W; Zulkeple, S K

    2014-01-01

    The space environment has grown intensively harmful to spacecraft and astronauts. Galactic cosmic rays (GCRs) are one of the radiation sources that composed of high energetic particles originated from space and capable of damaging electronic systems through single event upset (SEU) process. In this paper, we analyzed GCR fluxes at different altitudes by using Space Environment Information System (SPENVIS) software and the results are compared to determine their intensities with respect to distance in the Earth's orbit. The altitudes are set at low earth orbit (400 km and 685 km), medium earth orbit (19,100 km and 20,200 km) and high earth orbit (35,793 km and 1,000,000 km). Then, within Low Earth Orbit (LEO) near the equator (NEqO), we used altitude of 685 km to compare GCRs with the intensities of solar particles and trapped particles in the radiation belt to determine the significance of GCRs in the orbit itself.

  18. 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 main purpose of the Small Space-Based Geosynchronous Earth orbiting (GEO) satellite is to provide a space link to the user mission spacecraft for relaying data through ground networks to user Mission Control Centers. The Small Space Based Satellite (SSBS) will provide services comparable to those of a NASA Tracking Data Relay Satellite (TDRS) for the same type of links. The SSBS services will keep the user burden the same or lower than for TDRS and will support the same or higher data rates than those currently supported by TDRS. At present, TDRSS provides links and coverage below GEO; however, SSBS links and coverage capability to above GEO missions are being considered for the future, especially for Human Space Flight Missions (HSF). There is also a rising need for the capability to support high data rate links (exceeding 1 Gbps) for imaging applications. The communication payload on the SSBS will provide S/Ka-band single access links to the mission and a Ku-band link to the ground, with an optical communication payload as an option. To design the communication payload, various link budgets were analyzed and many possible operational scenarios examined. To reduce user burden, using a larger-sized antenna than is currently in use by TDRS was considered. Because of the SSBS design size, it was found that a SpaceX Falcon 9 rocket could deliver three SSBSs to GEO. This will greatly reduce the launch costs per satellite. Using electric propulsion was also evaluated versus using chemical propulsion; the power system size and time to orbit for various power systems were also considered. This paper will describe how the SSBS will meet future service requirements, concept of operations, and the design to meet NASA users' needs for below and above GEO missions. These users' needs not only address the observational mission requirements but also possible HSF missions to the year 2030. We will provide the trade-off analysis of the communication payload design in terms of

  19. Application of X-Ray Pulsar Navigation: A Characterization of the Earth Orbit Trade Space

    Science.gov (United States)

    Yu, Wayne Hong

    2016-01-01

    The potential for pulsars as a navigation source has been studied since their discovery in 1967. X-ray pulsar navigation (XNAV) is a celestial navigation system that uses the consistent timing nature of x-ray photons from millisecond pulsars (MSP) to perform space navigation. By comparing the detected arrival of x-ray photons to a reference database of expected pulsar light-curve timing models, one can infer a range and range rate measurement based on light time delay. Much of the challenge of XNAV comes from the faint signal, availability, and distant nature of pulsars. This is a study of potential pulsar XNAV measurements to measure extended Kalman filter (EKF) tracking performance with a wide trade space of bounded Earth orbits, using a simulation of existing x-ray detector space hardware. An example of an x-ray detector for XNAV is the NASA Station Explorer for X-ray Timing and Navigation (SEXTANT) mission, a technology demonstration of XNAV set to perform on the International Space Station (ISS) in late 2016early 2017. XNAV hardware implementation is driven by trajectory and environmental influences which add noise to the x-ray pulse signal. In a closed Earth orbit, the radiation environment can exponentially increase the signal noise from x-ray pulsar sources, decreasing the quality and frequency of measurements. The SEXTANT mission in particular improves on the signal to noise ratio by focusing an array of 56 x-ray silicon drift detectors at one pulsar target at a time. This reduces timing glitches and other timing noise contributions from ambient x-ray sources to within a 100 nanosecond resolution. This study also considers the SEXTANT scheduling challenges inherent in a single target observation. Finally, as the navigation sources are now relatively inertial targets, XNAV measurements are also subject to periods of occultation from various celestial bodies. This study focuses on the characterization of these drivers in closed Earth orbits and is not a

  20. Investigating fundamental physics and space environment with a dedicated Earth-orbiting spacecraft

    Science.gov (United States)

    Peron, Roberto

    The near-Earth environment is a place of first choice for performing fundamental physics experiments, given its proximity to Earth and at the same time being relatively quiet dynamically for particular orbital arrangements. This environment also sees a rich phenomenology for what concerns gravitation. In fact, the general theory of relativity is an incredibly accurate description of gravitational phenomenology. However, its overall validity is being questioned by the theories that aim at reconciling it with the microscopic domain. Challenges come also from the ‘mysteries’ of Dark Matter and Dark Energy, though mainly at scales from the galactic up to the cosmological. It is therefore important to precisely test the consequences of the theory -- as well as those of competing ones -- at all the accessible scales. At the same time, the development of high-precision experimental space techniques, which are needed for tests in fundamental physics, opens the way to complementary applications. The growth of the (man-made) orbital debris population is creating problems to the future development of space. The year 2009 witnessed the first accidental collision between two satellites in orbit (Iridium and Cosmos) that led to the creation of more debris. International and national agencies are intervening by issuing and/or adopting guidelines to mitigate the growth of orbital debris. A central tenet of these guidelines requires a presence in space shorter than 25 years to satellites in low Earth orbit (LEO) after the conclusion of their operational lives. However, the determination of the natural lifetime of a satellite in LEO is very uncertain due to a large extent to the short-term and long-term variability of the atmospheric density in LEO and the comparatively low-accuracy of atmospheric density models. Many satellites orbiting in the 500-1200 km region with circular or elliptical orbits will be hard pressed to establish before flight whether or not they meet the 25

  1. Space as a Tool for Astrobiology: Review and Recommendations for Experimentations in Earth Orbit and Beyond

    Science.gov (United States)

    Cottin, Hervé; Kotler, Julia Michelle; Billi, Daniela; Cockell, Charles; Demets, René; Ehrenfreund, Pascale; Elsaesser, Andreas; d'Hendecourt, Louis; van Loon, Jack J. W. A.; Martins, Zita; Onofri, Silvano; Quinn, Richard C.; Rabbow, Elke; Rettberg, Petra; Ricco, Antonio J.; Slenzka, Klaus; de la Torre, Rosa; de Vera, Jean-Pierre; Westall, Frances; Carrasco, Nathalie; Fresneau, Aurélien; Kawaguchi, Yuko; Kebukawa, Yoko; Nguyen, Dara; Poch, Olivier; Saiagh, Kafila; Stalport, Fabien; Yamagishi, Akihiko; Yano, Hajime; Klamm, Benjamin A.

    2017-07-01

    The space environment is regularly used for experiments addressing astrobiology research goals. The specific conditions prevailing in Earth orbit and beyond, notably the radiative environment (photons and energetic particles) and the possibility to conduct long-duration measurements, have been the main motivations for developing experimental concepts to expose chemical or biological samples to outer space, or to use the reentry of a spacecraft on Earth to simulate the fall of a meteorite. This paper represents an overview of past and current research in astrobiology conducted in Earth orbit and beyond, with a special focus on ESA missions such as Biopan, STONE (on Russian FOTON capsules) and EXPOSE facilities (outside the International Space Station). The future of exposure platforms is discussed, notably how they can be improved for better science return, and how to incorporate the use of small satellites such as those built in cubesat format.

  2. Magnetically levitated space elevator to low-earth orbit

    International Nuclear Information System (INIS)

    Hull, J. R.; Mulcahy, T. M.

    2001-01-01

    The properties of currently available NbTi superconductor and carbon-fiber structural materials enable the possibility of constructing a magnetically levitated space elevator from the earth's surface up to an altitude of(approx) 200 km. The magnetic part of the elevator consists of a long loop of current-carrying NbTi, composed of one length that is attached to the earth's surface in an east-west direction and a levitated-arch portion. The critical current density of NbTi is sufficiently high that these conductors will stably levitate in the earth's magnetic field. The magnetic self-field from the loop increases the levitational force and for some geometries assists levitational stability. The 200-km maximum height of the levitated arch is limited by the allowable stresses of the structural material. The loop is cryogenically cooled with helium, and the system utilizes intermediate pumping and cooling stations along both the ground and the levitated portion of the loop, similar to other large terrestrial cryogenic systems. Mechanically suspended from the basic loop is an elevator structure, upon which mass can be moved between the earth's surface and the top of the loop by a linear electric motor or other mechanical or electrical means. At the top of the loop, vehicles may be accelerated to orbital velocity or higher by rocket motors, electromagnetic propulsion, or hybrid methods

  3. Magnetically levitated space elevator to low-earth orbit.

    Energy Technology Data Exchange (ETDEWEB)

    Hull, J. R.; Mulcahy, T. M.

    2001-07-02

    The properties of currently available NbTi superconductor and carbon-fiber structural materials enable the possibility of constructing a magnetically levitated space elevator from the earth's surface up to an altitude of {approx} 200 km. The magnetic part of the elevator consists of a long loop of current-carrying NbTi, composed of one length that is attached to the earth's surface in an east-west direction and a levitated-arch portion. The critical current density of NbTi is sufficiently high that these conductors will stably levitate in the earth's magnetic field. The magnetic self-field from the loop increases the levitational force and for some geometries assists levitational stability. The 200-km maximum height of the levitated arch is limited by the allowable stresses of the structural material. The loop is cryogenically cooled with helium, and the system utilizes intermediate pumping and cooling stations along both the ground and the levitated portion of the loop, similar to other large terrestrial cryogenic systems. Mechanically suspended from the basic loop is an elevator structure, upon which mass can be moved between the earth's surface and the top of the loop by a linear electric motor or other mechanical or electrical means. At the top of the loop, vehicles may be accelerated to orbital velocity or higher by rocket motors, electromagnetic propulsion, or hybrid methods.

  4. A low cost automatic detection and ranging system for space surveillance in the medium Earth orbit region and beyond.

    Science.gov (United States)

    Danescu, Radu; Ciurte, Anca; Turcu, Vlad

    2014-02-11

    The space around the Earth is filled with man-made objects, which orbit the planet at altitudes ranging from hundreds to tens of thousands of kilometers. Keeping an eye on all objects in Earth's orbit, useful and not useful, operational or not, is known as Space Surveillance. Due to cost considerations, the space surveillance solutions beyond the Low Earth Orbit region are mainly based on optical instruments. This paper presents a solution for real-time automatic detection and ranging of space objects of altitudes ranging from below the Medium Earth Orbit up to 40,000 km, based on two low cost observation systems built using commercial cameras and marginally professional telescopes, placed 37 km apart, operating as a large baseline stereovision system. The telescopes are pointed towards any visible region of the sky, and the system is able to automatically calibrate the orientation parameters using automatic matching of reference stars from an online catalog, with a very high tolerance for the initial guess of the sky region and camera orientation. The difference between the left and right image of a synchronized stereo pair is used for automatic detection of the satellite pixels, using an original difference computation algorithm that is capable of high sensitivity and a low false positive rate. The use of stereovision provides a strong means of removing false positives, and avoids the need for prior knowledge of the orbits observed, the system being able to detect at the same time all types of objects that fall within the measurement range and are visible on the image.

  5. Cost-effective and robust mitigation of space debris in low earth orbit

    Science.gov (United States)

    Walker, R.; Martin, C.

    It is predicted that the space debris population in low Earth orbit (LEO) will continue to grow and in an exponential manner in the long-term due to an increasing rate of collisions between large objects, unless internationally-accepted space debris mitigation measures are adopted soon. Such measures are aimed at avoiding the future generation of space debris objects and primarily need to be effective in preventing significant long-term growth in the debris population, even in the potential scenario of an increase in future space activity. It is also important that mitigation measures can limit future debris population levels, and therefore the underlying collision risk to space missions, to the lowest extent possible. However, for their wide acceptance, the cost of implementation associated with mitigation measures needs to be minimised as far as possible. Generally, a lower collision risk will cost more to achieve and vice versa, so it is necessary to strike a balance between cost and risk in order to find a cost-effective set of mitigation measures. In this paper, clear criteria are established in order to assess the cost-effectiveness of space debris mitigation measures. A full cost-risk-benefit trade-off analysis of numerous mitigation scenarios is presented. These scenarios consider explosion prevention and post-mission disposal of space systems, including de-orbiting to limited lifetime orbits and re-orbiting above the LEO region. The ESA DELTA model is used to provide long-term debris environment projections for these scenarios as input to the benefit and risk parts of the trade-off analysis. Manoeuvre requirements for the different post-mission disposal scenarios were also calculated in order to define the cost-related element. A 25-year post-mission lifetime de-orbit policy, combined with explosion prevention and mission-related object limitation, was found to be the most cost-effective solution to the space debris problem in LEO. This package would also

  6. An optimum organizational structure for a large earth-orbiting multidisciplinary Space Base

    Science.gov (United States)

    Ragusa, J. M.

    1973-01-01

    The purpose of this exploratory study was to identify an optimum hypothetical organizational structure for a large earth-orbiting multidisciplinary research and applications (R&A) Space Base manned by a mixed crew of technologists. Since such a facility does not presently exist, in situ empirical testing was not possible. Study activity was, therefore, concerned with the identification of a desired organizational structural model rather than the empirical testing of it. The essential finding of this research was that a four-level project type 'total matrix' model will optimize the efficiency and effectiveness of Space Base technologists.

  7. FROM ORDER TO CHAOS IN EARTH SATELLITE ORBITS

    Energy Technology Data Exchange (ETDEWEB)

    Gkolias, Ioannis; Gachet, Fabien [Department of Mathematics, University of Rome Tor Vergata, I-00133 Rome (Italy); Daquin, Jérôme [IMCCE/Observatoire de Paris, Université Lille1, F-59000 Lille (France); Rosengren, Aaron J., E-mail: gkolias@mat.uniroma2.it [IFAC-CNR, 50019 Sesto Fiorentino, Florence (Italy)

    2016-11-01

    We consider Earth satellite orbits in the range of semimajor axes where the perturbing effects of Earth’s oblateness and lunisolar gravity are of comparable order. This range covers the medium-Earth orbits (MEO) of the Global Navigation Satellite Systems and the geosynchronous orbits (GEO) of the communication satellites. We recall a secular and quadrupolar model, based on the Milankovitch vector formulation of perturbation theory, which governs the long-term orbital evolution subject to the predominant gravitational interactions. We study the global dynamics of this two-and-a-half degrees-of-freedom Hamiltonian system by means of the fast Lyapunov indicator (FLI), used in a statistical sense. Specifically, we characterize the degree of chaoticity of the action space using angle-averaged normalized FLI maps, thereby overcoming the angle dependencies of the conventional stability maps. Emphasis is placed upon the phase-space structures near secular resonances, which are of primary importance to the space debris community. We confirm and quantify the transition from order to chaos in MEO, stemming from the critical inclinations and find that highly inclined GEO orbits are particularly unstable. Despite their reputed normality, Earth satellite orbits can possess an extraordinarily rich spectrum of dynamical behaviors and, from a mathematical perspective, have all the complications that make them very interesting candidates for testing the modern tools of chaos theory.

  8. Characteristic of the radiation field in low earth orbit and in deep space

    International Nuclear Information System (INIS)

    Reitz, Guenther

    2008-01-01

    The radiation exposure in space by cosmic radiation can be reduced through careful mission planning and constructive measures as example the provision of a radiation shelter, but it cannot be completely avoided. The reason for that are the extreme high energies of particles in this field and the herewith connected high penetration depth in matter. For missions outside the magnetosphere ionizing radiation is recognized as the key factor through its impact on crew health and performance. In absence of sporadic solar particle events the radiation exposure in Low Earth orbit (LEO) inside Spacecraft is determined by the galactic cosmic radiation (protons and heavier ions) and by the protons inside the South Atlantic Anomaly (SAA), an area where the radiation belt comes closer to the earth surface due to a displacement of the magnetic dipole axes from the Earth's center. In addition there is an albedo source of neutrons produced as interaction products of the primary galactic particles with the atoms of the earth atmosphere. Outside the spacecraft the dose is dominated by the electrons of the horns of the radiation belt located at about 60 latitude in Polar Regions. The radiation field has spatial and temporal variations in dependence of the Earth magnetic field and the solar cycle. The complexity of the radiation field inside a spacecraft is further increased through the interaction of the high energy components with the spacecraft shielding material and with the body of the astronauts. In interplanetary missions the radiation belt will be crossed in a couple of minutes and therefore its contribution to their radiation exposure is quite small, but subsequently the protection by the Earth magnetic field is lost, leaving only shielding measures as exposure reduction means. The report intends to describe the radiation field in space, the interaction of the particles with the magnetic field and shielding material and give some numbers on the radiation exposure in low earth

  9. Characteristic of the radiation field in low Earth orbit and in deep space.

    Science.gov (United States)

    Reitz, Guenther

    2008-01-01

    The radiation exposure in space by cosmic radiation can be reduced through careful mission planning and constructive measures as example the provision of a radiation shelter, but it cannot be completely avoided. The reason for that are the extreme high energies of particles in this field and the herewith connected high penetration depth in matter. For missions outside the magnetosphere ionizing radiation is recognized as the key factor through its impact on crew health and performance. In absence of sporadic solar particle events the radiation exposure in Low Earth orbit (LEO) inside Spacecraft is determined by the galactic cosmic radiation (protons and heavier ions) and by the protons inside the South Atlantic Anomaly (SAA), an area where the radiation belt comes closer to the earth surface due to a displacement of the magnetic dipole axes from the Earth's center. In addition there is an albedo source of neutrons produced as interaction products of the primary galactic particles with the atoms of the earth atmosphere. Outside the spacecraft the dose is dominated by the electrons of the horns of the radiation belt located at about 60" latitude in Polar Regions. The radiation field has spatial and temporal variations in dependence of the Earth magnetic field and the solar cycle. The complexity of the radiation field inside a spacecraft is further increased through the interaction of the high energy components with the spacecraft shielding material and with the body of the astronauts. In interplanetary missions the radiation belt will be crossed in a couple of minutes and therefore its contribution to their radiation exposure is quite small, but subsequently the protection by the Earth magnetic field is lost, leaving only shielding measures as exposure reduction means. The report intends to describe the radiation field in space, the interaction of the particles with the magnetic field and shielding material and give some numbers on the radiation exposure in low earth

  10. Theory and design methods of special space orbits

    CERN Document Server

    Zhang, Yasheng; Zhou, Haijun

    2017-01-01

    This book focuses on the theory and design of special space orbits. Offering a systematic and detailed introduction to the hovering orbit, spiral cruising orbit, multi-target rendezvous orbit, initiative approaching orbit, responsive orbit and earth pole-sitter orbit, it also discusses the concept, theory, design methods and application of special space orbits, particularly the design and control method based on kinematics and astrodynamics. In addition the book presents the latest research and its application in space missions. It is intended for researchers, engineers and postgraduates, especially those working in the fields of orbit design and control, as well as space-mission planning and research.

  11. IPv6 and IPsec Tests of a Space-Based Asset, the Cisco Router in Low Earth Orbit (CLEO)

    Science.gov (United States)

    Ivancic, William; Stewart, David; Wood, Lloyd; Jackson, Chris; Northam, James; Wilhelm, James

    2008-01-01

    This report documents the design of network infrastructure to support testing and demonstrating network-centric operations and command and control of space-based assets, using IPv6 and IPsec. These tests were performed using the Cisco router in Low Earth Orbit (CLEO), an experimental payload onboard the United Kingdom--Disaster Monitoring Constellation (UK-DMC) satellite built and operated by Surrey Satellite Technology Ltd (SSTL). On Thursday, 29 March 2007, NASA Glenn Research Center, Cisco Systems and SSTL performed the first configuration and demonstration of IPsec and IPv6 onboard a satellite in low Earth orbit. IPv6 is the next generation of the Internet Protocol (IP), designed to improve on the popular IPv4 that built the Internet, while IPsec is the protocol used to secure communication across IP networks. This demonstration was made possible in part by NASA s Earth Science Technology Office (ESTO) and shows that new commercial technologies such as mobile networking, IPv6 and IPsec can be used for commercial, military and government space applications. This has direct application to NASA s Vision for Space Exploration. The success of CLEO has paved the way for new spacebased Internet technologies, such as the planned Internet Routing In Space (IRIS) payload at geostationary orbit, which will be a U.S. Department of Defense Joint Capability Technology Demonstration. This is a sanitized report for public distribution. All real addressing has been changed to psueco addressing.

  12. GALILEO ORBITER EARTH POS EARTH2 FLYBY TRAJ V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — Galileo Orbiter 60 second sampled trajectory data from the Earth-2 flyby in GSE and GSM coordinates. These data cover the interval 1992-11-03 to 1992-12-20.

  13. GALILEO ORBITER EARTH POS EARTH1 FLYBY TRAJ V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — Galileo Orbiter 60 second sampled trajectory data from the Earth-1 flyby in GSE and GSM coordinates. These data cover the interval 1990-11-05 to 1990-12-31.

  14. Efficiency in Carrying Cargo to Earth Orbits: Spaceports Repositioning

    Directory of Open Access Journals (Sweden)

    Jakub Hospodka

    2016-10-01

    Full Text Available Space flights are in these days not any more question of technology, but more question of costs. One way how to decrease cost of launch is change of home spaceport. Change of home spaceport for different rockets is a way to achieve more efficient launches to space. The reason is different acceleration achieved from Earth rotation. We added several mathematical calculations of missions to Low Earth Orbit and Geostationary Earth Orbit to show bonuses from Earth rotation and effect of atmospheric drag on specific rockets used these days. We discussed only already used space vessels. Namely Arianne 5, Delta 4 heavy, Proton-M, Zenit and Falcon9. For reaching GEO we discuss possibility of using Hohmman transfer, because none of aforementioned vessels is available for direct GEO entry. As possible place for launch we discussed spaceports Baikonur, Kennedy Space center, Guyana Space center and Sea Launch platform. We present results in form of additional acceleration for each spaceport, and we also project this additional acceleration in means payload increase. In conclusion we find important differences between vessel effectivity based on spaceport used for launch. Change of launch location may bring significant cost decrease for operators.

  15. NASA's Space Launch System: A Flagship for Exploration Beyond Earth's Orbit

    Science.gov (United States)

    May, Todd A.

    2012-01-01

    The National Aeronautics and Space Administration's (NASA) Space Launch System (SLS) Program, managed at the Marshall Space Flight Center, is making progress toward delivering a new capability for exploration beyond Earth orbit in an austere economic climate. This fact drives the SLS team to find innovative solutions to the challenges of designing, developing, fielding, and operating the largest rocket in history. To arrive at the current SLS plan, government and industry experts carefully analyzed hundreds of architecture options and arrived at the one clear solution to stringent requirements for safety, affordability, and sustainability over the decades that the rocket will be in operation. This paper will explore ways to fit this major development within the funding guidelines by using existing engine assets and hardware now in testing to meet a first launch by 2017. It will explain the SLS Program s long-range plan to keep the budget within bounds, yet evolve the 70 metric ton (t) initial lift capability to 130-t lift capability after the first two flights. To achieve the evolved configuration, advanced technologies must offer appropriate return on investment to be selected through a competitive process. For context, the SLS will be larger than the Saturn V that took 12 men on 6 trips for a total of 11 days on the lunar surface over 4 decades ago. Astronauts train for long-duration voyages on the International Space Station, but have not had transportation to go beyond Earth orbit in modern times, until now. NASA is refining its mission manifest, guided by U.S. Space Policy and the Global Exploration Roadmap. Launching the Orion Multi-Purpose Crew Vehicle s (MPCV s) first autonomous certification flight in 2017, followed by a crewed flight in 2021, the SLS will offer a robust way to transport international crews and the air, water, food, and equipment they need for extended trips to asteroids, Lagrange Points, and Mars. In addition, the SLS will accommodate

  16. Preliminary feasibility assessment for Earth-to-space electromagnetic (Railgun) launchers

    Science.gov (United States)

    Rice, E. E.; Miller, L. A.; Earhart, R. W.

    1982-01-01

    An Earth to space electromagnetic (railgun) launcher (ESRL) for launching material into space was studied. Potential ESRL applications were identified and initially assessed to formulate preliminary system requirements. The potential applications included nuclear waste disposal in space, Earth orbital applications, deep space probe launchers, atmospheric research, and boost of chemical rockets. The ESRL system concept consisted of two separate railgun launcher tubes (one at 20 deg from the horizontal for Earth orbital missions, the other vertical for solar system escape disposal missions) powered by a common power plant. Each 2040 m launcher tube is surrounded by 10,200 homopolar generator/inductor units to transmit the power to the walls. Projectile masses are 6500 kg for Earth orbital missions and 2055 kg for nuclear waste disposal missions. For the Earth orbital missions, the projectile requires a propulsion system, leaving an estimated payload mass of 650 kg. For the nuclear waste disposal in space mission, the high level waste mass was estimated at 250 kg. This preliminary assessment included technical, environmental, and economic analyses.

  17. Advantage of Animal Models with Metabolic Flexibility for Space Research Beyond Low Earth Orbit

    Science.gov (United States)

    Griko, Yuri V.; Rask, Jon C.; Raychev, Raycho

    2017-01-01

    As the worlds space agencies and commercial entities continue to expand beyond Low Earth Orbit (LEO), novel approaches to carry out biomedical experiments with animals are required to address the challenge of adaptation to space flight and new planetary environments. The extended time and distance of space travel along with reduced involvement of Earth-based mission support increases the cumulative impact of the risks encountered in space. To respond to these challenges, it becomes increasingly important to develop the capability to manage an organisms self-regulatory control system, which would enable survival in extraterrestrial environments. To significantly reduce the risk to animals on future long duration space missions, we propose the use of metabolically flexible animal models as pathfinders, which are capable of tolerating the environmental extremes exhibited in spaceflight, including altered gravity, exposure to space radiation, chemically reactive planetary environments and temperature extremes.In this report we survey several of the pivotal metabolic flexibility studies and discuss the importance of utilizing animal models with metabolic flexibility with particular attention given to the ability to suppress the organism's metabolism in spaceflight experiments beyond LEO. The presented analysis demonstrates the adjuvant benefits of these factors to minimize damage caused by exposure to spaceflight and extreme planetary environments. Examples of microorganisms and animal models with dormancy capabilities suitable for space research are considered in the context of their survivability under hostile or deadly environments outside of Earth. Potential steps toward implementation of metabolic control technology in spaceflight architecture and its benefits for animal experiments and manned space exploration missions are discussed.

  18. Preservation of Near-Earth Space for Future Generations

    Science.gov (United States)

    Simpson, John A.

    2007-05-01

    List of contributors; Preface; Part I. Introduction: 1. Introduction J. A. Simpson; Part II. Defining the Problem: 2. The Earth satellite population: official growth and constituents Nicholas L. Johnson; 3. The current and future environment: an overall assessment Donald J. Kessler; 4. The current and future space debris environment as assessed in Europe Dietrich Rex; 5. Human survivability issues in the low Earth orbit space debris environment Bernard Bloom; 6. Protecting the space environment for astronomy Joel R. Primack; 7. Effects of space debris on commercial spacecraft - the RADARSAT example H. Robert Warren and M. J. Yelle; 8. Potential effects of the space debris environment on military space systems Albert E. Reinhardt; Part III. Mitigation of and Adaptation to the Space Environment: Techniques and Practices: 9. Precluding post-launch fragmentation of delta stages Irvin J. Webster and T. Y. Kawamura; 10. US international and interagency cooperation in orbital debris Daniel V. Jacobs; 11. ESA concepts for space debris mitigation and risk reduction Heiner Klinkrad; 12. Space debris: how France handles mitigation and adaptation Jean-Louis Marcé; 13. Facing seriously the issue of protection of the outer space environment Qi Yong Liang; 14. Space debris - mitigation and adaptation U. R. Rao; 15. Near Earth space contamination and counteractions Vladimir F. Utkin and S. V. Chekalin; 16. The current and future space debris environment as assessed in Japan Susumu Toda; 17. Orbital debris minimization and mitigation techniques Joseph P. Loftus Jr, Philip D. Anz-Meador and Robert Reynolds; Part IV. Economic Issues: 18. In pursuit of a sustainable space environment: economic issues in regulating space debris Molly K. Macauley; 19. The economics of space operations: insurance aspects Christopher T. W. Kunstadter; Part V. Legal Issues: 20. Environmental treatymaking: lessons learned for controlling pollution of outer space Winfried Lang; 21. Regulation of orbital

  19. 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.

  20. A high-orbit collimating infrared earth simulator

    International Nuclear Information System (INIS)

    Zhang Guoyu; Jiang Huilin; Fang Yang; Yu Huadong; Xu Xiping; Wang, Lingyun; Liu Xuli; Huang Lan; Yue Shixin; Peng Hui

    2007-01-01

    The earth simulator is the most important testing equipment ground-based for the infrared earth sensor, and it is also a key component in the satellite controlling system. for three orbit heights 18000Km, 35786Km and 42000Km, in this paper we adopt a project of collimation and replaceable earth diaphragm and develop a high orbit collimation earth simulator. This simulator can afford three angles 15.19 0 , 17.46 0 and 30.42 0 , resulting simulating the earth on the ground which can be seen in out space by the satellite. In this paper we introduce the components, integer structure, and the earth's field angles testing method of the earth simulator in detail. Germanium collimation lens is the most important component in the earth simulator. According to the optical configuration parameter of Germanium collimation lens, we find the location and size of the earth diaphragm and the hot earth by theoretical analyses and optics calculation, which offer foundation of design in the study of the earth simulator. The earth angle is the index to scale the precision of earth simulator. We test the three angles by experiment and the results indicate that three angles errors are all less than ±0.05 0

  1. Introducing Earth's Orbital Eccentricity

    Science.gov (United States)

    Oostra, Benjamin

    2015-01-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…

  2. [Anthropogenic sources of radiation hazard in the near-Earth space].

    Science.gov (United States)

    Fedoseev, G A

    2004-01-01

    All plausible artificial radioactive sources entering the near-Earth space (NES) were systematized and consequences of various large radiation accidents and catastrophes to Earth and NES were analyzed. Aggressive "population" of near-Earth orbits by space stations with rotating crews, unmanned research platforms and observatories extends "borderlines" of the noosphere raising at the same time concerns about the noosphere radiation safety and global radioecology. Specifically, consideration is given to the facts of negative effects of space power reactor facilities on results of orbital astrophysical investigations.

  3. The Orbital Space Environment and Space Situational Awareness Domain Ontology - Toward an International Information System for Space Data

    Science.gov (United States)

    Rovetto, R.

    2016-09-01

    The orbital space environment is home to natural and artificial satellites, debris, and space weather phenomena. As the population of orbital objects grows so do the potential hazards to astronauts, space infrastructure and spaceflight capability. Orbital debris, in particular, is a universal concern. This and other hazards can be minimized by improving global space situational awareness (SSA). By sharing more data and increasing observational coverage of the space environment we stand to achieve that goal, thereby making spaceflight safer and expanding our knowledge of near-Earth space. To facilitate data-sharing interoperability among distinct orbital debris and space object catalogs, and SSA information systems, I proposed ontology in (Rovetto, 2015) and (Rovetto and Kelso, 2016). I continue this effort toward formal representations and models of the overall domain that may serve to improve peaceful SSA and increase our scientific knowledge. This paper explains the project concept introduced in those publications, summarizing efforts to date as well as the research field of ontology development and engineering. I describe concepts for an ontological framework for the orbital space environment, near-Earth space environment and SSA domain. An ontological framework is conceived as a part of a potential international information system. The purpose of such a system is to consolidate, analyze and reason over various sources and types of orbital and SSA data toward the mutually beneficial goals of safer space navigation and scientific research. Recent internationals findings on the limitations of orbital data, in addition to existing publications on collaborative SSA, demonstrate both the overlap with this project and the need for datasharing and integration.

  4. METRIC: A Dedicated Earth-Orbiting Spacecraft for Investigating Gravitational Physics and the Space Environment

    Directory of Open Access Journals (Sweden)

    Roberto Peron

    2017-07-01

    Full Text Available A dedicated mission in low Earth orbit is proposed to test predictions of gravitational interaction theories and to directly measure the atmospheric density in a relevant altitude range, as well as to provide a metrological platform able to tie different space geodesy techniques. The concept foresees a small spacecraft to be placed in a dawn-dusk eccentric orbit between 450 and 1200 km of altitude. The spacecraft will be tracked from the ground with high precision, and a three-axis accelerometer package on-board will measure the non-gravitational accelerations acting on its surface. Estimates of parameters related to fundamental physics and geophysics should be obtained by a precise orbit determination, while the accelerometer data will be instrumental in constraining the atmospheric density. Along with the mission scientific objectives, a conceptual configuration is described together with an analysis of the dynamical environment experienced by the spacecraft and the accelerometer.

  5. The O/OREOS Mission - Astrobiology in Low Earth Orbit. [Astrobiology in Low Earth Orbit

    Science.gov (United States)

    Ehrenfreund, P.; Ricco, A. J.; Squires, D.; Kitts, C.; Agasid, E.; Bramall, N.; Bryson, K.; Chittenden, J.; Conley, C.; Cook, A.; hide

    2014-01-01

    The O/OREOS (Organism/Organic Exposure to Orbital Stresses) nanosatellite is the first science demonstration spacecraft and flight mission of the NASA Astrobiology Small- Payloads Program (ASP). O/OREOS was launched successfully on November 19, 2010, to a high-inclination (72 deg), 650-km Earth orbit aboard a US Air Force Minotaur IV rocket from Kodiak, Alaska. O/OREOS consists of 3 conjoined cubesat (each 1000 cu cm) modules: (i) a control bus; (ii) the Space Environment Survivability of Living Organisms (SESLO) experiment; and (iii) the Space Environment Viability of Organics (SEVO) experiment. Among the innovative aspects of the O/OREOS mission are a real-time analysis of the photostability of organics and biomarkers and the collection of data on the survival and metabolic activity for microorganisms at 3 times during the 6-month mission. We report on the spacecraft characteristics, payload capabilities, and present operational phase and flight data from the O/OREOS mission. The science and technology rationale of O/OREOS supports NASA0s scientific exploration program by investigating the local space environment as well as space biology relevant to Moon and Mars missions. It also serves as a precursor for experiments on small satellites, the International Space Station (ISS), future free-flyers and lunar surface exposure facilities.

  6. Retrieval of RTG'S in earth orbit

    International Nuclear Information System (INIS)

    Raab, B.; Frieder, M.A.; Skrabek, A.

    1982-01-01

    Since 1961, some ten Radioisotope Thermoelectric Generators (RTG's) have been placed into a variety of spacecraft which are now in earth orbit. All of these spacecraft are in orbits with lifetimes in excess of 100 years and pose no risk. However, since most of these spacecraft are no longer being actively used, these may be subject to an active removal program to reduce the population of objects in space. Therefore, a study was undertaken to evaluate the feasibility of retrieving or disposing of spacecraft with RTGs on board. Intervention scenarios are developed and an orbital rendezvous vehicle is conceptualized. The costs of RTG retrieval are derived and compared to the costs of RTG disposal, i.e., boost to a higher, multi-millenium-lifetime orbit, and are found to be not significantly different

  7. Analysis of orbit determination from Earth-based tracking for relay satellites in a perturbed areostationary orbit

    Science.gov (United States)

    Romero, P.; Pablos, B.; Barderas, G.

    2017-07-01

    Areostationary satellites are considered a high interest group of satellites to satisfy the telecommunications needs of the foreseen missions to Mars. An areostationary satellite, in an areoequatorial circular orbit with a period of 1 Martian sidereal day, would orbit Mars remaining at a fixed location over the Martian surface, analogous to a geostationary satellite around the Earth. This work addresses an analysis of the perturbed orbital motion of an areostationary satellite as well as a preliminary analysis of the aerostationary orbit estimation accuracy based on Earth tracking observations. First, the models for the perturbations due to the Mars gravitational field, the gravitational attraction of the Sun and the Martian moons, Phobos and Deimos, and solar radiation pressure are described. Then, the observability from Earth including possible occultations by Mars of an areostationary satellite in a perturbed areosynchronous motion is analyzed. The results show that continuous Earth-based tracking is achievable using observations from the three NASA Deep Space Network Complexes in Madrid, Goldstone and Canberra in an occultation-free scenario. Finally, an analysis of the orbit determination accuracy is addressed considering several scenarios including discontinuous tracking schedules for different epochs and different areoestationary satellites. Simulations also allow to quantify the aerostationary orbit estimation accuracy for various tracking series durations and observed orbit arc-lengths.

  8. A Framework for Orbital Performance Evaluation in Distributed Space Missions for Earth Observation

    Science.gov (United States)

    Nag, Sreeja; LeMoigne-Stewart, Jacqueline; Miller, David W.; de Weck, Olivier

    2015-01-01

    Distributed Space Missions (DSMs) are gaining momentum in their application to earth science missions owing to their unique ability to increase observation sampling in spatial, spectral and temporal dimensions simultaneously. DSM architectures have a large number of design variables and since they are expected to increase mission flexibility, scalability, evolvability and robustness, their design is a complex problem with many variables and objectives affecting performance. There are very few open-access tools available to explore the tradespace of variables which allow performance assessment and are easy to plug into science goals, and therefore select the most optimal design. This paper presents a software tool developed on the MATLAB engine interfacing with STK, for DSM orbit design and selection. It is capable of generating thousands of homogeneous constellation or formation flight architectures based on pre-defined design variable ranges and sizing those architectures in terms of predefined performance metrics. The metrics can be input into observing system simulation experiments, as available from the science teams, allowing dynamic coupling of science and engineering designs. Design variables include but are not restricted to constellation type, formation flight type, FOV of instrument, altitude and inclination of chief orbits, differential orbital elements, leader satellites, latitudes or regions of interest, planes and satellite numbers. Intermediate performance metrics include angular coverage, number of accesses, revisit coverage, access deterioration over time at every point of the Earth's grid. The orbit design process can be streamlined and variables more bounded along the way, owing to the availability of low fidelity and low complexity models such as corrected HCW equations up to high precision STK models with J2 and drag. The tool can thus help any scientist or program manager select pre-Phase A, Pareto optimal DSM designs for a variety of science

  9. Space and Earth Science Data Compression Workshop

    Science.gov (United States)

    Tilton, James C. (Editor)

    1991-01-01

    The workshop explored opportunities for data compression to enhance the collection and analysis of space and Earth science data. The focus was on scientists' data requirements, as well as constraints imposed by the data collection, transmission, distribution, and archival systems. The workshop consisted of several invited papers; two described information systems for space and Earth science data, four depicted analysis scenarios for extracting information of scientific interest from data collected by Earth orbiting and deep space platforms, and a final one was a general tutorial on image data compression.

  10. Earth Orbiting Support Systems for commercial low Earth orbit data relay: Assessing architectures through tradespace exploration

    Science.gov (United States)

    Palermo, Gianluca; Golkar, Alessandro; Gaudenzi, Paolo

    2015-06-01

    As small satellites and Sun Synchronous Earth Observation systems are assuming an increased role in nowadays space activities, including commercial investments, it is of interest to assess how infrastructures could be developed to support the development of such systems and other spacecraft that could benefit from having a data relay service in Low Earth Orbit (LEO), as opposed to traditional Geostationary relays. This paper presents a tradespace exploration study of the architecture of such LEO commercial satellite data relay systems, here defined as Earth Orbiting Support Systems (EOSS). The paper proposes a methodology to formulate architectural decisions for EOSS constellations, and enumerate the corresponding tradespace of feasible architectures. Evaluation metrics are proposed to measure benefits and costs of architectures; lastly, a multicriteria Pareto criterion is used to downselect optimal architectures for subsequent analysis. The methodology is applied to two case studies for a set of 30 and 100 customer-spacecraft respectively, representing potential markets for LEO services in Exploration, Earth Observation, Science, and CubeSats. Pareto analysis shows how increased performance of the constellation is always achieved by an increased node size, as measured by the gain of the communications antenna mounted on EOSS spacecraft. On the other hand, nonlinear trends in optimal orbital altitude, number of satellites per plane, and number of orbital planes, are found in both cases. An upward trend in individual node memory capacity is found, although never exceeding 256 Gbits of onboard memory for both cases that have been considered, assuming the availability of a polar ground station for EOSS data downlink. System architects can use the proposed methodology to identify optimal EOSS constellations for a given service pricing strategy and customer target, thus identifying alternatives for selection by decision makers.

  11. Permanent Habitats in Earth-Sol/Mars-Sol Orbit Positions

    Science.gov (United States)

    Greenspon, J.

    Project Outpost is a manned Earth-Sol/Mars-Sol platform that enables permanent occupation in deep space. In order to develop the program elements for this complex mission, Project Outpost will rely primarily on existing/nearterm technology and hardware for the construction of its components. For the purposes of this study, four mission requirements are considered: 1. Outpost - Man's 1st purpose-produced effort of space engineering, in which astructure is developed/constructed in an environment completely alien to currentpractices for EVA guidelines. 2. Newton - a concept study developed at StarGate Research, for the development ofa modified Hohmann personnel orbital transport operating between Earth andMars. Newton would serve as the primary crew delivery apparatus throughrepeatable transfer scheduling for all Earth-Lpoint-Mars activities. Thispermanent "transit system" would establish the foundations for Solar systemcolonization. 3. Cruis - a concept study developed at StarGate Research, for the development of amodified Hohmann cargo orbital transport operating between Earth and Mars.Cruis would serve as the primary equipment delivery apparatus throughrepeatable transfer scheduling for all Earth-Lpoint-Mars activities. Thispermanent "transit system" would establish the foundations for Solar systemcolonization, and 4. Ares/Diana - a more conventional space platform configuration for Lunar andMars orbit is included as a construction baseline. The operations of these assetsare supported, and used for the support, of the outpost. Outpost would be constructed over a 27-year period of launch opportunities into Earth-Sol or Mars-Sol Lagrange orbit (E-S/M-S L1, 4 or 5). The outpost consists of an operations core with a self-contained power generation ability, a docking and maintenance structure, a Scientific Research complex and a Habitation Section. After achieving initial activation, the core will provide the support and energy required to operate the outpost in a 365

  12. Exposure of phototrophs to 548 days in low Earth orbit: microbial selection pressures in outer space and on early earth.

    Science.gov (United States)

    Cockell, Charles S; Rettberg, Petra; Rabbow, Elke; Olsson-Francis, Karen

    2011-10-01

    An epilithic microbial community was launched into low Earth orbit, and exposed to conditions in outer space for 548 days on the European Space Agency EXPOSE-E facility outside the International Space Station. The natural phototroph biofilm was augmented with akinetes of Anabaena cylindrica and vegetative cells of Nostoc commune and Chroococcidiopsis. In space-exposed dark controls, two algae (Chlorella and Rosenvingiella spp.), a cyanobacterium (Gloeocapsa sp.) and two bacteria associated with the natural community survived. Of the augmented organisms, cells of A. cylindrica and Chroococcidiopsis survived, but no cells of N. commune. Only cells of Chroococcidiopsis were cultured from samples exposed to the unattenuated extraterrestrial ultraviolet (UV) spectrum (>110 nm or 200 nm). Raman spectroscopy and bright-field microscopy showed that under these conditions the surface cells were bleached and their carotenoids were destroyed, although cell morphology was preserved. These experiments demonstrate that outer space can act as a selection pressure on the composition of microbial communities. The results obtained from samples exposed to >200 nm UV (simulating the putative worst-case UV exposure on the early Earth) demonstrate the potential for epilithic colonization of land masses during that time, but that UV radiation on anoxic planets can act as a strong selection pressure on surface-dwelling organisms. Finally, these experiments have yielded new phototrophic organisms of potential use in biomass and oxygen production in space exploration.

  13. A numerical model of the electrodynamics of plasma within the contaminant gas cloud of the space shuttle orbiter at low Earth orbit

    International Nuclear Information System (INIS)

    Eccles, J.V.; Raitt, W.J.; Banks, P.M.

    1989-01-01

    This paper presents results from a two-dimensional, finite-difference model used to solve for the time evolution of low beta plasma within the neutral contaminant cloud in the vicinity of space platforms in low earth orbit. The model of the ambient and contaminant plasma dynamics takes into account the effects of the geomagnetic field, electric fields, background ionosphere, ion-neutral collisions, chemistry, and both Pederson and Hall currents. Net ionization and charge exchange source terms are included in the fluid equations to study electrodynamic effects of chemistry within a moving neutral cloud in the low earth orbit ionosphere. The model is then used with complete water cloud chemistry to simulate the known outgassing situation of the space shuttle Orbiter. A comparison is made of the model results with plasma observations made during daytime on OSS-1/STS-3 mission. The reported density enhancements of the OSS-1 mission are unattainable with normal photoionization and charge exchange rates of simple water cloud chemistry used in the two-dimensional model. The enhanced densities are only attained by a generic chemistry model if a net ionization rate 1,000 times higher than the photoionization rate of water is used. It is also shown that significant plasma buildup at the front of the contaminant neutral cloud can occur due to momentum transfer from the neutral outgas cloud to the plasma through elastic collisions and charge exchange. The currents caused by elastic and reactive collisions result in the generation of a small polarization electric field within the outgas cloud

  14. Towards the integration of orbital space use in Life Cycle Impact Assessment.

    Science.gov (United States)

    Maury, Thibaut; Loubet, Philippe; Ouziel, Jonathan; Saint-Amand, Maud; Dariol, Ludovic; Sonnemann, Guido

    2017-10-01

    A rising sustainability concern is occurring in the space sector: 29,000 human-made objects, larger than 10cm are orbiting the Earth but only 6% are operational spacecrafts. Today, space debris is today a significant and constant danger to all space missions. Consequently, it becomes compelled to design new space missions considering End-of-Life requirements in order to ensure the sustainable use of space orbits. Furthermore, Life Cycle Assessment (LCA) has been identified by the European Space Agency as an adequate tool to measure the environmental impact of spacecraft missions. Hence, our challenge is to integrate orbital space use into Life Cycle Impact Assessment (LCIA) to broaden the scope of LCA for space systems. The generation of debris in the near-Earth's orbital regions leads to a decrease in volume availability. The Area-of-Protection (AoP) 'resources' seems to be the most relevant reflection of this depletion. To address orbital space use in a comprehensive way, we propose a first attempt at establishing an impact pathway linking outer space use to resources. This framework will be the basis for defining new indicator(s) related to orbital space use. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Compendium of Single Event Effects (SEE) Test Results for COTS and Standard Electronics for Low Earth Orbit and Deep Space Applications

    Science.gov (United States)

    Reddell, Brandon; Bailey, Chuck; Nguyen, Kyson; O'Neill, Patrick; Gaza, Razvan; Patel, Chirag; Cooper, Jaime; Kalb, Theodore

    2017-01-01

    We present the results of SEE testing with high energy protons and with low and high energy heavy ions. This paper summarizes test results for components considered for Low Earth Orbit and Deep Space applications.

  16. Use of libration-point orbits for space observatories

    Science.gov (United States)

    Farquhar, Robert W.; Dunham, David W.

    1990-01-01

    The sun-earth libration points, L1 and L2, are located 1.5 million kilometers from the earth toward and away from the sun. Halo orbits about these points have significant advantages for space observatories in terms of viewing geometry, thermal and radiation environment, and delta-V expediture.

  17. Measurement of particle directions in low earth orbit with a Timepix

    International Nuclear Information System (INIS)

    Gohl, St.; Bergmann, B.; Granja, C.; Pichotka, M.; Polansky, S.; Pospisil, S.; Owens, A.

    2016-01-01

    In Low Earth Orbit (LEO) in space electronic equipment aboard satellites and space crews are exposed to high ionizing radiation levels. To reduce radiation damage and the exposure of astronauts, to improve shielding and to assess dose levels, it is valuable to know the composition of the radiation fields and particle directions. The presented measurements are carried out with the Space Application of Timepix Radiation Monitor (SATRAM). There, a Timepix detector (300 μm thick silicon sensor, pixel pitch 55 μm, 256 × 256 pixels) is attached to the Proba-V, an earth observing satellite of the European Space Agency (ESA). The Timepix detector's capability was used to determine the directions of energetic charged particles and their corresponding stopping powers. Data are continuously taken at an altitude of 820 km on a sun-synchronous orbit. The particles pitch angles with respect to the sensor layer were measured and converted to an Earth Centred Earth Fixed (ECEF) coordinate system. Deviations from an isotropic field are extracted by normalization of the observed angular distributions by a Geant4 Monte Carlo simulation —taking the systematics of the reconstruction algorithm and the pixelation into account.

  18. Prevalence of Earth-size planets orbiting Sun-like stars.

    Science.gov (United States)

    Petigura, Erik A; Howard, Andrew W; Marcy, Geoffrey W

    2013-11-26

    Determining whether Earth-like planets are common or rare looms as a touchstone in the question of life in the universe. We searched for Earth-size planets that cross in front of their host stars by examining the brightness measurements of 42,000 stars from National Aeronautics and Space Administration's Kepler mission. We found 603 planets, including 10 that are Earth size ( ) and receive comparable levels of stellar energy to that of Earth (1 - 2 R[Symbol: see text] ). We account for Kepler's imperfect detectability of such planets by injecting synthetic planet-caused dimmings into the Kepler brightness measurements and recording the fraction detected. We find that 11 ± 4% of Sun-like stars harbor an Earth-size planet receiving between one and four times the stellar intensity as Earth. We also find that the occurrence of Earth-size planets is constant with increasing orbital period (P), within equal intervals of logP up to ~200 d. Extrapolating, one finds 5.7(-2.2)(+1.7)% of Sun-like stars harbor an Earth-size planet with orbital periods of 200-400 d.

  19. Large-size space debris flyby in low earth orbits

    Science.gov (United States)

    Baranov, A. A.; Grishko, D. A.; Razoumny, Y. N.

    2017-09-01

    the analysis of NORAD catalogue of space objects executed with respect to the overall sizes of upper-stages and last stages of carrier rockets allows the classification of 5 groups of large-size space debris (LSSD). These groups are defined according to the proximity of orbital inclinations of the involved objects. The orbits within a group have various values of deviations in the Right Ascension of the Ascending Node (RAAN). It is proposed to use the RAANs deviations' evolution portrait to clarify the orbital planes' relative spatial distribution in a group so that the RAAN deviations should be calculated with respect to the concrete precessing orbital plane of the concrete object. In case of the first three groups (inclinations i = 71°, i = 74°, i = 81°) the straight lines of the RAAN relative deviations almost do not intersect each other. So the simple, successive flyby of group's elements is effective, but the significant value of total Δ V is required to form drift orbits. In case of the fifth group (Sun-synchronous orbits) these straight lines chaotically intersect each other for many times due to the noticeable differences in values of semi-major axes and orbital inclinations. The intersections' existence makes it possible to create such a flyby sequence for LSSD group when the orbit of one LSSD object simultaneously serves as the drift orbit to attain another LSSD object. This flyby scheme requiring less Δ V was called "diagonal." The RAANs deviations' evolution portrait built for the fourth group (to be studied in the paper) contains both types of lines, so the simultaneous combination of diagonal and successive flyby schemes is possible. The value of total Δ V and temporal costs were calculated to cover all the elements of the 4th group. The article is also enriched by the results obtained for the flyby problem solution in case of all the five mentioned LSSD groups. The general recommendations are given concerned with the required reserve of total

  20. Environmental studies using earth orbital photography

    Energy Technology Data Exchange (ETDEWEB)

    Wobber, F J

    1969-01-01

    Orbital remote sensing, and particularly orbital photography, can provide immediately useful data for scientists familiar with applying aerial photographic techniques to environmental problems. Despite the expansion of analytical techniques in the earth sciences, the environmental data base has remained relatively static compared with increased information needs because of the difficulty of effective worldwide surveys and the high cost of timely data collection. Color, color infrared and black and white space photographs obtained incident to the Gemini and Apollo programs provide unique synoptic tools for analyzing modern environments and processes, and data that cannot be duplicated by aerial photographic mosaics. Principal advantages of orbital surveys include repetitious worldwide coverage promising environmental synthesis within the full spectrum of seasonal contrasts, and synoptic observations on a scale generally impossible from aircraft. The general categories of environmental data that can be extracted from orbital photography are summarized. 26 references, 37 figures, 3 tables.

  1. Model-Based Trade Space Exploration for Near-Earth Space Missions

    Science.gov (United States)

    Cohen, Ronald H.; Boncyk, Wayne; Brutocao, James; Beveridge, Iain

    2005-01-01

    We developed a capability for model-based trade space exploration to be used in the conceptual design of Earth-orbiting space missions. We have created a set of reusable software components to model various subsystems and aspects of space missions. Several example mission models were created to test the tools and process. This technique and toolset has demonstrated itself to be valuable for space mission architectural design.

  2. International Space Station as a Base Camp for Exploration Beyond Low Earth Orbit

    Science.gov (United States)

    Raftery, Michael; Hoffman, Jeffrey

    2011-01-01

    The idea for using the International Space Station (ISS) as platform for exploration has matured in the past year and the concept continues to gain momentum. ISS provides a robust infrastructure which can be used to test systems and capabilities needed for missions to the Moon, Mars, asteroids and other potential destinations. International cooperation is a critical enabler and ISS has already demonstrated successful management of a large multi-national technical endeavor. Systems and resources needed for expeditions can be aggregated and thoroughly tested at ISS before departure thus providing wide operational flexibility and the best assurance of mission success. A small part of ISS called an Exploration Platform (ISS-EP) can be placed at Earth-Moon Libration point 1 (EML1) providing immediate benefits and flexibility for future exploration missions. We will show how ISS and the ISS-EP can be used to reduce risk and improve the operational flexibility for missions beyond low earth orbit. Life support systems and other technology developed for ISS can be evolved and adapted to the ISS-EP and other exploration spacecraft. New technology, such as electric propulsion and advanced life support systems can be tested and proven at ISS as part of an incremental development program. Commercial companies who are introducing transportation and other services will benefit with opportunities to contribute to the mission since ISS will serve as a focal point for the commercialization of low earth orbit services. Finally, we will show how use of ISS provides immediate benefits to the scientific community because its capabilities are available today and certain critical aspects of exploration missions can be simulated.

  3. The Space Launch System -The Biggest, Most Capable Rocket Ever Built, for Entirely New Human Exploration Missions Beyond Earth's Orbit

    Science.gov (United States)

    Shivers, C. Herb

    2012-01-01

    NASA is developing the Space Launch System -- an advanced heavy-lift launch vehicle that will provide an entirely new capability for human exploration beyond Earth's orbit. The Space Launch System will provide a safe, affordable and sustainable means of reaching beyond our current limits and opening up new discoveries from the unique vantage point of space. The first developmental flight, or mission, is targeted for the end of 2017. The Space Launch System, or SLS, will be designed to carry the Orion Multi-Purpose Crew Vehicle, as well as important cargo, equipment and science experiments to Earth's orbit and destinations beyond. Additionally, the SLS will serve as a backup for commercial and international partner transportation services to the International Space Station. The SLS rocket will incorporate technological investments from the Space Shuttle Program and the Constellation Program in order to take advantage of proven hardware and cutting-edge tooling and manufacturing technology that will significantly reduce development and operations costs. The rocket will use a liquid hydrogen and liquid oxygen propulsion system, which will include the RS-25D/E from the Space Shuttle Program for the core stage and the J-2X engine for the upper stage. SLS will also use solid rocket boosters for the initial development flights, while follow-on boosters will be competed based on performance requirements and affordability considerations.

  4. Space Radiation: The Number One Risk to Astronaut Health beyond Low Earth Orbit

    Science.gov (United States)

    Chancellor, Jeffery C.; Scott, Graham B. I.; Sutton, Jeffrey P.

    2014-01-01

    Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS) decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO). Shielding is an effective countermeasure against solar particle events (SPEs), but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR) nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts. PMID:25370382

  5. Space Radiation: The Number One Risk to Astronaut Health beyond Low Earth Orbit

    Directory of Open Access Journals (Sweden)

    Jeffery C. Chancellor

    2014-09-01

    Full Text Available Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO. Shielding is an effective countermeasure against solar particle events (SPEs, but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts.

  6. 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.

  7. Deep-space and near-Earth optical communications by coded orbital angular momentum (OAM) modulation.

    Science.gov (United States)

    Djordjevic, Ivan B

    2011-07-18

    In order to achieve multi-gigabit transmission (projected for 2020) for the use in interplanetary communications, the usage of large number of time slots in pulse-position modulation (PPM), typically used in deep-space applications, is needed, which imposes stringent requirements on system design and implementation. As an alternative satisfying high-bandwidth demands of future interplanetary communications, while keeping the system cost and power consumption reasonably low, in this paper, we describe the use of orbital angular momentum (OAM) as an additional degree of freedom. The OAM is associated with azimuthal phase of the complex electric field. Because OAM eigenstates are orthogonal the can be used as basis functions for N-dimensional signaling. The OAM modulation and multiplexing can, therefore, be used, in combination with other degrees of freedom, to solve the high-bandwidth requirements of future deep-space and near-Earth optical communications. The main challenge for OAM deep-space communication represents the link between a spacecraft probe and the Earth station because in the presence of atmospheric turbulence the orthogonality between OAM states is no longer preserved. We will show that in combination with LDPC codes, the OAM-based modulation schemes can operate even under strong atmospheric turbulence regime. In addition, the spectral efficiency of proposed scheme is N2/log2N times better than that of PPM.

  8. Options for Staging Orbits in Cis-Lunar Space

    Science.gov (United States)

    Martinez, Roland; Whitley, Ryan

    2016-01-01

    NASA has been studying options to conduct missions beyond Low Earth Orbit, but within the Earth-Moon system, in preparation for deep space exploration including human missions to Mars. Referred to as the Proving Ground, this arena of exploration activities will enable the development of human spaceflight systems and operations to satisfy future exploration objectives beyond the cis-lunar environment. One option being considered includes the deployment of a habitable element or elements, which could be used as a central location for aggregation of supplies and resources for human missions in cis-lunar space and beyond. Characterizing candidate orbit locations for this asset and the impacts on system design and mission operations is important in the overall assessment of the options being considered. The orbits described in this paper were initially selected by taking advantage of previous studies conducted by NASA and the work of other authors. In this paper orbits are assessed for their relative attractiveness based on various factors. A set of constraints related to the capability of the combined Orion and SLS system to deliver humans and cargo to and from the orbit are evaluated. Deployed assets intended to spend multiple years in the Proving Ground would ideally require minimal station keeping costs to reduce the mass budget allocated to this function. Additional mission design drivers include eclipse frequency, potential for uninterrupted communication with deployed assets, thermal, attitude control, communications, and other operational implications. Also the ability to support potential lunar surface activities and excursion missions beyond Earth-Moon space is considered. The results of the characterization and evaluation of the selected orbits indicate a Near Rectilinear Orbit (NRO) is an attractive candidate as an aggregation point or staging location for operations. In this paper, the NRO is further described in terms which balance a number of key

  9. Risk assessment and late effects of radiation in low-earth orbits

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1989-01-01

    The radiation dose rates in low-earth orbits are dependent on the altitude and orbital inclination. The doses to which the crews of space vehicles are exposed is governed by the duration of the mission and the shielding, and in low-earth orbit missions protons are the dominant particles encountered. The risk of concern with the low dose rates and the relatively low total doses of radiation that will be incurred on the space station is excess cancer. The National Council on Radiation Protection and Measurements has recently recommended career dose-equivalent limits that take into account sex and age. The new recommendations for career limits range from 1.0 Sv to 4 Sv, depending on sex and on the age at the time of their first space mission, compared to a single career limit of 4.0 Sv previously used by NASA. Risk estimates for radiated-induced cancer are evolving and changes in the current guidance may be required in the next few years. 10 refs., 1 fig., 3 tabs

  10. Mitigating Aviation Communication and Satellite Orbit Operations Surprises from Adverse Space Weather

    Science.gov (United States)

    Tobiska, W. Kent

    2008-01-01

    Adverse space weather affects operational activities in aviation and satellite systems. For example, large solar flares create highly variable enhanced neutral atmosphere and ionosphere electron density regions. These regions impact aviation communication frequencies as well as precision orbit determination. The natural space environment, with its dynamic space weather variability, is additionally changed by human activity. The increase in orbital debris in low Earth orbit (LEO), combined with lower atmosphere CO2 that rises into the lower thermosphere and causes increased cooling that results in increased debris lifetime, adds to the environmental hazards of navigating in near-Earth space. This is at a time when commercial space endeavors are posed to begin more missions to LEO during the rise of the solar activity cycle toward the next maximum (2012). For satellite and aviation operators, adverse space weather results in greater expenses for orbit management, more communication outages or aviation and ground-based high frequency radio used, and an inability to effectively plan missions or service customers with space-based communication, imagery, and data transferal during time-critical activities. Examples of some revenue-impacting conditions and solutions for mitigating adverse space weather are offered.

  11. Effects of DeOrbitSail as applied to Lifetime predictions of Low Earth Orbit Satellites

    Science.gov (United States)

    Afful, Andoh; Opperman, Ben; Steyn, Herman

    2016-07-01

    Orbit lifetime prediction is an important component of satellite mission design and post-launch space operations. Throughout its lifetime in space, a spacecraft is exposed to risk of collision with orbital debris or operational satellites. This risk is especially high within the Low Earth Orbit (LEO) region where the highest density of space debris is accumulated. This paper investigates orbital decay of some LEO micro-satellites and accelerating orbit decay by using a deorbitsail. The Semi-Analytical Liu Theory (SALT) and the Satellite Toolkit was employed to determine the mean elements and expressions for the time rates of change. Test cases of observed decayed satellites (Iridium-85 and Starshine-1) are used to evaluate the predicted theory. Results for the test cases indicated that the theory fitted observational data well within acceptable limits. Orbit decay progress of the SUNSAT micro-satellite was analysed using relevant orbital parameters derived from historic Two Line Element (TLE) sets and comparing with decay and lifetime prediction models. This paper also explored the deorbit date and time for a 1U CubeSat (ZACUBE-01). The use of solar sails as devices to speed up the deorbiting of LEO satellites is considered. In a drag sail mode, the deorbitsail technique significantly increases the effective cross-sectional area of a satellite, subsequently increasing atmospheric drag and accelerating orbit decay. The concept proposed in this study introduced a very useful technique of orbit decay as well as deorbiting of spacecraft.

  12. Compendium of Single Event Effects Test Results for Commercial Off-The-Shelf and Standard Electronics for Low Earth Orbit and Deep Space Applications

    Science.gov (United States)

    Reddell, Brandon D.; Bailey, Charles R.; Nguyen, Kyson V.; O'Neill, Patrick M.; Wheeler, Scott; Gaza, Razvan; Cooper, Jaime; Kalb, Theodore; Patel, Chirag; Beach, Elden R.; hide

    2017-01-01

    We present the results of Single Event Effects (SEE) testing with high energy protons and with low and high energy heavy ions for electrical components considered for Low Earth Orbit (LEO) and for deep space applications.

  13. Requirements for a near-earth space tug vehicle

    Science.gov (United States)

    Gunn, Charles R.

    1990-01-01

    The requirement for a small but powerful space tug, which will be capable of autonomous orbital rendezvous, docking and translating cargos between near-earth orbits by the end of this decade to support the growing national and international space infrastructure focused near the Space Station Freedom, is described. An aggregate of missions drives the need for a space tug including reboosting decaying satellites back to their operational altitudes, retrieving failed or exhausted satellites to Shuttle or SSF for on-orbit refueling or repair, and transporting a satellite servicer system with an FTS to ailing satellites for supervised in-place repair. It is shown that the development and operation of a space tug to perform such numerous missions is more cost effective than separate module and satellite systems to perform the same tasks.

  14. Orbit Determination of Spacecraft in Earth-Moon L1 and L2 Libration Point Orbits

    Science.gov (United States)

    Woodard, Mark; Cosgrove, Daniel; Morinelli, Patrick; Marchese, Jeff; Owens, Brandon; Folta, David

    2011-01-01

    The ARTEMIS mission, part of the THEMIS extended mission, is the first to fly spacecraft in the Earth-Moon Lissajous regions. In 2009, two of the five THEMIS spacecraft were redeployed from Earth-centered orbits to arrive in Earth-Moon Lissajous orbits in late 2010. Starting in August 2010, the ARTEMIS P1 spacecraft executed numerous stationkeeping maneuvers, initially maintaining a lunar L2 Lissajous orbit before transitioning into a lunar L1 orbit. The ARTEMIS P2 spacecraft entered a L1 Lissajous orbit in October 2010. In April 2011, both ARTEMIS spacecraft will suspend Lissajous stationkeeping and will be maneuvered into lunar orbits. The success of the ARTEMIS mission has allowed the science team to gather unprecedented magnetospheric measurements in the lunar Lissajous regions. In order to effectively perform lunar Lissajous stationkeeping maneuvers, the ARTEMIS operations team has provided orbit determination solutions with typical accuracies on the order of 0.1 km in position and 0.1 cm/s in velocity. The ARTEMIS team utilizes the Goddard Trajectory Determination System (GTDS), using a batch least squares method, to process range and Doppler tracking measurements from the NASA Deep Space Network (DSN), Berkeley Ground Station (BGS), Merritt Island (MILA) station, and United Space Network (USN). The team has also investigated processing of the same tracking data measurements using the Orbit Determination Tool Kit (ODTK) software, which uses an extended Kalman filter and recursive smoother to estimate the orbit. The orbit determination results from each of these methods will be presented and we will discuss the advantages and disadvantages associated with using each method in the lunar Lissajous regions. Orbit determination accuracy is dependent on both the quality and quantity of tracking measurements, fidelity of the orbit force models, and the estimation techniques used. Prior to Lissajous operations, the team determined the appropriate quantity of tracking

  15. An LDEF 2 dust instrument for discrimination between orbital debris and natural particles in near-Earth space

    Science.gov (United States)

    Tuzzolino, A. J.; Simpson, J. A.; Mckibben, R. B.; Voss, H. D.; Gursky, H.

    1993-01-01

    The characteristics of a space dust instrument which would be ideally suited to carry out near-Earth dust measurements on a possible Long Duraction Exposure Facility reflight mission (LDEF 2) is discussed. As a model for the trajectory portion of the instrument proposed for LDEF 2, the characteristics of a SPAce DUSt instrument (SPADUS) currently under development for flight on the USA ARGOS mission to measure the flux, mass, velocity, and trajectory of near-Earth dust is summarized. Since natural (cosmic) dust and man-made dust particles (orbital debris) have different velocity and trajectory distributions, they are distinguished by means of the SPADUS velocity/trajectory information. The SPADUS measurements will cover the dust mass range approximately 5 x 10(exp -12) g (2 microns diameter) to approximately 1 x 10(exp -5) g (200 microns diameter), with an expected mean error in particle trajectory of approximately 7 deg (isotropic flux). Arrays of capture cell devices positioned behind the trajectory instrumentation would provide for Earth-based chemical and isotopic analysis of captured dust. The SPADUS measurement principles, characteristics, its role in the ARGOS mission, and its application to an LDEF 2 mission are summarized.

  16. An optimum organizational structure for a large earth-orbiting multidisciplinary space base. Ph.D. Thesis - Fla. State Univ., 1973

    Science.gov (United States)

    Ragusa, J. M.

    1975-01-01

    An optimum hypothetical organizational structure was studied for a large earth-orbiting, multidisciplinary research and applications space base manned by a crew of technologists. Because such a facility does not presently exist, in situ empirical testing was not possible. Study activity was, therefore, concerned with the identification of a desired organizational structural model rather than with the empirical testing of the model. The essential finding of this research was that a four-level project type total matrix model will optimize the efficiency and effectiveness of space base technologists.

  17. Resonant Orbital Dynamics in LEO Region: Space Debris in Focus

    Directory of Open Access Journals (Sweden)

    J. C. Sampaio

    2014-01-01

    Full Text Available The increasing number of objects orbiting the earth justifies the great attention and interest in the observation, spacecraft protection, and collision avoidance. These studies involve different disturbances and resonances in the orbital motions of these objects distributed by the distinct altitudes. In this work, objects in resonant orbital motions are studied in low earth orbits. Using the two-line elements (TLE of the NORAD, resonant angles and resonant periods associated with real motions are described, providing more accurate information to develop an analytical model that describes a certain resonance. The time behaviors of the semimajor axis, eccentricity, and inclination of some space debris are studied. Possible irregular motions are observed by the frequency analysis and by the presence of different resonant angles describing the orbital dynamics of these objects.

  18. Comprehensive NASA Cis-Lunar Earth Moon Libration Orbit Reference and Web Application

    Data.gov (United States)

    National Aeronautics and Space Administration — This work will provide research and trajectory design analysis to develop a NASA Cis-Lunar / Earth-Moon Libration Orbit Reference and Web Application. A compendium...

  19. The Deep Space Gateway Lightning Mapper (DLM) - Monitoring Global Change and Thunderstorm Processes Through Observations of Earth's High-Latitude Lightning from Cis-Lunar Orbit

    Science.gov (United States)

    Lang, Timothy; Blakeslee, R. J.; Cecil, D. J.; Christian, H. J.; Gatlin, P. N.; Goodman, S. J.; Koshak, W. J.; Petersen, W. A.; Quick, M.; Schultz, C. J.; hide

    2018-01-01

    Function: Monitor global change and thunderstorm processes through observations of Earth's high-latitude lightning. This instrument will combine long-lived sampling of individual thunderstorms with long-term observations of lightning at high latitudes: How is global change affecting thunderstorm patterns; How do high-latitude thunderstorms differ from low-latitude? Why is the Gateway the optimal facility for this instrument / research: Expected DSG (Deep Space Gateway) orbits will provide nearly continuous viewing of the Earth's high latitudes (50 degrees latitude and poleward); These regions are not well covered by existing lightning mappers (e.g., Lightning Imaging Sensor / LIS, or Geostationary Lightning Mapper / GLM); Polar, Molniya, Tundra, etc. Earth orbits have significant drawbacks related to continuous coverage and/or stable FOVs (Fields of View).

  20. A Synthetic Biology Tool Kit for Manned Missions Outside Low Earth Orbit

    Data.gov (United States)

    National Aeronautics and Space Administration — Our goal is to make human missions outside low earth orbit safer and better able to handle the unexpected through the use of synthetic biology as an enabling...

  1. Impacts on Explorer 46 from an Earth orbiting population

    Science.gov (United States)

    Kessler, D. J.

    1985-01-01

    Explorer 46 was launched into Earth orbit in August 1972 to evaluate the effectiveness of using double-wall structures to protect against meteoroids. The data from the Meteoroid Bumper Experiment on Explorer 46 is reexamined and it is concluded that most of the impacts originated from an Earth orbiting population. The probable source of this orbiting population is solid rocket motors fired in Earth orbit.

  2. 78 FR 19172 - Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit...

    Science.gov (United States)

    2013-03-29

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 2 and 25 [IB Docket No. 12-376; FCC 12-161] Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit Space Stations... the Federal Register of March 8, 2013. The document proposed rules for Earth Stations Aboard Aircraft...

  3. Free Space Laser Communication Experiments from Earth to the Lunar Reconnaissance Orbiter in Lunar Orbit

    Science.gov (United States)

    Sun, Xiaoli; Skillman, David R.; Hoffman, Evan D.; Mao, Dandan; McGarry, Jan F.; Zellar, Ronald S.; Fong, Wai H; Krainak, Michael A.; Neumann, Gregory A.; Smith, David E.

    2013-01-01

    Laser communication and ranging experiments were successfully conducted from the satellite laser ranging (SLR) station at NASA Goddard Space Flight Center (GSFC) to the Lunar Reconnaissance Orbiter (LRO) in lunar orbit. The experiments used 4096-ary pulse position modulation (PPM) for the laser pulses during one-way LRO Laser Ranging (LR) operations. Reed-Solomon forward error correction codes were used to correct the PPM symbol errors due to atmosphere turbulence and pointing jitter. The signal fading was measured and the results were compared to the model.

  4. A MATLAB based Distributed Real-time Simulation of Lander-Orbiter-Earth Communication for Lunar Missions

    Science.gov (United States)

    Choudhury, Diptyajit; Angeloski, Aleksandar; Ziah, Haseeb; Buchholz, Hilmar; Landsman, Andre; Gupta, Amitava; Mitra, Tiyasa

    Lunar explorations often involve use of a lunar lander , a rover [1],[2] and an orbiter which rotates around the moon with a fixed radius. The orbiters are usually lunar satellites orbiting along a polar orbit to ensure visibility with respect to the rover and the Earth Station although with varying latency. Communication in such deep space missions is usually done using a specialized protocol like Proximity-1[3]. MATLAB simulation of Proximity-1 have been attempted by some contemporary researchers[4] to simulate all features like transmission control, delay etc. In this paper it is attempted to simulate, in real time, the communication between a tracking station on earth (earth station), a lunar orbiter and a lunar rover using concepts of Distributed Real-time Simulation(DRTS).The objective of the simulation is to simulate, in real-time, the time varying communication delays associated with the communicating elements with a facility to integrate specific simulation modules to study different aspects e.g. response due to a specific control command from the earth station to be executed by the rover. The hardware platform comprises four single board computers operating as stand-alone real time systems (developed by MATLAB xPC target and inter-networked using UDP-IP protocol). A time triggered DRTS approach is adopted. The earth station, the orbiter and the rover are programmed as three standalone real-time processes representing the communicating elements in the system. Communication from one communicating element to another constitutes an event which passes a state message from one element to another, augmenting the state of the latter. These events are handled by an event scheduler which is the fourth real-time process. The event scheduler simulates the delay in space communication taking into consideration the distance between the communicating elements. A unique time synchronization algorithm is developed which takes into account the large latencies in space

  5. Solar Power Beaming: From Space to Earth

    Energy Technology Data Exchange (ETDEWEB)

    Rubenchik, A M; Parker, J M; Beach, R J; Yamamoto, R M

    2009-04-14

    Harvesting solar energy in space and power beaming the collected energy to a receiver station on Earth is a very attractive way to help solve mankind's current energy and environmental problems. However, the colossal and expensive 'first step' required in achieving this goal has to-date stifled its initiation. In this paper, we will demonstrate that recent advance advances in laser and optical technology now make it possible to deploy a space-based system capable of delivering 1 MW of energy to a terrestrial receiver station, via a single unmanned commercial launch into Low Earth Orbit (LEO). Figure 1 depicts the overall concept of our solar power beaming system, showing a large solar collector in space, beaming a coherent laser beam to a receiving station on Earth. We will describe all major subsystems and provide technical and economic discussion to support our conclusions.

  6. Interaction between subdaily Earth rotation parameters and GPS orbits

    Science.gov (United States)

    Panafidina, Natalia; Seitz, Manuela; Hugentobler, Urs

    2013-04-01

    In processing GPS observations the geodetic parameters like station coordinates and ERPs (Earth rotation parameters) are estimated w.r.t. the celestial reference system realized by the satellite orbits. The interactions/correlations between estimated GPS orbis and other parameters may lead to numerical problems with the solution and introduce systematic errors in the computed values: the well known correlations comprise 1) the correlation between the orbital parameters determining the orientation of the orbital plane in inertial space and the nutation and 2) in the case of estimating ERPs with subdaily resolution the correlation between retrograde diurnal polar motion and nutation (and so the respective orbital elements). In this contribution we study the interaction between the GPS orbits and subdaily model for the ERPs. Existing subdaily ERP model recommended by the IERS comprises ~100 terms in polar motion and ~70 terms in Universal Time at diurnal and semidiurnal tidal periods. We use a long time series of daily normal equation systems (NEQ) obtaine from GPS observations from 1994 till 2007 where the ERPs with 1-hour resolution are transformed into tidal terms and the influence of the tidal terms with different frequencies on the estimated orbital parameters is considered. We found that although there is no algebraic correlation in the NEQ between the individual orbital parameters and the tidal terms, the changes in the amplitudes of tidal terms with periods close to 24 hours can be better accmodated by systematic changes in the orbital parameters than for tidal terms with other periods. Since the variation in Earth rotation with the period of siderial day (23.93h, tide K1) in terrestrial frame has in inertial space the same period as the period of revolution of GPS satellites, the K1 tidal term in polar motion is seen by the satellites as a permanent shift. The tidal terms with close periods (from ~24.13h to ~23.80h) are seen as a slow rotation of the

  7. MoonBEAM: A Beyond Earth-Orbit Gamma-Ray Burst Detector for Gravitational-Wave Astronomy

    Science.gov (United States)

    Hui, C. M.; Briggs, M. S.; Goldstein, A. M.; Jenke, P. A.; Kocevski, D.; Wilson-Hodge, C. A.

    2018-01-01

    Moon Burst Energetics All-sky Monitor (MoonBEAM) is a CubeSat concept of deploying gamma-ray detectors in cislunar space to improve localization precision for gamma-ray bursts by utilizing the light travel time difference between different orbits. We present here a gamma-ray SmallSat concept in Earth-Moon L3 halo orbit that is capable of rapid response and provide a timing baseline for localization improvement when partnered with an Earth-orbit instrument. Such an instrument would probe the extreme processes in cosmic collision of compact objects and facilitate multi-messenger time-domain astronomy to explore the end of stellar life cycles and black hole formations.

  8. Periodic orbit-attitude solutions along planar orbits in a perturbed circular restricted three-body problem for the Earth-Moon system

    Science.gov (United States)

    Bucci, Lorenzo; Lavagna, Michèle; Guzzetti, Davide; Howell, Kathleen C.

    2018-06-01

    Interest on Large Space Structures (LSS), orbiting in strategic and possibly long-term stable locations, is nowadays increasing in the space community. LSS can serve as strategic outpost to support a variety of manned and unmanned mission, or may carry scientific payloads for astronomical observations. The paper focuses on analysing LSS in the Earth-Moon system, exploring dynamical structures that are available within a multi-body gravitational environment. Coupling between attitude and orbital dynamics is investigated, with particular interest on the gravity gradient torque exerted by the two massive attractors. First, natural periodic orbit-attitude solutions are obtained; a LSS that exploits such solutions would benefit of a naturally periodic body rotation synchronous with the orbital motion, easing the effort of the attitude control system to satisfy pointing requirements. Then, the solar radiation pressure is introduced into the fully coupled dynamical model and its effects investigated, discovering novel periodic attitude solutions. Benefits of periodic behaviours that incorporate solar radiation pressure are discussed, and analysed via the variation of some parameters (e.g reflection/absorption coefficients, position of the centre of pressure). As a final step to refine the current perturbed orbit-attitude model, a structure flexibility is also superimposed to a reference orbit-attitude rigid body motion via a simple, yet effective model. The coupling of structural vibrations and attitude motion is preliminarily explored, and allows identification of possible challenges, that may be faced to position a LSS in a periodic orbit within the Earth-Moon system.

  9. Systems and Methods for Providing Energy to Support Missions in Near Earth Space

    Science.gov (United States)

    Fork, Richard (Inventor)

    2015-01-01

    A system has a plurality of spacecraft in orbit around the earth for collecting energy from the Sun in space, using stimulated emission to configure that energy as well defined states of the optical field and delivering that energy efficiently throughout the region of space surrounding Earth.

  10. Analysis of Approaches to the Near-Earth Orbit Cleanup from Space Debris of the Size Below10 cm

    Directory of Open Access Journals (Sweden)

    V. I. Maiorova

    2016-01-01

    Full Text Available Nowadays, there are a lot of concepts aimed at space debris removal from the near-Earth orbits being under way at different stages of detailed engineering and design. As opposed to large-size space debris (upper-stages, rocket bodies, non-active satellites, to track the small objects of space debris (SOSD, such as picosatellites, satellite fragments, pyrotechnic devices, and other items less than 10 cm in size, using the ground stations is, presently, a challenge.This SOSD feature allows the authors to propose the two most rational approaches, which use, respectively, a passive and an active (prompt maneuverable space vehicles (SV and appropriate schematic diagrams for their collection:1 Passive scheme – space vehicle (SV to be launched into an orbit is characterized by high mathematical expectation of collision with a large amount of SOSD and, accordingly, by high probability to be captured using both active or the passive tools. The SV does not execute any maneuvers, but can be equipped with a propulsion system required for orbit’s maintenance and correction and also for solving the tasks of long-range guidance.2 Active scheme – the SV is to be launched into the target or operating orbit and executes a number of maneuvers to capture the SOSD using both active and passive tools. Thus, such a SV has to be equipped with a rather high-trust propulsion system, which allows the change of its trajectory and also with the guidance system to provide it with target coordinates. The guidance system can be built on either radio or optical devices, it can be installed onboard the debris-removal SV or onboard the SV which operates as a supply unit (if such SVs are foreseen.The paper describes each approach, emphasizes advantages and disadvantages, and defines the cutting-edge technologies to be implemented.

  11. Unique Non-Keplerian Orbit Vantage Locations for Sun-Earth Connection and Earth Science Vision Roadmaps

    Science.gov (United States)

    Folta, David; Young, Corissa; Ross, Adam

    2001-01-01

    The purpose of this investigation is to determine the feasibility of attaining and maintaining unique non-Keplerian orbit vantage locations in the Earth/Moon environment in order to obtain continuous scientific measurements. The principal difficulty associated with obtaining continuous measurements is the temporal nature of astrodynamics, i.e., classical orbits. This investigation demonstrates advanced trajectory designs to meet demanding science requirements which cannot be met following traditional orbital mechanic logic. Examples of continuous observer missions addressed include Earth pole-sitters and unique vertical libration orbits that address Sun-Earth Connection and Earth Science Vision roadmaps.

  12. The Canadian Space Agency, Space Station, Strategic Technologies for Automation and Robotics Program technology development activity in protection of materials from the low Earth orbit space environment

    Science.gov (United States)

    Francoeur, J. R.

    1992-01-01

    The Strategic Technologies in Automation and Robotics (STEAR) program is managing a number of development contracts to improve the protection of spacecraft materials from the Low Earth Orbit (LEO) space environment. The project is structured in two phases over a 3 to 4 year period with a budget of 3 to 4 million dollars. Phase 1 is designed to demonstrate the technical feasibility and commercial potential of a coating/substrate system and its associated application process. The objective is to demonstrate a prototype fabrication capability using a full scale component of a commercially viable process for the protection of materials and surface finishes from the LEO space environment, and to demonstrate compliance with a set of performance requirements. Only phase 1 will be discussed in this paper.

  13. Global-scale Observations of the Limb and Disk (GOLD) Mission -Ultraviolet Remote Sensing of Earth's Space Environment from Geostationary Orbit

    Science.gov (United States)

    Burns, A. G.; Eastes, R.

    2017-12-01

    The GOLD mission of opportunity will fly a far ultraviolet imaging spectrograph in geostationary (GEO) orbit as a hosted payload. The mission is scheduled for launch in late January 2018 on SES-14, a commercial communications satellite that will be stationed over eastern South America at 47.5 degrees west longitude. GOLD is on schedule to be the first NASA science mission to fly as a hosted payload on a commercial communications satellite. The GOLD imager has two identical channels. Each channel can scan the full disk at a 30 minute cadence, making spectral images of Earth's UV emission from 132 to 162 nm, as well as make a measurement on the Earth's limb. Remote sensing techniques that have been proven on previous Low Earth Orbit (LEO) missions will be used to derive fundamental parameters for the neutral and ionized space environment. Parameters that will be derived include composition (O/N2 ratio) and temperature of the neutral atmosphere on the dayside disk. On the nightside, peak electron densities will be obtained in the low latitude ionosphere. Many of the algorithms developed for the mission are extensions of ones used on previous earth and planetary missions, with modifications for observations from geostationary orbit. All the algorithms have been tested using simulated observations based on the actual instrument performance. From geostationary orbit, GOLD can repeatedly image the same geographic locations over most of the hemisphere at a cadence comparable to that of the T-I system (order of an hour). Such time resolution and spatial coverage will allow the mission to track the changes due to geomagnetic storms, variations in solar extreme ultraviolet radiation, and forcing from the lower atmosphere. In addition to providing a new perspective by being able to repeatedly remotely sense the same hemisphere at a high cadence, GOLD's simultaneous measurements of not only composition but also temperatures across the disk will provide a valuable, new parameter

  14. Earth to Orbit Beamed Energy Experiment

    Science.gov (United States)

    Johnson, Les; Montgomery, Edward E.

    2017-01-01

    As a means of primary propulsion, beamed energy propulsion offers the benefit of offloading much of the propulsion system mass from the vehicle, increasing its potential performance and freeing it from the constraints of the rocket equation. For interstellar missions, beamed energy propulsion is arguably the most viable in the near- to mid-term. A near-term demonstration showing the feasibility of beamed energy propulsion is necessary and, fortunately, feasible using existing technologies. Key enabling technologies are large area, low mass spacecraft and efficient and safe high power laser systems capable of long distance propagation. NASA is currently developing the spacecraft technology through the Near Earth Asteroid Scout solar sail mission and has signed agreements with the Planetary Society to study the feasibility of precursor laser propulsion experiments using their LightSail-2 solar sail spacecraft. The capabilities of Space Situational Awareness assets and the advanced analytical tools available for fine resolution orbit determination now make it possible to investigate the practicalities of an Earth-to-orbit Beamed Energy eXperiment (EBEX) - a demonstration at delivered power levels that only illuminate a spacecraft without causing damage to it. The degree to which this can be expected to produce a measurable change in the orbit of a low ballistic coefficient spacecraft is investigated. Key system characteristics and estimated performance are derived for a near term mission opportunity involving the LightSail-2 spacecraft and laser power levels modest in comparison to those proposed previously. While the technology demonstrated by such an experiment is not sufficient to enable an interstellar precursor mission, if approved, then it would be the next step toward that goal.

  15. THE SYNERGY OF DIRECT IMAGING AND ASTROMETRY FOR ORBIT DETERMINATION OF EXO-EARTHS

    International Nuclear Information System (INIS)

    Shao, Michael; Catanzarite, Joseph; Pan Xiaopei

    2010-01-01

    The holy grail of exoplanet searches is an exo-Earth, an Earth mass planet in the habitable zone (HZ) around a nearby star. Mass is one of the most important characteristics of a planet and can only be measured by observing the motion of the star around the planet-star center of gravity. The planet's orbit can be measured either by imaging the planet at multiple epochs or by measuring the position of the star at multiple epochs by space-based astrometry. The measurement of an exoplanet's orbit by direct imaging is complicated by a number of factors. One is the inner working angle (IWA). A space coronagraph or interferometer imaging an exo-Earth can separate the light from the planet from the light from the star only when the star-planet separation is larger than the IWA. Second, the apparent brightness of a planet depends on the orbital phase. A single image of a planet cannot tell us whether the planet is in the HZ or distinguish whether it is an exo-Earth or a Neptune-mass planet. Third is the confusion that may arise from the presence of multiple planets. With two images of a multiple planet system, it is not possible to assign a dot to a planet based only on the photometry and color of the planet. Finally, the planet-star contrast must exceed a certain minimum value in order for the planet to be detected. The planet may be unobservable even when it is outside the IWA, such as when the bright side of the planet is facing away from us in a 'crescent' phase. In this paper we address the question: 'Can a prior astrometric mission that can identify which stars have Earth-like planets significantly improve the science yield of a mission to image exo-Earths?' In the case of the Occulting Ozone Observatory, a small external occulter mission that cannot measure spectra, we find that the occulter mission could confirm the orbits of ∼4 to ∼5 times as many exo-Earths if an astrometric mission preceded it to identify which stars had such planets. In the case of an

  16. The problems of cosmic ray particle simulation for the near-Earth orbital and interplanetary flight conditions

    International Nuclear Information System (INIS)

    Nymmik, R.A.

    1999-01-01

    A wide range of the galactic cosmic ray and SEP event flux simulation problems for the near-Earth satellite and manned spacecraft orbits and for the interplanetary mission trajectories are discussed. The models of the galactic cosmic ray and SEP events in the Earth orbit beyond the Earth's magnetosphere are used as a basis. The particle fluxes in the near-Earth orbits should be calculated using the transmission functions. To calculate the functions, the dependences of the cutoff rigidities on the magnetic disturbance level and on magnetic local time have to be known. In the case of space flights towards the Sun and to the boundary of the solar system, particular attention is paid to the changes in the SEP event occurrence frequency and size. The particle flux gradients are applied in this case to galactic cosmic ray fluxes

  17. Changes of Space Debris Orbits After LDR Operation

    Science.gov (United States)

    Wnuk, E.; Golebiewska, J.; Jacquelard, C.; Haag, H.

    2013-09-01

    A lot of technical studies are currently developing concepts of active removal of space debris to protect space assets from on orbit collision. For small objects, such concepts include the use of ground-based lasers to remove or reduce the momentum of the objects thereby lowering their orbit in order to facilitate their decay by re-entry into the Earth's atmosphere. The concept of the Laser Debris Removal (LDR) system is the main subject of the CLEANSPACE project. One of the CLEANSPACE objectives is to define a global architecture (including surveillance, identification and tracking) for an innovative ground-based laser solution, which can remove hazardous medium debris around selected space assets. The CLEANSPACE project is realized by a European consortium in the frame of the European Commission Seventh Framework Programme (FP7), Space topic. The use of sequence of laser operations to remove space debris, needs very precise predictions of future space debris orbital positions, on a level even better than 1 meter. Orbit determination, tracking (radar, optical and laser) and orbit prediction have to be performed with accuracy much better than so far. For that, the applied prediction tools have to take into account all perturbation factors that influence object orbit. The expected object's trajectory after the LDR operation is a lowering of its perigee. To prevent the debris with this new trajectory to collide with another object, a precise trajectory prediction after the LDR sequence is therefore the main task allowing also to estimate re-entry parameters. The LDR laser pulses change the debris object velocity v. The future orbit and re-entry parameters of the space debris after the LDR engagement can be calculated if the resulting ?v vector is known with the sufficient accuracy. The value of the ?v may be estimated from the parameters of the LDR station and from the characteristics of the orbital debris. However, usually due to the poor knowledge of the debris

  18. Earth Observation from Space - The Issue of Environmental Sustainability

    Science.gov (United States)

    Durrieu, Sylvie; Nelson, Ross F.

    2013-01-01

    Remote sensing scientists work under assumptions that should not be taken for granted and should, therefore, be challenged. These assumptions include the following: 1. Space, especially Low Earth Orbit (LEO), will always be available to governmental and commercial space entities that launch Earth remote sensing missions. 2. Space launches are benign with respect to environmental impacts. 3. Minimization of Type 1 error, which provides increased confidence in the experimental outcome, is the best way to assess the significance of environmental change. 4. Large-area remote sensing investigations, i.e. national, continental, global studies, are best done from space. 5. National space missions should trump international, cooperative space missions to ensure national control and distribution of the data products. At best, all of these points are arguable, and in some cases, they're wrong. Development of observational space systems that are compatible with sustainability principles should be a primary concern when Earth remote sensing space systems are envisioned, designed, and launched. The discussion is based on the hypothesis that reducing the environmental impacts of thedata acquisition step,which is at the very beginning of the information streamleading to decision and action, will enhance coherence in the information streamand strengthen the capacity of measurement processes to meet their stated functional goal, i.e. sustainable management of Earth resources. We suggest that unconventional points of view should be adopted and when appropriate, remedial measures considered that could help to reduce the environmental footprint of space remote sensing and of Earth observation and monitoring systems in general. This article discusses these five assumptions inthe contextof sustainablemanagementof Earth's resources. Takingeachassumptioninturn,we find the following: (1) Space debris may limit access to Low Earth Orbit over the next decades. (2) Relatively speaking, given

  19. FLUKA Calculation of the Neutron Albedo Encountered at Low Earth Orbits

    CERN Document Server

    Claret, Arnaud; Combier, Natacha; Ferrari, Alfredo; Laurent, Philippe

    2014-01-01

    This paper presents Monte-Carlo simulations based on the Fluka code aiming to calculate the contribution of the neutron albedo at a given date and altitude above the Earth chosen by the user. The main input parameters of our model are the solar modulation affecting the spectra of cosmic rays, and the date of the Earth’s geomagnetic fi eld. The results consist in a two-parameter distribution, the neutron energy and the angle to the tangent plane of the sphere containing the orbi t of interest, and are provided by geographical position above the E arth at the chosen altitude. This model can be used to predict the te mporal variation of the neutron fl ux encountered along the orbit, and thus constrain the determination of the instrumental backg round noise of space experiments in low earth orbit.

  20. AMS_02 Particle Physics Detector Technologies Orbiting the Earth (2/2)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    AMS-02 has taken the high performance technologies used in particle physics and implemented them for use in low Earth orbit. Safety aspects for the Space Shuttle flight, that carried AMS_02 to the International Space Station, Space environment and inaccessibility during the life of AMS_02 are some of the aspects which have driven the design of the experiment. The technical challenges to build such a detector have been surmounted through the close collaboration amongst the AMS scientists and industries around the world. Their efforts have resulted in the development of new technologies and higher standards of precision.

  1. AMS_02 Particle Physics Detector Technologies Orbiting the Earth (1/2)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    AMS-02 has taken the high performance technologies used in particle physics and implemented them for use in low Earth orbit. Safety aspects for the Space Shuttle flight, that carried AMS_02 to the International Space Station, Space environment and inaccessibility during the life of AMS_02 are some of the aspects which have driven the design of the experiment. The technical challenges to build such a detector have been surmounted through the close collaboration amongst the AMS scientists and industries around the world. Their efforts have resulted in the development of new technologies and higher standards of precision.

  2. Dynamic and reduced-dynamic precise orbit determination of satellites in low earth orbits

    International Nuclear Information System (INIS)

    Swatschina, P.

    2009-01-01

    The precise positioning of satellites in Low Earth Orbits (LEO) has become a key technology for advanced space missions. Dedicated satellite missions, such as CHAMP, GRACE and GOCE, that aim to map the Earths gravity field and its variation over time with unprecedented accuracy, initiated the demand for highly precise orbit solutions of LEO satellites. Furthermore, a wide range of additional science opportunities opens up with the capability to generate accurate LEO orbits. For all considered satellite missions, the primary measurement system for navigation is a spaceborne GPS receiver. The goal of this thesis is to establish and implement methods for Precise Orbit Determination (POD) of LEO satellites using GPS. Striving for highest precision using yet efficient orbit generation strategies, the attained orbit solutions are aimed to be competitive with the most advanced solutions of other institutions. Dynamic and reduced-dynamic orbit models provide the basic concepts of this work. These orbit models are subsequently adjusted to the highly accurate GPS measurements. The GPS measurements are introduced at the zero difference level in the ionosphere free linear combination. Appropriate procedures for GPS data screening and editing are established to detect erroneous data and to employ measurements of good quality only. For the dynamic orbit model a sophisticated force model, especially designed for LEO satellites, has been developed. In order to overcome the limitations that are induced by the deficiencies of the purely dynamical model, two different types of empirical parameters are introduced into the force model. These reduced-dynamic orbit models allow for the generation of much longer orbital arcs while preserving the spacecraft dynamics to the most possible extent. The two methods for reduced-dynamic orbit modeling are instantaneous velocity changes (pulses) or piecewise constant accelerations. For both techniques highly efficient modeling algorithms are

  3. Crowded orbits conflict and cooperation in space

    CERN Document Server

    James

    2014-01-01

    Written for all readers, this expert analysis details the basics of space technology, diplomacy, commerce, exploration, and military applications from the mid-twentieth century to today. Space has become increasingly crowded since the end of the Cold War, and this book pays particular attention to the politics and economics of space and recent debates over national security, focusing on the competing themes of international competition and cooperation and the effort to avoid dangerous conflicts. Unfortunately, the growth of human space activity and challenges to existing international tools of management, such as rules, laws, and treaties, have increased the likelihood of conflict over a diminishing pool of space resources close to Earth. Drawing on more than twenty years of experience in international space debates and policy, James Clay Moltz points to the logic of cooperation and collaboration among the expanding number of space actors, considering their shared challenges regarding space traffic, orbital d...

  4. Analytical investigation of the dynamics of tethered constellations in Earth orbit, phase 2

    Science.gov (United States)

    Lorenzini, Enrico C.; Gullahorn, Gordon E.; Cosmo, Mario L.; Estes, Robert D.; Grossi, Mario D.

    1994-01-01

    This final report covers nine years of research on future tether applications and on the actual flights of the Small Expendable Deployment System (SEDS). Topics covered include: (1) a description of numerical codes used to simulate the orbital and attitude dynamics of tethered systems during station keeping and deployment maneuvers; (2) a comparison of various tethered system simulators; (3) dynamics analysis, conceptual design, potential applications and propagation of disturbances and isolation from noise of a variable gravity/microgravity laboratory tethered to the Space Station; (4) stability of a tethered space centrifuge; (5) various proposed two-dimensional tethered structures for low Earth orbit for use as planar array antennas; (6) tethered high gain antennas; (7) numerical calculation of the electromagnetic wave field on the Earth's surface on an electrodynamically tethered satellite; (8) reentry of tethered capsules; (9) deployment dynamics of SEDS-1; (10) analysis of SEDS-1 flight data; and (11) dynamics and control of SEDS-2.

  5. An algorithm for enhanced formation flying of satellites in low earth orbit

    Science.gov (United States)

    Folta, David C.; Quinn, David A.

    1998-01-01

    With scientific objectives for Earth observation programs becoming more ambitious and spacecraft becoming more autonomous, the need for innovative technical approaches on the feasibility of achieving and maintaining formations of spacecraft has come to the forefront. The trend to develop small low-cost spacecraft has led many scientists to recognize the advantage of flying several spacecraft in formation to achieve the correlated instrument measurements formerly possible only by flying many instruments on a single large platform. Yet, formation flying imposes additional complications on orbit maintenance, especially when each spacecraft has its own orbit requirements. However, advances in automation and technology proposed by the Goddard Space Flight Center (GSFC) allow more of the burden in maneuver planning and execution to be placed onboard the spacecraft, mitigating some of the associated operational concerns. The purpose of this paper is to present GSFC's Guidance, Navigation, and Control Center's (GNCC) algorithm for Formation Flying of the low earth orbiting spacecraft that is part of the New Millennium Program (NMP). This system will be implemented as a close-loop flight code onboard the NMP Earth Orbiter-1 (EO-1) spacecraft. Results of this development can be used to determine the appropriateness of formation flying for a particular case as well as operational impacts. Simulation results using this algorithm integrated in an autonomous `fuzzy logic' control system called AutoCon™ are presented.

  6. A brief scenario about the ''space pollution'' around the Earth

    International Nuclear Information System (INIS)

    Brito, T P; Celestino, C C; Moraes, R V

    2013-01-01

    In this work is presented a brief review about the main events generating of space debris around the Earth, occurred up to the present day. How the clouds of debris ''polluted'' the neighborhood of orbits in which the bodies were initially allocated is here analyzed. The implications of the growth of space debris existing on space missions as well as safety rules to control sources of debris are discussed

  7. Pervasive orbital eccentricities dictate the habitability of extrasolar earths.

    Science.gov (United States)

    Kita, Ryosuke; Rasio, Frederic; Takeda, Genya

    2010-09-01

    The long-term habitability of Earth-like planets requires low orbital eccentricities. A secular perturbation from a distant stellar companion is a very important mechanism in exciting planetary eccentricities, as many of the extrasolar planetary systems are associated with stellar companions. Although the orbital evolution of an Earth-like planet in a stellar binary system is well understood, the effect of a binary perturbation on a more realistic system containing additional gas-giant planets has been very little studied. Here, we provide analytic criteria confirmed by a large ensemble of numerical integrations that identify the initial orbital parameters leading to eccentric orbits. We show that an extrasolar earth is likely to experience a broad range of orbital evolution dictated by the location of a gas-giant planet, which necessitates more focused studies on the effect of eccentricity on the potential for life.

  8. An Earth-mass planet orbiting α Centauri B.

    Science.gov (United States)

    Dumusque, Xavier; Pepe, Francesco; Lovis, Christophe; Ségransan, Damien; Sahlmann, Johannes; Benz, Willy; Bouchy, François; Mayor, Michel; Queloz, Didier; Santos, Nuno; Udry, Stéphane

    2012-11-08

    Exoplanets down to the size of Earth have been found, but not in the habitable zone--that is, at a distance from the parent star at which water, if present, would be liquid. There are planets in the habitable zone of stars cooler than our Sun, but for reasons such as tidal locking and strong stellar activity, they are unlikely to harbour water-carbon life as we know it. The detection of a habitable Earth-mass planet orbiting a star similar to our Sun is extremely difficult, because such a signal is overwhelmed by stellar perturbations. Here we report the detection of an Earth-mass planet orbiting our neighbour star α Centauri B, a member of the closest stellar system to the Sun. The planet has an orbital period of 3.236 days and is about 0.04 astronomical units from the star (one astronomical unit is the Earth-Sun distance).

  9. The Near-Earth Orbital Debris Problem and the Challenges for Environment Remediation

    Science.gov (United States)

    Liou, Jer-Chyi

    2012-01-01

    The near-Earth space environment has been gradually polluted with orbital debris (OD) since the beginning of space activities 55 years ago. Although this problem has been known to the research community for decades, the public was, in general, unaware of the issue until the anti-satellite test conducted by China in 2007 and the collision between Cosmos 2251 and the operational Iridium 33 in 2009. The latter also underlined the potential of an ongoing collision cascade effect (the "Kessler Syndrome") in the low Earth orbit (LEO, the region below 2000 km altitude). Recent modeling results have indicated that mitigation measures commonly adopted by the international space community will be insufficient to stabilize the LEO debris population. To better limit the OD population increase, more aggressive actions must be considered. There are three options for OD environment remediation-removal of large/massive intact objects to address the root cause of the OD population growth problem, removal of 5-mm-to-1 cm debris to mitigate the main mission-ending threats for the majority of operational spacecraft, and prevention of major debris-generating collisions as a temporary means to slow down the OD population increase. The technology, engineering, and cost challenges to carry out any of these three options are monumental. It will require innovative ideas, game-changing technologies, and major collaborations at the international level to address the OD problem and preserve the near-Earth environment for future generations.

  10. Limitations of Electromagnetic Ion Cyclotron Wave Observations in Low Earth Orbit

    Directory of Open Access Journals (Sweden)

    Junga Hwang

    2018-03-01

    Full Text Available Pc1 pulsations are geomagnetic fluctuations in the frequency range of 0.2 to 5 Hz. There have been several observations of Pc1 pulsations in low earth orbit by MAGSAT, DE-2, Viking, Freja, CHAMP, and SWARM satellites. However, there has been a clear limitation in resolving the spatial and temporal variations of the pulsation by using a single-point observation by a single satellite. To overcome such limitations of previous observations, a new space mission was recently initiated, using the concept of multi-satellites, named the Small scale magNetospheric and Ionospheric Plasma Experiments (SNIPE. The SNIPE mission consists of four nanosatellites (~10 kg, which will be launched into a polar orbit at an altitude of 600 km (TBD in 2020. Four satellites will be deployed in orbit, and the distances between each satellite will be controlled from 10 to 1,000 km by a high-end formation-flying algorithm. One of the possible science targets of the SNIPE mission is observing electromagnetic ion cyclotron (EMIC waves. In this paper, we report on examples of observations, showing the limitations of previous EMIC observations in low earth orbit, and suggest possibilities to overcome those limitations through a new mission.

  11. Landing in the future: Biological experiments on Earth and in space orbit

    Science.gov (United States)

    Pokrovskiy, A.

    1980-01-01

    The development of an Earth biosatellite to duplicate the parameters of pressure, temperature, humidity and others in a space environment onboard Cosmos-1129 is discussed. Effects of a space environment on fruit flies, dogs, laboratory rats in procreation, behavior, stress, biorhythm, body composition, gravitation preference, and cell cultures are examined. The space environment for agricultural products is also studied. The effects of heavy nuclei of galactic space radiation on biological objects inside and outside the satellite is studied, and methods of electrostatic protection are developed.

  12. Landing in the future: Biological experiments on Earth and in space orbit

    Science.gov (United States)

    Pokrovskiy, A.

    1980-09-01

    The development of an Earth biosatellite to duplicate the parameters of pressure, temperature, humidity and others in a space environment onboard Cosmos-1129 is discussed. Effects of a space environment on fruit flies, dogs, laboratory rats in procreation, behavior, stress, biorhythm, body composition, gravitation preference, and cell cultures are examined. The space environment for agricultural products is also studied. The effects of heavy nuclei of galactic space radiation on biological objects inside and outside the satellite is studied, and methods of electrostatic protection are developed.

  13. Orbit Propagation and Determination of Low Earth Orbit Satellites

    Directory of Open Access Journals (Sweden)

    Ho-Nien Shou

    2014-01-01

    Full Text Available This paper represents orbit propagation and determination of low Earth orbit (LEO satellites. Satellite global positioning system (GPS configured receiver provides position and velocity measures by navigating filter to get the coordinates of the orbit propagation (OP. The main contradictions in real-time orbit which is determined by the problem are orbit positioning accuracy and the amount of calculating two indicators. This paper is dedicated to solving the problem of tradeoffs. To plan to use a nonlinear filtering method for immediate orbit tasks requires more precise satellite orbit state parameters in a short time. Although the traditional extended Kalman filter (EKF method is widely used, its linear approximation of the drawbacks in dealing with nonlinear problems was especially evident, without compromising Kalman filter (unscented Kalman Filter, UKF. As a new nonlinear estimation method, it is measured at the estimated measurements on more and more applications. This paper will be the first study on UKF microsatellites in LEO orbit in real time, trying to explore the real-time precision orbit determination techniques. Through the preliminary simulation results, they show that, based on orbit mission requirements and conditions using UKF, they can satisfy the positioning accuracy and compute two indicators.

  14. Metrics in Keplerian orbits quotient spaces

    Science.gov (United States)

    Milanov, Danila V.

    2018-03-01

    Quotient spaces of Keplerian orbits are important instruments for the modelling of orbit samples of celestial bodies on a large time span. We suppose that variations of the orbital eccentricities, inclinations and semi-major axes remain sufficiently small, while arbitrary perturbations are allowed for the arguments of pericentres or longitudes of the nodes, or both. The distance between orbits or their images in quotient spaces serves as a numerical criterion for such problems of Celestial Mechanics as search for common origin of meteoroid streams, comets, and asteroids, asteroid families identification, and others. In this paper, we consider quotient sets of the non-rectilinear Keplerian orbits space H. Their elements are identified irrespective of the values of pericentre arguments or node longitudes. We prove that distance functions on the quotient sets, introduced in Kholshevnikov et al. (Mon Not R Astron Soc 462:2275-2283, 2016), satisfy metric space axioms and discuss theoretical and practical importance of this result. Isometric embeddings of the quotient spaces into R^n, and a space of compact subsets of H with Hausdorff metric are constructed. The Euclidean representations of the orbits spaces find its applications in a problem of orbit averaging and computational algorithms specific to Euclidean space. We also explore completions of H and its quotient spaces with respect to corresponding metrics and establish a relation between elements of the extended spaces and rectilinear trajectories. Distance between an orbit and subsets of elliptic and hyperbolic orbits is calculated. This quantity provides an upper bound for the metric value in a problem of close orbits identification. Finally the invariance of the equivalence relations in H under coordinates change is discussed.

  15. A Free-Return Earth-Moon Cycler Orbit for an Interplanetary Cruise Ship

    Science.gov (United States)

    Genova, Anthony L.; Aldrin, Buzz

    2015-01-01

    A periodic circumlunar orbit is presented that can be used by an interplanetary cruise ship for regular travel between Earth and the Moon. This Earth-Moon cycler orbit was revealed by introducing solar gravity and modest phasing maneuvers (average of 39 m/s per month) which yields close-Earth encounters every 7 or 10 days. Lunar encounters occur every 26 days and offer the chance for a smaller craft to depart the cycler and enter lunar orbit, or head for a Lagrange point (e.g., EM-L2 halo orbit), distant retrograde orbit (DRO), or interplanetary destination such as a near-Earth object (NEO) or Mars. Additionally, return-to-Earth abort options are available from many points along the cycling trajectory.

  16. High temperature heat pipe experiments in low earth orbit

    International Nuclear Information System (INIS)

    Woloshun, K.; Merrigan, M.A.; Sena, J.T.; Critchley, E.

    1993-01-01

    Although high temperature, liquid metal heat pipe radiators have become a standard component on most high power space power system designs, there is no experimental data on the operation of these heat pipes in a zero gravity or micro-gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation for testing in low earth orbit. It is anticipated that these heat pipes will be tested aborad the Space Shuttle in 1995. Three heat pipes will be tested in a cargo bay Get Away Special (GAS) canister. The heat pipes are SST/potassium, each with a different wick structure; homogeneous, arterial, and annular gap, the heat pipes have been designed, fabricated, and ground tested. In this paper, the heat pipe designs are specified, and transient and steady-state ground test data are presented

  17. Orbital and Landing Operations at Near-Earth

    Science.gov (United States)

    Scheeres, D. J.

    1995-01-01

    Orbital and landing operations about near-Earth asteroids are different than classical orbital operations about large bodies. The major differences lie with the small mass of the asteroid, the lower orbital velocities, the larger Solar tide and radiation pressure perturbations, the irregular shape of the asteroid and the potential for non-uniform rotation of the asteroid. These differences change the nature of orbits about an asteroid to where it is often common to find trajectories that evolve from stable, near-circular orbits to crashing or escaping orbits in a matter of days. The understanding and control of such orbits is important if a human or robotic presence at asteroids is to be commonplace in the future.

  18. Design and "As Flown" Radiation Environments for Materials in Low Earth Orbit

    Science.gov (United States)

    Minow, Joseph; McWilliams, Brett; Altstatt, Richard; Koontz, Steven

    2006-01-01

    A conservative design approach was adopted by the International Space Station Program for specifying total ionizing radiation dose requirements for use in selecting and qualifying materials for construction of the International Space Station. The total ionizing dose design environment included in SSP 30512 Space Station Ionizing Radiation Design Environment is based on trapped proton and electron fluence derived from the solar maximum versions of the AE-8 and AP-8 models, respectively, specified for a circular orbit at 500 km altitude and 51.7 degree inclination. Since launch, the range of altitudes utilized for Space Station operations vary from a minimum of approximately 330 km to a maximum of approximately 405 km with a mean operational altitude less than 400 km. The design environment, therefore, overestimates the radiation environment because the particle flux in the South Atlantic Anomaly is the primary contributor to radiation dose in low Earth orbit and flux within the Anomaly is altitude dependent. In addition, a 2X multiplier is often applied to the design environment to cover effects from the contributions of galactic cosmic rays, solar energetic particle events, geomagnetic storms, and uncertainties in the trapped radiation models which are not explicitly included in the design environment. Application of this environment may give radiation dose overestimates on the order of 1OX to 30X for materials exposed to the space environment, suggesting that materials originally qualified for ten year exposures on orbit may be used for longer periods without replacement. In this paper we evaluate the "as flown" radiation environments derived from historical records of the ISS flight trajectory since launch and compare the results with the SSP 30512 design environment to document the magnitude of the radiation dose overestimate provided by the design environment. "As flown" environments are obtained from application of the AE-8/AP-8 trapped particle models along

  19. Accelerated simulation of near-Earth-orbit polymer degradation

    Science.gov (United States)

    Laue, Eric

    1992-01-01

    There is a need to simulate the near-Earth-orbit environmental conditions, and it is useful to be able to monitor the changes in physical properties of spacecraft materials. Two different methods for simulating the vacuum-ultraviolet (VUV) and soft X-ray near-Earth-orbit flux are presented. Also, methods for monitoring the changes in optical ultraviolet transmission and mass loss are presented. The results of exposures to VUV photons and charged particles on these materials are discussed.

  20. On the effects of solar storms to the decaying orbital space debris

    International Nuclear Information System (INIS)

    Herdiwijaya, Dhani; Rachman, Abdul

    2014-01-01

    Any man-made object in Earth's orbit that no longer serves a useful purpose is classified as orbital debris. Debris objects come from a variety of sources. The majority is related to satellite fragmentation. Other major sources of debris are propulsion systems, and fragmentation of spent upper stages, payload and mission related debris. Serious concern about orbital debris has been growing. Knowledge of the future debris environment is important to both satellite designers, and mission planners, who need to know what hazards a satellite might encounter during the course of its mission. Therefore, it is important to know how much debris is in orbit, where it is located, and when it will decay. The debris environment is complex and dynamically evolving. Objects of different shape and size behave differently in orbit. The geoeffectiveness space environments include solar flux at 10.7 cm, solar energetic particles flux or speed, solar wind flow pressure, electric field, and geomagnetic indices. We study the decaying orbital debris from Tracking and Impact Prediction (TIP) messages in conjuction with geoeffectiveness space environments through time epoch correlation. We found that the decaying and reentry orbital debris are triggered by space environment enhancement within at least one week before reentry. It is not necessary a transient or high energetic and severe solar storm events are needed in decaying processes. We propose that the gradual enhancement processes of space environment will cause satellite surface charging due to energetic electron and enhance drag force

  1. On the effects of solar storms to the decaying orbital space debris

    Energy Technology Data Exchange (ETDEWEB)

    Herdiwijaya, Dhani, E-mail: dhani@as.itb.ac.id [Astronomy Division and Bosscha Observatory, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Ganesha 10, Bandung 40132 (Indonesia); Rachman, Abdul [Space Science Center, National Institute of Aeronautics and Space, Junjunan 133, Bandung 40173 (Indonesia)

    2014-03-24

    Any man-made object in Earth's orbit that no longer serves a useful purpose is classified as orbital debris. Debris objects come from a variety of sources. The majority is related to satellite fragmentation. Other major sources of debris are propulsion systems, and fragmentation of spent upper stages, payload and mission related debris. Serious concern about orbital debris has been growing. Knowledge of the future debris environment is important to both satellite designers, and mission planners, who need to know what hazards a satellite might encounter during the course of its mission. Therefore, it is important to know how much debris is in orbit, where it is located, and when it will decay. The debris environment is complex and dynamically evolving. Objects of different shape and size behave differently in orbit. The geoeffectiveness space environments include solar flux at 10.7 cm, solar energetic particles flux or speed, solar wind flow pressure, electric field, and geomagnetic indices. We study the decaying orbital debris from Tracking and Impact Prediction (TIP) messages in conjuction with geoeffectiveness space environments through time epoch correlation. We found that the decaying and reentry orbital debris are triggered by space environment enhancement within at least one week before reentry. It is not necessary a transient or high energetic and severe solar storm events are needed in decaying processes. We propose that the gradual enhancement processes of space environment will cause satellite surface charging due to energetic electron and enhance drag force.

  2. The Impact Imperative: A Space Infrastructure Enabling a Multi-Tiered Earth Defense

    Science.gov (United States)

    Campbell, Jonathan W.; Phipps, Claude; Smalley, Larry; Reilly, James; Boccio, Dona

    2003-01-01

    Impacting at hypervelocity, an asteroid struck the Earth approximately 65 million years ago in the Yucatan Peninsula a m . This triggered the extinction of almost 70% of the species of life on Earth including the dinosaurs. Other impacts prior to this one have caused even greater extinctions. Preventing collisions with the Earth by hypervelocity asteroids, meteoroids, and comets is the most important immediate space challenge facing human civilization. This is the Impact Imperative. We now believe that while there are about 2000 earth orbit crossing rocks greater than 1 kilometer in diameter, there may be as many as 200,000 or more objects in the 100 m size range. Can anything be done about this fundamental existence question facing our civilization? The answer is a resounding yes! By using an intelligent combination of Earth and space based sensors coupled with an infrastructure of high-energy laser stations and other secondary mitigation options, we can deflect inbound asteroids, meteoroids, and comets and prevent them &om striking the Earth. This can be accomplished by irradiating the surface of an inbound rock with sufficiently intense pulses so that ablation occurs. This ablation acts as a small rocket incrementally changing the shape of the rock's orbit around the Sun. One-kilometer size rocks can be moved sufficiently in about a month while smaller rocks may be moved in a shorter time span. We recommend that space objectives be immediately reprioritized to start us moving quickly towards an infrastructure that will support a multiple option defense capability. Planning and development for a lunar laser facility should be initiated immediately in parallel with other options. All mitigation options are greatly enhanced by robust early warning, detection, and tracking resources to find objects sufficiently prior to Earth orbit passage in time to allow significant intervention. Infrastructure options should include ground, LEO, GEO, Lunar, and libration point

  3. PRODUCTION OF NEAR-EARTH ASTEROIDS ON RETROGRADE ORBITS

    International Nuclear Information System (INIS)

    Greenstreet, S.; Gladman, B.; Ngo, H.; Granvik, M.; Larson, S.

    2012-01-01

    While computing an improved near-Earth object (NEO) steady-state orbital distribution model, we discovered in the numerical integrations the unexpected production of retrograde orbits for asteroids that had originally exited from the accepted main-belt source regions. Our model indicates that ∼0.1% (a factor of two uncertainty) of the steady-state NEO population (perihelion q < 1.3 AU) is on retrograde orbits. These rare outcomes typically happen when asteroid orbits flip to a retrograde configuration while in the 3:1 mean-motion resonance with Jupiter and then live for ∼0.001 to 100 Myr. The model predicts, given the estimated near-Earth asteroid (NEA) population, that a few retrograde 0.1-1 km NEAs should exist. Currently, there are two known MPC NEOs with asteroidal designations on retrograde orbits which we therefore claim could be escaped asteroids instead of devolatilized comets. This retrograde NEA population may also answer a long-standing question in the meteoritical literature regarding the origin of high-strength, high-velocity meteoroids on retrograde orbits.

  4. Space Debris Attitude Simulation - IOTA (In-Orbit Tumbling Analysis)

    Science.gov (United States)

    Kanzler, R.; Schildknecht, T.; Lips, T.; Fritsche, B.; Silha, J.; Krag, H.

    Today, there is little knowledge on the attitude state of decommissioned intact objects in Earth orbit. Observational means have advanced in the past years, but are still limited with respect to an accurate estimate of motion vector orientations and magnitude. Especially for the preparation of Active Debris Removal (ADR) missions as planned by ESA's Clean Space initiative or contingency scenarios for ESA spacecraft like ENVISAT, such knowledge is needed. The In-Orbit Tumbling Analysis tool (IOTA) is a prototype software, currently in development within the framework of ESA's “Debris Attitude Motion Measurements and Modelling” project (ESA Contract No. 40000112447), which is led by the Astronomical Institute of the University of Bern (AIUB). The project goal is to achieve a good understanding of the attitude evolution and the considerable internal and external effects which occur. To characterize the attitude state of selected targets in LEO and GTO, multiple observation methods are combined. Optical observations are carried out by AIUB, Satellite Laser Ranging (SLR) is performed by the Space Research Institute of the Austrian Academy of Sciences (IWF) and radar measurements and signal level determination are provided by the Fraunhofer Institute for High Frequency Physics and Radar Techniques (FHR). Developed by Hyperschall Technologie Göttingen GmbH (HTG), IOTA will be a highly modular software tool to perform short- (days), medium- (months) and long-term (years) propagation of the orbit and attitude motion (six degrees-of-freedom) of spacecraft in Earth orbit. The simulation takes into account all relevant acting forces and torques, including aerodynamic drag, solar radiation pressure, gravitational influences of Earth, Sun and Moon, eddy current damping, impulse and momentum transfer from space debris or micro meteoroid impact, as well as the optional definition of particular spacecraft specific influences like tank sloshing, reaction wheel behaviour

  5. Modelling the near-Earth space environment using LDEF data

    Science.gov (United States)

    Atkinson, Dale R.; Coombs, Cassandra R.; Crowell, Lawrence B.; Watts, Alan J.

    1992-01-01

    Near-Earth space is a dynamic environment, that is currently not well understood. In an effort to better characterize the near-Earth space environment, this study compares the results of actual impact crater measurement data and the Space Environment (SPENV) Program developed in-house at POD, to theoretical models established by Kessler (NASA TM-100471, 1987) and Cour-Palais (NASA SP-8013, 1969). With the continuing escalation of debris there will exist a definite hazard to unmanned satellites as well as manned operations. Since the smaller non-trackable debris has the highest impact rate, it is clearly necessary to establish the true debris environment for all particle sizes. Proper comprehension of the near-Earth space environment and its origin will permit improvement in spacecraft design and mission planning, thereby reducing potential disasters and extreme costs. Results of this study directly relate to the survivability of future spacecraft and satellites that are to travel through and/or reside in low Earth orbit (LEO). More specifically, these data are being used to: (1) characterize the effects of the LEO micrometeoroid an debris environment on satellite designs and components; (2) update the current theoretical micrometeoroid and debris models for LEO; (3) help assess the survivability of spacecraft and satellites that must travel through or reside in LEO, and the probability of their collision with already resident debris; and (4) help define and evaluate future debris mitigation and disposal methods. Combined model predictions match relatively well with the LDEF data for impact craters larger than approximately 0.05 cm, diameter; however, for smaller impact craters, the combined predictions diverge and do not reflect the sporadic clouds identified by the Interplanetary Dust Experiment (IDE) aboard LDEF. The divergences cannot currently be explained by the authors or model developers. The mean flux of small craters (approximately 0.05 cm diameter) is

  6. Regional positioning using a low Earth orbit satellite constellation

    Science.gov (United States)

    Shtark, Tomer; Gurfil, Pini

    2018-02-01

    Global and regional satellite navigation systems are constellations orbiting the Earth and transmitting radio signals for determining position and velocity of users around the globe. The state-of-the-art navigation satellite systems are located in medium Earth orbits and geosynchronous Earth orbits and are characterized by high launching, building and maintenance costs. For applications that require only regional coverage, the continuous and global coverage that existing systems provide may be unnecessary. Thus, a nano-satellites-based regional navigation satellite system in Low Earth Orbit (LEO), with significantly reduced launching, building and maintenance costs, can be considered. Thus, this paper is aimed at developing a LEO constellation optimization and design method, using genetic algorithms and gradient-based optimization. The preliminary results of this study include 268 LEO constellations, aimed at regional navigation in an approximately 1000 km × 1000 km area centered at the geographic coordinates [30, 30] degrees. The constellations performance is examined using simulations, and the figures of merit include total coverage time, revisit time, and geometric dilution of precision (GDOP) percentiles. The GDOP is a quantity that determines the positioning solution accuracy and solely depends on the spatial geometry of the satellites. Whereas the optimization method takes into account only the Earth's second zonal harmonic coefficient, the simulations include the Earth's gravitational field with zonal and tesseral harmonics up to degree 10 and order 10, Solar radiation pressure, drag, and the lunisolar gravitational perturbation.

  7. A Dynamic/Anisotropic Low Earth Orbit (LEO) Ionizing Radiation Model

    Science.gov (United States)

    Badavi, Francis F.; West, Katie J.; Nealy, John E.; Wilson, John W.; Abrahms, Briana L.; Luetke, Nathan J.

    2006-01-01

    The International Space Station (ISS) provides the proving ground for future long duration human activities in space. Ionizing radiation measurements in ISS form the ideal tool for the experimental validation of ionizing radiation environmental models, nuclear transport code algorithms, and nuclear reaction cross sections. Indeed, prior measurements on the Space Transportation System (STS; Shuttle) have provided vital information impacting both the environmental models and the nuclear transport code development by requiring dynamic models of the Low Earth Orbit (LEO) environment. Previous studies using Computer Aided Design (CAD) models of the evolving ISS configurations with Thermo Luminescent Detector (TLD) area monitors, demonstrated that computational dosimetry requires environmental models with accurate non-isotropic as well as dynamic behavior, detailed information on rack loading, and an accurate 6 degree of freedom (DOF) description of ISS trajectory and orientation.

  8. Solar Effects of Low-Earth Orbit objects in ORDEM 3.0

    Science.gov (United States)

    Vavrin, A. B.; Anz-Meador, P.; Kelley, R. L.

    2014-01-01

    Variances in atmospheric density are directly related to the variances in solar flux intensity between 11- year solar cycles. The Orbital Debris Engineering Model (ORDEM 3.0) uses a solar flux table as input for calculating orbital lifetime of intact and debris objects in Low-Earth Orbit. Long term projections in solar flux activity developed by the NASA Orbital Debris Program Office (ODPO) extend the National Oceanic and Atmospheric Administration Space Environment Center (NOAA/SEC) daily historical flux values with a 5-year projection. For purposes of programmatic scheduling, the Q2 2009 solar flux table was chosen for ORDEM 3.0. Current solar flux activity shows that the current solar cycle has entered a period of lower solar flux intensity than previously forecasted in 2009. This results in a deviation of the true orbital debris environment propagation in ORDEM 3.0. In this paper, we present updated orbital debris populations in LEO using the latest solar flux values. We discuss the effects on recent breakup events such as the FY-1C anti-satellite test and the Iridium 33 / Cosmos 2251 accidental collision. Justifications for chosen solar flux tables are discussed.

  9. Mitigating Climate Change with Earth Orbital Sunshades

    Science.gov (United States)

    Coverstone, Victoria; Johnson, Les

    2015-01-01

    An array of rotating sunshades based on emerging solar sail technology will be deployed in a novel Earth orbit to provide near-continuous partial shading of the Earth, reducing the heat input to the atmosphere by blocking a small percentage of the incoming sunlight, and mitigating local weather effects of anticipated climate change over the next century. The technology will provide local cooling relief during extreme heat events (and heating relief during extreme cold events) thereby saving human lives, agriculture, livestock, water and energy needs. A synthesis of the solar sail design, the sails' operational modes, and the selected orbit combine to provide local weather modification.

  10. To orbit and back again how the space shuttle flew in space

    CERN Document Server

    Sivolella, Davide

    2014-01-01

    The question may be simple, but the answer is not as easy to give. This book describes the structures and systems used each time the Shuttle was launched, and then follows an imaginary mission, explaining how those structures and systems were used in orbital operations and the return to Earth. Details of how anomalous events were dealt with on individual missions are also provided, as are the recollections of those who built and flew the Shuttle. Highly illustrated with many diagrams, photographs and technical drawings, To Orbit and Back Again • focuses on the engineering aspects of the Shuttle • describes the systems and subsystems in clear, non-technical terms • brings to the fore the design work behind the Space Shuttle and the mission itself.    .

  11. Early Mission Maneuver Operations for the Deep Space Climate Observatory Sun-Earth L1 Libration Point Mission

    Science.gov (United States)

    Roberts, Craig; Case, Sara; Reagoso, John; Webster, Cassandra

    2015-01-01

    The Deep Space Climate Observatory mission launched on February 11, 2015, and inserted onto a transfer trajectory toward a Lissajous orbit around the Sun-Earth L1 libration point. This paper presents an overview of the baseline transfer orbit and early mission maneuver operations leading up to the start of nominal science orbit operations. In particular, the analysis and performance of the spacecraft insertion, mid-course correction maneuvers, and the deep-space Lissajous orbit insertion maneuvers are discussed, com-paring the baseline orbit with actual mission results and highlighting mission and operations constraints..

  12. SmallSat Missions Traveling to Planetary Targets from Near-Earth-Space: Applications for Space Physics

    Science.gov (United States)

    Espley, J. R.; Folta, D.

    2017-12-01

    Recent advances in propulsion technology and interplanetary navigation theoretically allow very small spacecraft to travel directly to planetary destinations from near-Earth-space. Because there are currently many launches with excess mass capability (NASA, military, and even commercial), we anticipate a dramatic increase in the number of opportunities for missions to planetary targets. Spacecraft as small as 12U CubeSats can use solar electric propulsion to travel from Earth-orbit to Mars-orbit in approximately 2-3 years. Space physics missions are particularly well suited for such mission architectures since state-of-the-art instrumentation to answer fundamental science questions can be accommodated in relatively small payload packages. For example, multi-point measurements of the martian magnetosphere, ionosphere, and crustal magnetic fields would yield important new science results regarding atmospheric escape and the geophysical history of the martian surface. These measurements could be accomplished by a pair of 12U CubeSats with world-class instruments that require only modest mass, power, and telemetry resources (e.g. Goddard's mini-fluxgate vector magnetometer).

  13. Space Station Freedom assembly and operation at a 51.6 degree inclination orbit

    Science.gov (United States)

    Troutman, Patrick A.; Brewer, Laura M.; Heck, Michael L.; Kumar, Renjith R.

    1993-01-01

    This study examines the implications of assembling and operating Space Station Freedom at a 51.6 degree inclination orbit utilizing an enhanced lift Space Shuttle. Freedom assembly is currently baselined at a 220 nautical mile high, 28.5 degree inclination orbit. Some of the reasons for increasing the orbital inclination are (1) increased ground coverage for Earth observations, (2) greater accessibility from Russian and other international launch sites, and (3) increased number of Assured Crew Return Vehicle (ACRV) landing sites. Previous studies have looked at assembling Freedom at a higher inclination using both medium and heavy lift expendable launch vehicles (such as Shuttle-C and Energia). The study assumes that the shuttle is used exclusively for delivering the station to orbit and that it can gain additional payload capability from design changes such as a lighter external tank that somewhat offsets the performance decrease that occurs when the shuttle is launched to a 51.6 degree inclination orbit.

  14. Degradation of Spacesuit Fabrics in Low Earth Orbit

    Science.gov (United States)

    Gaier, James R.; Baldwin, Sammantha M.; Folz, Angela D.; Waters, Deborah L.; McCue, Terry R.; Jaworske, Donald A.; Clark, Gregory W.; Rogers, Kerry J.; Batman, Brittany; Bruce, John; hide

    2012-01-01

    Six samples of pristine and dust-abraded outer layer spacesuit fabrics were included in the Materials International Space Station Experiment-7, in which they were exposed to the wake-side low Earth orbit environment on the International Space Station (ISS) for 18 months in order to determine whether abrasion by lunar dust increases radiation degradation. The fabric samples were characterized using optical microscopy, optical spectroscopy, field emission scanning electron microscopy, atomic force microscopy, and tensile testing before and after exposure on the ISS. Comparison of pre- and post-flight characterizations showed that the environment darkened and reddened all six fabrics, increasing their integrated solar absorptance by 7 to 38 percent. There was a decrease in the ultimate tensile strength and elongation to failure of lunar dust abraded Apollo spacesuit fibers by a factor of four and an increase in the elastic modulus by a factor of two.

  15. Comprehensive Evaluation of Attitude and Orbit Estimation Using Actual Earth Magnetic Field Data

    Science.gov (United States)

    Deutschmann, Julie K.; Bar-Itzhack, Itzhack Y.

    2000-01-01

    A single, augmented Extended Kalman Filter (EKF), which simultaneously and autonomously estimates spacecraft attitude and orbit has been developed and successfully tested with real magnetometer and gyro data only. Because the earth magnetic field is a function of time and position, and because time is known quite precisely, the differences between the computed and measured magnetic field components, as measured by the magnetometers throughout the entire spacecraft orbit, are a function of both orbit and attitude errors. Thus, conceivably these differences could be used to estimate both orbit and attitude; an observability study validated this assumption. The results of testing the EKF with actual magnetometer and gyro data, from four satellites supported by the NASA Goddard Space Flight Center (GSFC) Guidance, Navigation, and Control Center, are presented and evaluated. They confirm the assumption that a single EKF can estimate both attitude and orbit when using gyros and magnetometers only.

  16. Implementation of National Space Policy on US Air Force End of Life Operations and Orbital Debris Mitigation

    Science.gov (United States)

    2012-06-01

    Space Development and Test Directorate, Kirtland AFB, NM, 87117 Recent changes to US space policy regarding the execution of satellite End of Life ( EOL ...procedures have been driven by the rising significance of the orbital debris problem in Low Earth Orbit (LEO). Therefore current EOL plans are...considerations for writing operational EOL plans, with special applicability to military missions and focus on LEO satellites that are unable to relocate

  17. Optimization method of star tracker orientation for sun-synchronous orbit based on space light distribution.

    Science.gov (United States)

    Wang, Geng; Xing, Fei; Wei, Minsong; Sun, Ting; You, Zheng

    2017-05-20

    Star trackers, optical attitude sensors with high precision, are susceptible to space light from the Sun and the Earth albedo. Until now, research in this field has lacked systematic analysis. In this paper, we propose an installation orientation method for a star tracker onboard sun-synchronous-orbit spacecraft and analyze the space light distribution by transforming the complicated relative motion among the Sun, Earth, and the satellite to the body coordinate system of the satellite. Meanwhile, the boundary-curve equations of the areas exposed to the stray light from the Sun and the Earth albedo were calculated by the coordinate-transformation matrix under different maneuver attitudes, and the installation orientation of the star tracker was optimized based on the boundary equations instead of the traditional iterative simulation method. The simulation and verification experiment indicate that this installation orientation method is effective and precise and can provide a reference for the installation of sun-synchronous orbit star trackers free from the stray light.

  18. Potentiality of an orbiting interferometer for space-time experiments

    International Nuclear Information System (INIS)

    Grassi Strini, A.M.; Strini, G.; Tagliaferri, G.

    1979-01-01

    It is suggested that by putting a Michelson interferometer aboard a spacecraft orbiting around the earth, very substantial progress could be made in space-time experiments. It is estimated that in measurements of e.g. some anisotropy of the light velocity, a spacecraft-borne interferometer of quite small size (0.1 m arm-length) would reach a sensitivity greater by a factor of approximately 10 8 than the best achievements to date of ground-based devices. (author)

  19. THE NASA-UC ETA-EARTH PROGRAM. III. A SUPER-EARTH ORBITING HD 97658 AND A NEPTUNE-MASS PLANET ORBITING Gl 785

    International Nuclear Information System (INIS)

    Howard, Andrew W.; Marcy, Geoffrey W.; Isaacson, Howard; Johnson, John Asher; Fischer, Debra A.; Wright, Jason T.; Henry, Gregory W.; Valenti, Jeff A.; Anderson, Jay; Piskunov, Nikolai E.

    2011-01-01

    We report the discovery of planets orbiting two bright, nearby early K dwarf stars, HD 97658 and Gl 785. These planets were detected by Keplerian modeling of radial velocities measured with Keck-HIRES for the NASA-UC Eta-Earth Survey. HD 97658 b is a close-in super-Earth with minimum mass Msin i = 8.2 ± 1.2 M + , orbital period P = 9.494 ± 0.005 days, and an orbit that is consistent with circular. Gl 785 b is a Neptune-mass planet with Msin i = 21.6 ± 2.0 M + , P = 74.39 ± 0.12 days, and orbital eccentricity e = 0.30 ± 0.09. Photometric observations with the T12 0.8 m automatic photometric telescope at Fairborn Observatory show that HD 97658 is photometrically constant at the radial velocity period to 0.09 mmag, supporting the existence of the planet.

  20. A low earth orbit dynamic model for the proton anisotropy validation

    Science.gov (United States)

    Badavi, Francis F.

    2011-11-01

    Ionizing radiation measurements at low earth orbit (LEO) form the ideal tool for the experimental validation of radiation environmental models, nuclear transport code algorithms and nuclear reaction cross sections. Indeed, prior measurements on the space transportation system (STS; shuttle) have provided vital information impacting both the environmental models and the nuclear transport code development by requiring dynamic models of the LEO environment. Previous studies using computer aided design (CAD) models of the international space station (ISS) have demonstrated that the dosimetric prediction for a spacecraft at LEO requires the description of an environmental model with accurate anisotropic as well as dynamic behavior. This paper describes such a model for the trapped proton. The described model is a component of a suite of codes collectively named GEORAD (GEOmagnetic RADiation) which computes cutoff rigidity, trapped proton and trapped electron environments. The web version of GEORAD is named OLTARIS (On-line Tool for the Assessment of Radiation in Space). GEORAD suite is applicable to radiation environment prediction at LEO, medium earth orbit (MEO) and geosynchronous earth orbit (GEO) at quiet solar periods. GEORAD interest is in the study of long term effect of the trapped environment and therefore it does not account for any short term external field contribution due to solar activity. With the concentration of the paper on the LEO protons only, the paper presents the validation of the trapped proton model within GEORAD with reported measurements from the compact environment anomaly sensor (CEASE) science instrument package, flown onboard the tri-service experiment-5 (TSX-5) satellite during the period of June 2000 to July 2006. The spin stabilized satellite was flown in a 410 × 1710 km, 69° inclination elliptical orbit, allowing it to be exposed to a broad range of the LEO regime. The paper puts particular emphasize on the validation of the

  1. Exotic Optical Fibers and Glasses: Innovative Material Processing Opportunities in Earth's Orbit.

    Science.gov (United States)

    Cozmuta, Ioana; Rasky, Daniel J

    2017-09-01

    Exotic optical fibers and glasses are the platform material for photonics applications, primarily due to their superior signal transmission (speed, low attenuation), with extending bandwidth deep into the infrared, exceeding that of silica fibers. Gravitational effects (convection sedimentation) have a direct impact on the phase diagram of these materials and influence melting properties, crystallization temperatures, and viscosity of the elemental mix during the manufacturing process. Such factors constitute limits to the yield, transmission quality, and strength and value of these fibers; they also constrain the range of applications. Manufacturing in a gravity-free environment such as the Earth's Orbit also helps with other aspects of the fabrication process (i.e., improved form factor of the manufacturing unit, sustainability). In this article, revolutionary developments in the field of photonics over the past decade merge with the paradigm shift in the privatization of government-owned capabilities supporting a more diverse infrastructure (parabolic, suborbital, orbital), reduced price, and increased frequency to access space and the microgravity environment. With the increased dependence on data (demand, bandwidth, efficiency), space and the microgravity environment provide opportunities for optimized performance of these exotic optical fibers and glasses underlying the development of enabling technologies to meet future data demand. Existing terrestrial markets (Internet, telecommunications, market transactions) and emerging space markets (on-orbit satellite servicing, space manufacturing, space resources, space communications, etc.) seem to converge, and this innovative material processing opportunity of exotic optical fibers and glasses might just be that "killer app": technologically competitive, economically viable, and with the ability to close the business case.

  2. Trade Study for Neutron Transport at Low Earth Orbit: Adding Fidelity to DIORAMA

    Energy Technology Data Exchange (ETDEWEB)

    McClanahan, Tucker Caden [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wakeford, Daniel Tyler [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-22

    The Distributed Infrastructure Offering Real-Time Access to Modeling and Analysis (DIORAMA) software provides performance modeling capabilities of the United States Nuclear Detonation Detection System (USNDS) with a focus on the characterization of Space-Based Nuclear Detonation Detection (SNDD) instrument performance [1]. A case study was done to add the neutron propagation capabilities of DIORAMA to low earth orbit (LEO), and compare the back-calculated incident energy from the time-of- ight (TOF) spectrum with the scored incident energy spectrum. As the scoring altitude lowers, the time increase due to scattering takes up much more of the fraction of total TOF; whereas at geosynchronous earth orbit (GEO), the time increase due to scattering is a negligible fraction of the total TOF [2]. The scattering smears out the TOF enough to make the back-calculation of the initial energy spectrum from the TOF spectrum very convoluted.

  3. Collisional cascading - The limits of population growth in low earth orbit

    Science.gov (United States)

    Kessler, Donald J.

    1991-01-01

    Random collisions between made-made objects in earth orbit will lead to a significant source of orbital debris, but there are a number of uncertainties in these models, and additional analysis and data are required to fully characterize the future environment. However, the nature of these uncertainties are such that while the future environment is uncertain, the fact that collisions will control the future environment is less uncertain. The data that already exist is sufficient to show that cascading collisions will control the future debris environment with no, or very minor increases in the current low-earth-orbit population. Two populations control this process: explosion fragments and expended rocket bodies and payloads. Practices are already changing to limit explosions in low earth orbit; it is necessary to begin limiting the number of expended rocket bodies and payloads in orbit.

  4. A Small Spacecraft Swarm Deployment and Stationkeeping Strategy for Sun-Earth L1 Halo Orbits

    Science.gov (United States)

    Renea Conn, Tracie; Bookbinder, Jay

    2018-01-01

    Spacecraft orbits about the Sun-Earth librarian point L1 have been of interest since the 1950s. An L1 halo orbit was first achieved with the International Sun-Earth Explorer-3 (ISEE-3) mission, and similar orbits around Sun-Earth L1 were achieved in the Solar and Heliospheric Observatory (SOHO), Advanced Composition Explorer (ACE), Genesis, and Deep Space Climate Observatory (DSCOVR) missions. With recent advancements in CubeSat technology, we envision that it will soon be feasible to deploy CubeSats at L1. As opposed to these prior missions where one large satellite orbited alone, a swarm of CubeSats at L1 would enable novel science data return, providing a topology for intersatellite measurements of heliophysics phenomena both spatially and temporally, at varying spatial scales.The purpose of this iPoster is to present a flight dynamics strategy for a swarm of numerous CubeSats orbiting Sun-Earth L1. The presented method is a coupled, two-part solution. First, we present a deployment strategy for the CubeSats that is optimized to produce prescribed, time-varying intersatellite baselines for the purposes of collecting magnetometer data as well as radiometric measurements from cross-links. Second, we employ a loose control strategy that was successfully applied to SOHO and ACE for minimized stationkeeping propellant expenditure. We emphasize that the presented solution is practical within the current state-of-the-art and heritage CubeSat technology, citing capabilities of CubeSat designs that will launch on the upcoming Exploration Mission 1 (EM-1) to lunar orbits and beyond. Within this iPoster, we present animations of the simulated deployment strategy and resulting spacecraft trajectories. Mission design parameters such as total Δv required for long-term station keeping and minimum/maximum/mean spacecraft separation distances are also presented.

  5. Nuclear space power systems for orbit raising and maneuvering

    International Nuclear Information System (INIS)

    Buden, D.; Sullivan, J.A.

    1984-01-01

    Reference is made to recent studies which have shown that direct thrust nuclear rockets for routine orbit raising and near-earth space tug missions are probably not cost-effective. The need for additional trade-off studies and comparisons of direct-thrust nuclear systems with chemical systems to clarify the role of nuclear rockets in missions requiring rapid orbit maneuvering is stressed. Attention is confined here to nuclear electric propulsion considerations. Low-mass nuclear power plants are constructed to optimize nuclear electric propulsion systems. Electric power levels from 100 kilowatts to as much as several megawatts are desirable. The goals for the power plant specific mass are 20-30 kg/kW at the lower powers to 2-4 kg/kW at the higher powers

  6. Wastes in space

    International Nuclear Information System (INIS)

    2011-01-01

    As human space activities have created more wastes on low and high Earth orbits over the past 50 years than the solar system injected meteorites over billions of years, this report gives an overview of this problem. It identifies the origins of these space debris and wastes (launchers, combustion residues, exploitation wastes, out-of-use satellites, accidental explosions, accidental collisions, voluntary destructions, space erosion), and proposes a stock list of space wastes. Then, it distinguishes the situation for the different orbits: low Earth orbit or LEO (traffic, presence of the International Space Station), medium Earth orbits or MEO (traffic, operating satellites, wastes), geostationary Earth orbit or GEO (traffic, operating satellites, wastes). It also discusses wastes and bacteria present on the moon (due to Apollo missions or to crash tests). It evokes how space and nuclear industry is concerned, and discusses the re-entry issue (radioactive boomerang, metallic boomerang). It also indicates elements of international law

  7. Medical Implications of Space Radiation Exposure Due to Low-Altitude Polar Orbits.

    Science.gov (United States)

    Chancellor, Jeffery C; Auñon-Chancellor, Serena M; Charles, John

    2018-01-01

    Space radiation research has progressed rapidly in recent years, but there remain large uncertainties in predicting and extrapolating biological responses to humans. Exposure to cosmic radiation and solar particle events (SPEs) may pose a critical health risk to future spaceflight crews and can have a serious impact on all biomedical aspects of space exploration. The relatively minimal shielding of the cancelled 1960s Manned Orbiting Laboratory (MOL) program's space vehicle and the high inclination polar orbits would have left the crew susceptible to high exposures of cosmic radiation and high dose-rate SPEs that are mostly unpredictable in frequency and intensity. In this study, we have modeled the nominal and off-nominal radiation environment that a MOL-like spacecraft vehicle would be exposed to during a 30-d mission using high performance, multicore computers. Projected doses from a historically large SPE (e.g., the August 1972 solar event) have been analyzed in the context of the MOL orbit profile, providing an opportunity to study its impact to crew health and subsequent contingencies. It is reasonable to presume that future commercial, government, and military spaceflight missions in low-Earth orbit (LEO) will have vehicles with similar shielding and orbital profiles. Studying the impact of cosmic radiation to the mission's operational integrity and the health of MOL crewmembers provides an excellent surrogate and case-study for future commercial and military spaceflight missions.Chancellor JC, Auñon-Chancellor SM, Charles J. Medical implications of space radiation exposure due to low-altitude polar orbits. Aerosp Med Hum Perform. 2018; 89(1):3-8.

  8. Use and Protection of GPS Sidelobe Signals for Enhanced Navigation Performance in High Earth Orbit

    Science.gov (United States)

    Parker, Joel J. K.; Valdez, Jennifer E.; Bauer, Frank H.; Moreau, Michael C.

    2016-01-01

    GPS (Global Positioning System) Space Service Volume (SSV) signal environment is from 3,000-36,000 kilometers altitude. Current SSV specifications only capture performance provided by signals transmitted within 23.5(L1) or 26(L2-L5) off-nadir angle. Recent on-orbit data lessons learned show significant PNT (Positioning, Navigation and Timing) performance improvements when the full aggregate signal is used. Numerous military civil operational missions in High Geosynchronous Earth Orbit (HEOGEO) utilize the full signal to enhance vehicle PNT performance

  9. Preserving the Near-Earth Space Environment with Green Engineering and Operations

    Science.gov (United States)

    Johnson, Nicholas L.

    2009-01-01

    Green engineering and operations are essential to preserving the near-Earth space environment for future generations. The U.S. and the international aerospace community have been proactive in addressing the threat of the increasing orbital debris population and the risks to people and property from reentering debris. NASA has led this activity first by devoting resources to thoroughly understand the technical issues and then by developing effective and acceptable policies and guidelines. NASA also worked closely with the international community to ensure that the US aerospace industry was not placed at an economic disadvantage. In the long term, the removal of large orbital debris will be essential to the sustainability of space operations.

  10. Advanced Earth-to-orbit propulsion technology information, dissemination and research

    Science.gov (United States)

    Wu, S. T.

    1995-01-01

    In this period of performance a conference (The 1994 Conference on Advanced Earth-to-Orbit Propulsion Technology) was organized and implemented by the University of Alabama in Huntsville and held May 15-17 to assemble and disseminate the current information on Advanced Earth-to-Orbit Propulsion Technology. The results were assembled for publication as NASA-CP-3282, Volume 1 and 2 and NASA-CP-3287.

  11. A comprehensive mission to planet Earth: Woods Hole Space Science and Applications Advisory Committee Planning Workshop

    Science.gov (United States)

    1991-01-01

    The NASA program Mission to Planet Earth (MTPE) is described in this set of visuals presented in Massachusetts on July 29, 1991. The problem presented in this document is that the earth system is changing and that human activity accelerates the rate of change resulting in increased greenhouse gases, decreasing levels of stratospheric ozone, acid rain, deforestation, decreasing biodiversity, and overpopulation. Various national and international organizations are coordinating global change research. The complementary space observations for this activity are sun-synchronous polar orbits, low-inclination, low altitude orbits, geostationary orbits, and ground measurements. The Geostationary Earth Observatory is the major proposed mission of MTPE. Other proposed missions are EOS Synthetic Aperture Radar, ARISTOTELES Magnetic Field Experiment, and the Global Topography Mission. Use of the NASA DC-8 aircraft is outlined as carrying out the Airborne Science and Applications Program. Approved Earth Probes Program include the Total Ozone Mapping Spectrometer (TOMS). Other packages for earth observation are described.

  12. Improved Space Object Orbit Determination Using CMOS Detectors

    Science.gov (United States)

    Schildknecht, T.; Peltonen, J.; Sännti, T.; Silha, J.; Flohrer, T.

    2014-09-01

    CMOS-sensors, or in general Active Pixel Sensors (APS), are rapidly replacing CCDs in the consumer camera market. Due to significant technological advances during the past years these devices start to compete with CCDs also for demanding scientific imaging applications, in particular in the astronomy community. CMOS detectors offer a series of inherent advantages compared to CCDs, due to the structure of their basic pixel cells, which each contains their own amplifier and readout electronics. The most prominent advantages for space object observations are the extremely fast and flexible readout capabilities, feasibility for electronic shuttering and precise epoch registration, and the potential to perform image processing operations on-chip and in real-time. The major challenges and design drivers for ground-based and space-based optical observation strategies have been analyzed. CMOS detector characteristics were critically evaluated and compared with the established CCD technology, especially with respect to the above mentioned observations. Similarly, the desirable on-chip processing functionalities which would further enhance the object detection and image segmentation were identified. Finally, we simulated several observation scenarios for ground- and space-based sensor by assuming different observation and sensor properties. We will introduce the analyzed end-to-end simulations of the ground- and space-based strategies in order to investigate the orbit determination accuracy and its sensitivity which may result from different values for the frame-rate, pixel scale, astrometric and epoch registration accuracies. Two cases were simulated, a survey using a ground-based sensor to observe objects in LEO for surveillance applications, and a statistical survey with a space-based sensor orbiting in LEO observing small-size debris in LEO. The ground-based LEO survey uses a dynamical fence close to the Earth shadow a few hours after sunset. For the space-based scenario

  13. Observations on the reliability of COTS-device-based solid state data recorders operating in low-earth orbit

    International Nuclear Information System (INIS)

    Underwood, C.I.

    1999-01-01

    This paper presents the results of Surrey Space Centre's experience in using different coding schemes and hardware configurations to protect data and protect data and software stored in COTS-device (Commercial-Off-The-Shelf) based memories on-board operational spacecraft in low Earth orbit. (author)

  14. Active Debris Removal mission design in Low Earth Orbit

    Science.gov (United States)

    Martin, Th.; Pérot, E.; Desjean, M.-Ch.; Bitetti, L.

    2013-03-01

    Active Debris Removal (ADR) aims at removing large sized intact objects ― defunct satellites, rocket upper-stages ― from space crowded regions. Why? Because they constitute the main source of the long-term debris environment deterioration caused by possible future collisions with fragments and worse still with other intact but uncontrolled objects. In order to limit the growth of the orbital debris population in the future (referred to as the Kessler syndrome), it is now highly recommended to carry out such ADR missions, together with the mitigation measures already adopted by national agencies (such as postmission disposal). At the French Space Agency, CNES, and in the frame of advanced studies, the design of such an ADR mission in Low Earth Orbit (LEO) is under evaluation. A two-step preliminary approach has been envisaged. First, a reconnaissance mission based on a small demonstrator (˜500 kg) rendezvousing with several targets (observation and in-flight qualification testing). Secondly, an ADR mission based on a larger vehicle (inherited from the Orbital Transfer Vehicle (OTV) concept) being able to capture and deorbit several preselected targets by attaching a propulsive kit to these targets. This paper presents a flight dynamics level tradeoff analysis between different vehicle and mission concepts as well as target disposal options. The delta-velocity, times, and masses required to transfer, rendezvous with targets and deorbit are assessed for some propelled systems and propellant less options. Total mass budgets are then derived for two end-to-end study cases corresponding to the reconnaissance and ADR missions mentioned above.

  15. Preliminary results on the dynamics of large and flexible space structures in Halo orbits

    Science.gov (United States)

    Colagrossi, Andrea; Lavagna, Michèle

    2017-05-01

    The global exploration roadmap suggests, among other ambitious future space programmes, a possible manned outpost in lunar vicinity, to support surface operations and further astronaut training for longer and deeper space missions and transfers. In particular, a Lagrangian point orbit location - in the Earth- Moon system - is suggested for a manned cis-lunar infrastructure; proposal which opens an interesting field of study from the astrodynamics perspective. Literature offers a wide set of scientific research done on orbital dynamics under the Three-Body Problem modelling approach, while less of it includes the attitude dynamics modelling as well. However, whenever a large space structure (ISS-like) is considered, not only the coupled orbit-attitude dynamics should be modelled to run more accurate analyses, but the structural flexibility should be included too. The paper, starting from the well-known Circular Restricted Three-Body Problem formulation, presents some preliminary results obtained by adding a coupled orbit-attitude dynamical model and the effects due to the large structure flexibility. In addition, the most relevant perturbing phenomena, such as the Solar Radiation Pressure (SRP) and the fourth-body (Sun) gravity, are included in the model as well. A multi-body approach has been preferred to represent possible configurations of the large cis-lunar infrastructure: interconnected simple structural elements - such as beams, rods or lumped masses linked by springs - build up the space segment. To better investigate the relevance of the flexibility effects, the lumped parameters approach is compared with a distributed parameters semi-analytical technique. A sensitivity analysis of system dynamics, with respect to different configurations and mechanical properties of the extended structure, is also presented, in order to highlight drivers for the lunar outpost design. Furthermore, a case study for a large and flexible space structure in Halo orbits around

  16. Near Earth Architectural Options for a Future Deep Space Optical Communications Network

    Science.gov (United States)

    Edwards, B. L.; Liebrecht, P. E.; Fitzgerald, R. J.

    2004-01-01

    In the near future the National Aeronautics and Space Administration anticipates a significant increase in demand for long-haul communications services from deep space to Earth. Distances will range from 0.1 to 40 AU, with data rate requirements in the 1's to 1000's of Mbits/second. The near term demand is driven by NASA's Space Science Enterprise which wishes to deploy more capable instruments onboard spacecraft and increase the number of deep space missions. The long term demand is driven by missions with extreme communications challenges such as very high data rates from the outer planets, supporting sub-surface exploration, or supporting NASA's Human Exploration and Development of Space Enterprise beyond Earth orbit. Laser communications is a revolutionary communications technology that will dramatically increase NASA's ability to transmit information across the solar system. Lasercom sends information using beams of light and optical elements, such as telescopes and optical amplifiers, rather than RF signals, amplifiers, and antennas. This paper provides an overview of different network options at Earth to meet NASA's deep space lasercom requirements. It is based mainly on work done for the Mars Laser Communications Demonstration Project, a joint project between NASA's Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory, California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL). It reports preliminary conclusions from the Mars Lasercom Study conducted at MIT/LL and on additional work done for the Tracking and Data Relay Satellite System Continuation Study at GSFC. A lasercom flight terminal will be flown on the Mars Telesat Orbiter (MTO) to be launched by NASA in 2009, and will be the first high rate deep space demonstration of this revolutionary technology.

  17. Adaptive optics correction into single mode fiber for a low Earth orbiting space to ground optical communication link using the OPALS downlink.

    Science.gov (United States)

    Wright, Malcolm W; Morris, Jeffery F; Kovalik, Joseph M; Andrews, Kenneth S; Abrahamson, Matthew J; Biswas, Abhijit

    2015-12-28

    An adaptive optics (AO) testbed was integrated to the Optical PAyload for Lasercomm Science (OPALS) ground station telescope at the Optical Communications Telescope Laboratory (OCTL) as part of the free space laser communications experiment with the flight system on board the International Space Station (ISS). Atmospheric turbulence induced aberrations on the optical downlink were adaptively corrected during an overflight of the ISS so that the transmitted laser signal could be efficiently coupled into a single mode fiber continuously. A stable output Strehl ratio of around 0.6 was demonstrated along with the recovery of a 50 Mbps encoded high definition (HD) video transmission from the ISS at the output of the single mode fiber. This proof of concept demonstration validates multi-Gbps optical downlinks from fast slewing low-Earth orbiting (LEO) spacecraft to ground assets in a manner that potentially allows seamless space to ground connectivity for future high data-rates network.

  18. Fuel Optimization for Low Earth Orbit Maintenance

    Directory of Open Access Journals (Sweden)

    Yong Jae Park

    2008-06-01

    Full Text Available The resolution of Earth images taken from a satellite has close relation with satellite's altitude. If a satellite has lower altitude, it gets a picture having better resolution. However the satellite will be exposed to heavier air drag and will spend more fuel to maintain its altitude for a desired mission. Therefore, in this study, the required fuel to maintain very low earth orbit(LEO with severe air drag is analyzed using optimization method such as collocation method. The required fuel to maintain the low altitude has significantly increased as the mission altitude is lowered and the solar activity is maximized. This study also shows that the fuel reduced by increasing the period of the satellite maneuver is very small, and that slightly increasing the satellite's mission altitude is much effective in reducing the amount of fuel to maintain its altitude. The calculated fuel to maintain very low earth orbit in this study would give useful information in planning the budget of fuel and cost for LEO satellites.

  19. Status of High Data Rate Intersatellite Laser Communication as an Enabler for Earth and Space Science

    Science.gov (United States)

    Heine, F.; Zech, H.; Motzigemba, M.

    2017-12-01

    Space based laser communication is supporting earth observation and science missions with Gbps data download capabilities. Currently the Sentinel 1 and Sentinel 2 spacecrafts from the Copernicus earth observation program of the European Commission are using the Gbps laser communication links developed by Tesat Spacecom to download low latency data products via a commercial geostationary laser relay station- the European Data Relay Service- (EDRS) as a standard data path, in parallel to the conventional radio frequency links. The paper reports on the status of high bandwidth space laser communication as an enabler for small and large space science missions ranging from cube sat applications in low earth orbit to deep space missions. Space based laser communication has left the experimental phase and will support space science missions with unprecedented data rates.

  20. Mass, Energy, Space And Time System Theory---MEST A way to help our earth

    Science.gov (United States)

    Cao, Dayong

    2009-03-01

    There are two danger to our earth. The first, the sun will expand to devour our earth, for example, the ozonosphere of our earth is be broken; The second, the asteroid will impact near our earth. According to MEST, there is a interaction between Black hole (and Dark matter-energy) and Solar system. The orbit of Jupiter is a boundary of the interaction between Black hole (and Dark matter-energy) and Solar system. Because there are four terrestrial planets which is mass-energy center as solar system, and there are four or five Jovian planets which is gas (space-time) center as black hole system. According to MEST, dark matter-energy take the velocity of Jupiter gose up. So there are a lot of asteroids and dark matter-energy near the orbit of Jupiter-the boundary. Dark matter-energy can change the orbit of asteroid, and take it impacted near our earth. Because the Dark matter-energy will pressure the Solar system. It is a inverse process with sun's expandedness. So the ``two danger'' is from a new process of the balance system between Black hole (and Dark matter-energy) and Solar system. According to MEST, We need to find the right point for our earth in the ``new process of the balance system.''

  1. Environmental Durability Issues for Solar Power Systems in Low Earth Orbit

    Science.gov (United States)

    Degroh, Kim K.; Banks, Bruce A.; Smith, Daniela C.

    1994-01-01

    Space solar power systems for use in the low Earth orbit (LEO) environment experience a variety of harsh environmental conditions. Materials used for solar power generation in LEO need to be durable to environmental threats such as atomic oxygen, ultraviolet (UV) radiation, thermal cycling, and micrometeoroid and debris impact. Another threat to LEO solar power performance is due to contamination from other spacecraft components. This paper gives an overview of these LEO environmental issues as they relate to space solar power system materials. Issues addressed include atomic oxygen erosion of organic materials, atomic oxygen undercutting of protective coatings, UV darkening of ceramics, UV embrittlement of Teflon, effects of thermal cycling on organic composites, and contamination due to silicone and organic materials. Specific examples of samples from the Long Duration Exposure Facility (LDEF) and materials returned from the first servicing mission of the Hubble Space Telescope (HST) are presented. Issues concerning ground laboratory facilities which simulate the LEO environment are discussed along with ground-to-space correlation issues.

  2. Econometric comparisons of liquid rocket engines for dual-fuel advanced earth-to-orbit shuttles

    Science.gov (United States)

    Martin, J. A.

    1978-01-01

    Econometric analyses of advanced Earth-to-orbit vehicles indicate that there are economic benefits from development of new vehicles beyond the space shuttle as traffic increases. Vehicle studies indicate the advantage of the dual-fuel propulsion in single-stage vehicles. This paper shows the economic effect of incorporating dual-fuel propulsion in advanced vehicles. Several dual-fuel propulsion systems are compared to a baseline hydrogen and oxygen system.

  3. Comet/Asteroid Protection System (CAPS): A Space-Based System Concept for Revolutionizing Earth Protection and Utilization of Near-Earth Objects

    Science.gov (United States)

    Mazanek, Daniel D.; Roithmayr, Carlos M.; Antol, Jeffrey; Kay-Bunnell, Linda; Werner, Martin R.; Park, Sang-Young; Kumar, Renjith R.

    2002-01-01

    There exists an infrequent, but significant hazard to life and property due to impacting asteroids and comets. There is currently no specific search for long-period comets, smaller near-Earth asteroids, or smaller short-period comets. These objects represent a threat with potentially little or no warning time using conventional ground-based telescopes. These planetary bodies also represent a significant resource for commercial exploitation, long-term sustained space exploration, and scientific research. The Comet/Asteroid Protection System (CAPS) would expand the current detection effort to include long-period comets, as well as small asteroids and short-period comets capable of regional destruction. A space-based detection system, despite being more costly and complex than Earth-based initiatives, is the most promising way of expanding the range of detectable objects, and surveying the entire celestial sky on a regular basis. CAPS is a future spacebased system concept that provides permanent, continuous asteroid and comet monitoring, and rapid, controlled modification of the orbital trajectories of selected bodies. CAPS would provide an orbit modification system capable of diverting kilometer class objects, and modifying the orbits of smaller asteroids for impact defense and resource utilization. This paper provides a summary of CAPS and discusses several key areas and technologies that are being investigated.

  4. Acquisition/expulsion system for earth orbital propulsion system study. Volume 1: Summary report. [cryogenic storage and fuel flow regulation system for space shuttle orbiter

    Science.gov (United States)

    1973-01-01

    Design, construction, and quality control tests on a dual screen liner device for the space shuttle orbiter cryogenic fuel tank and feedliner system are summarized. The dual stainless steel mesh of the device encloses eight liquid fuel channels and provides the liquid/vapor interface stability required for low gravity orbits.

  5. A Reflight of the Explorer-1 Science Mission: The Montana EaRth Orbiting Pico Explorer (MEROPE)

    Science.gov (United States)

    Klumpar, D. M.; Obland, M.; Hunyadi, G.; Jepsen, S.; Larsen, B.; Kankelborg, C.; Hiscock, W.

    2001-05-01

    Montana State University's interdisciplinary Space Science and Engineering Laboratory (SSEL) under support from the Montana NASA Space Grant Consortium is engaged in an earth orbiting satellite student design and flight project. The Montana EaRth Orbiting Pico Explorer (MEROPE) will carry a modern-day reproduction of the scientific payload carried on Explorer-1. On February 1, 1958 the United States launched its first earth orbiting satellite carrying a 14 kg scientific experiment built by Professor James Van Allen's group at the State University of Iowa (now The University of Iowa). The MEROPE student satellite will carry a reproduction, using current-day technology, of the scientific payload flown on Explorer-1. The CubeSat-class satellite will use currently available, low cost technologies to produce a payload-carrying satellite with a total orbital mass of 1 kg in a volume of 1 cubic liter. The satellite is to be launched in late 2001 into a 600 km, 65° inclination orbit. MEROPE will utilize passive magnetic orientation for 2-axis attitude control. A central microprocessor provides timing, controls on-board operations and switching, and enables data storage. Body mounted GaAs solar arrays are expected to provide in excess of 1.5 W. to maintain battery charge and operate the bus and payload. The Geiger counter will be operated at approximately 50% duty cycle, primarily during transits of the earth's radiation belts. Data will be stored on board and transmitted approximately twice per day to a ground station located on the Bozeman campus of the Montana State University. Owing to the 65° inclination, the instrument will also detect the higher energy portion of the electron spectrum responsible for the production of the Aurora Borealis. This paper describes both the technical implementation and design of the satellite and its payload as well as the not inconsiderable task of large team organization and management. As of March 2001, the student team consists of

  6. Simulation of Micron-Sized Debris Populations in Low Earth Orbit

    Science.gov (United States)

    Xu, Y.-L.; Matney, M.; Liou, J.-C.; Hyde, J. L.; Prior, T. G.

    2010-01-01

    The update of ORDEM2000, the NASA Orbital Debris Engineering Model, to its new version . ORDEM2010, is nearly complete. As a part of the ORDEM upgrade, this paper addresses the simulation of micro-debris (greater than 10 micron and smaller than 1 mm in size) populations in low Earth orbit. The principal data used in the modeling of the micron-sized debris populations are in-situ hypervelocity impact records, accumulated in post-flight damage surveys on the space-exposed surfaces of returned spacecrafts. The development of the micro-debris model populations follows the general approach to deriving other ORDEM2010-required input populations for various components and types of debris. This paper describes the key elements and major steps in the statistical inference of the ORDEM2010 micro-debris populations. A crucial step is the construction of a degradation/ejecta source model to provide prior information on the micron-sized objects (such as orbital and object-size distributions). Another critical step is to link model populations with data, which is rather involved. It demands detailed information on area-time/directionality for all the space-exposed elements of a shuttle orbiter and damage laws, which relate impact damage with the physical properties of a projectile and impact conditions such as impact angle and velocity. Also needed are model-predicted debris fluxes as a function of object size and impact velocity from all possible directions. In spite of the very limited quantity of the available shuttle impact data, the population-derivation process is satisfactorily stable. Final modeling results obtained from shuttle window and radiator impact data are reasonably convergent and consistent, especially for the debris populations with object-size thresholds at 10 and 100 micron.

  7. Size Dependence of Dust Distribution around the Earth Orbit

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Takahiro; Takeuchi, Taku [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo, 152-8551 (Japan); Kobayashi, Hiroshi; Ishihara, Daisuke; Kondo, Toru; Kaneda, Hidehiro, E-mail: t.ueda@geo.titech.ac.jp [Graduate School of Science, Nagoya University, Nagoya, Aichi, 464-8602 (Japan)

    2017-05-01

    In the solar system, interplanetary dust particles (IDPs) originating mainly from asteroid collisions and cometary activities drift to Earth orbit due to Poynting–Robertson drag. We analyzed the thermal emission from IDPs that was observed by the first Japanese infrared astronomical satellite, AKARI . The observed surface brightness in the trailing direction of the Earth orbit is 3.7% greater than that in the leading direction in the 9 μ m band and 3.0% in the 18 μ m band. In order to reveal dust properties causing leading–trailing surface brightness asymmetry, we numerically integrated orbits of the Sun, the Earth, and a dust particle as a restricted three-body problem including radiation from the Sun. The initial orbits of particles are determined according to the orbits of main-belt asteroids or Jupiter-family comets. Orbital trapping in mean motion resonances results in a significant leading–trailing asymmetry so that intermediate sized dust (∼10–100 μ m) produces a greater asymmetry than zodiacal light. The leading–trailing surface brightness difference integrated over the size distribution of the asteroidal dust is obtained to be 27.7% and 25.3% in the 9 μ m and 18 μ m bands, respectively. In contrast, the brightness difference for cometary dust is calculated as 3.6% and 3.1% in the 9 μ m and 18 μ m bands, respectively, if the maximum dust radius is set to be s {sub max} = 3000 μ m. Taking into account these values and their errors, we conclude that the contribution of asteroidal dust to the zodiacal infrared emission is less than ∼10%, while cometary dust of the order of 1 mm mainly accounts for the zodiacal light in infrared.

  8. Size Dependence of Dust Distribution around the Earth Orbit

    International Nuclear Information System (INIS)

    Ueda, Takahiro; Takeuchi, Taku; Kobayashi, Hiroshi; Ishihara, Daisuke; Kondo, Toru; Kaneda, Hidehiro

    2017-01-01

    In the solar system, interplanetary dust particles (IDPs) originating mainly from asteroid collisions and cometary activities drift to Earth orbit due to Poynting–Robertson drag. We analyzed the thermal emission from IDPs that was observed by the first Japanese infrared astronomical satellite, AKARI . The observed surface brightness in the trailing direction of the Earth orbit is 3.7% greater than that in the leading direction in the 9 μ m band and 3.0% in the 18 μ m band. In order to reveal dust properties causing leading–trailing surface brightness asymmetry, we numerically integrated orbits of the Sun, the Earth, and a dust particle as a restricted three-body problem including radiation from the Sun. The initial orbits of particles are determined according to the orbits of main-belt asteroids or Jupiter-family comets. Orbital trapping in mean motion resonances results in a significant leading–trailing asymmetry so that intermediate sized dust (∼10–100 μ m) produces a greater asymmetry than zodiacal light. The leading–trailing surface brightness difference integrated over the size distribution of the asteroidal dust is obtained to be 27.7% and 25.3% in the 9 μ m and 18 μ m bands, respectively. In contrast, the brightness difference for cometary dust is calculated as 3.6% and 3.1% in the 9 μ m and 18 μ m bands, respectively, if the maximum dust radius is set to be s max  = 3000 μ m. Taking into account these values and their errors, we conclude that the contribution of asteroidal dust to the zodiacal infrared emission is less than ∼10%, while cometary dust of the order of 1 mm mainly accounts for the zodiacal light in infrared.

  9. Dynamical analysis of rendezvous and docking with very large space infrastructures in non-Keplerian orbits

    Science.gov (United States)

    Colagrossi, Andrea; Lavagna, Michèle

    2018-03-01

    A space station in the vicinity of the Moon can be exploited as a gateway for future human and robotic exploration of the solar system. The natural location for a space system of this kind is about one of the Earth-Moon libration points. The study addresses the dynamics during rendezvous and docking operations with a very large space infrastructure in an EML2 Halo orbit. The model takes into account the coupling effects between the orbital and the attitude motion in a circular restricted three-body problem environment. The flexibility of the system is included, and the interaction between the modes of the structure and those related with the orbital motion is investigated. A lumped parameter technique is used to represents the flexible dynamics. The parameters of the space station are maintained as generic as possible, in a way to delineate a global scenario of the mission. However, the developed model can be tuned and updated according to the information that will be available in the future, when the whole system will be defined with a higher level of precision.

  10. The NASA GOLD Mission: Exploring the Interface between Earth and Space

    Science.gov (United States)

    Mason, T.; Costanza, B.

    2017-12-01

    NASA's Global-scale Observations of the Limb and Disk, or GOLD, mission will explore a little understood area close to home, but historically hard to observe: the interface between Earth and space, a dynamic area of near-Earth space that responds both to space weather above, and the lower atmosphere below. GOLD, scheduled to launch into geostationary orbit in early 2018, will collect observations with a 30-minute cadence, much higher than any mission that has come before it. This will enable GOLD to be the first mission to study the day-to-day weather of a region of space—the thermosphere and ionosphere—rather than its long-term climate. GOLD will explore the near-Earth space environment, which is home to astronauts, radio signals used to guide airplanes and ships, and satellites that provide our communications and GPS systems. GOLD's unprecedented images and data will enable research that can improve situational awareness to help protect astronauts, spacecraft, and humans on the ground. As part of the GOLD communications and outreach program, the Office of Communications & Outreach at the Laboratory for Atmospheric and Space Physics (LASP) is developing a suite of products and programs to introduce the science of the GOLD mission to a broad range of public audiences, including students, teachers, journalists, social media practitioners, and the wider planetary and Earth science communities. We plan to showcase with this poster some of the tools we are developing to achieve this goal.

  11. Thermal Orbital Environmental Parameter Study on the Propulsive Small Expendable Deployer System (ProSEDS) Using Earth Radiation Budget Experiment (ERBE) Data

    Science.gov (United States)

    Sharp, John R.; McConnaughey, Paul K. (Technical Monitor)

    2002-01-01

    The natural thermal environmental parameters used on the Space Station Program (SSP 30425) were generated by the Space Environmental Effects Branch at NASA's Marshall Space Flight Center (MSFC) utilizing extensive data from the Earth Radiation Budget Experiment (ERBE), a series of satellites which measured low earth orbit (LEO) albedo and outgoing long-wave radiation. Later, this temporal data was presented as a function of averaging times and orbital inclination for use by thermal engineers in NASA Technical Memorandum TM 4527. The data was not presented in a fashion readily usable by thermal engineering modeling tools and required knowledge of the thermal time constants and infrared versus solar spectrum sensitivity of the hardware being analyzed to be used properly. Another TM was recently issued as a guideline for utilizing these environments (NASA/TM-2001-211221) with more insight into the utilization by thermal analysts. This paper gives a top-level overview of the environmental parameters presented in the TM and a study of the effects of implementing these environments on an ongoing MSFC project, the Propulsive Small Expendable Deployer System (ProSEDS), compared to conventional orbital parameters that had been historically used.

  12. The Effect of Air Drag in Optimal Power-Limited Rendezvous Between Coplanar Low-Earth Orbits

    Directory of Open Access Journals (Sweden)

    Gil-Young Maeng

    1998-06-01

    Full Text Available The effect of air drag was researched when a low-earth orbit spacecraft using power-limited thruster rendezvoused another low-earth orbit spacecraft. The air density was assumed to decrease exponentially. The radius of parking orbit was 6655.935 km and that of target orbit was 7321.529 km. From the trajectories of active vehicles, the fuel consumption and the magnitude of thrust acceleration, we could conclude that the effect of air drag had to be considered in fuel optimal rendezvous problem between low-earth orbit spacecrafts. In multiple-revolution rendezvous case, the air drag was more effective.

  13. Angles-only relative orbit determination in low earth orbit

    Science.gov (United States)

    Ardaens, Jean-Sébastien; Gaias, Gabriella

    2018-06-01

    The paper provides an overview of the angles-only relative orbit determination activities conducted to support the Autonomous Vision Approach Navigation and Target Identification (AVANTI) experiment. This in-orbit endeavor was carried out by the German Space Operations Center (DLR/GSOC) in autumn 2016 to demonstrate the capability to perform spaceborne autonomous close-proximity operations using solely line-of-sight measurements. The images collected onboard have been reprocessed by an independent on-ground facility for precise relative orbit determination, which served as ultimate instance to monitor the formation safety and to characterize the onboard navigation and control performances. During two months, several rendezvous have been executed, generating a valuable collection of images taken at distances ranging from 50 km to only 50 m. Despite challenging experimental conditions characterized by a poor visibility and strong orbit perturbations, angles-only relative positioning products could be continuously derived throughout the whole experiment timeline, promising accuracy at the meter level during the close approaches. The results presented in the paper are complemented with former angles-only experience gained with the PRISMA satellites to better highlight the specificities induced by different orbits and satellite designs.

  14. Global optimum spacecraft orbit control subject to bounded thrust in presence of nonlinear and random disturbances in a low earth orbit

    Directory of Open Access Journals (Sweden)

    Tamer Mekky Ahmed Habib

    2012-06-01

    Full Text Available The primary objective of this work is to develop an effective spacecraft orbit control algorithm suitable for spacecraft orbital maneuver and/or rendezvous. The actual governing equation of a spacecraft orbiting the earth is merely nonlinear. Disturbance forces resulting from aerodynamic drag, oblateness of the earth till the fourth order (i.e. J4, and random disturbances are modeled for the initial and target orbits. These disturbances increase the complexity of nonlinear governing equations. Global optimum solutions of the control algorithm parameters are determined throughout real coded genetic algorithms such that the steady state difference between the actual and desired trajectories is minimized. The resulting solutions are constrained to avoid spacecraft collision with the surface of the earth taking into account limited thrust budget.

  15. Astrometric detectability of systems with unseen companions: effects of the Earth orbital motion

    Science.gov (United States)

    Butkevich, Alexey G.

    2018-06-01

    The astrometric detection of an unseen companion is based on an analysis of the apparent motion of its host star around the system's barycentre. Systems with an orbital period close to 1 yr may escape detection if the orbital motion of their host stars is observationally indistinguishable from the effects of parallax. Additionally, an astrometric solution may produce a biased parallax estimation for such systems. We examine the effects of the orbital motion of the Earth on astrometric detectability in terms of a correlation between the Earth's orbital position and the position of the star relative to its system barycentre. The χ2 statistic for parallax estimation is calculated analytically, leading to expressions that relate the decrease in detectability and accompanying parallax bias to the position correlation function. The impact of the Earth's motion critically depends on the exoplanet's orbital period, diminishing rapidly as the period deviates from 1 yr. Selection effects against 1-yr-period systems is, therefore, expected. Statistical estimation shows that the corresponding loss of sensitivity results in a typical 10 per cent increase in the detection threshold. Consideration of eccentric orbits shows that the Earth's motion has no effect on detectability for e≳ 0.5. The dependence of the detectability on other parameters, such as orbital phases and inclination of the orbital plane to the ecliptic, are smooth and monotonic because they are described by simple trigonometric functions.

  16. Space augmentation of military high-level waste disposal

    International Nuclear Information System (INIS)

    English, T.; Lees, L.; Divita, E.

    1979-01-01

    Space disposal of selected components of military high-level waste (HLW) is considered. This disposal option offers the promise of eliminating the long-lived radionuclides in military HLW from the earth. A space mission which meets the dual requirements of long-term orbital stability and a maximum of one space shuttle launch per week over a period of 20-40 years, is a heliocentric orbit about halfway between the orbits of earth and Venus. Space disposal of high-level radioactive waste is characterized by long-term predicability and short-term uncertainties which must be reduced to acceptably low levels. For example, failure of either the Orbit Transfer Vehicle after leaving low earth orbit, or the storable propellant stage failure at perihelion would leave the nuclear waste package in an unplanned and potentially unstable orbit. Since potential earth reencounter and subsequent burn-up in the earth's atmosphere is unacceptable, a deep space rendezvous, docking, and retrieval capability must be developed

  17. Plasma flow measurements in a simulated low earth orbit plasma

    International Nuclear Information System (INIS)

    Gabriel, S.B.; Mccoy, J.E.; Carruth, M.R. Jr.

    1982-01-01

    The employment of large, higher power solar arrays for space operation has been considered, taking into account a utilization of high operating voltages. In connection with the consideration of such arrays, attention must be given to the fact that the ambient environment of space contains a tenuous low energy plasma which can interact with the high voltage array causing power 'leakage' and arcing. An investigation has been conducted with the aim to simulate the behavior of such an array in low-earth-orbit (LEO). During the experiments, local concentrations of the 'leakage' current were observed when the panel was at a high voltage. These concentrations could overload or damage a small area of cells in a large string. It was hypothesized that this effect was produced by electrostatic focusing of the particles by the sheath fields. To verify this experimentally, an end-effect Langmuir probe was employed. The obtained results are discussed

  18. The Earth System Science Pathfinder Orbiting Carbon Observatory (OCO) Mission

    Science.gov (United States)

    Crisp, David

    2003-01-01

    A viewgraph presentation describing the Earth System Science Pathfinder Orbiting Carbon Observatory (OCO) Mission is shown. The contents include: 1) Why CO2?; 2) What Processes Control CO2 Sinks?; 3) OCO Science Team; 4) Space-Based Measurements of CO2; 5) Driving Requirement: Precise, Bias-Free Global Measurements; 6) Making Precise CO2 Measurements from Space; 7) OCO Spatial Sampling Strategy; 8) OCO Observing Modes; 9) Implementation Approach; 10) The OCO Instrument; 11) The OCO Spacecraft; 12) OCO Will Fly in the A-Train; 13) Validation Program Ensures Accuracy and Minimizes Spatially Coherent Biases; 14) Can OCO Provide the Required Precision?; 15) O2 Column Retrievals with Ground-based FTS; 16) X(sub CO2) Retrieval Simulations; 17) Impact of Albedo and Aerosol Uncertainty on X(sub CO2) Retrievals; 18) Carbon Cycle Modeling Studies: Seasonal Cycle; 19) Carbon Cycle Modeling Studies: The North-South Gradient in CO2; 20) Carbon Cycle Modeling Studies: Effect of Diurnal Biases; 21) Project Status and Schedule; and 22) Summary.

  19. The magnetic field of the earth - Performance considerations for space-based observing systems

    Science.gov (United States)

    Webster, W. J., Jr.; Taylor, P. T.; Schnetzler, C. C.; Langel, R. A.

    1985-01-01

    Basic problems inherent in carrying out observations of the earth magnetic field from space are reviewed. It is shown that while useful observations of the core and crustal fields are possible at the peak of the solar cycle, the greatest useful data volume is obtained during solar minimum. During the last three solar cycles, the proportion of data with a planetary disturbance index of less than 2 at solar maximum was in the range 0.4-0.8 in comparison with solar minimum. It is found that current state of the art orbit determination techniques should eliminate orbit error as a problem in gravitational field measurements from space. The spatial resolution obtained for crustal field anomalies during the major satellite observation programs of the last 30 years are compared in a table. The relationship between observing altitude and the spatial resolution of magnetic field structures is discussed. Reference is made to data obtained using the Magsat, the Polar Orbiting Geophysical Observatory (POGO), and instruments on board the Space Shuttle.

  20. Space-based pseudo-fixed latitude observation mode based on the characteristics of geosynchronous orbit belt

    Science.gov (United States)

    Hu, Yun-peng; Chen, Lei; Huang, Jian-yu

    2017-08-01

    The US Lincoln Laboratory proved that space-based visible (SBV) observation is efficient to observe space objects, especially Geosynchronous Orbit (GEO) objects. After that, SBV observation plays an important role in the space surveillance. In this paper, a novel space-based observation mode is designed to observe all the GEO objects in a relatively short time. A low earth orbit (LEO) satellite, especially a dawn-dusk sun-synchronous orbit satellite, is useful for space-based observation. Thus, the observation mode for GEO objects is based on a dawn-dusk sun-synchronous orbit satellite. It is found that the Pinch Point (PP) regions proposed by the US Lincoln Laboratory are spreading based on the analysis of the evolution principles of GEO objects. As the PP regions becoming more and more widely in the future, many strategies based on it may not be efficient any more. Hence, the key point of the space-based observation strategy design for GEO objects should be emphasized on the whole GEO belt as far as possible. The pseudo-fixed latitude observation mode is proposed in this paper based on the characteristics of GEO belt. Unlike classical space-based observation modes, pseudo-fixed latitude observation mode makes use of the one-dimensional attitude adjustment of the observation satellite. The pseudo-fixed latitude observation mode is more reliable and simple in engineering, compared with the gazing observation mode which needs to adjust the attitude from the two dimensions. It includes two types of attitude adjustment, i.e. daily and continuous attitude adjustment. Therefore, the pseudo-fixed latitude observation mode has two characteristics. In a day, the latitude of the observation region is fixed and the scanning region is about a rectangle, while the latitude of the observation region centre changes each day in a long term based on a daily strategy. The capabilities of a pseudo-fixed latitude observation instrument with a 98° dawn-dusk sun-synchronous orbit are

  1. On the lunar node resonance of the orbital plane evolution of the Earth's satellite orbits

    Science.gov (United States)

    Zhu, Ting-Lei

    2018-06-01

    This paper aims to investigate the effects of lunar node resonance on the circular medium Earth orbits (MEO). The dynamical model is established in classical Hamiltonian systems with the application of Lie transform to remove the non-resonant terms. Resonant condition, stability and phase structures are studied. The lunar node resonance occurs when the secular changing rates of the orbital node (with respect to the equator) and the lunar node (with respect to the ecliptic) form a simple integer ratio. The resonant conditions are satisfied for both inclined and equatorial orbits. The orbital plane would have long period (with typical timescales of several centuries) fluctuation due to the resonance.

  2. Migration of Trans-Neptunian Objects to a Near-Earth Space

    Science.gov (United States)

    Ipatov, S. I.; Mather, J. C.; Oegerle, William (Technical Monitor)

    2002-01-01

    Our estimates of the migration of trans-Neptunian objects (TNOs) to a near-Earth space are based on the results of investigations of orbital evolution of TNOs and Jupiter-crossing objects (JCOs). The orbital evolution of TNOs was considered in many papers. Recently we investigated the evolution for intervals of at least 5-10 Myr of 2500 JCOs under the gravitational influence of all planets, except for Mercury and Pluto (without dissipative factors). In the first series we considered N=2000 orbits near the orbits of 30 real Jupiter-family comets with period P(sub alpha)less than 10 yr, and in the second series we took N=500 orbits close to the orbit of Comet 10P Tempel 2 (alpha=3.1 AU, e=0.53, i=12 deg). We calculated the probabilities of collisions of objects with the terrestrial planets, using orbital elements obtained with a step equal to 500 yr, and then summarized the results for all time intervals and all bodies, obtaining the total probability P(sub sigma) of collisions with a planet and the total time interval T(sub sigma) during which perihelion distance q of bodies was less than a semimajor axis of the planet.

  3. International Space Station Nickel-Hydrogen Battery On-Orbit Performance

    Science.gov (United States)

    Dalton, Penni; Cohen, Fred

    2002-01-01

    International Space Station (ISS) Electric Power System (EPS) utilizes Nickel-Hydrogen (Ni-H2) batteries as part of its power system to store electrical energy. The batteries are charged during insolation and discharged during eclipse. The batteries are designed to operate at a 35 percent depth of discharge (DOD) maximum during normal operation. Thirty-eight individual pressure vessel (IPV) Ni-H2 battery cells are series-connected and packaged in an Orbital Replacement Unit (ORU). Two ORUs are series-connected utilizing a total of 76 cells to form one battery. The ISS is the first application for low earth orbit (LEO) cycling of this quantity of series-connected cells. The P6 (Port) Integrated Equipment Assembly (IEA) containing the initial ISS high-power components was successfully launched on November 30, 2000. The IEA contains 12 Battery Subassembly ORUs (6 batteries) that provide station power during eclipse periods. This paper will discuss the battery performance data after eighteen months of cycling.

  4. NASA's Evolution to K(sub a)- Band Space Communications for Near-Earth Spacecraft

    Science.gov (United States)

    McCarthy, Kevin P.; Stocklin, Frank J.; Geldzahler, Barry J.; Friedman, Daniel E.; Celeste, Peter B.

    2010-01-01

    Over the next several years, NASA plans to launch multiple earth-science missions which will send data from low-Earth orbits to ground stations at 1-3 Gbps, to achieve data throughputs of 5-40 terabits per day. These transmission rates exceed the capabilities of S-band and X-band frequency allocations used for science probe downlinks in the past. Accordingly, NASA is exploring enhancements to its space communication capabilities to provide the Agency's first Ka-band architecture solution for next generation missions in the near-earth regime. This paper describes the proposed Ka-band solution's drivers and concept, constraints and analyses which shaped that concept, and expansibility for future needs

  5. Solar radiation pressure application for orbital motion stabilization near the Sun-Earth collinear libration point

    Science.gov (United States)

    Polyakhova, Elena; Shmyrov, Alexander; Shmyrov, Vasily

    2018-05-01

    Orbital maneuvering in a neighborhood of the collinear libration point L1 of Sun-Earth system has specific properties, primarily associated with the instability L1. For a long stay in this area of space the stabilization problem of orbital motion requires a solution. Numerical experiments have shown that for stabilization of motion it is requires very small control influence in comparison with the gravitational forces. On the other hand, the stabilization time is quite long - months, and possibly years. This makes it highly desirable to use solar pressure forces. In this paper we illustrate the solar sail possibilities for solving of stabilization problem in a neighborhood L1 with use of the model example.

  6. UV SURFACE ENVIRONMENT OF EARTH-LIKE PLANETS ORBITING FGKM STARS THROUGH GEOLOGICAL EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Rugheimer, S.; Sasselov, D. [Harvard Smithsonian Center for Astrophysics, 60 Garden st., 02138 MA Cambridge (United States); Segura, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México (Mexico); Kaltenegger, L., E-mail: srugheimer@cfa.harvard.edu [Carl Sagan Institute, Cornell University, Ithaca, NY 14853 (United States)

    2015-06-10

    The UV environment of a host star affects the photochemistry in the atmosphere, and ultimately the surface UV environment for terrestrial planets and therefore the conditions for the origin and evolution of life. We model the surface UV radiation environment for Earth-sized planets orbiting FGKM stars in the circumstellar Habitable Zone for Earth through its geological evolution. We explore four different types of atmospheres corresponding to an early-Earth atmosphere at 3.9 Gyr ago and three atmospheres covering the rise of oxygen to present-day levels at 2.0 Gyr ago, 0.8 Gyr ago, and modern Earth. In addition to calculating the UV flux on the surface of the planet, we model the biologically effective irradiance, using DNA damage as a proxy for biological damage. We find that a pre-biotic Earth (3.9 Gyr ago) orbiting an F0V star receives 6 times the biologically effective radiation as around the early Sun and 3520 times the modern Earth–Sun levels. A pre-biotic Earth orbiting GJ 581 (M3.5 V) receives 300 times less biologically effective radiation, about 2 times modern Earth–Sun levels. The UV fluxes calculated here provide a grid of model UV environments during the evolution of an Earth-like planet orbiting a range of stars. These models can be used as inputs into photo-biological experiments and for pre-biotic chemistry and early life evolution experiments.

  7. UV SURFACE ENVIRONMENT OF EARTH-LIKE PLANETS ORBITING FGKM STARS THROUGH GEOLOGICAL EVOLUTION

    International Nuclear Information System (INIS)

    Rugheimer, S.; Sasselov, D.; Segura, A.; Kaltenegger, L.

    2015-01-01

    The UV environment of a host star affects the photochemistry in the atmosphere, and ultimately the surface UV environment for terrestrial planets and therefore the conditions for the origin and evolution of life. We model the surface UV radiation environment for Earth-sized planets orbiting FGKM stars in the circumstellar Habitable Zone for Earth through its geological evolution. We explore four different types of atmospheres corresponding to an early-Earth atmosphere at 3.9 Gyr ago and three atmospheres covering the rise of oxygen to present-day levels at 2.0 Gyr ago, 0.8 Gyr ago, and modern Earth. In addition to calculating the UV flux on the surface of the planet, we model the biologically effective irradiance, using DNA damage as a proxy for biological damage. We find that a pre-biotic Earth (3.9 Gyr ago) orbiting an F0V star receives 6 times the biologically effective radiation as around the early Sun and 3520 times the modern Earth–Sun levels. A pre-biotic Earth orbiting GJ 581 (M3.5 V) receives 300 times less biologically effective radiation, about 2 times modern Earth–Sun levels. The UV fluxes calculated here provide a grid of model UV environments during the evolution of an Earth-like planet orbiting a range of stars. These models can be used as inputs into photo-biological experiments and for pre-biotic chemistry and early life evolution experiments

  8. Robotics in near-earth space

    Science.gov (United States)

    Card, Michael E.

    1991-01-01

    The areas of space exploration in which robotic devices will play a part are identified, and progress to date in the space agency plans to acquire this capability is briefly reviewed. Roles and functions on orbit for robotic devices include well known activities, such as inspection and maintenance, assembly, docking, berthing, deployment, retrieval, materials handling, orbital replacement unit exchange, and repairs. Missions that could benefit from a robotic capability are discussed.

  9. In-situ detection of micron-sized dust particles in near-Earth space

    Science.gov (United States)

    Gruen, E.; Zook, H. A.

    1985-01-01

    In situ detectors for micron sized dust particles based on the measurement of impact ionization have been flown on several space missions (Pioneer 8/9, HEOS-2 and Helios 1/2). Previous measurements of small dust particles in near-Earth space are reviewed. An instrument is proposed for the measurement of micron sized meteoroids and space debris such as solid rocket exhaust particles from on board an Earth orbiting satellite. The instrument will measure the mass, speed, flight direction and electrical charge of individually impacting debris and meteoritic particles. It is a multicoincidence detector of 1000 sq cm sensitive area and measures particle masses in the range from 10 to the -14th power g to 10 to the -8th power g at an impact speed of 10 km/s. The instrument is lightweight (5 kg), consumes little power (4 watts), and requires a data sampling rate of about 100 bits per second.

  10. THE OCCURRENCE RATE OF EARTH ANALOG PLANETS ORBITING SUN-LIKE STARS

    International Nuclear Information System (INIS)

    Catanzarite, Joseph; Shao, Michael

    2011-01-01

    Kepler is a space telescope that searches Sun-like stars for planets. Its major goal is to determine η Earth , the fraction of Sun-like stars that have planets like Earth. When a planet 'transits' or moves in front of a star, Kepler can measure the concomitant dimming of the starlight. From analysis of the first four months of those measurements for over 150,000 stars, Kepler's Science Team has determined sizes, surface temperatures, orbit sizes, and periods for over a thousand new planet candidates. In this paper, we characterize the period probability distribution function of the super-Earth and Neptune planet candidates with periods up to 132 days, and find three distinct period regimes. For candidates with periods below 3 days, the density increases sharply with increasing period; for periods between 3 and 30 days, the density rises more gradually with increasing period, and for periods longer than 30 days, the density drops gradually with increasing period. We estimate that 1%-3% of stars like the Sun are expected to have Earth analog planets, based on the Kepler data release of 2011 February. This estimate of η Earth is based on extrapolation from a fiducial subsample of the Kepler planet candidates that we chose to be nominally 'complete' (i.e., no missed detections) to the realm of the Earth-like planets, by means of simple power-law models. The accuracy of the extrapolation will improve as more data from the Kepler mission are folded in. Accurate knowledge of η Earth is essential for the planning of future missions that will image and take spectra of Earth-like planets. Our result that Earths are relatively scarce means that a substantial effort will be needed to identify suitable target stars prior to these future missions.

  11. Satellite laser ranging to low Earth orbiters: orbit and network validation

    Science.gov (United States)

    Arnold, Daniel; Montenbruck, Oliver; Hackel, Stefan; Sośnica, Krzysztof

    2018-04-01

    Satellite laser ranging (SLR) to low Earth orbiters (LEOs) provides optical distance measurements with mm-to-cm-level precision. SLR residuals, i.e., differences between measured and modeled ranges, serve as a common figure of merit for the quality assessment of orbits derived by radiometric tracking techniques. We discuss relevant processing standards for the modeling of SLR observations and highlight the importance of line-of-sight-dependent range corrections for the various types of laser retroreflector arrays. A 1-3 cm consistency of SLR observations and GPS-based precise orbits is demonstrated for a wide range of past and present LEO missions supported by the International Laser Ranging Service (ILRS). A parameter estimation approach is presented to investigate systematic orbit errors and it is shown that SLR validation of LEO satellites is not only able to detect radial but also along-track and cross-track offsets. SLR residual statistics clearly depend on the employed precise orbit determination technique (kinematic vs. reduced-dynamic, float vs. fixed ambiguities) but also reveal pronounced differences in the ILRS station performance. Using the residual-based parameter estimation approach, corrections to ILRS station coordinates, range biases, and timing offsets are derived. As a result, root-mean-square residuals of 5-10 mm have been achieved over a 1-year data arc in 2016 using observations from a subset of high-performance stations and ambiguity-fixed orbits of four LEO missions. As a final contribution, we demonstrate that SLR can not only validate single-satellite orbit solutions but also precise baseline solutions of formation flying missions such as GRACE, TanDEM-X, and Swarm.

  12. Magnus Effect on a Spinning Satellite in Low Earth Orbit

    Science.gov (United States)

    Ramjatan, Sahadeo; Fitz-Coy, Norman; Yew, Alvin Garwai

    2016-01-01

    A spinning body in a flow field generates an aerodynamic lift or Magnus effect that displaces the body in a direction normal to the freestream flow. Earth orbiting satellites with substantial body rotation in appreciable atmospheric densities may generate a Magnus force to perturb orbital dynamics. We investigate the feasibility of using this effect for spacecraft at a perigee of 80km using the Systems Tool Kit (STK). Results show that for a satellite of reasonable properties, the Magnus effect doubles the amount of time in orbit. Orbital decay was greatly mitigated for satellites spinning at 10000 and 15000RPM. This study demonstrates that the Magnus effect has the potential to sustain a spacecraft's orbit at a low perigee altitude and could also serve as an orbital maneuver capability.

  13. Orbital Debris and NASA's Measurement Program

    Science.gov (United States)

    Africano, J. L.; Stansbery, E. G.

    2002-05-01

    Since the launch of Sputnik in 1957, the number of manmade objects in orbit around the Earth has dramatically increased. The United States Space Surveillance Network (SSN) tracks and maintains orbits on over nine thousand objects down to a limiting diameter of about ten centimeters. Unfortunately, active spacecraft are only a small percentage ( ~ 7%) of this population. The rest of the population is orbital debris or ``space junk" consisting of expended rocket bodies, dead payloads, bits and pieces from satellite launches, and fragments from satellite breakups. The number of these smaller orbital debris objects increases rapidly with decreasing size. It is estimated that there are at least 130,000 orbital debris objects between one and ten centimeters in diameter. Most objects smaller than 10 centimeters go untracked! As the orbital debris population grows, the risk to other orbiting objects, most importantly manned space vehicles, of a collision with a piece of debris also grows. The kinetic energy of a solid 1 cm aluminum sphere traveling at an orbital velocity of 10 km/sec is equivalent to a 400 lb. safe traveling at 60 mph. Fortunately, the volume of space in which the orbiting population resides is large, collisions are infrequent, but they do occur. The Space Shuttle often returns to earth with its windshield pocked with small pits or craters caused by collisions with very small, sub-millimeter-size pieces of debris (paint flakes, particles from solid rocket exhaust, etc.), and micrometeoroids. To get a more complete picture of the orbital-debris environment, NASA has been using both radar and optical techniques to monitor the orbital debris environment. This paper gives an overview of the orbital debris environment and NASA's measurement program.

  14. GPS Based Reduced-Dynamic Orbit Determination for Low Earth Orbiters with Ambiguity Fixing

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2015-01-01

    Full Text Available With the ever-increasing number of satellites in Low Earth Orbit (LEO for scientific missions, the precise determination of the position and velocity of the satellite is a necessity. GPS (Global Positioning System based reduced-dynamic orbit determination (RPOD method is commonly used in the post processing with high precision. This paper presents a sequential RPOD strategy for LEO satellite in the framework of Extended Kalman Filter (EKF. Precise Point Positioning (PPP technique is used to process the GPS observations, with carrier phase ambiguity resolution using Integer Phase Clocks (IPCs products. A set of GRACE (Gravity Recovery And Climate Experiment mission data is used to test and validate the RPOD performance. Results indicate that orbit determination accuracy could be improved by 15% in terms of 3D RMS error in comparison with traditional RPOD method with float ambiguity solutions.

  15. 25th Space Simulation Conference. Environmental Testing: The Earth-Space Connection

    Science.gov (United States)

    Packard, Edward

    2008-01-01

    to Acquire, Process, Trend Data and Produce Radiometric System Assessment Reports; Exhaustive Thresholds and Resistance Checkpoints; Reconfigurable HIL Testing of Earth Satellites; FPGA Control System for the Automated Test of MicroShutters; Ongoing Capabilities and Developments of Re-Entry Plasma Ground Tests at EADS-ASTRIUM; Operationally Responsive Space Standard Bus Battery Thermal Balance Testing and Heat Dissipation Analysis; Galileo - The Serial-Production AIT Challenge; The Space Systems Environmental Test Facility Database (SSETFD), Website Development Status; Simulated Reentry Heating by Torching; Micro-Vibration Measurements on Thermally Loaded Multi-Layer Insulation Samples in Vacuum; High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suit Gas Processing System (GPS) Carbon Dioxide Scrubber; The Planning and Implementation of Test Facility Improvements; and Development of a Silicon Carbide Molecular Beam Nozzle for Simulation Planetary Flybys and Low-Earth Orbit.

  16. Wastes in space; Les dechets dans l'espace

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    As human space activities have created more wastes on low and high Earth orbits over the past 50 years than the solar system injected meteorites over billions of years, this report gives an overview of this problem. It identifies the origins of these space debris and wastes (launchers, combustion residues, exploitation wastes, out-of-use satellites, accidental explosions, accidental collisions, voluntary destructions, space erosion), and proposes a stock list of space wastes. Then, it distinguishes the situation for the different orbits: low Earth orbit or LEO (traffic, presence of the International Space Station), medium Earth orbits or MEO (traffic, operating satellites, wastes), geostationary Earth orbit or GEO (traffic, operating satellites, wastes). It also discusses wastes and bacteria present on the moon (due to Apollo missions or to crash tests). It evokes how space and nuclear industry is concerned, and discusses the re-entry issue (radioactive boomerang, metallic boomerang). It also indicates elements of international law

  17. EARTH FROM SPACE

    Indian Academy of Sciences (India)

    Table of contents. EARTH FROM SPACE · Slide 2 · Earth System · Slide 4 · Global water cycle · Slide 6 · Slide 7 · Direct Observations of Recent Climate Change · Slide 9 · Slide 10 · Snow cover and Arctic sea ice are decreasing · Polar Melting & Global Heat Transport · Antarctica: Melting and Thickening · Slide 14 · Slide 15.

  18. Orbital Noise in the Earth System and Climate Fluctuations

    Science.gov (United States)

    Liu, Han-Shou; Smith, David E. (Technical Monitor)

    2001-01-01

    Frequency noise in the variations of the Earth's obliquity (tilt) can modulate the insolation signal for climate change. Including this frequency noise effect on the incoming solar radiation, we have applied an energy balance climate model to calculate the climate fluctuations for the past one million years. Model simulation results are in good agreement with the geologically observed paleoclimate data. We conclude that orbital noise in the Earth system may be the major cause of the climate fluctuation cycles.

  19. Looking at the earth from space

    Science.gov (United States)

    Geller, Marvin A.

    1988-01-01

    Some of the scientific accomplishments attained in observing the earth from space are discussed. A brief overview of findings concerning the atmosphere, the oceans and sea ice, the solid earth, and the terrestrial hydrosphere and biosphere is presented, and six examples are examined in which space data have provided unique information enabling new knowledge concerning the workings of the earth to be derived. These examples concern stratospheric water vapor, hemispheric differences in surface and atmosphere parameters, Seasat altimeter mesoscale variability, variability of Antarctic sea ice, variations in the length of day, and spaceborne radar imaging of ancient rivers. Future space observations of the earth are briefly addressed.

  20. Dynamical evolution of space debris on high-elliptical orbits near high-order resonance zones

    Science.gov (United States)

    Kuznetsov, Eduard; Zakharova, Polina

    Orbital evolution of objects on Molniya-type orbits is considered near high-order resonance zones. Initial conditions correspond to high-elliptical orbits with the critical inclination 63.4 degrees. High-order resonances are analyzed. Resonance orders are more than 5 and less than 50. Frequencies of perturbations caused by the effect of sectorial and tesseral harmonics of the Earth's gravitational potential are linear combinations of the mean motion of a satellite, angular velocities of motion of the pericenter and node of its orbit, and the angular velocity of the Earth. Frequencies of perturbations were calculated by taking into account secular perturbations from the Earth oblateness, the Moon, the Sun, and a solar radiation pressure. Resonance splitting effect leads to three sub-resonances. The study of dynamical evolution on long time intervals was performed on the basis of the results of numerical simulation. We used "A Numerical Model of the Motion of Artificial Earth's Satellites", developed by the Research Institute of Applied Mathematics and Mechanics of the Tomsk State University. The model of disturbing forces taken into account the main perturbing factors: the gravitational field of the Earth, the attraction of the Moon and the Sun, the tides in the Earth’s body, the solar radiation pressure, taking into account the shadow of the Earth, the Poynting-Robertson effect, and the atmospheric drag. Area-to-mass ratio varied from small values corresponding to satellites to big ones corresponding to space debris. The locations and sizes of resonance zones were refined from numerical simulation. The Poynting-Robertson effect results in a secular decrease in the semi-major axis of a spherically symmetrical satellite. In resonance regions the effect weakens slightly. Reliable estimates of secular perturbations of the semi-major axis were obtained from the numerical simulation. Under the Poynting-Robertson effect objects pass through the regions of high

  1. MESSENGER, MErcury: Surface, Space ENvironment, GEochemistry, and Ranging; A Mission to Orbit and Explore the Planet Mercury

    Science.gov (United States)

    1999-01-01

    MESSENGER is a scientific mission to Mercury. Understanding this extraordinary planet and the forces that have shaped it is fundamental to understanding the processes that have governed the formation, evolution, and dynamics of the terrestrial planets. MESSENGER is a MErcury Surface, Space ENvironment, GEochemistry and Ranging mission to orbit Mercury for one Earth year after completing two flybys of that planet following two flybys of Venus. The necessary flybys return significant new data early in the mission, while the orbital phase, guided by the flyby data, enables a focused scientific investigation of this least-studied terrestrial planet. Answers to key questions about Mercury's high density, crustal composition and structure, volcanic history, core structure, magnetic field generation, polar deposits, exosphere, overall volatile inventory, and magnetosphere are provided by an optimized set of miniaturized space instruments. Our goal is to gain new insight into the formation and evolution of the solar system, including Earth. By traveling to the inner edge of the solar system and exploring a poorly known world, MESSENGER fulfills this quest.

  2. Optimal Sunshade Configurations for Space-Based Geoengineering near the Sun-Earth L1 Point.

    Directory of Open Access Journals (Sweden)

    Joan-Pau Sánchez

    Full Text Available Within the context of anthropogenic climate change, but also considering the Earth's natural climate variability, this paper explores the speculative possibility of large-scale active control of the Earth's radiative forcing. In particular, the paper revisits the concept of deploying a large sunshade or occulting disk at a static position near the Sun-Earth L1 Lagrange equilibrium point. Among the solar radiation management methods that have been proposed thus far, space-based concepts are generally seen as the least timely, albeit also as one of the most efficient. Large occulting structures could potentially offset all of the global mean temperature increase due to greenhouse gas emissions. This paper investigates optimal configurations of orbiting occulting disks that not only offset a global temperature increase, but also mitigate regional differences such as latitudinal and seasonal difference of monthly mean temperature. A globally resolved energy balance model is used to provide insights into the coupling between the motion of the occulting disks and the Earth's climate. This allows us to revise previous studies, but also, for the first time, to search for families of orbits that improve the efficiency of occulting disks at offsetting climate change on both global and regional scales. Although natural orbits exist near the L1 equilibrium point, their period does not match that required for geoengineering purposes, thus forced orbits were designed that require small changes to the disk attitude in order to control its motion. Finally, configurations of two occulting disks are presented which provide the same shading area as previously published studies, but achieve reductions of residual latitudinal and seasonal temperature changes.

  3. Optimal Sunshade Configurations for Space-Based Geoengineering near the Sun-Earth L1 Point.

    Science.gov (United States)

    Sánchez, Joan-Pau; McInnes, Colin R

    2015-01-01

    Within the context of anthropogenic climate change, but also considering the Earth's natural climate variability, this paper explores the speculative possibility of large-scale active control of the Earth's radiative forcing. In particular, the paper revisits the concept of deploying a large sunshade or occulting disk at a static position near the Sun-Earth L1 Lagrange equilibrium point. Among the solar radiation management methods that have been proposed thus far, space-based concepts are generally seen as the least timely, albeit also as one of the most efficient. Large occulting structures could potentially offset all of the global mean temperature increase due to greenhouse gas emissions. This paper investigates optimal configurations of orbiting occulting disks that not only offset a global temperature increase, but also mitigate regional differences such as latitudinal and seasonal difference of monthly mean temperature. A globally resolved energy balance model is used to provide insights into the coupling between the motion of the occulting disks and the Earth's climate. This allows us to revise previous studies, but also, for the first time, to search for families of orbits that improve the efficiency of occulting disks at offsetting climate change on both global and regional scales. Although natural orbits exist near the L1 equilibrium point, their period does not match that required for geoengineering purposes, thus forced orbits were designed that require small changes to the disk attitude in order to control its motion. Finally, configurations of two occulting disks are presented which provide the same shading area as previously published studies, but achieve reductions of residual latitudinal and seasonal temperature changes.

  4. Toward Microsatellite Based Space Situational Awareness

    Science.gov (United States)

    Scott, L.; Wallace, B.; Sale, M.; Thorsteinson, S.

    2013-09-01

    The NEOSSat microsatellite is a dual mission space telescope which will perform asteroid detection and Space Situational Awareness (SSA) observation experiments on deep space, earth orbiting objects. NEOSSat was launched on 25 February 2013 into a 800 dawn-dusk sun synchronous orbit and is currently undergoing satellite commissioning. The microsatellite consists of a small aperture optical telescope, GPS receiver, high performance attitude control system, and stray light rejection baffle designed to reject stray light from the Sun while searching for asteroids with elongations 45 degrees along the ecliptic. The SSA experimental mission, referred to as HEOSS (High Earth Orbit Space Surveillance), will focus on objects in deep space orbits. The HEOSS mission objective is to evaluate the utility of microsatellites to perform catalog maintenance observations of resident space objects in a manner consistent with the needs of the Canadian Forces. The advantages of placing a space surveillance sensor in low Earth orbit are that the observer can conduct observations without the day-night interruption cycle experienced by ground based telescopes, the telescope is insensitive to adverse weather and the system has visibility to deep space resident space objects which are not normally visible from ground based sensors. Also, from a photometric standpoint, the microsatellite is able to conduct observations on objects with a rapidly changing observer position. The possibility of spin axis estimation on geostationary satellites may be possible and an experiment characterize spin axis of distant resident space objects is being planned. Also, HEOSS offers the ability to conduct observations of satellites at high phase angles which can potentially extend the trackable portion of space in which deep space objects' orbits can be monitored. In this paper we describe the HEOSS SSA experimental data processing system and the preliminary findings of the catalog maintenance experiments

  5. Lageos orbit decay due to infrared radiation from earth

    Science.gov (United States)

    Rubincam, David Parry

    1987-01-01

    Infrared radiation from the earth may be the principal reason for the decay of Lageos' orbit. The radiation heats up the laser retroreflectors embedded in Lageos' aluminum surface. This creates a north-south temperature gradient on the satellite. The gradient in turn causes a force to be exerted on Lageos because of recoil from photons leaving its surface. The delayed heating of the retroreflectors due to their thermal inertia gives the force a net along-track component which always acts like drag. A simple thermal model for the retroreflectors indicates that this thermal drag accounts for about half the observed average along-track acceleration of -3.3 x 10 to the -10th power m/sec squared. The contribution from the aluminum surface to this effect is negligible. The infrared effect cannot explain the large observed fluctuations in drag which occur mainly when the orbit intersects the earth's shadow.

  6. Space Technology 5 Multi-point Measurements of Near-Earth Magnetic Fields: Initial Results

    Science.gov (United States)

    Slavin, James A.; Le, G.; Strangeway, R. L.; Wang, Y.; Boardsen, S.A.; Moldwin, M. B.; Spence, H. E.

    2007-01-01

    The Space Technology 5 (ST-5) mission successfully placed three micro-satellites in a 300 x 4500 km dawn-dusk orbit on 22 March 2006. Each spacecraft carried a boom-mounted vector fluxgate magnetometer that returned highly sensitive and accurate measurements of the geomagnetic field. These data allow, for the first time, the separation of temporal and spatial variations in field-aligned current (FAC) perturbations measured in low-Earth orbit on time scales of approximately 10 sec to 10 min. The constellation measurements are used to directly determine field-aligned current sheet motion, thickness and current density. In doing so, we demonstrate two multi-point methods for the inference of FAC current density that have not previously been possible in low-Earth orbit; 1) the "standard method," based upon s/c velocity, but corrected for FAC current sheet motion, and 2) the "gradiometer method" which uses simultaneous magnetic field measurements at two points with known separation. Future studies will apply these methods to the entire ST-5 data set and expand to include geomagnetic field gradient analyses as well as field-aligned and ionospheric currents.

  7. THE NASA-UC ETA-EARTH PROGRAM. I. A SUPER-EARTH ORBITING HD 7924

    International Nuclear Information System (INIS)

    Howard, Andrew W.; Marcy, Geoffrey W.; Johnson, John Asher; Fischer, Debra A.; Giguere, Matthew J.; Isaacson, Howard; Wright, Jason T.; Henry, Gregory W.; Valenti, Jeff A.; Anderson, Jay; Piskunov, Nikolai E.

    2009-01-01

    We report the discovery of the first low-mass planet to emerge from the NASA-UC Eta-Earth Program, a super-Earth orbiting the K0 dwarf HD 7924. Keplerian modeling of precise Doppler radial velocities reveals a planet with minimum mass M P sin i = 9.26 M + in a P = 5.398 d orbit. Based on Keck-HIRES measurements from 2001 to 2008, the planet is robustly detected with an estimated false alarm probability of less than 0.001. Photometric observations using the Automated Photometric Telescopes at Fairborn Observatory show that HD 7924 is photometrically constant over the radial velocity period to 0.19 mmag, supporting the existence of the planetary companion. No transits were detected down to a photometric limit of ∼0.5 mmag, eliminating transiting planets with a variety of compositions. HD 7924b is one of only eight planets detected by the radial velocity technique with M P sin i + and as such is a member of an emerging family of low-mass planets that together constrain theories of planet formation.

  8. Total-dose hardness assurance for low earth orbit

    International Nuclear Information System (INIS)

    Maurer, R.H.; Suter, J.J.

    1987-01-01

    The Low Earth Orbit radiation environment has two significant characteristics that make laboratory simulation exposures difficult: (1) a low dose rate and (2) many cycles of low dose accumulation followed by dose-free annealing. Hardness assurance considerations for this environment are discussed and related to data from the testing of Advanced Low Power Schottky and High-speed CMOS devices

  9. Lasers in space.

    CSIR Research Space (South Africa)

    Michaelis, MM

    2008-04-01

    Full Text Available cube, laser beam reflectors, placed on the Moon half a century ago. These early achievements will soon be followed by a plethora of experiments involving lasers in low earth orbit (LEO) or at Lagrange points. And not much later, laser communications... will stretch out as far as Mars and beyond. One important low Earth orbit (LEO) application is the removal of space debris by Earth based or LEO relayed lasers as promoted by Phipps et al.3. Another is military communication. The prominent L1 laser space...

  10. Low-energy near Earth asteroid capture using Earth flybys and aerobraking

    Science.gov (United States)

    Tan, Minghu; McInnes, Colin; Ceriotti, Matteo

    2018-04-01

    Since the Sun-Earth libration points L1 and L2 are regarded as ideal locations for space science missions and candidate gateways for future crewed interplanetary missions, capturing near-Earth asteroids (NEAs) around the Sun-Earth L1/L2 points has generated significant interest. Therefore, this paper proposes the concept of coupling together a flyby of the Earth and then capturing small NEAs onto Sun-Earth L1/L2 periodic orbits. In this capture strategy, the Sun-Earth circular restricted three-body problem (CRTBP) is used to calculate target Lypaunov orbits and their invariant manifolds. A periapsis map is then employed to determine the required perigee of the Earth flyby. Moreover, depending on the perigee distance of the flyby, Earth flybys with and without aerobraking are investigated to design a transfer trajectory capturing a small NEA from its initial orbit to the stable manifolds associated with Sun-Earth L1/L2 periodic orbits. Finally, a global optimization is carried out, based on a detailed design procedure for NEA capture using an Earth flyby. Results show that the NEA capture strategies using an Earth flyby with and without aerobraking both have the potential to be of lower cost in terms of energy requirements than a direct NEA capture strategy without the Earth flyby. Moreover, NEA capture with an Earth flyby also has the potential for a shorter flight time compared to the NEA capture strategy without the Earth flyby.

  11. Lunar oxygen and metal for use in near-Earth space: Magma electrolysis

    Science.gov (United States)

    Colson, Russell O.; Haskin, Larry A.

    1990-01-01

    Because it is energetically easier to get material from the Moon to Earth orbit than from the Earth itself, the Moon is a potentially valuable source of materials for use in space. The unique conditions on the Moon, such as vacuum, absence of many reagents common on the Earth, and the presence of very nontraditional ores suggest that a unique and nontraditional process for extracting materials from the ores may prove the most practical. With this in mind, an investigation of unfluxed silicate electrolysis as a method for extracting oxygen, iron, and silicon from lunar regolith was initiated and is discussed. The advantages of the process include simplicity of concept, absence of need to supply reagents from Earth, and low power and mass requirements for the processing plant. Disadvantages include the need for uninterrupted high temperature and the highly corrosive nature of the high-temperature silicate melts which has made identifying suitable electrode and container materials difficult.

  12. Production of activation products in space-craft components by protons in low earth orbit

    International Nuclear Information System (INIS)

    Normand, E.; Johnson, M.L.

    1986-01-01

    A spacecraft orbiting the Earth through trapped radiation belts will be subject to an induced effect as well as to the direct irradiation by the protons and electrons of the trapped belts. This induced effect is activation of the spacecraft materials by the trapped belt protons. This activation will produce many radioisotopes having half-lives ranging from seconds to millions of years, and emitting various types of radiation. Of primary concern are radioisotopes that emit gamma rays and have half-lives of several years or less. Cross-section data sets are currently being compiled for proton-induced activation products by the Los Alamos National Laboratory. Despite uncertainties in cross-section data, it is instructive to illustrate the magnitude of activation levels and the resulting dose rates calculated in an approximate manner. A number of simplifying assumptions are made

  13. SPACE: Enhancing Life on Earth. Proceedings Report

    Science.gov (United States)

    Hobden, Alan (Editor); Hobden, Beverly (Editor); Bagley, Larry E. (Editor); Bolton, Ed (Editor); Campaigne, Len O. (Editor); Cole, Ron (Editor); France, Marty (Editor); Hand, Rich (Editor); McKinley, Cynthia (Editor); Zimkas, Chuck (Editor)

    1996-01-01

    The proceedings of the 12th National Space Symposium on Enhancing Life on Earth is presented. Technological areas discussed include: Space applications and cooperation; Earth sensing, communication, and navigation applications; Global security interests in space; and International space station and space launch capabilities. An appendices that include featured speakers, program participants, and abbreviation & acronyms glossary is also attached.

  14. A 3D Visualization and Analysis Model of the Earth Orbit, Milankovitch Cycles and Insolation.

    Science.gov (United States)

    Kostadinov, Tihomir; Gilb, Roy

    2013-04-01

    Milankovitch theory postulates that periodic variability of Earth's orbital elements is a major climate forcing mechanism. Although controversies remain, ample geologic evidence supports the major role of the Milankovitch cycles in climate, e.g. glacial-interglacial cycles. There are three Milankovitch orbital parameters: orbital eccentricity (main periodicities of ~100,000 and ~400,000 years), precession (quantified as the longitude of perihelion, main periodicities 19,000-24,000 years) and obliquity of the ecliptic (Earth's axial tilt, main periodicity 41,000 years). The combination of these parameters controls the spatio-temporal patterns of incoming solar radiation (insolation) and the timing of the seasons with respect to perihelion, as well as season duration. The complex interplay of the Milankovitch orbital parameters on various time scales makes assessment and visualization of Earth's orbit and insolation variability challenging. It is difficult to appreciate the pivotal importance of Kepler's laws of planetary motion in controlling the effects of Milankovitch cycles on insolation patterns. These factors also make Earth-Sun geometry and Milankovitch theory difficult to teach effectively. Here, an astronomically precise and accurate Earth orbit visualization model is presented. The model offers 3D visualizations of Earth's orbital geometry, Milankovitch parameters and the ensuing insolation forcings. Both research and educational uses are envisioned for the model, which is developed in Matlab® as a user-friendly graphical user interface (GUI). We present the user with a choice between the Berger et al. (1978) and Laskar et al. (2004) astronomical solutions for eccentricity, obliquity and precession. A "demo" mode is also available, which allows the three Milankovitch parameters to be varied independently of each other (and over much larger ranges than the naturally occurring ones), so the user can isolate the effects of each parameter on orbital geometry

  15. Geo-oculus: high resolution multi-spectral earth imaging mission from geostationary orbit

    Science.gov (United States)

    Vaillon, L.; Schull, U.; Knigge, T.; Bevillon, C.

    2017-11-01

    Geo-Oculus is a GEO-based Earth observation mission studied by Astrium for ESA in 2008-2009 to complement the Sentinel missions, the space component of the GMES (Global Monitoring for Environment & Security). Indeed Earth imaging from geostationary orbit offers new functionalities not covered by existing LEO observation missions, like real-time monitoring and fast revisit capability of any location within the huge area in visibility of the satellite. This high revisit capability is exploited by the Meteosat meteorogical satellites, but with a spatial resolution (500 m nadir for the third generation) far from most of GMES needs (10 to 100 m). To reach such ground resolution from GEO orbit with adequate image quality, large aperture instruments (> 1 m) and high pointing stability (challenges of such missions. To address the requirements from the GMES user community, the Geo-Oculus mission is a combination of routine observations (daily systematic coverage of European coastal waters) with "on-demand" observation for event monitoring (e.g. disasters, fires and oil slicks). The instrument is a large aperture imaging telescope (1.5 m diameter) offering a nadir spatial sampling of 10.5 m (21 m worst case over Europe, below 52.5°N) in a PAN visible channel used for disaster monitoring. The 22 multi-spectral channels have resolutions over Europe ranging from 40 m in UV/VNIR (0.3 to 1 μm) to 750 m in TIR (10-12 μm).

  16. Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit

    Science.gov (United States)

    Bank, Bruce A.; de Groh, Kim K.; Backus, Jane A.

    2008-01-01

    A predictive tool was developed to estimate the low Earth orbit (LEO) atomic oxygen erosion yield of polymers based on the results of the Polymer Erosion and Contamination Experiment (PEACE) Polymers experiment flown as part of the Materials International Space Station Experiment 2 (MISSE 2). The MISSE 2 PEACE experiment accurately measured the erosion yield of a wide variety of polymers and pyrolytic graphite. The 40 different materials tested were selected specifically to represent a variety of polymers used in space as well as a wide variety of polymer chemical structures. The resulting erosion yield data was used to develop a predictive tool which utilizes chemical structure and physical properties of polymers that can be measured in ground laboratory testing to predict the in-space atomic oxygen erosion yield of a polymer. The properties include chemical structure, bonding information, density and ash content. The resulting predictive tool has a correlation coefficient of 0.914 when compared with actual MISSE 2 space data for 38 polymers and pyrolytic graphite. The intent of the predictive tool is to be able to make estimates of atomic oxygen erosion yields for new polymers without requiring expensive and time consumptive in-space testing.

  17. On the atmospheric drag in orbit determination for low Earth orbit

    Science.gov (United States)

    Tang, Jingshi; Liu, Lin; Miao, Manqian

    2012-07-01

    The atmosphere model is always a major limitation for low Earth orbit (LEO) in orbit prediction and determination. The accelerometer can work around the non-gravitational perturbations in orbit determination, but it helps little to improve the atmosphere model or to predict the orbit. For certain satellites, there may be some specific software to handle the orbit problem. This solution can improve the orbit accuracy for both prediction and determination, yet it always contains empirical terms and is exclusive for certain satellites. This report introduces a simple way to handle the atmosphere drag for LEO, which does not depend on instantaneous atmosphere conditions and improves accuracy of predicted orbit. This approach, which is based on mean atmospheric density, is supported by two reasons. One is that although instantaneous atmospheric density is very complicated with time and height, the major pattern is determined by the exponential variation caused by hydrostatic equilibrium and periodic variation caused by solar radiation. The mean density can include the major variations while neglect other minor details. The other reason is that the predicted orbit is mathematically the result from integral and the really determinant factor is the mean density instead of instantaneous density for every time and spot. Using the mean atmospheric density, which is mainly determined by F10.7 solar flux and geomagnetic index, can be combined into an overall parameter B^{*} = C_{D}(S/m)ρ_{p_{0}}. The combined parameter contains several less accurate parameters and can be corrected during orbit determination. This approach has been confirmed in various LEO computations and an example is given below using Tiangong-1 spacecraft. Precise orbit determination (POD) is done using one-day GPS positioning data without any accurate a-priori knowledge on spacecraft or atmosphere conditions. Using the corrected initial state vector of the spacecraft and the parameter B^* from POD, the

  18. Update on International Space Station Nickel-Hydrogen Battery On-Orbit Performance

    Science.gov (United States)

    Dalton, Penni; Cohen, Fred

    2003-01-01

    International Space Station (ISS) Electric Power System (EPS) utilizes Nickel-Hydrogen (Ni-H2) batteries as part of its power system to store electrical energy. The batteries are charged during insolation and discharged during eclipse. The batteries are designed to operate at a 35% depth of discharge (DOD) maximum during normal operation. Thirty-eight individual pressure vessel (IPV) Ni-H2 battery cells are series-connected and packaged in an Orbital Replacement Unit (ORU). Two ORUs are series-connected utilizing a total of 76 cells, to form one battery. The ISS is the first application for low earth orbit (LEO) cycling of this quantity of series-connected cells. The P6 (Port) Integrated Equipment Assembly (IEA) containing the initial ISS high-power components was successfully launched on November 30, 2000. The IEA contains 12 Battery Subassembly ORUs (6 batteries) that provide station power during eclipse periods. This paper will discuss the battery performance data after two and a half years of cycling.

  19. Monte Carlo simulations of the secondary neutron ambient and effective dose equivalent rates from surface to suborbital altitudes and low Earth orbit.

    Science.gov (United States)

    El-Jaby, Samy; Richardson, Richard B

    2015-07-01

    Occupational exposures from ionizing radiation are currently regulated for airline travel (Earth orbit (∼300-400 km). Aircrew typically receive between 1 and 6 mSv of occupational dose annually, while aboard the International Space Station, the area radiation dose equivalent measured over just 168 days was 106 mSv at solar minimum conditions. It is anticipated that space tourism vehicles will reach suborbital altitudes of approximately 100 km and, therefore, the annual occupational dose to flight crew during repeated transits is expected to fall somewhere between those observed for aircrew and astronauts. Unfortunately, measurements of the radiation environment at the high altitudes reached by suborbital vehicles are sparse, and modelling efforts have been similarly limited. In this paper, preliminary MCNPX radiation transport code simulations are developed of the secondary neutron flux profile in air from surface altitudes up to low Earth orbit at solar minimum conditions and excluding the effects of spacecraft shielding. These secondary neutrons are produced by galactic cosmic radiation interacting with Earth's atmosphere and are among the sources of radiation that can pose a health risk. Associated estimates of the operational neutron ambient dose equivalent, used for radiation protection purposes, and the neutron effective dose equivalent that is typically used for estimates of stochastic health risks, are provided in air. Simulations show that the neutron radiation dose rates received at suborbital altitudes are comparable to those experienced by aircrew flying at 7 to 14 km. We also show that the total neutron dose rate tails off beyond the Pfotzer maximum on ascension from surface up to low Earth orbit. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  20. Utilizing Solar Power Technologies for On-Orbit Propellant Production

    Science.gov (United States)

    Fikes, John C.; Howell, Joe T.; Henley, Mark W.

    2006-01-01

    The cost of access to space beyond low Earth orbit may be reduced if vehicles can refuel in orbit. The cost of access to low Earth orbit may also be reduced by launching oxygen and hydrogen propellants in the form of water. To achieve this reduction in costs of access to low Earth orbit and beyond, a propellant depot is considered that electrolyzes water in orbit, then condenses and stores cryogenic oxygen and hydrogen. Power requirements for such a depot require Solar Power Satellite technologies. A propellant depot utilizing solar power technologies is discussed in this paper. The depot will be deployed in a 400 km circular equatorial orbit. It receives tanks of water launched into a lower orbit from Earth, converts the water to liquid hydrogen and oxygen, and stores up to 500 metric tons of cryogenic propellants. This requires a power system that is comparable to a large Solar Power Satellite capable of several 100 kW of energy. Power is supplied by a pair of solar arrays mounted perpendicular to the orbital plane, which rotates once per orbit to track the Sun. The majority of the power is used to run the electrolysis system. Thermal control is maintained by body-mounted radiators; these also provide some shielding against orbital debris. The propellant stored in the depot can support transportation from low Earth orbit to geostationary Earth orbit, the Moon, LaGrange points, Mars, etc. Emphasis is placed on the Water-Ice to Cryogen propellant production facility. A very high power system is required for cracking (electrolyzing) the water and condensing and refrigerating the resulting oxygen and hydrogen. For a propellant production rate of 500 metric tons (1,100,000 pounds) per year, an average electrical power supply of 100 s of kW is required. To make the most efficient use of space solar power, electrolysis is performed only during the portion of the orbit that the Depot is in sunlight, so roughly twice this power level is needed for operations in sunlight

  1. Solar radiation pressure resonances in Low Earth Orbits

    Science.gov (United States)

    Alessi, Elisa Maria; Schettino, Giulia; Rossi, Alessandro; Valsecchi, Giovanni B.

    2018-01-01

    The aim of this work is to highlight the crucial role that orbital resonances associated with solar radiation pressure can have in Low Earth Orbit. We review the corresponding literature, and provide an analytical tool to estimate the maximum eccentricity which can be achieved for well-defined initial conditions. We then compare the results obtained with the simplified model with the results obtained with a more comprehensive dynamical model. The analysis has important implications both from a theoretical point of view, because it shows that the role of some resonances was underestimated in the past, and also from a practical point of view in the perspective of passive deorbiting solutions for satellites at the end-of-life.

  2. Space and Atmospheric Environments: From Low Earth Orbits to Deep Space

    Science.gov (United States)

    Barth, Janet L.

    2003-01-01

    Natural space and atmospheric environments pose a difficult challenge for designers of technological systems in space. The deleterious effects of environment interactions with the systems include degradation of materials, thermal changes, contamination, excitation, spacecraft glow, charging, radiation damage, and induced background interference. Design accommodations must be realistic with minimum impact on performance while maintaining a balance between cost and risk. The goal of applied research in space environments and effects is to limit environmental impacts at low cost relative to spacecraft cost and to infuse enabling and commercial off-the-shelf technologies into space programs. The need to perform applied research to understand the space environment in a practical sense and to develop methods to mitigate these environment effects is frequently underestimated by space agencies and industry. Applied science research in this area is critical because the complexity of spacecraft systems is increasing, and they are exposed simultaneously to a multitude of space environments.

  3. A Wide Field Auroral Imager (WFAI for low Earth orbit missions

    Directory of Open Access Journals (Sweden)

    N. P. Bannister

    2007-03-01

    Full Text Available A comprehensive understanding of the solar wind interaction with Earth's coupled magnetosphere-ionosphere system requires an ability to observe the charged particle environment and auroral activity from the same platform, generating particle and photon image data which are matched in time and location. While unambiguous identification of the particles giving rise to the aurora requires a Low Earth Orbit satellite, obtaining adequate spatial coverage of aurorae with the relatively limited field of view of current space bourne auroral imaging systems requires much higher orbits. A goal for future satellite missions, therefore, is the development of compact, wide field-of-view optics permitting high spatial and temporal resolution ultraviolet imaging of the aurora from small spacecraft in low polar orbit. Microchannel plate optics offer a method of achieving the required performance. We describe a new, compact instrument design which can observe a wide field-of-view with the required spatial resolution. We report the focusing of 121.6 nm radiation using a spherically-slumped, square-pore microchannel plate with a focal length of 32 mm and an F number of 0.7. Measurements are compared with detailed ray-trace simulations of imaging performance. The angular resolution is 2.7±0.2° for the prototype, corresponding to a footprint ~33 km in diameter for an aurora altitude of 110 km and a spacecraft altitude of 800 km. In preliminary analysis, a more recent optic has demonstrated a full width at half maximum of 5.0±0.3 arcminutes, corresponding to a footprint of ~1 km from the same spacecraft altitude. We further report the imaging properties of a convex microchannel plate detector with planar resistive anode readout; this detector, whose active surface has a radius of curvature of only 100 mm, is shown to meet the spatial resolution and sensitivity requirements of the new wide field auroral imager (WFAI.

  4. Trapped Proton Environment in Medium-Earth Orbit (2000-2010)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yue [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Friedel, Reinhard Hans [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kippen, Richard Marc [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-31

    This report describes the method used to derive fluxes of the trapped proton belt along the GPS orbit (i.e., a Medium-Earth Orbit) during 2000 – 2010, a period almost covering a solar cycle. This method utilizes a newly developed empirical proton radiation-belt model, with the model output scaled by GPS in-situ measurements, to generate proton fluxes that cover a wide range of energies (50keV- 6MeV) and keep temporal features as well. The new proton radiation-belt model is developed based upon CEPPAD proton measurements from the Polar mission (1996 – 2007). Comparing to the de-facto standard empirical model of AP8, this model is not only based upon a new data set representative of the proton belt during the same period covered by GPS, but can also provide statistical information of flux values such as worst cases and occurrence percentiles instead of solely the mean values. The comparison shows quite different results from the two models and suggests that the commonly accepted error factor of 2 on the AP8 flux output over-simplifies and thus underestimates variations of the proton belt. Output fluxes from this new model along the GPS orbit are further scaled by the ns41 in-situ data so as to reflect the dynamic nature of protons in the outer radiation belt at geomagnetically active times. Derived daily proton fluxes along the GPS ns41 orbit, whose data files are delivered along with this report, are depicted to illustrate the trapped proton environment in the Medium-Earth Orbit. Uncertainties on those daily proton fluxes from two sources are evaluated: One is from the new proton-belt model that has error factors < ~3; the other is from the in-situ measurements and the error factors could be ~ 5.

  5. ISS EarthKam: Taking Photos of the Earth from Space

    Science.gov (United States)

    Haste, Turtle

    2008-01-01

    NASA is involved in a project involving the International Space Station (ISS) and an Earth-focused camera called EarthKam, where schools, and ultimately students, are allowed to remotely program the EarthKAM to take images. Here the author describes how EarthKam was used to help middle school students learn about biomes and develop their…

  6. Space Power Theory: Controlling the Medium Without Weapons in Space

    National Research Council Canada - National Science Library

    Wilkerson, Don L

    2008-01-01

    .... strategic space assets and the ability to negate enemy space systems is essential to U.S. space strategy in controlling the geographical environment of space, predominately in the Lower Earth Orbit (LEO...

  7. On-Orbit Gradiometry with the scientific instrument of the French Space Mission MICROSCOPE

    Science.gov (United States)

    Foulon, B.; Baghi, Q.; Panet, I.; Rodrigues, M.; Metris, G.; Touboul, P.

    2017-12-01

    The MICROSCOPE mission is fully dedicated to the in-orbit test of the universality of free fall, the so-called Weak Equivalence Principle (WEP). Based on a CNES Myriade microsatellite launched on the 25th of April 2016, MICROSCOPE is a CNES-ESA-ONERA-CNRS-OCA mission, the scientific objective of which is to test of the Equivalence Principle with an extraordinary accuracy at the level of 10-15. The measurement will be obtained from the T-SAGE (Twin Space Accelerometer for Gravitational Experimentation) instrument constituted by two ultrasensitive differential accelerometers. One differential electrostatic accelerometer, labeled SU-EP, contains, at its center, two proof masses made of Titanium and Platinum and is used for the test. The twin accelerometer, labeled SU-REF, contains two Platinum proof masses and is used as a reference instrument. Separated by a 17 cm-length arm, they are embarked in a very stable and soft environment on board a satellite equipped with a drag-free control system and orbiting on a sun synchronous circular orbit at 710 km above the Earth. In addition to the WEP test, this configuration can be interesting for various applications, and one of the proposed ideas is to use MICROSCOPE data for the measurement of Earth's gravitational gradient. Considering the gradiometer formed by the inner Platinum proof-masses of the two differential accelerometers and the arm along the Y-axis of the instrument which is perpendicular to the orbital plane, possibly 3 components of the gradient can be measured: Txy, Tyy and Tzy. Preliminary studies suggest that the errors can be lower than 10mE. Taking advantage of its higher altitude with respect to GOCE, the low frequency signature of Earth's potential seen by MICROSCOPE could provide an additional observable in gradiometry to discriminate between different models describing the large scales of the mass distribution in the Earth's deep mantle. The poster will shortly present the MICROSCOPE mission

  8. Two Earth-sized planets orbiting Kepler-20.

    Science.gov (United States)

    Fressin, Francois; Torres, Guillermo; Rowe, Jason F; Charbonneau, David; Rogers, Leslie A; Ballard, Sarah; Batalha, Natalie M; Borucki, William J; Bryson, Stephen T; Buchhave, Lars A; Ciardi, David R; Désert, Jean-Michel; Dressing, Courtney D; Fabrycky, Daniel C; Ford, Eric B; Gautier, Thomas N; Henze, Christopher E; Holman, Matthew J; Howard, Andrew; Howell, Steve B; Jenkins, Jon M; Koch, David G; Latham, David W; Lissauer, Jack J; Marcy, Geoffrey W; Quinn, Samuel N; Ragozzine, Darin; Sasselov, Dimitar D; Seager, Sara; Barclay, Thomas; Mullally, Fergal; Seader, Shawn E; Still, Martin; Twicken, Joseph D; Thompson, Susan E; Uddin, Kamal

    2011-12-20

    Since the discovery of the first extrasolar giant planets around Sun-like stars, evolving observational capabilities have brought us closer to the detection of true Earth analogues. The size of an exoplanet can be determined when it periodically passes in front of (transits) its parent star, causing a decrease in starlight proportional to its radius. The smallest exoplanet hitherto discovered has a radius 1.42 times that of the Earth's radius (R(⊕)), and hence has 2.9 times its volume. Here we report the discovery of two planets, one Earth-sized (1.03R(⊕)) and the other smaller than the Earth (0.87R(⊕)), orbiting the star Kepler-20, which is already known to host three other, larger, transiting planets. The gravitational pull of the new planets on the parent star is too small to measure with current instrumentation. We apply a statistical method to show that the likelihood of the planetary interpretation of the transit signals is more than three orders of magnitude larger than that of the alternative hypothesis that the signals result from an eclipsing binary star. Theoretical considerations imply that these planets are rocky, with a composition of iron and silicate. The outer planet could have developed a thick water vapour atmosphere.

  9. Resistance of CFRP structures to environmental degradation in low Earth orbit

    Science.gov (United States)

    Suliga, Agnieszka

    Within this study, a development of a protection strategy for ultra-thin CFRP structures from degrading effects of low Earth orbit (LEO) is presented. The proposed strategy involves an application of a modified epoxy resin system on outer layers of the structure, which is cycloaliphatic in its chemical character and reinforced with POSS nanoparticles. The core of the CFRP structure is manufactured using a highly aromatic epoxy resin system which provides excellent mechanical properties, however, its long-term ageing performance in space is not satisfactory, and hence a surface treatment is required to improve its longevity. The developed resin system presented in this thesis is a hybrid material, designed in such a way that its individual constituents each contribute to combating the detrimental effects of radiation, atomic oxygen (AO), temperature extremes and vacuum induced outgassing of exposed material surfaces while operating in LEO. The cycloaliphatic nature of the outer epoxy increases UV resistance and the embedded silicon nanoparticles improve AO and thermal stability. During the study, a material characterization of the developed cycloaliphatic epoxy resins was performed including the effects of nanoparticles on morphology, curing behaviour, thermal-mechanical properties and surface chemistry. Following on that, the efficacy of the modified resin system on space-like resistance was studied. It was found that when the ultra-thin CFRP structures are covered with the developed resin system, their AO resistance is approximately doubled, UV susceptibility decreased by 80% and thermal stability improved by 20%. Following on the successful launch of the InflateSail mission earlier this year, which demonstrated a sail deployment and a controlled de-orbiting, the findings of this study are of importance for the future generation of similar, but significantly longer missions. Ensuring resistance of CFRP structures in a highly corrosive LEO environment is a critical

  10. Diagnosing low earth orbit satellite anomalies using NOAA-15 electron data associated with geomagnetic perturbations

    Science.gov (United States)

    Ahmad, Nizam; Herdiwijaya, Dhani; Djamaluddin, Thomas; Usui, Hideyuki; Miyake, Yohei

    2018-05-01

    A satellite placed in space is constantly affected by the space environment, resulting in various impacts from temporary faults to permanent failures depending on factors such as satellite orbit, solar and geomagnetic activities, satellite local time, and satellite construction material. Anomaly events commonly occur during periods of high geomagnetic activity that also trigger plasma variation in the low Earth orbit (LEO) environment. In this study, we diagnosed anomalies in LEO satellites using electron data from the Medium Energy Proton and Electron Detector onboard the National Oceanic and Atmospheric Administration (NOAA)-15 satellite. In addition, we analyzed the fluctuation of electron flux in association with geomagnetic disturbances 3 days before and after the anomaly day. We selected 20 LEO anomaly cases registered in the Satellite News Digest database for the years 2000-2008. Satellite local time, an important parameter for anomaly diagnosis, was determined using propagated two-line element data in the SGP4 simplified general perturbation model to calculate the longitude of the ascending node of the satellite through the position and velocity vectors. The results showed that the majority of LEO satellite anomalies are linked to low-energy electron fluxes of 30-100 keV and magnetic perturbations that had a higher correlation coefficient ( 90%) on the day of the anomaly. The mean local time calculation for the anomaly day with respect to the nighttime migration of energetic electrons revealed that the majority of anomalies (65%) occurred on the night side of Earth during the dusk-to-dawn sector of magnetic local time.

  11. Optical Orbit Determination of a Geosynchronous Earth Orbit Satellite Effected by Baseline Distances between Various Ground-based Tracking Stations Ⅱ: COMS Case with Analysis of Actual Observation Data

    Directory of Open Access Journals (Sweden)

    Ju Young Son

    2015-09-01

    Full Text Available We estimated the orbit of the Communication, Ocean and Meteorological Satellite (COMS, a Geostationary Earth Orbit (GEO satellite, through data from actual optical observations using telescopes at the Sobaeksan Optical Astronomy Observatory (SOAO of the Korea Astronomy and Space Science Institute (KASI, Optical Wide field Patrol (OWL at KASI, and the Chungbuk National University Observatory (CNUO from August 1, 2014, to January 13, 2015. The astrometric data of the satellite were extracted from the World Coordinate System (WCS in the obtained images, and geometrically distorted errors were corrected. To handle the optically observed data, corrections were made for the observation time, light-travel time delay, shutter speed delay, and aberration. For final product, the sequential filter within the Orbit Determination Tool Kit (ODTK was used for orbit estimation based on the results of optical observation. In addition, a comparative analysis was conducted between the precise orbit from the ephemeris of the COMS maintained by the satellite operator and the results of orbit estimation using optical observation. The orbits estimated in simulation agree with those estimated with actual optical observation data. The error in the results using optical observation data decreased with increasing number of observatories. Our results are useful for optimizing observation data for orbit estimation.

  12. Feasibility analysis of cislunar flight using the Shuttle Orbiter

    Science.gov (United States)

    Haynes, Davy A.

    1991-01-01

    A first order orbital mechanics analysis was conducted to examine the possibility of utilizing the Space Shuttle Orbiter to perform payload delivery missions to lunar orbit. In the analysis, the earth orbit of departure was constrained to be that of Space Station Freedom. Furthermore, no enhancements of the Orbiter's thermal protection system were assumed. Therefore, earth orbit insertion maneuvers were constrained to be all propulsive. Only minimal constraints were placed on the lunar orbits and no consideration was given to possible landing sites for lunar surface payloads. The various phases and maneuvers of the mission are discussed for both a conventional (Apollo type) and an unconventional mission profile. The velocity impulses needed, and the propellant masses required are presented for all of the mission maneuvers. Maximum payload capabilities were determined for both of the mission profiles examined. In addition, other issues relating to the feasibility of such lunar shuttle missions are discussed. The results of the analysis indicate that the Shuttle Orbiter would be a poor vehicle for payload delivery missions to lunar orbit.

  13. Mapping the space radiation environment in LEO orbit by the SATRAM Timepix payload on board the Proba-V satellite

    Energy Technology Data Exchange (ETDEWEB)

    Granja, Carlos, E-mail: carlos.granja@utef.cvut.cz; Polansky, Stepan

    2016-07-07

    Detailed spatial- and time-correlated maps of the space radiation environment in Low Earth Orbit (LEO) are produced by the spacecraft payload SATRAM operating in open space on board the Proba-V satellite from the European Space Agency (ESA). Equipped with the hybrid semiconductor pixel detector Timepix, the compact radiation monitor payload provides the composition and spectral characterization of the mixed radiation field with quantum-counting and imaging dosimetry sensitivity, energetic charged particle tracking, directionality and energy loss response in wide dynamic range in terms of particle types, dose rates and particle fluxes. With a polar orbit (sun synchronous, 98° inclination) at the altitude of 820 km the payload samples the space radiation field at LEO covering basically the whole planet. First results of long-period data evaluation in the form of time-and spatially-correlated maps of total dose rate (all particles) are given.

  14. SSC Tenant Meeting: NASA Near Earth Network (NEN) Overview

    Science.gov (United States)

    Carter, David; Larsen, David; Baldwin, Philip; Wilson, Cristy; Ruley, LaMont

    2018-01-01

    The Near Earth Network (NEN) consists of globally distributed tracking stations that are strategically located throughout the world which provide Telemetry, Tracking, and Commanding (TTC) services support to a variety of orbital and suborbital flight missions, including Low Earth Orbit (LEO), Geosynchronous Earth Orbit (GEO), highly elliptical, and lunar orbits. Swedish Space Corporation (SSC), which is one of the NEN Commercial Service Provider, has provided the NEN with TTC services support from its Alaska, Hawaii, Chile and Sweden. The presentation will give an overview of the NEN and its support from SSC.

  15. The Role of Cis-Lunar Space in Future Global Space Exploration

    Science.gov (United States)

    Bobskill, Marianne R.; Lupisella, Mark L.

    2012-01-01

    Cis-lunar space offers affordable near-term opportunities to help pave the way for future global human exploration of deep space, acting as a bridge between present missions and future deep space missions. While missions in cis-lunar space have value unto themselves, they can also play an important role in enabling and reducing risk for future human missions to the Moon, Near-Earth Asteroids (NEAs), Mars, and other deep space destinations. The Cis-Lunar Destination Team of NASA's Human Spaceflight Architecture Team (HAT) has been analyzing cis-lunar destination activities and developing notional missions (or "destination Design Reference Missions" [DRMs]) for cis-lunar locations to inform roadmap and architecture development, transportation and destination elements definition, operations, and strategic knowledge gaps. The cis-lunar domain is defined as that area of deep space under the gravitational influence of the earth-moon system. This includes a set of earth-centered orbital locations in low earth orbit (LEO), geosynchronous earth orbit (GEO), highly elliptical and high earth orbits (HEO), earth-moon libration or "Lagrange" points (E-ML1 through E-ML5, and in particular, E-ML1 and E-ML2), and low lunar orbit (LLO). To help explore this large possibility space, we developed a set of high level cis-lunar mission concepts in the form of a large mission tree, defined primarily by mission duration, pre-deployment, type of mission, and location. The mission tree has provided an overall analytical context and has helped in developing more detailed design reference missions that are then intended to inform capabilities, operations, and architectures. With the mission tree as context, we will describe two destination DRMs to LEO and GEO, based on present human space exploration architectural considerations, as well as our recent work on defining mission activities that could be conducted with an EML1 or EML2 facility, the latter of which will be an emphasis of this

  16. Transverse and Longitudinal Doppler Effects of the Sunbeam Spectra and Earth-Self Rotation and Orbital Velocities, the Mass of the Sun and Others

    OpenAIRE

    Nam, Sang Boo

    2009-01-01

    The transverse and longitudinal Doppler effects of the sunbeam spectra are shown to result in the earth parameters such as the earth-self rotation and revolution velocities, the earth orbit semi-major axis, the earth orbital angular momentum, the earth axial tilt, the earth orbit eccentricity, the local latitude and the mass of the sun. The sunbeam global positioning scheme is realized, including the earth orbital position. PACS numbers: 91.10.Fc, 95.10.Km, 91.10.Da, 91.10.Jf.

  17. Near-Earth Object Orbit Linking with the Large Synoptic Survey Telescope

    Science.gov (United States)

    Vereš, Peter; Chesley, Steven R.

    2017-07-01

    We have conducted a detailed simulation of the ability of the Large Synoptic Survey Telescope (LSST) to link near-Earth and main belt asteroid detections into orbits. The key elements of the study were a high-fidelity detection model and the presence of false detections in the form of both statistical noise and difference image artifacts. We employed the Moving Object Processing System (MOPS) to generate tracklets, tracks, and orbits with a realistic detection density for one month of the LSST survey. The main goals of the study were to understand whether (a) the linking of near-Earth objects (NEOs) into orbits can succeed in a realistic survey, (b) the number of false tracks and orbits will be manageable, and (c) the accuracy of linked orbits would be sufficient for automated processing of discoveries and attributions. We found that the overall density of asteroids was more than 5000 per LSST field near opposition on the ecliptic, plus up to 3000 false detections per field in good seeing. We achieved 93.6% NEO linking efficiency for H< 22 on tracks composed of tracklets from at least three distinct nights within a 12 day interval. The derived NEO catalog was comprised of 96% correct linkages. Less than 0.1% of orbits included false detections, and the remainder of false linkages stemmed from main belt confusion, which was an artifact of the short time span of the simulation. The MOPS linking efficiency can be improved by refined attribution of detections to known objects and by improved tuning of the internal kd-tree linking algorithms.

  18. Space Operations Learning Center (SOLC) iPhone/iPad Application

    Science.gov (United States)

    Binebrink, Daniel; Kuok, Heng; Hammond, Malinda; Hull, Scott

    2013-01-01

    This iPhone application, Space Junk Sammy, is intended to be an educational application designed for Apple iPhones and iPads. This new concept educates kids in an innovative way about how orbital debris affects space missions. Orbital debris is becoming a very significant concern for NASA and all Earthorbiting space missions. Spacecraft in low-Earth orbit are in constant danger of being potentially damaged or destroyed by debris. High-profile spacecraft such as the International Space Station (ISS) and Hubble Space Telescope are dealing with orbital debris on a regular basis. Other basic educational concepts that are portrayed are low-Earth orbits, satellites, ISS, attitude control, and other facts that can be presented in betweenlevel popup screens. The Orbital Debris Cleanup game is relatively simple from the user s technical standpoint. It is a 2D game where the user s avatar is a satellite buddy, named Sammy, in orbit around Earth. Sammy is controlled by the user with the device s gyroscope as well as touchscreen controls. It has equipment used for taking care of the space debris objects on the screen. Sammy also has a claw, a laser deflector, and hydrazine rockets to grab or push the debris objects into a higher orbit or into a lower orbit to burn up in the Earth s atmosphere. The user interface shows Sammy and space debris objects constantly moving from left to right, where Sammy is trying to catch the debris objects before they move off the right side of the screen. Everything will be in constant motion to increase fun and add to the realism of orbiting the Earth. The satellite buddy is used to clean up the space debris and protect other satellites. Later levels will include a laser deflector and hydrazine rockets instead of a robotic claw to push the orbital debris into a higher orbit and out of the path of other satellites

  19. Laboratory investigations: Low Earth orbit environment chemistry with spacecraft surfaces

    Science.gov (United States)

    Cross, Jon B.

    1990-01-01

    Long-term space operations that require exposure of material to the low earth orbit (LEO) environment must take into account the effects of this highly oxidative atmosphere on material properties and the possible contamination of the spacecraft surroundings. Ground-based laboratory experiments at Los Alamos using a newly developed hyperthermal atomic oxygen (AO) source have shown that not only are hydrocarbon based materials effected but that inorganic materials such as MoS2 are also oxidized and that thin protective coatings such as Al2O3 can be breached, producing oxidation of the underlying substrate material. Gas-phase reaction products, such as SO2 from oxidation of MoS2 and CO and CO2 from hydrocarbon materials, have been detected and have consequences in terms of spacecraft contamination. Energy loss through gas-surface collisions causing spacecraft drag has been measured for a few select surfaces and has been found to be highly dependent on the surface reactivity.

  20. Feasibility Study for a Near Term Demonstration of Laser-Sail Propulsion from the Ground to Low Earth Orbit

    Science.gov (United States)

    Montgomery, Edward E., IV; Johnson, Les; Thomas, Herbert D.

    2016-01-01

    This paper adds to the body of research related to the concept of propellant-less in-space propulsion utilizing an external high energy laser (HEL) to provide momentum to an ultra-lightweight (gossamer) spacecraft. It has been suggested that the capabilities of Space Situational Awareness assets and the advanced analytical tools available for fine resolution orbit determination make it possible to investigate the practicalities of a ground to Low Earth Orbit (LEO) demonstration at delivered power levels that only illuminate a spacecraft without causing damage to it. The degree to which this can be expected to produce a measurable change in the orbit of a low ballistic coefficient spacecraft is investigated. Key system characteristics and estimated performance are derived for a near term mission opportunity involving the LightSail 2 spacecraft and laser power levels modest in comparison to those proposed previously by Forward, Landis, or Marx. [1,2,3] A more detailed investigation of accessing LightSail 2 from Santa Rosa Island on Eglin Air Force Base on the United States coast of the Gulf of Mexico is provided to show expected results in a specific case.

  1. Autonomous Mars ascent and orbit rendezvous for earth return missions

    Science.gov (United States)

    Edwards, H. C.; Balmanno, W. F.; Cruz, Manuel I.; Ilgen, Marc R.

    1991-01-01

    The details of tha assessment of autonomous Mars ascent and orbit rendezvous for earth return missions are presented. Analyses addressing navigation system assessments, trajectory planning, targeting approaches, flight control guidance strategies, and performance sensitivities are included. Tradeoffs in the analysis and design process are discussed.

  2. Final report of the SPS space transportation workshop

    Energy Technology Data Exchange (ETDEWEB)

    1980-10-01

    After a brief description of space power system concepts and the current status of the SPS program, issues relevant to earth-surface-to-low-earth-orbit (ESLEO) and orbit-to-orbit transport are discussed. For ESLEO, vehicle concepts include shuttle transportation systems, heavy lift launch vehicles, and single-stage-to-orbit vehicles. Orbit transfer vehicle missions include transport of cargo and the SPS module from low earth orbit to geosynchronous earth orbit as well as personnel transport. Vehicles discussed for such missions include chemical rocket orbital transfer vehicles, and electric orbital transfer vehicles. Further discussions include SPS station-keeping and attitude control, intra-orbit transport, and advanced propulsion and vehicle concepts. (LEW)

  3. Automated Construction of Molecular Active Spaces from Atomic Valence Orbitals.

    Science.gov (United States)

    Sayfutyarova, Elvira R; Sun, Qiming; Chan, Garnet Kin-Lic; Knizia, Gerald

    2017-09-12

    We introduce the atomic valence active space (AVAS), a simple and well-defined automated technique for constructing active orbital spaces for use in multiconfiguration and multireference (MR) electronic structure calculations. Concretely, the technique constructs active molecular orbitals capable of describing all relevant electronic configurations emerging from a targeted set of atomic valence orbitals (e.g., the metal d orbitals in a coordination complex). This is achieved via a linear transformation of the occupied and unoccupied orbital spaces from an easily obtainable single-reference wave function (such as from a Hartree-Fock or Kohn-Sham calculations) based on projectors to targeted atomic valence orbitals. We discuss the premises, theory, and implementation of the idea, and several of its variations are tested. To investigate the performance and accuracy, we calculate the excitation energies for various transition-metal complexes in typical application scenarios. Additionally, we follow the homolytic bond breaking process of a Fenton reaction along its reaction coordinate. While the described AVAS technique is not a universal solution to the active space problem, its premises are fulfilled in many application scenarios of transition-metal chemistry and bond dissociation processes. In these cases the technique makes MR calculations easier to execute, easier to reproduce by any user, and simplifies the determination of the appropriate size of the active space required for accurate results.

  4. Prevalence of Earth-size planets orbiting Sun-like stars

    OpenAIRE

    Petigura, Erik A.; Howard, Andrew W.; Marcy, Geoffrey W.

    2013-01-01

    Determining whether Earth-like planets are common or rare looms as a touchstone in the question of life in the universe. We searched for Earth-size planets that cross in front of their host stars by examining the brightness measurements of 42,000 stars from National Aeronautics and Space Administration's Kepler mission. We found 603 planets, including 10 that are Earth size (1-2 Earth-radii) and receive comparable levels of stellar energy to that of Earth (within a factor of four). We account...

  5. Space exercise and Earth benefits.

    Science.gov (United States)

    Macias, Brandon R; Groppo, Eli R; Eastlack, Robert K; Watenpaugh, Donald E; Lee, Stuart M C; Schneider, Suzanne M; Boda, Wanda L; Smith, Scott M; Cutuk, Adnan; Pedowitz, Robert A; Meyer, R Scott; Hargens, Alan R

    2005-08-01

    The detrimental impact of long duration space flight on physiological systems necessitates the development of exercise countermeasures to protect work capabilities in gravity fields of Earth, Moon and Mars. The respective rates of physiological deconditioning for different organ systems during space flight has been described as a result of data collected during and after missions on the Space Shuttle, International Space Station, Mir, and bed rest studies on Earth. An integrated countermeasure that simulates the body's hydrostatic pressure gradient, provides mechanical stress to the bones and muscles, and stimulates the neurovestibular system may be critical for maintaining health and well being of crew during long-duration space travel, such as a mission to Mars. Here we review the results of our studies to date of an integrated exercise countermeasure for space flight, lower body negative pressure (LBNP) treadmill exercise, and potential benefits of its application to athletic training on Earth. Additionally, we review the benefits of Lower Body Positive Pressure (LBPP) exercise for rehabilitation of postoperative patients. Presented first are preliminary data from a 30-day bed rest study evaluating the efficacy of LBNP exercise as an integrated exercise countermeasure for the deconditioning effects of microgravity. Next, we review upright LBNP exercise as a training modality for athletes by evaluating effects on the cardiovascular system and gait mechanics. Finally, LBPP exercise as a rehabilitation device is examined with reference to gait mechanics and safety in two groups of postoperative patients.

  6. Autonomous scheduling technology for Earth orbital missions

    Science.gov (United States)

    Srivastava, S.

    1982-01-01

    The development of a dynamic autonomous system (DYASS) of resources for the mission support of near-Earth NASA spacecraft is discussed and the current NASA space data system is described from a functional perspective. The future (late 80's and early 90's) NASA space data system is discussed. The DYASS concept, the autonomous process control, and the NASA space data system are introduced. Scheduling and related disciplines are surveyed. DYASS as a scheduling problem is also discussed. Artificial intelligence and knowledge representation is considered as well as the NUDGE system and the I-Space system.

  7. Tidal Heating of Earth-like Exoplanets around M Stars: Thermal, Magnetic, and Orbital Evolutions.

    Science.gov (United States)

    Driscoll, P E; Barnes, R

    2015-09-01

    The internal thermal and magnetic evolution of rocky exoplanets is critical to their habitability. We focus on the thermal-orbital evolution of Earth-mass planets around low-mass M stars whose radiative habitable zone overlaps with the "tidal zone," where tidal dissipation is expected to be a significant heat source in the interior. We develop a thermal-orbital evolution model calibrated to Earth that couples tidal dissipation, with a temperature-dependent Maxwell rheology, to orbital circularization and migration. We illustrate thermal-orbital steady states where surface heat flow is balanced by tidal dissipation and cooling can be stalled for billions of years until circularization occurs. Orbital energy dissipated as tidal heat in the interior drives both inward migration and circularization, with a circularization time that is inversely proportional to the dissipation rate. We identify a peak in the internal dissipation rate as the mantle passes through a viscoelastic state at mantle temperatures near 1800 K. Planets orbiting a 0.1 solar-mass star within 0.07 AU circularize before 10 Gyr, independent of initial eccentricity. Once circular, these planets cool monotonically and maintain dynamos similar to that of Earth. Planets forced into eccentric orbits can experience a super-cooling of the core and rapid core solidification, inhibiting dynamo action for planets in the habitable zone. We find that tidal heating is insignificant in the habitable zone around 0.45 (or larger) solar-mass stars because tidal dissipation is a stronger function of orbital distance than stellar mass, and the habitable zone is farther from larger stars. Suppression of the planetary magnetic field exposes the atmosphere to stellar wind erosion and the surface to harmful radiation. In addition to weak magnetic fields, massive melt eruption rates and prolonged magma oceans may render eccentric planets in the habitable zone of low-mass stars inhospitable for life.

  8. The Effects of Solar Maximum on the Earth's Satellite Population and Space Situational Awareness

    Science.gov (United States)

    Johnson, Nicholas L.

    2012-01-01

    The rapidly approaching maximum of Solar Cycle 24 will have wide-ranging effects not only on the number and distribution of resident space objects, but also on vital aspects of space situational awareness, including conjunction assessment processes. The best known consequence of high solar activity is an increase in the density of the thermosphere, which, in turn, increases drag on the vast majority of objects in low Earth orbit. The most prominent evidence of this is seen in a dramatic increase in space object reentries. Due to the massive amounts of new debris created by the fragmentations of Fengyun-1C, Cosmos 2251 and Iridium 33 during the recent period of Solar Minimum, this effect might reach epic levels. However, space surveillance systems are also affected, both directly and indirectly, historically leading to an increase in the number of lost satellites and in the routine accuracy of the calculation of their orbits. Thus, at a time when more objects are drifting through regions containing exceptionally high-value assets, such as the International Space Station and remote sensing satellites, their position uncertainties increase. In other words, as the possibility of damaging and catastrophic collisions increases, our ability to protect space systems is degraded. Potential countermeasures include adjustments to space surveillance techniques and the resetting of collision avoidance maneuver thresholds.

  9. Space Elevators: Building a Permanent Bridge for Space Exploration and Economic Development

    Science.gov (United States)

    Smitherman, David V., Jr.; Howell, Joe T. (Technical Monitor)

    2000-01-01

    A space elevator is a physical connection from the surface of the Earth to a geo-stationary orbit above the Earth approximately 35,786 km in altitude. Its center of mass is at the geo-stationary point such that it has a 24-hour orbit, and stays over the same point above the equator as the Earth rotates on its axis. The structure is utilized as a transportation and utility system for moving payloads, power, and gases between the surface of the Earth and space. It makes the physical connection from Earth to space in the same way a bridge connects two cities across a body of' water. The space elevator may be an important concept for the future development of space in the latter part of the 21th century. It has the potential to provide mass-transportation to space in the same way highways, railroads, power lines, and pipelines provide mass-transportation across the Earth's surface. The low energy requirements for moving payloads up and down the elevator make it one of only a few concepts that has the potential of lowering the cost to orbit to less than $10 per kilogram. This paper will summarize the findings from a 1999 NASA workshop on Space Elevators held at the NASA Marshall Space Flight Center (MSFC). The workshop was sponsored by the Advanced Projects Office in the Flight Projects Directorate at MSFC, and was organized in cooperation with the Advanced Space Transportation Program at MSFC and the Advanced Concepts Office in the Office of Space Flight at NASA Headquarters. New concepts will be examined for space elevator construction and a number of issues will be discussed that has helped to bring the space elevator concept out of the realm of science fiction and into the realm of possibility. In conclusion, it appears that the space elevator concept may well he possible in the latter part of the 21st century if proper planning and technology development is emphasized to resolve key issues in the development of this advanced space infrastructure concept.

  10. Application of Semi-analytical Satellite Theory orbit propagator to orbit determination for space object catalog maintenance

    Science.gov (United States)

    Setty, Srinivas J.; Cefola, Paul J.; Montenbruck, Oliver; Fiedler, Hauke

    2016-05-01

    Catalog maintenance for Space Situational Awareness (SSA) demands an accurate and computationally lean orbit propagation and orbit determination technique to cope with the ever increasing number of observed space objects. As an alternative to established numerical and analytical methods, we investigate the accuracy and computational load of the Draper Semi-analytical Satellite Theory (DSST). The standalone version of the DSST was enhanced with additional perturbation models to improve its recovery of short periodic motion. The accuracy of DSST is, for the first time, compared to a numerical propagator with fidelity force models for a comprehensive grid of low, medium, and high altitude orbits with varying eccentricity and different inclinations. Furthermore, the run-time of both propagators is compared as a function of propagation arc, output step size and gravity field order to assess its performance for a full range of relevant use cases. For use in orbit determination, a robust performance of DSST is demonstrated even in the case of sparse observations, which is most sensitive to mismodeled short periodic perturbations. Overall, DSST is shown to exhibit adequate accuracy at favorable computational speed for the full set of orbits that need to be considered in space surveillance. Along with the inherent benefits of a semi-analytical orbit representation, DSST provides an attractive alternative to the more common numerical orbit propagation techniques.

  11. Space Facility for Orbital Remote Manufacturing (SPACEFORM), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA need in continued cost efficient International Space Station (ISS) exploration FOMS Inc. proposes to develop and deploy Space Facility for Orbital...

  12. Extrasolar Giant Planet in Earth-like Orbit

    Science.gov (United States)

    1999-07-01

    companion . iota Hor b has an orbital period of 320 days. From this period, the known mass of the central star (1.03 solar masses) and the amplitude of the velocity changes, a mass of at least 2.26 times that of planet Jupiter is deduced for the planet. It revolves around the host star in a somewhat elongated orbit (the eccentricity is 0.16). If it were located in our own solar system, this orbit would stretch from just outside the orbit of Venus (at 117 million km or 0.78 Astronomical Units from the Sun) to just outside the orbit of the Earth (the point farthest from the Sun, at 162 million km or 1.08 Astronomical Units) The new giant planet is thus moving in an orbit not unlike that of the Earth. In fact, of all the planets discovered so far, the orbit of iota Hor b is the most Earth-like. Also, with a spectral type of G0 V , its host star is quite similar to the Sun (G2 V). iota Hor b is, however, at least 720 times more massive than the Earth and it is probably more similar to planet Jupiter in our own solar system. While the radial velocity technique described above only determines a minimum value for the planet's mass, an analysis of the velocity with which the star turns around its own axis suggests that the true mass of iota Hor b is unlikely to be much higher. A difficult case Natural phenomena with periods near one solar year always present a particular challenge to astronomers. This is one of the reasons why it has been necessary to observe the iota Hor system for such a long time to be absolutely sure about the present result. First, special care must be taken to verify that the radial velocity variations found in the data are not an artefact of the Earth's movement around the Sun. In any case, the effect of this movement on the measurements must be accurately accounted for; it reaches about ± 30 km/sec over one year, i.e. much larger than the effect of the new planet. In the present case of iota Hor , this was thoroughly tested and any residual influence of

  13. A Numerical Approach to Estimate the Ballistic Coefficient of Space Debris from TLE Orbital Data

    Science.gov (United States)

    Narkeliunas, Jonas

    2016-01-01

    Low Earth Orbit (LEO) is full of space debris, which consist of spent rocket stages, old satellites and fragments from explosions and collisions. As of 2009, more than 21,000 orbital debris larger than 10 cm are known to exist], and while it is hard to track anything smaller than that, the estimated population of particles between 1 and 10 cm in diameter is approximately 500,000, whereas small as 1 cm exceeds 100 million. These objects orbit Earth with huge kinetic energies speeds usually exceed 7 kms. The shape of their orbit varies from almost circular to highly elliptical and covers all LEO, a region in space between 160 and 2,000 km above sea level. Unfortunately, LEO is also the place where most of our active satellites are situated, as well as, International Space Station (ISS) and Hubble Space Telescope, whose orbits are around 400 and 550 km above sea level, respectively.This poses a real threat as debris can collide with satellites and deal substantial damage or even destroy them.Collisions between two or more debris create clouds of smaller debris, which are harder to track and increase overall object density and collision probability. At some point, the debris density couldthen reach a critical value, which would start a chain reaction and the number of space debris would grow exponentially. This phenomenon was first described by Kessler in 1978 and he concluded that it would lead to creation of debris belt, which would vastly complicate satellite operations in LEO. The debris density is already relatively high, as seen from several necessary debris avoidance maneuvers done by Shuttle, before it was discontinued, and ISS. But not all satellites have a propulsion system to avoid collision, hence different methods need to be applied. One of the proposed collision avoidance concepts is called LightForce and it suggests using photon pressure to induce small orbital corrections to deflect debris from colliding. This method is very efficient as seen from

  14. Air-Cored Linear Induction Motor for Earth-to-Orbit Systems

    Science.gov (United States)

    Zabar, Zivan; Levi, Enrico; Birenbaum, Leo

    1996-01-01

    The need for lowering the cost of Earth-to-Orbit (ETO) launches has prompted consideration of electromagnetic launchers. A preliminary design based on the experience gained in an advanced type of coilgun and on innovative ideas shows that such a launcher is technically feasible with almost off-the-shelf components.

  15. Dynamics of Orbits near 3:1 Resonance in the Earth-Moon System

    Science.gov (United States)

    Dichmann, Donald J.; Lebois, Ryan; Carrico, John P., Jr.

    2013-01-01

    The Interstellar Boundary Explorer (IBEX) spacecraft is currently in a highly elliptical orbit around Earth with a period near 3:1 resonance with the Moon. Its orbit is oriented so that apogee does not approach the Moon. Simulations show this orbit to be remarkably stable over the next twenty years. This article examines the dynamics of such orbits in the Circular Restricted 3-Body Problem (CR3BP). We look at three types of periodic orbits, each exhibiting a type of symmetry of the CR3BP. For each of the orbit types, we assess the local stability using Floquet analysis. Although not all of the periodic solutions are stable in the mathematical sense, any divergence is so slow as to produce practical stability over several decades. We use Poincare maps with twenty-year propagations to assess the nonlinear stability of the orbits, where the perturbation magnitudes are related to the orbit uncertainty for the IBEX mission. Finally we show that these orbits belong to a family of orbits connected in a bifurcation diagram that exhibits exchange of stability. The analysis of these families of period orbits provides a valuable starting point for a mission orbit trade study.

  16. NASA Earth-to-Orbit Engineering Design Challenges: Thermal Protection Systems

    Science.gov (United States)

    National Aeronautics and Space Administration (NASA), 2010

    2010-01-01

    National Aeronautics and Space Administration (NASA) Engineers at Marshall Space Flight Center, Dryden Flight Research Center, and their partners at other NASA centers and in private industry are currently developing X-33, a prototype to test technologies for the next generation of space transportation. This single-stage-to-orbit reusable launch…

  17. Noncommutative Phase Spaces by Coadjoint Orbits Method

    Directory of Open Access Journals (Sweden)

    Ancille Ngendakumana

    2011-12-01

    Full Text Available We introduce noncommutative phase spaces by minimal couplings (usual one, dual one and their mixing. We then realize some of them as coadjoint orbits of the anisotropic Newton-Hooke groups in two- and three-dimensional spaces. Through these constructions the positions and the momenta of the phase spaces do not commute due to the presence of a magnetic field and a dual magnetic field.

  18. Optimal selection of Orbital Replacement Unit on-orbit spares - A Space Station system availability model

    Science.gov (United States)

    Schwaab, Douglas G.

    1991-01-01

    A mathematical programing model is presented to optimize the selection of Orbital Replacement Unit on-orbit spares for the Space Station. The model maximizes system availability under the constraints of logistics resupply-cargo weight and volume allocations.

  19. Capturing near-Earth asteroids around Earth

    Science.gov (United States)

    Hasnain, Zaki; Lamb, Christopher A.; Ross, Shane D.

    2012-12-01

    The list of detected near-Earth asteroids (NEAs) is constantly growing. NEAs are likely targets for resources to support space industrialization, as they may be the least expensive source of certain needed raw materials. The limited supply of precious metals and semiconducting elements on Earth may be supplemented or even replaced by the reserves floating in the form of asteroids around the solar system. Precious metals make up a significant fraction NEAs by mass, and even one metallic asteroid of ˜1km size and fair enrichment in platinum-group metals would contain twice the tonnage of such metals already harvested on Earth. There are ˜1000 NEAs with a diameter of greater than 1 km. Capturing these asteroids around the Earth would expand the mining industry into an entirely new dimension. Having such resources within easy reach in Earth's orbit could provide an off-world environmentally friendly remedy for impending terrestrial shortages, especially given the need for raw materials in developing nations. In this paper, we develop and implement a conceptually simple algorithm to determine trajectory characteristics necessary to move NEAs into capture orbits around the Earth. Altered trajectories of asteroids are calculated using an ephemeris model. Only asteroids of eccentricity less than 0.1 have been studied and the model is restricted to the ecliptic plane for simplicity. We constrain the time of retrieval to be 10 years or less, based on considerations of the time to return on investment. For the heliocentric phase, constant acceleration is assumed. The acceleration required for transporting these asteroids from their undisturbed orbits to the sphere of influence of the Earth is the primary output, along with the impulse or acceleration necessary to effect capture to a bound orbit once the Earth's sphere of influence is reached. The initial guess for the constant acceleration is provided by a new estimation method, similar in spirit to Edelbaum's. Based on the

  20. EFFECT OF UV RADIATION ON THE SPECTRAL FINGERPRINTS OF EARTH-LIKE PLANETS ORBITING M STARS

    Energy Technology Data Exchange (ETDEWEB)

    Rugheimer, S. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kaltenegger, L. [Carl Sagan Institute, Cornell University, Ithaca, NY 14853 (United States); Segura, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México (Mexico); Linsky, J. [JILA, University of Colorado and NIST, 440 UCB, Boulder, CO 80309-0440 (United States); Mohanty, S. [Imperial College London, 1010 Blackett Lab, Prince Consort Road, London SW7 2AZ (United Kingdom)

    2015-08-10

    We model the atmospheres and spectra of Earth-like planets orbiting the entire grid of M dwarfs for active and inactive stellar models with T{sub eff} = 2300 K to T{sub eff} = 3800 K and for six observed MUSCLES M dwarfs with UV radiation data. We set the Earth-like planets at the 1 AU equivalent distance and show spectra from the visible to IR (0.4–20 μm) to compare detectability of features in different wavelength ranges with the James Webb Space Telescope and other future ground- and spaced-based missions to characterize exo-Earths. We focus on the effect of UV activity levels on detectable atmospheric features that indicate habitability on Earth, namely, H{sub 2}O, O{sub 3}, CH{sub 4}, N{sub 2}O, and CH{sub 3}Cl. To observe signatures of life—O{sub 2}/O{sub 3} in combination with reducing species like CH{sub 4}—we find that early and active M dwarfs are the best targets of the M star grid for future telescopes. The O{sub 2} spectral feature at 0.76 μm is increasingly difficult to detect in reflected light of later M dwarfs owing to low stellar flux in that wavelength region. N{sub 2}O, another biosignature detectable in the IR, builds up to observable concentrations in our planetary models around M dwarfs with low UV flux. CH{sub 3}Cl could become detectable, depending on the depth of the overlapping N{sub 2}O feature. We present a spectral database of Earth-like planets around cool stars for directly imaged planets as a framework for interpreting future light curves, direct imaging, and secondary eclipse measurements of the atmospheres of terrestrial planets in the habitable zone to design and assess future telescope capabilities.

  1. EFFECT OF UV RADIATION ON THE SPECTRAL FINGERPRINTS OF EARTH-LIKE PLANETS ORBITING M STARS

    International Nuclear Information System (INIS)

    Rugheimer, S.; Kaltenegger, L.; Segura, A.; Linsky, J.; Mohanty, S.

    2015-01-01

    We model the atmospheres and spectra of Earth-like planets orbiting the entire grid of M dwarfs for active and inactive stellar models with T eff = 2300 K to T eff = 3800 K and for six observed MUSCLES M dwarfs with UV radiation data. We set the Earth-like planets at the 1 AU equivalent distance and show spectra from the visible to IR (0.4–20 μm) to compare detectability of features in different wavelength ranges with the James Webb Space Telescope and other future ground- and spaced-based missions to characterize exo-Earths. We focus on the effect of UV activity levels on detectable atmospheric features that indicate habitability on Earth, namely, H 2 O, O 3 , CH 4 , N 2 O, and CH 3 Cl. To observe signatures of life—O 2 /O 3 in combination with reducing species like CH 4 —we find that early and active M dwarfs are the best targets of the M star grid for future telescopes. The O 2 spectral feature at 0.76 μm is increasingly difficult to detect in reflected light of later M dwarfs owing to low stellar flux in that wavelength region. N 2 O, another biosignature detectable in the IR, builds up to observable concentrations in our planetary models around M dwarfs with low UV flux. CH 3 Cl could become detectable, depending on the depth of the overlapping N 2 O feature. We present a spectral database of Earth-like planets around cool stars for directly imaged planets as a framework for interpreting future light curves, direct imaging, and secondary eclipse measurements of the atmospheres of terrestrial planets in the habitable zone to design and assess future telescope capabilities

  2. Active Radiation Detectors for Use in Space Beyond Low Earth Orbit: Spatial and Energy Resolution Requirements and Methods for Heavy Ion Charge Classification

    Science.gov (United States)

    McBeth, Rafe A.

    Space radiation exposure to astronauts will need to be carefully monitored on future missions beyond low earth orbit. NASA has proposed an updated radiation risk framework that takes into account a significant amount of radiobiological and heavy ion track structure information. These models require active radiation detection systems to measure the energy and ion charge Z. However, current radiation detection systems cannot meet these demands. The aim of this study was to investigate several topics that will help next generation detection systems meet the NASA objectives. Specifically, this work investigates the required spatial resolution to avoid coincident events in a detector, the effects of energy straggling and conversion of dose from silicon to water, and methods for ion identification (Z) using machine learning. The main results of this dissertation are as follows: 1. Spatial resolution on the order of 0.1 cm is required for active space radiation detectors to have high confidence in identifying individual particles, i.e., to eliminate coincident events. 2. Energy resolution of a detector system will be limited by energy straggling effects and the conversion of dose in silicon to dose in biological tissue (water). 3. Machine learning methods show strong promise for identification of ion charge (Z) with simple detector designs.

  3. Getting a Crew into Orbit

    Science.gov (United States)

    Riddle, Bob

    2011-01-01

    Despite the temporary setback in our country's crewed space exploration program, there will continue to be missions requiring crews to orbit Earth and beyond. Under the NASA Authorization Act of 2010, NASA should have its own heavy launch rocket and crew vehicle developed by 2016. Private companies will continue to explore space, as well. At the…

  4. Novel Space-based Solar Power Technologies and Architectures for Earth and Beyond

    Science.gov (United States)

    Howell, Joe T.; Fikes, John C.; O'Neill, Mark J.

    2005-01-01

    Research, development and studies of novel space-based solar power systems, technologies and architectures for Earth and beyond are needed to reduce the cost of clean electrical power for terrestrial use and to provide a stepping stone for providing an abundance of power in space, i.e., manufacturing facilities, tourist facilities, delivery of power between objects in space, and between space and surface sites. The architectures, technologies and systems needed for space to Earth applications may also be used for in-space applications. Advances in key technologies, i.e., power generation, power management and distribution, power beaming and conversion of beamed power are needed to achieve the objectives of both terrestrial and extraterrestrial applications. Power beaming or wireless power transmission (WPT) can involve lasers or microwaves along with the associated power interfaces. Microwave and laser transmission techniques have been studied with several promising approaches to safe and efficient WPT identified. These investigations have included microwave phased array transmitters, as well as laser transmission and associated optics. There is a need to produce "proof-of-concept" validation of critical WPT technologies for both the near-term, as well as far-term applications. Investments may be harvested in near-term beam safe demonstrations of commercial WPT applications. Receiving sites (users) include ground-based stations for terrestrial electrical power, orbital sites to provide power for satellites and other platforms, future space elevator systems, space vehicle propulsion, and space to surface sites. This paper briefly discusses achieving a promising approach to the solar power generation and beamed power conversion. The approach is based on a unique high-power solar concentrator array called Stretched Lens Array (SLA) for both solar power generation and beamed power conversion. Since both versions (solar and laser) of SLA use many identical components

  5. A model perspective on orbital forcing of monsoons and Mediterranean climate using EC-Earth

    NARCIS (Netherlands)

    Bosmans, J.H.C.

    2014-01-01

    This thesis focuses on orbitally forced changes of monsoons and Mediterranean climate. Changes in the shape of the Earths orbit around the Sun and its rotational axis govern the seasonal and latitudinal distribution of incoming solar radiation on time scales of thousands to millions of years. The

  6. K-Band Phased Array Developed for Low- Earth-Orbit Satellite Communications

    Science.gov (United States)

    Anzic, Godfrey

    1999-01-01

    Future rapid deployment of low- and medium-Earth-orbit satellite constellations that will offer various narrow- to wide-band wireless communications services will require phased-array antennas that feature wide-angle and superagile electronic steering of one or more antenna beams. Antennas, which employ monolithic microwave integrated circuits (MMIC), are perfectly suited for this application. Under a cooperative agreement, an MMIC-based, K-band phased-array antenna is being developed with 50/50 cost sharing by the NASA Lewis Research Center and Raytheon Systems Company. The transmitting array, which will operate at 19 gigahertz (GHz), is a state-of-the-art design that features dual, independent, electronically steerable beam operation ( 42 ), a stand-alone thermal management, and a high-density tile architecture. This array can transmit 622 megabits per second (Mbps) in each beam from Earth orbit to small Earth terminals. The weight of the total array package is expected to be less than 8 lb. The tile integration technology (flip chip MMIC tile) chosen for this project represents a major advancement in phased-array engineering and holds much promise for reducing manufacturing costs.

  7. Critical Technologies for the Development of Future Space Elevator Systems

    Science.gov (United States)

    Smitherman, David V., Jr.

    2005-01-01

    A space elevator is a tether structure extending through geosynchronous earth orbit (GEO) to the surface of the earth. Its center of mass is in GEO such that it orbits the earth in sync with the earth s rotation. In 2004 and 2005, the NASA Marshall Space Flight Center and the Institute for Scientific Research, Inc. worked under a cooperative agreement to research the feasibility of space elevator systems, and to advance the critical technologies required for the future development of space elevators for earth to orbit transportation. The discovery of carbon nanotubes in the early 1990's was the first indication that it might be possible to develop materials strong enough to make space elevator construction feasible. This report presents an overview of some of the latest NASA sponsored research on space elevator design, and the systems and materials that will be required to make space elevator construction possible. In conclusion, the most critical technology for earth-based space elevators is the successful development of ultra high strength carbon nanotube reinforced composites for ribbon construction in the 1OOGPa range. In addition, many intermediate technology goals and demonstration missions for the space elevator can provide significant advancements to other spaceflight and terrestrial applications.

  8. Space Elevator Concept Considered a Reality

    Science.gov (United States)

    2000-01-01

    The `once upon a time' science fiction concept of a space elevator has been envisioned and studied as a real mass transportation system in the latter part of the 21st century. David Smitherman of NASA's Marshall Space Flight Center's Advanced Projects Office has compiled plans for such an elevator. The space elevator concept is a structure extending from the surface of the Earth to geostationary Earth orbit (GEO) at 35,786 km in altitude. The tower would be approximately 50 km tall with a cable tethered to the top. Its center mass would be at GEO such that the entire structure orbits the Earth in sync with the Earth's rotation maintaining a stationary position over its base attachment at the equator. Electromagnetic vehicles traveling along the cable could serve as a mass transportation system for transporting people, payloads, and power between space and Earth. This illustration by artist Pat Rawling shows the concept of a space elevator as viewed from the geostationary transfer station looking down the length of the elevator towards the Earth.

  9. High-Definition Television (HDTV) Images for Earth Observations and Earth Science Applications

    Science.gov (United States)

    Robinson, Julie A.; Holland, S. Douglas; Runco, Susan K.; Pitts, David E.; Whitehead, Victor S.; Andrefouet, Serge M.

    2000-01-01

    As part of Detailed Test Objective 700-17A, astronauts acquired Earth observation images from orbit using a high-definition television (HDTV) camcorder, Here we provide a summary of qualitative findings following completion of tests during missions STS (Space Transport System)-93 and STS-99. We compared HDTV imagery stills to images taken using payload bay video cameras, Hasselblad film camera, and electronic still camera. We also evaluated the potential for motion video observations of changes in sunlight and the use of multi-aspect viewing to image aerosols. Spatial resolution and color quality are far superior in HDTV images compared to National Television Systems Committee (NTSC) video images. Thus, HDTV provides the first viable option for video-based remote sensing observations of Earth from orbit. Although under ideal conditions, HDTV images have less spatial resolution than medium-format film cameras, such as the Hasselblad, under some conditions on orbit, the HDTV image acquired compared favorably with the Hasselblad. Of particular note was the quality of color reproduction in the HDTV images HDTV and electronic still camera (ESC) were not compared with matched fields of view, and so spatial resolution could not be compared for the two image types. However, the color reproduction of the HDTV stills was truer than colors in the ESC images. As HDTV becomes the operational video standard for Space Shuttle and Space Station, HDTV has great potential as a source of Earth-observation data. Planning for the conversion from NTSC to HDTV video standards should include planning for Earth data archiving and distribution.

  10. Orbit Determination Using Vinti’s Solution

    Science.gov (United States)

    2016-09-15

    crew capsule orbited the earth twice and then experienced re-entry as part of an experimental test flight (Orion EFT -1). With a flight duration of almost...utility greatly outweighs these initial difficulties. A summary of efforts required to tap into these benefits follows. • The current research developed...and Lear, D., “Orion EFT -1 Postflight MMOD Inspection,” Orbital Debris Quarterly News, Vol. 19, April 2015, pp. 6–9. [16] European Space Agency, “Space

  11. Space-to-Space Power Beaming Enabling High Performance Rapid Geocentric Orbit Transfer

    Science.gov (United States)

    Dankanich, John W.; Vassallo, Corinne; Tadge, Megan

    2015-01-01

    The use of electric propulsion is more prevalent than ever, with industry pursuing all electric orbit transfers. Electric propulsion provides high mass utilization through efficient propellant transfer. However, the transfer times become detrimental as the delta V transitions from near-impulsive to low-thrust. Increasing power and therefore thrust has diminishing returns as the increasing mass of the power system limits the potential acceleration of the spacecraft. By using space-to-space power beaming, the power system can be decoupled from the spacecraft and allow significantly higher spacecraft alpha (W/kg) and therefore enable significantly higher accelerations while maintaining high performance. This project assesses the efficacy of space-to-space power beaming to enable rapid orbit transfer while maintaining high mass utilization. Concept assessment requires integrated techniques for low-thrust orbit transfer steering laws, efficient large-scale rectenna systems, and satellite constellation configuration optimization. This project includes the development of an integrated tool with implementation of IPOPT, Q-Law, and power-beaming models. The results highlight the viability of the concept, limits and paths to infusion, and comparison to state-of-the-art capabilities. The results indicate the viability of power beaming for what may be the only approach for achieving the desired transit times with high specific impulse.

  12. Mechanical properties of silicate glasses exposed to a low-Earth orbit

    Science.gov (United States)

    Wiedlocher, David E.; Tucker, Dennis S.; Nichols, Ron; Kinser, Donald L.

    1992-01-01

    The effects of a 5.8 year exposure to low earth orbit environment upon the mechanical properties of commercial optical fused silica, low iron soda-lime-silica, Pyrex 7740, Vycor 7913, BK-7, and the glass ceramic Zerodur were examined. Mechanical testing employed the ASTM-F-394 piston on 3-ball method in a liquid nitrogen environment. Samples were exposed on the Long Duration Exposure Facility (LDEF) in two locations. Impacts were observed on all specimens except Vycor. Weibull analysis as well as a standard statistical evaluation were conducted. The Weibull analysis revealed no differences between control samples and the two exposed samples. We thus concluded that radiation components of the Earth orbital environment did not degrade the mechanical strength of the samples examined within the limits of experimental error. The upper bound of strength degradation for meteorite impacted samples based upon statistical analysis and observation was 50 percent.

  13. Low energy trajectories for the Moon-to-Earth space flight

    Indian Academy of Sciences (India)

    The Moon-to-Earth low energy trajectories of `detour'type are found and studied within the frame of the Moon –Earth –Sun-particle system. ... This results in the particle flight to a distance of about 1.5 million km from the Earth where the Sun gravitation decreases the particle orbit perigee distance to a small value that leads to ...

  14. The international earth observing system: a cultural debate about earth sciences from space

    NARCIS (Netherlands)

    Menenti, M.

    1996-01-01

    This paper gives an overview of the International Earth Observing System, i.e. the combined earth observation programmes of space agencies worldwide and of the relevance of advanced space-borne sensor systems to the study and understanding of interactions between land surface and atmosphere. The

  15. Earth and space science information systems

    Energy Technology Data Exchange (ETDEWEB)

    Zygielbaum, A. (ed.) (Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States))

    1993-01-01

    These proceedings represent papers presented at the Earth and Space Science Information Systems (ESSIS) Conference. The attendees included scientists and engineers across many disciplines. New trends in information organizations were reviewed. One hundred and twenty eight papers are included in this volume, out of these two have been abstracted for the Energy Science and Technology database. The topics covered in the papers range from Earth science and technology to astronomy and space, planetary science and education. (AIP)

  16. Satellite orbits in Levi-Civita space

    Science.gov (United States)

    Humi, Mayer

    2018-03-01

    In this paper we consider satellite orbits in central force field with quadratic drag using two formalisms. The first using polar coordinates in which the satellite angular momentum plays a dominant role. The second is in Levi-Civita coordinates in which the energy plays a central role. We then merge these two formalisms by introducing polar coordinates in Levi-Civita space and derive a new equation for satellite orbits which unifies these two paradigms. In this equation energy and angular momentum appear on equal footing and thus characterize the orbit by its two invariants. Using this formalism we show that equatorial orbits around oblate spheroids can be expressed analytically in terms of Elliptic functions. In the second part of the paper we derive in Levi-Civita coordinates a linearized equation for the relative motion of two spacecrafts whose trajectories are in the same plane. We carry out also a numerical verification of these equations.

  17. Space Shuttle Orbiter Endeavour STS-47 Launch

    Science.gov (United States)

    1992-01-01

    A smooth countdown culminated in a picture-perfect launch as the Space Shuttle Orbiter Endeavour (STS-47) climbed skyward atop a ladder of billowing smoke on September 12, 1992. The primary payload for the plarned seven-day flight was the Spacelab-J science laboratory. The second flight of Endeavour marks a number of historic firsts: the first space flight of an African-American woman, the first Japanese citizen to fly on a Space Shuttle, and the first married couple to fly in space.

  18. Biofilms On Orbit and On Earth: Current Methods, Future Needs

    Science.gov (United States)

    Vega, Leticia

    2013-01-01

    Biofilms have played a significant role on the effectiveness of life support hardware on the Space Shuttle and International Space Station (ISS). This presentation will discuss how biofilms impact flight hardware, how on orbit biofilms are analyzed from an engineering and research perspective, and future needs to analyze and utilize biofilms for long duration, deep space missions.

  19. The Near-Earth Space Radiation Environment

    Science.gov (United States)

    Xapsos, Michael

    2008-01-01

    This viewgraph presentation reviews the effects of the Near-Earth space radiation environment on NASA missions. Included in this presentation is a review of The Earth s Trapped Radiation Environment, Solar Particle Events, Galactic Cosmic Rays and Comparison to Accelerator Facilities.

  20. Planetarium Inversum -- a space vision for Earth education.

    Science.gov (United States)

    Lotsch, B

    2003-01-01

    In a planetarium, the visitor is sitting on Earth and looking into an imaginary space. The Planetarium Inversum is the opposite: visitors are sitting in a space station, looking down on Mother Earth. It is a scientifically-based information show with visitors involvement, its elements being partially virtual (Earth in space has to be projected with highest possible resolution) but also containing real structures, such as the visitors' Earth observatory with adjacent biological systems (plant cultures and other ecological life support components). Its main message concerns the limits and the vulnerability of our home planet, its uniqueness, beauty and above all, its irreplaceableness: Earth does not have an emergency exit. The Earth observatory is part of a ring shaped, rotating space station of the type designed by Wernher von Braun decades ago. Visitors are told that gravity is being substituted by centrifugal force. Both types of life support systems are being demonstrated--self regenerative life based ones and technical ones as a backup (solar electric splitting of water and chemical absorption of respiratory CO2). c2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  1. A Geostationary Earth Orbit Satellite Model Using Easy Java Simulation

    Science.gov (United States)

    Wee, Loo Kang; Goh, Giam Hwee

    2013-01-01

    We develop an Easy Java Simulation (EJS) model for students to visualize geostationary orbits near Earth, modelled using a Java 3D implementation of the EJS 3D library. The simplified physics model is described and simulated using a simple constant angular velocity equation. We discuss four computer model design ideas: (1) a simple and realistic…

  2. Radiolarian abundance - A monsoon proxy responding to the Earth`s orbital forcing: Inferences on the mid-Brunhes climate shift

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, S.M.

    stream_size 32348 stream_content_type text/plain stream_name Earth_Sci_India_2_1.pdf.txt stream_source_info Earth_Sci_India_2_1.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 Gupta http://www....earthscienceindia.info/Gupta.htm 1 of 8 1/28/2009 3:14 PM Earth Science India Vol.2 (I),January, 2009, pp. 1-20 http://www.earthscienceindia.info/ Radiolarian abundance - a monsoon proxy responding to the Earth’s orbital forcing: Inferences on the mid-Brunhes climate shift Shyam...

  3. Three Super-Earths Orbiting HD 7924

    Science.gov (United States)

    Fulton, Benjamin J.; Weiss, Lauren M.; Sinukoff, Evan; Isaacson, Howard; Howard, Andrew W.; Marcy, Geoffrey W.; Henry, Gregory W.; Holden, Bradford P.; Kibrick, Robert I.

    2015-06-01

    We report the discovery of two super-Earth-mass planets orbiting the nearby K0.5 dwarf HD 7924, which was previously known to host one small planet. The new companions have masses of 7.9 and 6.4 {{M}\\oplus }, and orbital periods of 15.3 and 24.5 days. We perform a joint analysis of high-precision radial velocity data from Keck/HIRES and the new Automated Planet Finder Telescope (APF) to robustly detect three total planets in the system. We refine the ephemeris of the previously known planet using 5 yr of new Keck data and high-cadence observations over the last 1.3 yr with the APF. With this new ephemeris, we show that a previous transit search for the inner-most planet would have covered 70% of the predicted ingress or egress times. Photometric data collected over the last eight years using the Automated Photometric Telescope shows no evidence for transits of any of the planets, which would be detectable if the planets transit and their compositions are hydrogen-dominated. We detect a long-period signal that we interpret as the stellar magnetic activity cycle since it is strongly correlated with the Ca ii H and K activity index. We also detect two additional short-period signals that we attribute to rotationally modulated starspots and a one-month alias. The high-cadence APF data help to distinguish between the true orbital periods and aliases caused by the window function of the Keck data. The planets orbiting HD 7924 are a local example of the compact, multi-planet systems that the Kepler Mission found in great abundance. Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. Keck time was granted for this project by the University of Hawai‘i, the University of California, and NASA.

  4. Near Earth Objects

    DEFF Research Database (Denmark)

    Wolff, Stefan

    2006-01-01

    , Near Earth Objects: Asteroids and comets following paths that bring them near the Earth. NEOs have collided with the Earth since its formation, some causing local devastation, some causing global climate changes, yet the threat from a collision with a near Earth object has only recently been recognised...... and accepted. The European Space Agency mission Gaia is a proposed space observatory, designed to perform a highly accurate census of our galaxy, the Milky Way, and beyond. Through accurate measurement of star positions, Gaia is expected to discover thousands of extra-solar planets and follow the bending...... of starlight by the Sun, and therefore directly observe the structure of space-time. This thesis explores several aspects of the observation of NEOs with Gaia, emphasising detection of NEOs and the quality of orbits computed from Gaia observations. The main contribution is the work on motion detection...

  5. ROGER a potential orbital space debris removal system

    Science.gov (United States)

    Starke, Juergen; Bischof, Bernd; Foth, W.-O.; -J., J.; Günther

    The previous activities in the field of On Orbit Servicing studied in the 1990's included in partic-ular the capability of vehicles in GEO to capture and support satellites (mainly communication satellites) to enable repair and continuation of operations, and finally the controlled transfer the target into a permanent graveyard orbit. The specific capture tools for these applications were mostly based on robotic systems to capture and fix the target under specific dynamic constraints (e.g. slowly tumbling target) without damage, and to allow the stabilization, re-orientation and potential repair of the target and subsequent release or transport to the final disposal orbit. Due to the drastically increasing number of debris particularly in the Low Earth Orbits (SSO) the active debris removal is now necessary to counteract to the predicted debris production cascade (Kessler Syndrome), which means the pollution of the total sphere in low earth orbit and not only the SSO area. In most of the debris congresses it was recommended to start removal with the still integrated systems as soon as possible. In the case of large debris objects, the soft capture system can be replaced by a simpler and robust system able to operate from a safe distance to the target and flexible enough to capture and hold different types of targets such as deactivated and/or defective satellites, upper stages and big fragments. These nominally non -cooperative targets might be partially destroyed by the capture process, but the production of additional debris shall be avoided. A major argument for the commercial applications is a multi-target mission potential, which is possible at GEO because the transfer propellant requirement to the disposal orbit and the return to the orbit of the next potential target is relative low (orbits with similar inclination and altitude). The proposed ROGER system is designed as a spacecraft with rendezvous capabilities including inspection in the vicinity of the

  6. Two planetary systems with transiting Earth-size and super-Earth planets orbiting late-type dwarf stars

    Science.gov (United States)

    Alonso, E. Díez; Hernández, J. I. González; Suárez Gómez, S. L.; Aguado, D. S.; González Gutiérrez, C.; Suárez Mascareño, A.; Cabrera-Lavers, A.; González-Nuevo, J.; Toledo-Padrón, B.; Gracia, J.; de Cos Juez, F. J.; Rebolo, R.

    2018-06-01

    We present two new planetary systems found around cool dwarf stars with data from the K2 mission. The first system was found in K2-XX1 (EPIC 248545986), characterized in this work as M3.0V and observed in the 14th campaign of K2. It consists of three Earth-size transiting planets with radii of 1.1, 1.0 and 1.1 R⊕, showing a compact configuration with orbital periods of 5.24, 7.78 and 10.1 days, close to 2:3:4 resonance. The second was found in K2-XX2 (EPIC 249801827), characterized in this work as M0.5V and observed in the 15th campaign. It consists of two transiting super-Earths with radii 2.0 and 1.8 R⊕ and orbital periods of 6.03 and 20.5 days. The equilibrium temperatures of the atmospheres of these planets are estimated to be in the range of 380-600 K and the amplitudes of signals in transmission spectroscopy are estimated at ˜ 10 ppm.

  7. Multi-layered foil capture of micrometeoroids and orbital debris in low Earth orbit

    Science.gov (United States)

    Kearsley, A.; Graham, G.

    Much of our knowledge concerning the sub-millimetre orbital debris population that poses a threat to orbiting satellites has been gleaned from examination of surfaces retrieved and subsequently analysed as part of post-flight investigations. The preservation of the hypervelocity impact-derived remnants located on these surfaces is very variable, whether of space debris or micrometeoroid origin. Whilst glass and metallic materials show highly visible impact craters when examined using optical and electron microscopes, complex mixing between the target material and the impacting particle may make unambiguous interpretation of the impactor origin difficult or impossible. Our recent detailed examination of selected multi-layered insulation (MLI) foils from the ISAS Space Flyer Unit (SFU), and our preliminary study of NASA's Trek blanket, exposed on the Mir station, show that these constructions have the potential to preserve abundant residue material of a quality sufficient for detailed analysis. Although there are still limitations on the recognition of certain sources of orbital debris, the foils complement the metal and glass substrates. We suggest that a purpose-built multi-layered foil structure may prove to be extremely effective for rapid collection and unambiguous analysis of impact- derived residues. Such a collector could be used an environmental monitor for ISS, as it would have low mass, high durability, easy deployment, recovery and storage, making it an economically viable and attractive option.

  8. Contamination of optical surfaces in Earth orbit

    Science.gov (United States)

    Kinser, Donald L.; Weller, Robert A.; Mendenhall, M. H.; Wiedlocher, D. E.; Nichols, R.; Tucker, D.; Whitaker, A.

    1992-01-01

    Glass and glass ceramic samples exposed to the low earth orbit environment for approximately 5.5 years on the Long Duration Exposure Facility (LDEF) were found to display limited degradation in optical transmission. Commercial optical quality fused silica samples display decreases in transmission in the 200 to 400 nm wavelength region, and this degradation appears to be a consequence of surface contamination. The contamination, found only on internal surfaces of samples, was measured by medium energy backscattering spectrometry and found to be primarily carbon. Additional thin film contamination by a species with atomic mass near 64, which was present at the level of about 8 x 10 exp 14/sq. cm has not been identified. These observations are consistent with the interpretation that organic binders used in the black absorbing paint (Chem Glaze Z-306) inside the sample holding tray were concentrated in the vicinity of the samples and photolytically cracked by solar UV radiation. The resulting decomposition products were deposited on the interior sample surface and gave rise to the optical transmission loss. No detectable contamination was observed on the external or space exposed surface of the samples. No measurable damage was detected which could be attributed to the direct action of gamma or UV radiation on the glass samples. These results emphasize the need for special precautions in the preparation of spacecraft carrying precision optical components on long duration missions.

  9. Space transportation and destination considerations for extraterrestrial disposal of radioactive waste

    Science.gov (United States)

    Zimmerman, A. V.; Thompson, R. L.; Lubick, R. J.

    1973-01-01

    A feasibility study is summarized of extraterrestrial (space) disposal of radioactive waste. The initial work on the evaluation and comparison of possible space destinations and launch vehicles is reported. Only current or planned space transportation systems were considered. The currently planned space shuttle was found to be more cost effective than current expendable launch vehicles, by about a factor of two. The space shuttle will require a third stage to perform the disposal missions. Depending on the particular mission this could be either a reusable space tug or an expendable stage such as a Centaur. Of the destinations considered, high earth orbits (between geostationary and lunar orbit altitudes), solar orbits (such as a 0.90 AU circular solar orbit) or a direct injection to solar system escape appear to be the best candidates. Both earth orbits and solar orbits have uncertainties regarding orbit stability and waste package integrity for times on the order of a million years.

  10. Harvesting space for a greener earth

    CERN Document Server

    Matloff, Greg; Johnson, Les

    2014-01-01

    What was our planet like in years past? How has our civilization affected Earth and its ecology? Harvesting Space for a Greener Planet, the Second Edition of Paradise Regained: The Regreening of the Earth, begins by discussing these questions, and then generates a scenario for the restoration of Earth. It introduces new and innovative ideas on how we could use the Solar System and its resources for terrestrial benefit. The environmental challenges that face us today cannot be resolved by conservation and current technologies alone. Harvesting Space highlights the risk of humankind’s future extinction from environmental degradation. Population growth, global climate change, and maintaining sustainability of habitats for wildlife are all considered, among other issues. Rather than losing heart, we need to realize that the solutions to these problems lie in being good stewards of the planet and in the development of space. Not only will the solutions offered here avert a crisis, they will also provide the basi...

  11. Earth study from space

    Science.gov (United States)

    Sidorenko, A. V.

    1981-01-01

    The significance that space studies are making to all Earth sciences in the areas of geography, geodesy, cartography, geology, meteorology, oceanology, agronomy, and ecology is discussed. It is predicted that cosmonautics will result in a revolution in science and technology.

  12. Comprehensive evaluation of attitude and orbit estimation using real earth magnetic field data

    Science.gov (United States)

    Deutschmann, Julie; Bar-Itzhack, Itzhack

    1997-01-01

    A single, augmented extended Kalman filter (EKF) which simultaneously and autonomously estimates spacecraft attitude and orbit was developed and tested with simulated and real magnetometer and rate data. Since the earth's magnetic field is a function of time and position, and since time is accurately known, the differences between the computed and measured magnetic field components, as measured by the magnetometers throughout the entire spacecraft's orbit, are a function of orbit and attitude errors. These differences can be used to estimate the orbit and attitude. The test results of the EKF with magnetometer and gyro data from three NASA satellites are presented and evaluated.

  13. Extension of Earth-Moon libration point orbits with solar sail propulsion

    NARCIS (Netherlands)

    Heiligers, M.J.; Macdonald, Malcolm; Parker, Jeffrey S.

    2016-01-01

    This paper presents families of libration point orbits in the Earth-Moon system that originate from complementing the classical circular restricted three-body problem with a solar sail. Through the use of a differential correction scheme in combination with a continuation on the solar sail

  14. Orbital transport

    International Nuclear Information System (INIS)

    Oertel, H. Jr.; Koerner, H.

    1993-01-01

    The Third Aerospace Symposium in Braunschweig presented, for the first time, the possibility of bringing together the classical disciplines of aerospace engineering and the natural science disciplines of meteorology and air chemistry in a european setting. In this way, aspects of environmental impact on the atmosphere could be examined quantitatively. An essential finding of the european conference, is the unrestricted agreement of the experts that the given launch frequencies of the present orbital transport result in a negligible amount of pollutants being released in the atmosphere. The symposium does, however, call attention to the increasing need to consider the effect of orbital and atmospheric environmental impact of a future increase in launch frequencies of orbital transport in connection with future space stations. The Third Aerospace Symposium, 'Orbital Transport, Technical, Meteorological and Chemical Aspects', constituted a first forum of discussion for engineers and scientists. Questions of new orbital transport technologies and their environmental impact were to be discussed towards a first consensus. Through the 34 reports and articles, the general problems of space transportation and environmental protection were addressed, as well as particular aspects of high temperatures during reentry in the atmosphere of the earth, precision navigation of flight vehicles or flow behavior and air chemistry in the stratosphere. (orig./CT). 342 figs

  15. Comparison of Meteoroid Flux Models for Near Earth Space

    Science.gov (United States)

    Drolshagen, G.; Liou, J.-C.; Dikarev, V.; Landgraf, M.; Krag, H.; Kuiper, W.

    2007-01-01

    Over the last decade several new models for the sporadic interplanetary meteoroid flux have been developed. These include the Meteoroid Engineering Model (MEM), the Divine-Staubach model and the Interplanetary Meteoroid Engineering Model (IMEM). They typically cover mass ranges from 10-12 g (or lower) to 1 g and are applicable for model specific sun distance ranges between 0.2 A.U. and 10 A.U. Near 1 A.U. averaged fluxes (over direction and velocities) for all these models are tuned to the well established interplanetary model by Gr?n et. al. However, in many respects these models differ considerably. Examples are the velocity and directional distributions and the assumed meteoroid sources. In this paper flux predictions by the various models to Earth orbiting spacecraft are compared. Main differences are presented and analysed. The persisting differences even for near Earth space can be seen as surprising in view of the numerous ground based (optical, radar) and in-situ (captured IDPs, in-situ detectors and analysis of retrieved hardware) measurements and simulations. Remaining uncertainties and potential additional studies to overcome the existing model discrepancies are discussed.

  16. Targeting Ballistic Lunar Capture Trajectories Using Periodic Orbits in the Sun-Earth CRTBP

    Science.gov (United States)

    Cooley, D.S.; Griesemer, Paul Ricord; Ocampo, Cesar

    2009-01-01

    A particular periodic orbit in the Earth-Sun circular restricted three body problem is shown to have the characteristics needed for a ballistic lunar capture transfer. An injection from a circular parking orbit into the periodic orbit serves as an initial guess for a targeting algorithm. By targeting appropriate parameters incrementally in increasingly complicated force models and using precise derivatives calculated from the state transition matrix, a reliable algorithm is produced. Ballistic lunar capture trajectories in restricted four body systems are shown to be able to be produced in a systematic way.

  17. Orbital tomography: Molecular band maps, momentum maps and the imaging of real space orbitals of adsorbed molecules

    Energy Technology Data Exchange (ETDEWEB)

    Offenbacher, Hannes; Lüftner, Daniel; Ules, Thomas; Reinisch, Eva Maria; Koller, Georg, E-mail: georg.koller@uni-graz.at; Puschnig, Peter; Ramsey, Michael G., E-mail: michael.ramsey@uni-graz.at

    2015-10-01

    Highlights: • Orbital tomography within the plane wave final state approximation. • One electron orbital predictions versus angle resolved photoemission experiment. • Geometric and electronic structure of organic thin films elucidated by ARUPS. • Influence of molecular conformation and orientation on ARUPS. • Retrieval of sexiphenyl and pentacene orbitals in real space. - Abstract: The frontier orbitals of molecules are the prime determinants of their chemical, optical and electronic properties. Arguably, the most direct method of addressing the (filled) frontier orbitals is ultra-violet photoemission spectroscopy (UPS). Although UPS is a mature technique from the early 1970s on, the angular distribution of the photoemitted electrons was thought to be too complex to be analysed quantitatively. Recently angle resolved UPS (ARUPS) work on conjugated molecules both, in ordered thick films and chemisorbed monolayers, has shown that the angular (momentum) distribution of the photocurrent from orbital emissions can be simply understood. The approach, based on the assumption of a plane wave final state is becoming known as orbital tomography. Here we will demonstrate, with selected examples of pentacene (5A) and sexiphenyl (6P), the potential of orbital tomography. First it will be shown how the full angular distribution of the photocurrent (momentum map) from a specific orbital is related to the real space orbital by a Fourier transform. Examples of the reconstruction of 5A orbitals will be given and the procedure for recovering the lost phase information will be outlined. We then move to examples of sexiphenyl where we interrogate the original band maps of thick sexiphenyl in the light of our understanding of orbital tomography that has developed since then. With comparison to theoretical simulations of the molecular band maps, the molecular conformation and orientation will be concluded. New results for the sexiphenyl monolayer on Al(1 1 0) will then be

  18. A Novel Double Cluster and Principal Component Analysis-Based Optimization Method for the Orbit Design of Earth Observation Satellites

    Directory of Open Access Journals (Sweden)

    Yunfeng Dong

    2017-01-01

    Full Text Available The weighted sum and genetic algorithm-based hybrid method (WSGA-based HM, which has been applied to multiobjective orbit optimizations, is negatively influenced by human factors through the artificial choice of the weight coefficients in weighted sum method and the slow convergence of GA. To address these two problems, a cluster and principal component analysis-based optimization method (CPC-based OM is proposed, in which many candidate orbits are gradually randomly generated until the optimal orbit is obtained using a data mining method, that is, cluster analysis based on principal components. Then, the second cluster analysis of the orbital elements is introduced into CPC-based OM to improve the convergence, developing a novel double cluster and principal component analysis-based optimization method (DCPC-based OM. In DCPC-based OM, the cluster analysis based on principal components has the advantage of reducing the human influences, and the cluster analysis based on six orbital elements can reduce the search space to effectively accelerate convergence. The test results from a multiobjective numerical benchmark function and the orbit design results of an Earth observation satellite show that DCPC-based OM converges more efficiently than WSGA-based HM. And DCPC-based OM, to some degree, reduces the influence of human factors presented in WSGA-based HM.

  19. Earth's external magnetic fields at low orbital altitudes

    Science.gov (United States)

    Klumpar, D. M.

    1990-01-01

    Under our Jun. 1987 proposal, Magnetic Signatures of Near-Earth Distributed Currents, we proposed to render operational a modeling procedure that had been previously developed to compute the magnetic effects of distributed currents flowing in the magnetosphere-ionosphere system. After adaptation of the software to our computing environment we would apply the model to low altitude satellite orbits and would utilize the MAGSAT data suite to guide the analysis. During the first year, basic computer codes to run model systems of Birkeland and ionospheric currents and several graphical output routines were made operational on a VAX 780 in our research facility. Software performance was evaluated using an input matchstick ionospheric current array, field aligned currents were calculated and magnetic perturbations along hypothetical satellite orbits were calculated. The basic operation of the model was verified. Software routines to analyze and display MAGSAT satellite data in terms of deviations with respect to the earth's internal field were also made operational during the first year effort. The complete set of MAGSAT data to be used for evaluation of the models was received at the end of the first year. A detailed annual report in May 1989 described these first year activities completely. That first annual report is included by reference in this final report. This document summarizes our additional activities during the second year of effort and describes the modeling software, its operation, and includes as an attachment the deliverable computer software specified under the contract.

  20. Phase-space curvature in spin-orbit-coupled ultracold atomic systems

    Science.gov (United States)

    Armaitis, J.; Ruseckas, J.; Anisimovas, E.

    2017-04-01

    We consider a system with spin-orbit coupling and derive equations of motion which include the effects of Berry curvatures. We apply these equations to investigate the dynamics of particles with equal Rashba-Dresselhaus spin-orbit coupling in one dimension. In our derivation, the adiabatic transformation is performed first and leads to quantum Heisenberg equations of motion for momentum and position operators. These equations explicitly contain position-space, momentum-space, and phase-space Berry curvature terms. Subsequently, we perform the semiclassical approximation and obtain the semiclassical equations of motion. Taking the low-Berry-curvature limit results in equations that can be directly compared to previous results for the motion of wave packets. Finally, we show that in the semiclassical regime, the effective mass of the equal Rashba-Dresselhaus spin-orbit-coupled system can be viewed as a direct effect of the phase-space Berry curvature.

  1. Preferred Spatial Directions in the Universe. Part II. Matter Distributed along Orbital Trajectories, and Energy Produced from It

    Directory of Open Access Journals (Sweden)

    Borissova L.

    2006-10-01

    Full Text Available Using General Relativity we study the rotating space of an orbiting body (of the Earth in the Galaxy, for example. In such a space Einstein’s equations predict that: (1 the space cannot be empty; (2 it abhors a vacuum (i. e. a pure λ-field, and so it must also possess a substantive distribution (e. g. gas, dust, radiations, etc.. In order for Maxwell’s equations to satisfy Einstein’s equations, it is shown that: (1 a free electromagnetic field along the trajectory of an orbiting body must be present, by means of purely magnetic “standing” waves; (2 electromagnetic fields don’t satisfy the Einstein equations in a region of orbiting space bodies if there is no distribution of another substance (e. g. dust, gas or something else. The braking energy of a medium pervading space equals the energy of the space non-holonomic field. The energy transforms into heat and radiations within stars by a stellar energy mechanism due to the background space non-holonomity, so a star takes energy for luminosity from the space during the orbit. Employing this mechanism in an Earth-bound laboratory, we can obtain a new source of energy due to the fact that the Earth orbits in the non-holonomic fields of the space.

  2. A Delphi-Based Framework for systems architecting of in-orbit exploration infrastructure for human exploration beyond Low Earth Orbit

    Science.gov (United States)

    Aliakbargolkar, Alessandro; Crawley, Edward F.

    2014-01-01

    The current debate in the U.S. Human Spaceflight Program focuses on the development of the next generation of man-rated heavy lift launch vehicles. While launch vehicle systems are of critical importance for future exploration, a comprehensive analysis of the entire exploration infrastructure is required to avoid costly pitfalls at early stages of the design process. This paper addresses this need by presenting a Delphi-Based Systems Architecting Framework for integrated architectural analysis of future in-orbit infrastructure for human space exploration beyond Low Earth Orbit. The paper is structured in two parts. The first part consists of an expert elicitation study to identify objectives for the in-space transportation infrastructure. The study was conducted between November 2011 and January 2012 with 15 senior experts involved in human spaceflight in the United States and Europe. The elicitation study included the formation of three expert panels representing exploration, science, and policy stakeholders engaged in a 3-round Delphi study. The rationale behind the Delphi approach, as imported from social science research, is discussed. Finally, a novel version of the Delphi method is presented and applied to technical decision-making and systems architecting in the context of human space exploration. The second part of the paper describes a tradespace exploration study of in-orbit infrastructure coupled with a requirements definition exercise informed by expert elicitation. The uncertainties associated with technical requirements and stakeholder goals are explicitly considered in the analysis. The outcome of the expert elicitation process portrays an integrated view of perceived stakeholder needs within the human spaceflight community. Needs are subsequently converted into requirements and coupled to the system architectures of interest to analyze the correlation between exploration, science, and policy goals. Pareto analysis is used to identify architectures

  3. Space Technospheres

    Science.gov (United States)

    Vidmachenko, A. P.; Steklov, A. F.; Primak, N. V.

    2000-01-01

    Two main tendencies of making the Solar System habitable are regarding nowadays: (1) making objects of the Solar System habitable; and (2) making the space of the Solar System habitable. We think that it's better to combine them. We should dezine and build settlements ('technospheres') on such objects as asteroids and comets, using their resources. That is, it is necessary to create 'space technospheres' - a long-termed human settlements in the space. To save energy resources it is necessary to use Near-Earth asteroids enriched with water ice (i. e. extinguished comets) with Near-Earth orbits. To realize listed conceptions it is necessary to decrease (up to 100 times) the cost price of the long-termed settlements. That's why even average UN country will be able to create it's own space house - artificial planet ('technosphere') and maintain life activities there. About 50-100 such artificial planets will represent the future civilization of our Solar System. At the same time Earth will stay basic, maternal planet. There is an interesting problem of correcting orbits of that objects. Orbits can be changed into circular or elongated to make them comfortable for living activities of 5000-10000 settlers, and to maintain connection with maternal planet. Technospheres with the elongated orbits are more advantageous to assimilate the Solar System. While technospheres with circular orbits suit to the industrial cycle with certain specialization. The specialization of the technosphere will depend on mine-workings and/or chosen high-technology industrial process. Because it is profitable to convert raw materials at the technosphere and then to transport finished products to the maternal planet. It worth to be mentioned that because of the low gravitation and changed life cycle technosphere settlers, new 'Columb' of the Solar System will transform into new mankind. It will happen though it is difficult to imaging this. Because long ago, when fish left the ocean, they didn

  4. Phase-space distributions and orbital angular momentum

    Directory of Open Access Journals (Sweden)

    Pasquini B.

    2014-06-01

    Full Text Available We review the concept of Wigner distributions to describe the phase-space distributions of quarks in the nucleon, emphasizing the information encoded in these functions about the quark orbital angular momentum.

  5. Earth Observations from Space: The First 50 Years of Scientific Achievements

    Science.gov (United States)

    2008-01-01

    Observing Earth from space over the past 50 years has fundamentally transformed the way people view our home planet. The image of the "blue marble" is taken for granted now, but it was revolutionary when taken in 1972 by the crew on Apollo 17. Since then the capability to look at Earth from space has grown increasingly sophisticated and has evolved from simple photographs to quantitative measurements of Earth properties such as temperature, concentrations of atmospheric trace gases, and the exact elevation of land and ocean. Imaging Earth from space has resulted in major scientific accomplishments; these observations have led to new discoveries, transformed the Earth sciences, opened new avenues of research, and provided important societal benefits by improving the predictability of Earth system processes. This report highlights the scientific achievements made possible by the first five decades of Earth satellite observations by space-faring nations. It follows on a recent report from the National Research Council (NRC) entitled Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, also referred to as the "decadal survey." Recognizing the increasing need for space observations, the decadal survey identifies future directions and priorities for Earth observations from space. This companion report was requested by the National Aeronautics and Space Administration (NASA) to highlight, through selected examples, important past contributions of Earth observations from space to our current understanding of the planet.

  6. TELEMETRY AND TELECOMMAND SYSTEM OF LOW-EARTH-ORBIT MICROSATELLITE, KITSAT-1 AND 2

    Directory of Open Access Journals (Sweden)

    Sungheon Kim

    1996-06-01

    Full Text Available The telecommand system of KITSAT micorsatellite receives commands from ground stations or on-board computers. It decodes, validates and delivers commands to sub-system. The telemetry system is to collect, process and format satellite housekeeping and mission data for use by on-board computer and ground station. It is crucial for the telemetry and telecommand system to have high reliability since the spacecraft operation is mostly based on the function of this system. The telemetry and telecommand(TTC systems for KITSAT-1 and 2 had been developed under the consideratin of the space environment of Low-Earth-Orbit and the limited mass, volume and power of micorsatellite. Since both satellites were launched in August 1992 and September 1993 respectively, the have shown to be working successfully as well as the TTC systems on-board both satellites.

  7. Confirmation of Earth-Mass Planets Orbiting the Millisecond Pulsar PSR B1257 + 12.

    Science.gov (United States)

    Wolszczan, A

    1994-04-22

    The discovery of two Earth-mass planets orbiting an old ( approximately 10(9) years), rapidly spinning neutron star, the 6.2-millisecond radio pulsar PSR B1257+12, was announced in early 1992. It was soon pointed out that the approximately 3:2 ratio of the planets' orbital periods should lead to accurately predictable and possibly measurable gravitational perturbations of their orbits. The unambiguous detection of this effect, after 3 years of systematic timing observations of PSR B1257+12 with the 305-meter Arecibo radiotelescope, as well as the discovery of another, moon-mass object in orbit around the pulsar, constitutes irrefutable evidence that the first planetary system around a star other than the sun has been identified.

  8. Orbital Noise in the Earth System is a Common Cause of Climate and Greenhouse-Gas Fluctuation

    Science.gov (United States)

    Liu, H. S.; Kolenkiewicz, R.; Wade, C., Jr.; Smith, David E. (Technical Monitor)

    2002-01-01

    The mismatch between fossil isotopic data and climate models known as the cool-tropic paradox implies that either the data are flawed or we understand very little about the climate models of greenhouse warming. Here we question the validity of the climate models on the scientific background of orbital noise in the Earth system. Our study shows that the insolation pulsation induced by orbital noise is the common cause of climate change and atmospheric concentrations of carbon dioxide and methane. In addition, we find that the intensity of the insolation pulses is dependent on the latitude of the Earth. Thus, orbital noise is the key to understanding the troubling paradox in climate models.

  9. Stamping the Earth from space

    CERN Document Server

    Dicati, Renato

    2017-01-01

    This unique book presents a historical and philatelic survey of Earth exploration from space. It covers all areas of research in which artificial satellites have contributed in designing a new image of our planet and its environment: the atmosphere and ionosphere, the magnetic field, radiation belts and the magnetosphere, weather, remote sensing, mapping of the surface, observation of the oceans and marine environments, geodesy, and the study of life and ecological systems. Stamping the Earth from Space presents the results obtained with the thousands of satellites launched by the two former superpowers, the Soviet Union and the United States, and also those of the many missions carried out by the ESA, individual European countries, Japan, China, India, and the many emerging space nations. Beautifully illustrated, it contains almost 1100 color reproductions of philatelic items. In addition to topical stamps and thematic postal documents, the book provides an extensive review of astrophilatelic items. The most...

  10. Secure space-to-space interferometric communications and its nexus to the physics of quantum entanglement

    Science.gov (United States)

    Duarte, F. J.

    2016-12-01

    The history of the probability amplitude equation | ψ > = ( | x , y > - | y , x > ) applicable to quanta pairs, propagating in different directions with entangled polarizations, is reviewed and traced back to the 1947-1949 period. The interferometric Dirac foundations common to | ψ > = ( | x , y > - | y , x > ) and the generalized N-slit interferometric equation, for indistinguishable quanta, are also described. The results from a series of experiments on N-slit laser interferometers, with intra interferometric propagation paths up to 527 m, are reviewed. Particular attention is given to explain the generation of interferometric characters, for secure space-to-space communications, which immediately collapse on attempts of interception. The design of a low divergence N-slit laser interferometer for low Earth orbit-low Earth orbit (LEO-LEO), and LEO-geostationary Earth orbit (LEO-GEO), secure interferometric communications is described and a weight assessment is provided.

  11. JSC Orbital Debris Website Description

    Science.gov (United States)

    Johnson, Nicholas L.

    2006-01-01

    Purpose: The website provides information about the NASA Orbital Debris Program Office at JSC, which is the lead NASA center for orbital debris research. It is recognized world-wide for its leadership in addressing orbital debris issues. The NASA Orbital Debris Program Office has taken the international lead in conducting measurements of the environment and in developing the technical consensus for adopting mitigation measures to protect users of the orbital environment. Work at the center continues with developing an improved understanding of the orbital debris environment and measures that can be taken to control its growth. Major Contents: Orbital Debris research is divided into the following five broad efforts. Each area of research contains specific information as follows: 1) Modeling - NASA scientists continue to develop and upgrade orbital debris models to describe and characterize the current and future debris environment. Evolutionary and engineering models are described in detail. Downloadable items include a document in PDF format and executable software. 2) Measurements - Measurements of near-Earth orbital debris are accomplished by conducting ground-based and space-based observations of the orbital debris environment. The data from these sources provide validation of the environment models and identify the presence of new sources. Radar, optical and surface examinations are described. External links to related topics are provided. 3) Protection - Orbital debris protection involves conducting hypervelocity impact measurements to assess the risk presented by orbital debris to operating spacecraft and developing new materials and new designs to provide better protection from the environment with less weight penalty. The data from this work provides the link between the environment defined by the models and the risk presented by that environment to operating spacecraft and provides recommendations on design and operations procedures to reduce the risk as

  12. Space Surveillance Catalog growth during SBIRS low deployment.

    Science.gov (United States)

    Hoult, C. P.; Wright, R. P.

    The Space Surveillance Catalog is a database of all Resident Space Objects (RSOs) on Earth orbit. It is expected to grow in the future as more RSOs accumulate on orbit. Potentially still more dramatic growth could follow the deployment of the Space Based Infrared System Low Earth Orbit Component (SBTRS Low). SBIRS Low, currently about to enter development, offers the potential to detect and acquire much smaller debris RSOs than can be seen by the current ground-based Space Surveillance Network (SSN). SBIRS Low will host multicolor infrared/visible sensors on each satellite in a proliferated constellation on low Earth orbit, and if appropriately tasked, these sensors could provide significant space surveillance capability. Catalog growth during SBIRS Low deployment was analyzed using a highly aggregated code that numerically integrates the Markov equations governing the state transitions of RSOs from uncataloged to cataloged, and back again. It was assumed that all newly observed debris RSOs will be detected as by-products of routine Catalog maintenance, not including any post breakup searches, and if sufficient sensor resources are available, be acquired into the Catalog. Debris over the entire low to high altitude regime were considered.

  13. Low energy trajectories for the Moon-to-Earth space flight

    Indian Academy of Sciences (India)

    The Moon-to-Earth low energy trajectories of 'detour' type are found and studied within the frame ... km from the Earth where the Sun gravitation decreases the particle orbit perigee distance to a small value .... The solid curve in fig- ... the Moon, respectively, as is the semimajor axis .... inclination i0 = 90 .... Then, according to.

  14. Improved model for solar cosmic ray exposure in manned Earth orbital flights

    International Nuclear Information System (INIS)

    Wilson, J.W.; Nealy, J.E.; Atwell, W.; Cucinotta, F.A.; Shinn, J.L.; Townsend, L.W.

    1990-06-01

    A calculational model is derived for use in estimating Solar cosmic ray exposure to critical body organs in low-Earth orbit at the center of a large spherical shield of fixed thickness. The effects of the Earth's geomagnetic field and the astronauts' self-shielding are evaluated explicitly. The geomagnetic field model is an approximate tilted eccentric dipole with geomagnetic storms represented as a uniform-impressed field. The storm field is related to the planetary geomagnetic index K(sub p). The code is applied to the Shuttle geometry using the Shuttle mass distribution surrounding two locations on the flight deck. The Shuttle is treated as pure aluminum and the astronaut as soft tissue. Short-term, average fluence over a single orbit is calculated as a function of the location of the lines of nodes or long-term averages over all lines of nodes for a fixed inclination

  15. GPS Space Service Volume: Ensuring Consistent Utility Across GPS Design Builds for Space Users

    Science.gov (United States)

    Bauer, Frank H.; Parker, Joel Jefferson Konkl; Valdez, Jennifer Ellen

    2015-01-01

    GPS availability and signal strength originally specified for users on or near surface of Earth with transmitted power levels specified at edge-of-Earth, 14.3 degrees. Prior to the SSV specification, on-orbit performance of GPS varied from block build to block build (IIA, IIRM, IIF) due to antenna gain and beam width variances. Unstable on-orbit performance results in significant risk to space users. Side-lobe signals, although not specified, were expected to significantly boost GPS signal availability for users above the constellation. During GPS III Phase A, NASA noted significant discrepancies in power levels specified in GPS III specification documents, and measured on-orbit performance. To stabilize the signal for high altitude space users, NASA DoD team in 2003-2005 led the creation of new Space Service Volume (SSV) definition and specifications.

  16. The Revolution in Earth and Space Science Education.

    Science.gov (United States)

    Barstow, Daniel; Geary, Ed; Yazijian, Harvey

    2002-01-01

    Explains the changing nature of earth and space science education such as using inquiry-based teaching, how technology allows students to use satellite images in inquiry-based investigations, the consideration of earth and space as a whole system rather than a sequence of topics, and increased student participation in learning opportunities. (YDS)

  17. On-Orbit Propulsion and Methods of Momentum Management for the International Space Station

    Science.gov (United States)

    Russell, Samuel P.; Spencer, Victor; Metrocavage, Kevin; Swanson, Robert A.; Krajchovich, Mark; Beisner, Matthew; Kamath, Ulhas P.

    2010-01-01

    Since the first documented design of a space station in 1929, it has been a dream of many to sustain a permanent presence in space. Russia and the US spent several decades competing for a sustained human presence in low Earth orbit. In the 1980 s, Russia and the US began to openly collaborate to achieve this goal. This collaboration lead to the current design of the ISS. Continuous improvement of procedures for controlling the ISS have lead to more efficient propellant management over the years. Improved efficiency combined with the steady use of cargo vehicles has kept ISS propellant levels well above their defined thresholds in all categories. The continuing evolution of propellant and momentum management operational strategies demonstrates the capability and flexibility of the ISS propulsion system. The hard work and cooperation of the international partners and the evolving operational strategies have made the ISS safe and successful. The ISS s proven success is the foundation for the future of international cooperation for sustaining life in space.

  18. Periodic orbits and TDHF phase space structure

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Yukio; Iwasawa, Kazuo [Tsukuba Univ., Ibaraki (Japan). Inst. of Physics; Tsukuma, Hidehiko; Sakata, Fumihiko

    1998-03-01

    The collective motion of atomic nuclei is closely coupled with the motion of nucleons, therefore, it is nonlinear, and the contents of the motion change largely with the increase of its amplitude. As the framework which describes the collective motion accompanied by the change of internal structure, time-dependent Hurtley Fock (TDHF) method is suitable. At present, the authors try to make the method for studying the large region structure in quantum system by utilizing the features of the TDHF phase space. The studies made so far are briefed. In this report, the correspondence of the large region patterns appearing in the band structure chart of three-level model with the periodic orbit group in the TDHF phase space is described. The Husimi function is made, and it possesses the information on the form of respective corresponding intrinsic state. The method of making the band structure chart is explained. There are three kinds of the tendency in the intrinsic state group. The E-T charts are made for the band structure charts to quantitatively express the large region tendency. The E-T chart and the T{sub r}-T chart are drawn for a selected characteristic orbit group. It became to be known that the large region properties of the quantum intrinsic state group of three-level model can be forecast by examining the properties of the periodic orbit group in the TDHF phase space. (K.I.)

  19. Internet-to-orbit gateway and virtual ground station: A tool for space research and scientific outreach

    Science.gov (United States)

    Jaffer, Ghulam; Nader, Ronnie; Koudelka, Otto

    2011-09-01

    Students in higher education, and scientific and technological researchers want to communicate with the International Space Station (ISS), download live satellite images, and receive telemetry, housekeeping and science/engineering data from nano-satellites and larger spacecrafts. To meet this need the Ecuadorian Civilian Space Agency (EXA) has recently provided the civilian world with an internet-to-orbit gateway (Hermes-A/Minotaur) Space Flight Control Center (SFCC) available for public use. The gateway has a maximum range of tracking and detection of 22,000 km and sensitivity such that it can receive and discriminate the signals from a satellite transmitter with power˜0.1 W. The capability is enough to receive the faintest low-earth-orbit (LEO) satellites. This gateway virtually connects participating internet clients around the world to a remote satellite ground station (GS), providing a broad community for multinational cooperation. The goal of the GS is to lower financial and engineering barriers that hinder access to science and engineering data from orbit. The basic design of the virtual GS on a user side is based on free software suites. Using these and other software tools the GS is able to provide access to orbit for a multitude of users without each having to go through the costly setups. We present the design and implementation of the virtual GS in a higher education and scientific outreach settings. We also discuss the basic architecture of the single existing system and the benefits of a proposed distributed system. Details of the software tools and their applicability to synchronous round-the-world tracking, monitoring and processing performed by students and teams at Graz University of Technology, Austria, EXA-Ecuador, University of Michigan, USA and JAXA who have participated in various mission operations and have investigated real-time satellite data download and image acquisition and processing. Students and other remote users at these

  20. Near-Earth Asteroids: Destinations for Human Exploration

    Science.gov (United States)

    Barbee, Brent W.

    2014-01-01

    The Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) is a system that monitors the near-Earth asteroid (NEA) population to identify NEAs whose orbital characteristics may make them potential destinations for future round-trip human space flight missions. To accomplish this monitoring, Brent Barbee (GSFC) developed and automated a system that applies specialized trajectory processing to the orbits of newly discovered NEAs, and those for which we have updated orbit knowledge, obtained from the JPL Small Bodies Database (SBDB). This automated process executes daily and the results are distributed to the general public and the astronomy community. This aids in prioritizing telescope radar time allocations for obtaining crucial follow-up observations of highly accessible NEAs during the critical, because it is often fleeting, time period surrounding the time at which the NEAs are initially discovered.

  1. Near-Earth Space Radiation Models

    Science.gov (United States)

    Xapsos, Michael A.; O'Neill, Patrick M.; O'Brien, T. Paul

    2012-01-01

    Review of models of the near-Earth space radiation environment is presented, including recent developments in trapped proton and electron, galactic cosmic ray and solar particle event models geared toward spacecraft electronics applications.

  2. Spectral properties of near-Earth asteroids on cometary orbits

    Science.gov (United States)

    Popescu, M.; Vaduvescu, O.; de Leon, J.; Boaca, I. L.; Gherase, R. M.; Nedelcu, D. A.; INT students, I. N. G.

    2017-09-01

    We studied the spectral distributions of near-Earth asteroids on cometary orbits (NEACOs) in order to identify potential dormant or extinct comets among these objects. We present the spectral observations for 19 NEACOs obtained with Isaac Newton Telescope and Infrared Telescope Facility (IRTF). Although initially classified as asteroid, one of our targets - 2007 VA85 was confirmed to be active comet 333P/LINEAR on its 2016 appearance. We found that the NEACOs population is a mixing of different compositional classes.

  3. Estimating spacecraft attitude based on in-orbit sensor measurements

    DEFF Research Database (Denmark)

    Jakobsen, Britt; Lyn-Knudsen, Kevin; Mølgaard, Mathias

    2014-01-01

    of 2014/15. To better evaluate the performance of the payload, it is desirable to couple the payload data with the satellite's orientation. With AAUSAT3 already in orbit it is possible to collect data directly from space in order to evaluate the performance of the attitude estimation. An extended kalman...... filter (EKF) is used for quaternion-based attitude estimation. A Simulink simulation environment developed for AAUSAT3, containing a "truth model" of the satellite and the orbit environment, is used to test the performance The performance is tested using different sensor noise parameters obtained both...... from a controlled environment on Earth as well as in-orbit. By using sensor noise parameters obtained on Earth as the expected parameters in the attitude estimation, and simulating the environment using the sensor noise parameters from space, it is possible to assess whether the EKF can be designed...

  4. Capturing asteroids into bound orbits around the earth: Massive early return on an asteroid terminal defense system

    International Nuclear Information System (INIS)

    Hills, J.G.

    1992-01-01

    Nuclear explosives may be used to capture small asteroids (e.g., 20--50 meters in diameter) into bound orbits around the earth. The captured objects could be used for construction material for manned and unmanned activity in Earth orbit. Asteroids with small approach velocities, which are the ones most likely to have close approaches to the Earth, require the least energy for capture. They are particularly easy to capture if they pass within one Earth radius of the surface of the Earth. They could be intercepted with intercontinental missiles if the latter were retrofit with a more flexible guiding and homing capability. This asteroid capture-defense system could be implemented in a few years at low cost by using decommissioned ICMs. The economic value of even one captured asteroid is many times the initial investment. The asteroid capture system would be an essential part of the learning curve for dealing with larger asteroids that can hit the earth

  5. A novel orbiter mission concept for venus with the EnVision proposal

    Science.gov (United States)

    de Oliveira, Marta R. R.; Gil, Paulo J. S.; Ghail, Richard

    2018-07-01

    In space exploration, planetary orbiter missions are essential to gain insight into planets as a whole, and to help uncover unanswered scientific questions. In particular, the planets closest to the Earth have been a privileged target of the world's leading space agencies. EnVision is a mission proposal designed for Venus and competing for ESA's next launch opportunity with the objective of studying Earth's closest neighbor. The main goal is to study geological and atmospheric processes, namely surface processes, interior dynamics and atmosphere, to determine the reasons behind Venus and Earth's radically different evolution despite the planets' similarities. To achieve these goals, the operational orbit selection is a fundamental element of the mission design process. The design of an orbit around Venus faces specific challenges, such as the impossibility of choosing Sun-synchronous orbits. In this paper, an innovative genetic algorithm optimization was applied to select the optimal orbit based on the parameters with more influence in the mission planning, in particular the mission duration and the coverage of sites of interest on the Venusian surface. The solution obtained is a near-polar circular orbit with an altitude of 259 km that enables the coverage of all priority targets almost two times faster than with the parameters considered before this study.

  6. Cryogenic implications of orbit selection of the Space Infrared Telescope Facility (SIRTF)

    International Nuclear Information System (INIS)

    Lee, J.H.; Brooke, W.F.; Maa, S.

    1986-01-01

    The Infrared Astronomical Satellite (IRAS) which completed the first all sky survey in the infrared demonstrated the tremendous advantage of space-based infrared astronomy. The ability to cool the telescope optics and focal plane to liquid helium temperatures and the absence of atmospheric disturbances which cause ''seeing'' effects resulted in the discovery of 250,000 IR sources and many interesting phenomena including dust clouds around Vega and the infrared ''cirrus'' at 100 μm. To realize the true benefit of space infrared astronomy, NASA is now studying the Space Infrared Telescope Facility, a long-life space-based observatory, to follow up on the survey results of IRAS. The choice of orbits is a critical program decision. The objective of this paper is to compare the performance of an all superfluid helium SIRTF system in the two possible orbit inclinations, polar orbit (99 0 ) and the low inclination orbit (28.5 0 )

  7. What Threats to Human Health Does Space Radiation Pose in Orbit

    Science.gov (United States)

    Wu, Honglu; Semones, Eddie; Weyland, Mark; Zapp, Neal; Cucinotta, Francis A.

    2011-01-01

    The Space Shuttle program spanned more than the entire length of a solar cycle. Investigations aimed towards understanding the health risks of the astronauts from exposures to space radiation involved mostly physical measurements of the dose and the linear energy transfer (LET) spectrum. Measurement of the dose rate on the Shuttle provided invariable new data for different periods of the solar cycle, whereas measurement of the LET spectrum using the tissue equivalent proportional counter (TEPC) produced the most complete mapping of the radiation environment of the low Earth orbits (LEO). Exposures to the Shuttle astronauts were measured by the personal dosimeter worn by the crewmembers. Analysis of over 300 personal dosimeter readings indicated a dependence on the mission duration, the altitude and inclination of the orbit, and the solar cycle, with the crewmembers on the launch and repair of the Hubble telescope receiving the highest doses due to the altitude of the mission. Secondary neutrons inside the Shuttle were determined by recoil protons or with Bonner spheres, and may contribute significantly to the risks of the crewmembers. In addition, the skin dose and the doses received at different organs were compared using a human phantom onboard a Shuttle mission. A number of radiobiology investigations wer e also performed. The biological doses were determined on six astronauts/cosmonauts on long-duration Shuttle/Mir missions and on two crewmembers on a Hubble repair mission by analyzing the damages in the chromosomes of the crewmembers? white blood cells. Several experiments were also conducted to address the question of possible synergistic effects of spaceflight, microgravity in particular, on the repair of radiation-induced DNA damages. The experimental design included exposure of cells before launch, during flight, or after landing. These physical and biological studies were invaluable in predicting the health risks for astronauts on ISS and future

  8. 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.

  9. A novel emergency system for low earth orbit satellites using Galileo GNSS

    NARCIS (Netherlands)

    Gill, E.K.A.; Helderweirt, A.

    2010-01-01

    Low Earth Orbit (LEO) satellites have a limited direct contact time with the stations of their ground segment. This fundamentally constraints a timeliness reaction of the mission control center in case of emergency situations onboard the LEO spacecraft. To enable such a rapid reaction to emergency

  10. Cost Per Pound From Orbit

    Science.gov (United States)

    Merriam, M. L.

    2002-01-01

    Traditional studies of Reusable Launch Vehicle (RLV) designs have focused on designs that are completely reusable except for the fuel. This may not be realistic with current technology . An alternate approach is to look at partially reusable launch vehicles. This raises the question of which parts should be reused and which parts should be expendable. One approach is to consider the cost/pound of returning these parts from orbit. With the shuttle, this cost is about three times the cost/pound of launching payload into orbit. A subtle corollary is that RLVs are much less practical for higher orbits, such as the one on which the International Space Station resides, than they are for low earth orbits.

  11. Analysis of Periodic Orbits about the Triangular Solutions of the Restricted Sum-Jupiter and Earth-Moon Problem

    Directory of Open Access Journals (Sweden)

    Sang-Young Park

    1988-12-01

    Full Text Available Using the numerical solution in the plane restricted problem of three bodies, about 490 periodic orbits are computed numerically around the L5 of Sun-Jupiter and about 1600 periodic orbits also be done around the L5 of Earth-Moon system. As period increase, the energy and the shape of periodic orbits increase around the L5 of Sun-Jupiter system. But, in Earth-Moon system, the complex shapes and dents appear around the L5 and periodic orbits intersect one another in the place where dents are shown. And there is a region that three different periodic orbits exist with the same period in this region. The regions can exist around the L5 of Sun-Jupiter system where periodic orbit can be unstable by perturbation of other force besides the gravitational force of Jupiter. These regions which is close to L5 are a ~5.12 AU and a ~5.29 AU. The Trojan asteroids that have a small eccentricity and inclination can not exist in this region.

  12. The Sun/Earth System and Space Weather

    Science.gov (United States)

    Poland, Arthur I.; Fox, Nicola; Lucid, Shannon

    2003-01-01

    Solar variability and solar activity are now seen as significant drivers with respect to the Earth and human technology systems. Observations over the last 10 years have significantly advanced our understanding of causes and effects in the Sun/Earth system. On a practical level the interactions between the Sun and Earth dictate how we build our systems in space (communications satellites, GPS, etc), and some of our ground systems (power grids). This talk will be about the Sun/Earth system: how it changes with time, its magnetic interactions, flares, the solar wind, and how the Sun effects human systems. Data will be presented from some current spacecraft which show, for example, how we are able to currently give warnings to the scientific community, the Government and industry about space storms and how this data has improved our physical understanding of processes on the Sun and in the magnetosphere. The scientific advances provided by our current spacecraft has led to a new program in NASA to develop a 'Space Weather' system called 'Living With a Star'. The current plan for the 'Living With a Star' program will also be presented.

  13. Observing the Anthropocene from Space

    Science.gov (United States)

    Dittus, Hansjörg

    2016-07-01

    Influence of mankind on Earth's climate is evident. The growing population using the resources available, especially by burning goal, oil and gas, changes the composition of the Earth's atmosphere with the result of a continuously increasing temperature. Effects are not limited to the regional scale but are evident on the whole planet, meanwhile named Anthropocene. According to this global influence, it's necessary to also extend monitoring to the entire planet. Space-based observation systems are not limited by any artificial borders and are in principle able, to cover the whole Earth. In principle, two different ways of observation can be selected: Either a dedicated spacecraft will be send into low earth orbit (LEO) or existing platforms are used. Advantages of satellites are the more or less freely selectable orbit (with orbits covering also the polar regions) and the possible adaption of spacecraft platform for the dedicated instrument. On the other hand platforms like the ISS space station enable continuous long term coverage with different instruments. The drawback of an only limited coverage based on the orbit inclination is made up by the possibility to service systems on the station. Furthermore different generations of sensors can be run in parallel and therefore cross calibrated if needed. This paper reviews the currently available sensors types and discusses potential future needs. Included in this discussion is the international space station as an already available platform for earth observation. Furthermore, discussion should also take into account, that an increasing number of constellations with dozens or even thousand satellites are planned. Are these constellations also an option for an increased temporal and spatial monitoring of the Earth?

  14. What Makes Earth and Space Science Sexy? A Model for Developing Systemic Change in Earth and Space Systems Science Curriculum and Instruction

    Science.gov (United States)

    Slutskin, R. L.

    2001-12-01

    Earth and Space Science may be the neglected child in the family of high school sciences. In this session, we examine the strategies that Anne Arundel County Public Schools and NASA Goddard Space Flight Center used to develop a dynamic and highly engaging program which follows the vision of the National Science Education Standards, is grounded in key concepts of NASA's Earth Science Directorate, and allows students to examine and apply the current research of NASA scientists. Find out why Earth/Space Systems Science seems to have usurped biology and has made students, principals, and teachers clamor for similar instructional practices in what is traditionally thought of as the "glamorous" course.

  15. Physics at the edge of the earth

    International Nuclear Information System (INIS)

    Allen, J.P.

    1988-01-01

    The author recounts experiences he had as an astronaut, and the ways this allowed him to practice physics in a very applied manner. He describes some of the phenomena observed in the zero gravity of space flight which are very different, and hard to imagine, by minds immersed in the images and experiences of normal gravity. Most of the paper is devoted to a description of the task of recovering lost communication satellites and returning them to earth for repair and potential redeployment. From his perspective as a physicist and astronaut he explains briefly the orbital mechanics experienced in earth orbit, and the problems in compensating for these effects which maneuvering in space untethered to the shuttle. This presents hard practical problems to be met and solved in order to accomplish the task. Using a manned maneuvering unit his mission was able to successfully couple to the satellite and bring it to the shuttle. This involved a lot of practice of the classical physics principles of orbital dynamics, and the influence that perception in a space environment has upon these laws

  16. SPACE-BASED MICROLENS PARALLAX OBSERVATION AS A WAY TO RESOLVE THE SEVERE DEGENERACY BETWEEN MICROLENS-PARALLAX AND LENS-ORBITAL EFFECTS

    Energy Technology Data Exchange (ETDEWEB)

    Han, C. [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Udalski, A.; Szymański, M. K.; Soszyński, I.; Skowron, J.; Mróz, P.; Poleski, R.; Pietrukowicz, P.; Kozłowski, S.; Ulaczyk, K.; Wyrzykowski, Ł.; Pawlak, M. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Lee, C.-U.; Gould, A.; Chung, S.-J.; Kim, S.-L.; Cha, S.-M. [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of); Bozza, V. [Dipartimento di Fisica “E. R. Caianiello”, Uńiversitá di Salerno, Via Giovanni Paolo II, I-84084 Fisciano (Italy); Albrow, M. D. [University of Canterbury, Department of Physics and Astronomy, Private Bag 4800, Christchurch 8020 (New Zealand); Jung, Y. K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, 02138 (United States); Collaboration: OGLE Collaboration; KMTNet Collaboration; and others

    2016-08-10

    In this paper, we demonstrate the severity of the degeneracy between the microlens-parallax and lens-orbital effects by presenting the analysis of the gravitational binary-lens event OGLE-2015-BLG-0768. Despite the obvious deviation from the model based on the linear observer motion and the static binary, it is found that the residual can be almost equally well explained by either the parallactic motion of the Earth or the rotation of the binary-lens axis, resulting in the severe degeneracy between the two effects. We show that the degeneracy can be readily resolved with the additional data provided by space-based microlens parallax observations. By enabling us to distinguish between the two higher-order effects, space-based microlens parallax observations will not only make it possible to accurately determine the physical lens parameters but also to further constrain the orbital parameters of binary lenses.

  17. Magnetoshell Aerocapture for Manned Missions and Planetary Deep Space Orbiters

    Data.gov (United States)

    National Aeronautics and Space Administration — It is clear from past mission studies that a manned Mars mission, as well as deep space planetary orbiters will require aerobraking and aerocapture which use...

  18. On-Orbit Verification of Luminance Based Target Tracking and Faint Body Extractions by a Small Telescope on the World's First Micro-Interplanetary Space Probe

    OpenAIRE

    Ariu, Kaito; Ikari, Satoshi; Kawabata, Yosuke; Nagata, Kazutaka; Matsuguma, Toshihiro; Inamori, Takaya; Miyamura, Norihide; Funase, Ryu; Nakasuka, Shinichi

    2016-01-01

    In recent years, low cost and quick development of very small satellites ranging from CubeSats of 1 kg to micro-satellites of approximately 50 kg have allowed advances in space development and application. Although most of these satellites are in Earth orbits, a small spacecraft for deep-space missions has been developed and launched for the first time in the world. The Proximate Object Close Flyby with Optical Navigation (PROCYON) micro-interplanetary spacecraft, developed by the University ...

  19. Technology Development and Demonstration Concepts for the Space Elevator

    Science.gov (United States)

    Smitherman, David V., Jr.

    2004-01-01

    During the 1990s several discoveries and advances in the development of carbon nano-tube (CNT) materials indicated that material strengths many times greater than common high-strength composite materials might be possible. Progress in the development of this material led to renewed interest in the space elevator concept for construction of a tether structure from the surface of the Earth through a geostationary orbit (GEO) and thus creating a new approach to Earth-to-orbit transportation infrastructures. To investigate this possibility the author, in 1999, managed for NASA a space elevator work:hop at the Marshall Space Flight Center to explore the potential feasibility of space elevators in the 21 century, and to identify the critical technologies and demonstration missions needed to make development of space elevators feasible. Since that time, a NASA Institute for Advanced Concepts (NIAC) funded study of the Space Elevator proposed a concept for a simpler first space elevator system using more near-term technologies. This paper will review some of the latest ideas for space elevator development, the critical technologies required, and some of the ideas proposed for demonstrating the feasibility for full-scale development of an Earth to GEO space elevator. Critical technologies include CNT composite materials, wireless power transmission, orbital object avoidance, and large-scale tether deployment and control systems. Numerous paths for technology demonstrations have been proposed utilizing ground experiments, air structures. LEO missions, the space shuttle, the international Space Station, GEO demonstration missions, demonstrations at the lunar L1 or L2 points, and other locations. In conclusion, this paper finds that the most critical technologies for an Earth to GEO space elevator include CNT composite materials development and object avoidance technologies; that lack of successful development of these technologies need not preclude continued development of

  20. Ground Track Acquisition and Maintenance Maneuver Modeling for Low-Earth Orbit Satellite

    Directory of Open Access Journals (Sweden)

    Byoung-Sun Lee

    1997-12-01

    Full Text Available This paper presents a comprehensive analytical approach for determining key maneuver parameters associated with the acquisition and maintenance of the ground track for a low-earth orbit. A livearized model relating changes in the drift rate of the ground track directly to changes in the orbital semi-major axis is also developed. The effect of terrestrial atmospheric drag on the semi-major axis is also explored, being quantified through an analytical expression for the decay rate as a function of density. The non-singular Lagrange planetary equations, further simplified for nearly circular orbits, provide the desired relationships between the corrective in-plane impulsive velocity increments and the corresponding effects on the orbit elements. The resulting solution strategy offers excellent insight into the dynamics affecting the timing, magnitude, and frequency of these maneuvers. Simulations are executed for the ground track acquisition and maintenance maneuver as a pre-flight planning and analysis.

  1. Survival of spores of the UV-resistant Bacillus subtilis strain MW01 after exposure to low-earth orbit and simulated martian conditions: data from the space experiment ADAPT on EXPOSE-E.

    Science.gov (United States)

    Wassmann, Marko; Moeller, Ralf; Rabbow, Elke; Panitz, Corinna; Horneck, Gerda; Reitz, Günther; Douki, Thierry; Cadet, Jean; Stan-Lotter, Helga; Cockell, Charles S; Rettberg, Petra

    2012-05-01

    In the space experiment "Molecular adaptation strategies of microorganisms to different space and planetary UV climate conditions" (ADAPT), bacterial endospores of the highly UV-resistant Bacillus subtilis strain MW01 were exposed to low-Earth orbit (LEO) and simulated martian surface conditions for 559 days on board the European Space Agency's exposure facility EXPOSE-E, mounted outside the International Space Station. The survival of B. subtilis MW01 spores from both assays (LEO and simulated martian conditions) was determined by a colony-formation assay after retrieval. It was clearly shown that solar extraterrestrial UV radiation (λ≥110 nm) as well as the martian UV spectrum (λ≥200 nm) was the most deleterious factor applied; in some samples only a few spore survivors were recovered from B. subtilis MW01 spores exposed in monolayers. However, if shielded from solar irradiation, about 8% of MW01 spores survived in LEO conditions, and 100% survived in simulated martian conditions, compared to the laboratory controls. The results demonstrate the effect of shielding against the high inactivation potential of extraterrestrial solar UV radiation, which limits the chances of survival of even the highly UV-resistant strain of B. subtilis MW01 in the harsh environments of outer space and the martian surface.

  2. Immersive Earth: Teaching Earth and Space with inexpensive immersive technology

    Science.gov (United States)

    Reiff, P. H.; Sumners, C.; Law, C. C.; Handron, K.

    2003-12-01

    In 1995 we pioneered "Space Update", the Digital Library for the rest of us", software that was so simple that a child could use it without a keyboard and yet would allow one-click updating of the daily earth and space science images without the dangers of having an open web browser on display. Thanks to NASA support, it allowed museums and schools to have a powerful exhibit for a tiny price. Over 40,000 disks in our series have been distributed so far to educators and the public. In 2003, with our partners we are again revolutionizing educational technology with a low-cost hardware and software solution to creating and displaying immersive content. Recently selected for funding as part of the REASoN competition, Immersive Earth is a partnership of scientists, museums, educators, and content providers. The hardware consists of a modest projector with a special fisheye lens to be used in an inflatable dome which many schools already have. This, coupled with a modest personal computer, can now easily project images and movies of earth and space, allows training students in 3-D content at a tiny fraction of the cost of a cave or fullscale dome theater. Another low-cost solution is the "Imove" system, where spherical movies can play on a personal computer, with the user changing the viewing direction with a joystick. We were the first to create immersive earth science shows, remain the leader in creating educational content that people want to see. We encourage people with "allsky" images or movies to bring it and see what it looks like inside a dome! Your content could be in our next show!

  3. Periodic orbits of solar sail equipped with reflectance control device in Earth-Moon system

    Science.gov (United States)

    Yuan, Jianping; Gao, Chen; Zhang, Junhua

    2018-02-01

    In this paper, families of Lyapunov and halo orbits are presented with a solar sail equipped with a reflectance control device in the Earth-Moon system. System dynamical model is established considering solar sail acceleration, and four solar sail steering laws and two initial Sun-sail configurations are introduced. The initial natural periodic orbits with suitable periods are firstly identified. Subsequently, families of solar sail Lyapunov and halo orbits around the L1 and L2 points are designed with fixed solar sail characteristic acceleration and varying reflectivity rate and pitching angle by the combination of the modified differential correction method and continuation approach. The linear stabilities of solar sail periodic orbits are investigated, and a nonlinear sliding model controller is designed for station keeping. In addition, orbit transfer between the same family of solar sail orbits is investigated preliminarily to showcase reflectance control device solar sail maneuver capability.

  4. 78 FR 14952 - Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit...

    Science.gov (United States)

    2013-03-08

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 2 [IB Docket No. 12-376; FCC 12-161] Earth Stations... (NPRM) seeks comment on a proposal to elevate the allocation status of Earth Stations Aboard Aircraft... with GSO space stations of the FSS on a primary basis in the 11.7-12.2 GHz band (space-to-Earth), on an...

  5. A New Method of Space Travel Optimized for Space Tourism and Colonization

    Science.gov (United States)

    Turek, Philip A.

    2006-01-01

    High costs associated with expendable rockets are stifling the development of permanent space colonies. A new method of space travel is presented that enjoys significantly increased performance and reduced cost relative to competing concepts. Based on recycling the kinetic energy of an arriving spacecraft, up to 200 MW of average electrical power is generated and sustained for 2 minutes, and is immediately applied in launching a departing partner spacecraft. The resulting required delta vee for a round trip between low Earth orbit (LEO) and geosynchronous orbit (GEO) drops from 7.6 km/s to 0.54 km/s when 3 recycling stations with an 80 % energy coupling efficiency are used to exchange kinetic energy between 8 partner spacecraft transiting the same route. This method is well suited for round trip high volume space travel such as space tourism traffic to LEO, lunar orbit, and beyond. As the kinetic energy of an arriving spacecraft is the power source for launching departing spacecraft, nascent lunar colonies can electrically launch 26,000 kg payloads long before sustained 100 MW level power supplies become locally available. A pair of recycling stations at an orbiting space colony construction site provides a resource of net impulse, net torque, and electrical power to the colony irrespective of the contents of the arriving payloads. Kinetic energy recycling technology, configuration, operations, and near Earth applications are described.

  6. Space Shuttle Orbiter logistics - Managing in a dynamic environment

    Science.gov (United States)

    Renfroe, Michael B.; Bradshaw, Kimberly

    1990-01-01

    The importance and methods of monitoring logistics vital signs, logistics data sources and acquisition, and converting data into useful management information are presented. With the launch and landing site for the Shuttle Orbiter project at the Kennedy Space Center now totally responsible for its own supportability posture, it is imperative that logistics resource requirements and management be continually monitored and reassessed. Detailed graphs and data concerning various aspects of logistics activities including objectives, inventory operating levels, customer environment, and data sources are provided. Finally, some lessons learned from the Shuttle Orbiter project and logistics options which should be considered by other space programs are discussed.

  7. Space Weathering of Super-Earths: Model Simulations of Exospheric Sodium Escape from 61 Virgo b

    Energy Technology Data Exchange (ETDEWEB)

    Yoneda, M.; Berdyugina, S.; Kuhn, J. [Kiepenheuer Institute for Solar Physics, Schöneckstraße 6, 79104 Freiburg im Breisgau (Germany)

    2017-10-01

    Rocky exoplanets are expected to be eroded by space weather in a similar way as in the solar system. In particular, Mercury is one of the dramatically eroded planets whose material continuously escapes into its exosphere and further into space. This escape is well traced by sodium atoms scattering sunlight. Due to solar wind impact, micrometeorite impacts, photo-stimulated desorption and thermal desorption, sodium atoms are released from surface regolith. Some of these released sodium atoms are escaping from Mercury’s gravitational-sphere. They are dragged anti-Sun-ward and form a tail structure. We expect similar phenomena on exoplanets. The hot super-Earth 61 Vir b orbiting a G3V star at only 0.05 au may show a similar structure. Because of its small separation from the star, the sodium release mechanisms may be working more efficiently on hot super-Earths than on Mercury, although the strong gravitational force of Earth-sized or even more massive planets may be keeping sodium atoms from escaping from the planet. Here, we performed model simulations for Mercury (to verify our model) and 61 Vir b as a representative super-Earth. We have found that sodium atoms can escape from this exoplanet due to stellar wind sputtering and micrometeorite impacts, to form a sodium tail. However, in contrast to Mercury, the tail on this hot super-Earth is strongly aligned with the anti-starward direction because of higher light pressure. Our model suggests that 61 Vir b seems to have an exo-base atmosphere like that of Mercury.

  8. Space Weathering of Super-Earths: Model Simulations of Exospheric Sodium Escape from 61 Virgo b

    International Nuclear Information System (INIS)

    Yoneda, M.; Berdyugina, S.; Kuhn, J.

    2017-01-01

    Rocky exoplanets are expected to be eroded by space weather in a similar way as in the solar system. In particular, Mercury is one of the dramatically eroded planets whose material continuously escapes into its exosphere and further into space. This escape is well traced by sodium atoms scattering sunlight. Due to solar wind impact, micrometeorite impacts, photo-stimulated desorption and thermal desorption, sodium atoms are released from surface regolith. Some of these released sodium atoms are escaping from Mercury’s gravitational-sphere. They are dragged anti-Sun-ward and form a tail structure. We expect similar phenomena on exoplanets. The hot super-Earth 61 Vir b orbiting a G3V star at only 0.05 au may show a similar structure. Because of its small separation from the star, the sodium release mechanisms may be working more efficiently on hot super-Earths than on Mercury, although the strong gravitational force of Earth-sized or even more massive planets may be keeping sodium atoms from escaping from the planet. Here, we performed model simulations for Mercury (to verify our model) and 61 Vir b as a representative super-Earth. We have found that sodium atoms can escape from this exoplanet due to stellar wind sputtering and micrometeorite impacts, to form a sodium tail. However, in contrast to Mercury, the tail on this hot super-Earth is strongly aligned with the anti-starward direction because of higher light pressure. Our model suggests that 61 Vir b seems to have an exo-base atmosphere like that of Mercury.

  9. RFI and Remote Sensing of the Earth from Space

    Science.gov (United States)

    Le Vine, D. M.; Johnson, J. T.; Piepmeier, J.

    2016-01-01

    Passive microwave remote sensing of the Earth from space provides information essential for understanding the Earth's environment and its evolution. Parameters such as soil moisture, sea surface temperature and salinity, and profiles of atmospheric temperature and humidity are measured at frequencies determined by the physics (e.g. sensitivity to changes in desired parameters) and by the availability of suitable spectrum free from interference. Interference from manmade sources (radio frequency interference) is an impediment that in many cases limits the potential for accurate measurements from space. A review is presented here of the frequencies employed in passive microwave remote sensing of the Earth from space and the associated experience with RFI.

  10. Developing Earth and Space Scientists for the Future

    Science.gov (United States)

    Manduca, Cathryn A.; Cifuentes, Inés

    2007-09-01

    As the world's largest organization of Earth and space scientists, AGU safeguards the future of pioneering research by ensuring that ``the number and diversity of Earth and space scientists continue to grow through the flow of young talent into the field'' (AGU Strategic Plan 2008, Goal IV). Achieving this goal is the focus of the AGU Committee on Education and Human Resources (CEHR), one of the Union's three outreach committees.

  11. 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

  12. Preparation, analysis, and release of simulated interplanetary grains into low earth orbit

    International Nuclear Information System (INIS)

    Stephens, J.R.; Strong, I.B.; Kunkle, T.D.

    1985-01-01

    Astronomical observations which reflect the optical and dynamical properties of interstellar and interplanetary grains are the primary means of identifying the shape, size, and the chemistry of extraterrestrial grain materials and is a major subject of this workshop. Except for recent samplings of extraterrestrial particles in near-Earth orbit and in the stratosphere, observations have been the only method of deducing the properties of extraterrestrial particles. Terrestrial laboratory experiments typically seek not to reproduce astrophysical conditions but to illuminate fundamental dust processes and properties which must be extrapolated to interesting astrophysical conditions. In this report, we discuss the formation and optical characterization of simulated interstellar and interplanetary dust with particular emphasis on studying the properties on irregularly shaped particles. We also discuss efforts to develop the techniques to allow dust experiments to be carried out in low-Earth orbit, thus extending the conditions under which dust experiments may be performed. The objectives of this study are threefold: (1) Elucidate the optical properties, including scattering and absorption, of simulated interstellar grains including SiC, silicates, and carbon grains produced in the laboratory. (2) Develop the capabilities to release grains and volatile materials into the near-Earth environment and study their dynamics and optical properties. (3) Study the interaction of released materials with the near-Earth environment to elucidate grain behavior in astrophysical environments. Interaction of grains with their environment may, for example, lead to grain alignment or coagulation, which results in observable phenomena such as polarization of lighter or a change of the scattering properties of the grains

  13. Impacts of Earth rotation parameters on GNSS ultra-rapid orbit prediction: Derivation and real-time correction

    Science.gov (United States)

    Wang, Qianxin; Hu, Chao; Xu, Tianhe; Chang, Guobin; Hernández Moraleda, Alberto

    2017-12-01

    Analysis centers (ACs) for global navigation satellite systems (GNSSs) cannot accurately obtain real-time Earth rotation parameters (ERPs). Thus, the prediction of ultra-rapid orbits in the international terrestrial reference system (ITRS) has to utilize the predicted ERPs issued by the International Earth Rotation and Reference Systems Service (IERS) or the International GNSS Service (IGS). In this study, the accuracy of ERPs predicted by IERS and IGS is analyzed. The error of the ERPs predicted for one day can reach 0.15 mas and 0.053 ms in polar motion and UT1-UTC direction, respectively. Then, the impact of ERP errors on ultra-rapid orbit prediction by GNSS is studied. The methods for orbit integration and frame transformation in orbit prediction with introduced ERP errors dominate the accuracy of the predicted orbit. Experimental results show that the transformation from the geocentric celestial references system (GCRS) to ITRS exerts the strongest effect on the accuracy of the predicted ultra-rapid orbit. To obtain the most accurate predicted ultra-rapid orbit, a corresponding real-time orbit correction method is developed. First, orbits without ERP-related errors are predicted on the basis of ITRS observed part of ultra-rapid orbit for use as reference. Then, the corresponding predicted orbit is transformed from GCRS to ITRS to adjust for the predicted ERPs. Finally, the corrected ERPs with error slopes are re-introduced to correct the predicted orbit in ITRS. To validate the proposed method, three experimental schemes are designed: function extrapolation, simulation experiments, and experiments with predicted ultra-rapid orbits and international GNSS Monitoring and Assessment System (iGMAS) products. Experimental results show that using the proposed correction method with IERS products considerably improved the accuracy of ultra-rapid orbit prediction (except the geosynchronous BeiDou orbits). The accuracy of orbit prediction is enhanced by at least 50

  14. Area Students Get a Call from Orbiting Space Shuttle Discovery

    OpenAIRE

    Naval Postgraduate School Public Affairs Office

    2010-01-01

    More than 1,000 students, parents and members of the NPS community packed King Auditorium Saturday morning where they received a call from the Space Shuttle Discovery orbiting more than 200 miles into space — part of the NPS Centennial’s Education Downlink STS-131, Teaching from Space event.

  15. Inversion of the Earth spherical albedo from radiation-pressure

    Science.gov (United States)

    Wilkman, Olli; Herranen, Joonas; Näränen, Jyri; Virtanen, Jenni; Koivula, Hannu; Poutanen, Markku; Penttilä, Antti; Gritsevich, Maria; Muinonen, Karri

    2017-04-01

    We are studying the retrieval of the spherical albedo and net radiation of the Earth from the perturbations caused by the planet's radiation on the dynamics of its satellites. The spherical or Bond albedo gives the ratio of the fluxes incident on and scattered by the planet. The net radiation represents the net heat input into the planet's climate system and drives changes in its atmospheric, surface, and ocean temperatures. The ultimate aim of the study is inverting the problem and estimating the Earth albedo based on observations of satellites, simultaneously improving the space-geodetic positioning accuracy. Here we investigate the effect of the spherical albedo on satellite orbits with the help of a simplified model. We simulate the propagation of satellite orbits using a new simulation software. The simulation contains the main perturbing forces on medium and high Earth orbits, used by, e.g., navigation satellites, including the radiation pressure of reflected sunlight from the Earth. An arbitrary satellite shape model can be used, and the rotation of the satellite is modeled. In this first study, we use a box-wing satellite model with a simple surface BRDF. We also assume a diffusely reflecting Earth with a single global albedo value. We vary the Earth albedo and search for systematic effects on different orbits. Thereafter, we estimate the dependence of the albedo accuracy on the satellite positioning and timing data available. We show that the inversion of the spherical albedo with reasonable accuracy is feasible from the current space-geodetic measurements.

  16. Studying the Earth from space

    Science.gov (United States)

    ,

    1981-01-01

    Space age technology contains a key to increased knowledge about the Earth's resources; this key is remote sensing detecting the nature or condition of something without actually touching it. An early and still most useful form of remote sensing is photography which records the

  17. Migration of Small Bodies and Dust to Near-Earth Space

    Science.gov (United States)

    Ipatov, S. I.; Mather, J. C.

    Computer simulations of the orbital evolution of Jupiter-family comets (JFCs), resonant asteroids, and asteroidal, kuiperoidal, and cometary dust particles were made. The gravitational influence of planets (exclusive of Pluto and sometimes of Mercury) was taken into account. For dust particles we also considered radiation pressure, Poynting-Robertson drag, and solar wind drag. A few JFCs got Earth-crossing orbits with semi-major axes adisintegrated into mini-comets and dust during a smaller part of their dynamical lifetimes if these lifetimes are not small. The obtained results show that during the accumulation of the giant planets the total mass of icy bodies delivered to the Earth could be about the mass of water in Earth's oceans. In our runs for dust particles, the values of the ratio β between the radiation pressure force and the gravitational force varied from 0.0004 to 0.4 (for silicates, such values correspond to particle diameters between 1000 and 1 microns). For β >0.01 the collision probabilities of dust particles with the terrestrial planets during lifetimes of particles were considerably greater for larger asteroidal and cometary particles. At β ≥ 0.1 and β ≤ 0.001 some asteroidal particles migrated beyond Jupiter's orbit. The peaks in the distribution of migrating asteroidal dust particles with semi-major axis corresponding to the n:(n+1) resonances with Earth and Venus and the gaps associated with the 1:1 resonances with these planets are more pronounced for larger particles. Several our papers on this problem were put in http://arXiv.org/format/astro-ph/ (e.g., 0305519, 0308448, 0308450). This work was supported by INTAS (00-240) and NASA (NAG5-10776).

  18. Comparison of technologies for deorbiting spacecraft from low-earth-orbit at end of mission

    Science.gov (United States)

    Sánchez-Arriaga, G.; Sanmartín, J. R.; Lorenzini, E. C.

    2017-09-01

    An analytical comparison of four technologies for deorbiting spacecraft from Low-Earth-Orbit at end of mission is presented. Basic formulas based on simple physical models of key figures of merit for each device are found. Active devices - rockets and electrical thrusters - and passive technologies - drag augmentation devices and electrodynamic tethers - are considered. A basic figure of merit is the deorbit device-to-spacecraft mass ratio, which is, in general, a function of environmental variables, technology development parameters and deorbit time. For typical state-of-the-art values, equal deorbit time, middle inclination and initial altitude of 850 km, the analysis indicates that tethers are about one and two orders of magnitude lighter than active technologies and drag augmentation devices, respectively; a tether needs a few percent mass-ratio for a deorbit time of a couple of weeks. For high inclination, the performance drop of the tether system is moderate: mass ratio and deorbit time increase by factors of 2 and 4, respectively. Besides collision risk with other spacecraft and system mass considerations, such as main driving factors for deorbit space technologies, the analysis addresses other important constraints, like deorbit time, system scalability, manoeuver capability, reliability, simplicity, attitude control requirement, and re-entry and multi-mission capability (deorbit and re-boost) issues. The requirements and constraints are used to make a critical assessment of the four technologies as functions of spacecraft mass and initial orbit (altitude and inclination). Emphasis is placed on electrodynamic tethers, including the latest advances attained in the FP7/Space project BETs. The superiority of tape tethers as compared to round and multi-line tethers in terms of deorbit mission performance is highlighted, as well as the importance of an optimal geometry selection, i.e. tape length, width, and thickness, as function of spacecraft mass and initial

  19. Space Transportation Infrastructure Supported By Propellant Depots

    Science.gov (United States)

    Smitherman, David; Woodcock, Gordon

    2012-01-01

    A space transportation infrastructure is described that utilizes propellant depot servicing platforms to support all foreseeable missions in the Earth-Moon vicinity and deep space out to Mars. The infrastructure utilizes current expendable launch vehicle (ELV) systems such as the Delta IV Heavy, Atlas V, and Falcon 9, for all crew, cargo, and propellant launches to orbit. Propellant launches are made to Low-Earth-Orbit (LEO) Depot and an Earth-Moon Lagrange Point 1 (L1) Depot to support a new reusable in-space transportation vehicles. The LEO Depot supports missions to Geosynchronous Earth Orbit (GEO) for satellite servicing and to L1 for L1 Depot missions. The L1 Depot supports Lunar, Earth-Sun L2 (ESL2), Asteroid and Mars Missions. New vehicle design concepts are presented that can be launched on current 5 meter diameter ELV systems. These new reusable vehicle concepts include a Crew Transfer Vehicle (CTV) for crew transportation between the LEO Depot, L1 Depot and missions beyond L1; a new reusable lunar lander for crew transportation between the L1 Depot and the lunar surface; and Mars orbital Depot are based on International Space Station (ISS) heritage hardware. Data provided includes the number of launches required for each mission utilizing current ELV systems (Delta IV Heavy or equivalent) and the approximate vehicle masses and propellant requirements. Also included is a discussion on affordability with ideas on technologies that could reduce the number of launches required and thoughts on how this infrastructure include competitive bidding for ELV flights and propellant services, developments of new reusable in-space vehicles and development of a multiuse infrastructure that can support many government and commercial missions simultaneously.

  20. On the gauge orbit space stratification: a review

    International Nuclear Information System (INIS)

    Rudolph, G.; Schmidt, M.; Volobuev, I.P.

    2002-01-01

    First, we review the basic mathematical structures and results concerning the gauge orbit space stratification. This includes general properties of the gauge group action, fibre bundle structures induced by this action, basic properties of the stratification and the natural Riemannian structures of the strata. In the second part, we study the stratification for theories with gauge group SU(n) in spacetime dimension 4. We develop a general method for determining the orbit types and their partial ordering, based on the 1-1 correspondence between orbit types and holonomy-induced Howe subbundles of the underlying principal SU(n)-bundle. We show that the orbit types are classified by certain cohomology elements of spacetime satisfying two relations and that the partial ordering is characterized by a system of algebraic equations. Moreover, operations for generating direct successors and direct predecessors are formulated, which allow one to construct the set of orbit types, starting from the principal type. Finally, we discuss an application to nodal configurations in Yang-Mills-Chern-Simons theory. (author)

  1. A SUPER-EARTH-SIZED PLANET ORBITING IN OR NEAR THE HABITABLE ZONE AROUND A SUN-LIKE STAR

    Energy Technology Data Exchange (ETDEWEB)

    Barclay, Thomas; Burke, Christopher J.; Howell, Steve B.; Rowe, Jason F.; Huber, Daniel; Jenkins, Jon M.; Quintana, Elisa V.; Still, Martin; Twicken, Joseph D.; Bryson, Stephen T.; Borucki, William J.; Caldwell, Douglas A.; Clarke, Bruce D.; Christiansen, Jessie L; Coughlin, Jeffrey L. [NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States); Isaacson, Howard; Kolbl, Rea; Marcy, Geoffrey W. [Department of Astronomy, University of California at Berkeley, Berkeley, CA 94720 (United States); Ciardi, David [NASA Exoplanet Science Institute, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Fischer, Debra A. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); and others

    2013-05-10

    We present the discovery of a super-Earth-sized planet in or near the habitable zone of a Sun-like star. The host is Kepler-69, a 13.7 mag G4V-type star. We detect two periodic sets of transit signals in the 3-year flux time series of Kepler-69, obtained with the Kepler spacecraft. Using the very high precision Kepler photometry, and follow-up observations, our confidence that these signals represent planetary transits is >99.3%. The inner planet, Kepler-69b, has a radius of 2.24{sup +0.44}{sub -0.29} R{sub Circled-Plus} and orbits the host star every 13.7 days. The outer planet, Kepler-69c, is a super-Earth-sized object with a radius of 1.7{sup +0.34}{sub -0.23} R{sub Circled-Plus} and an orbital period of 242.5 days. Assuming an Earth-like Bond albedo, Kepler-69c has an equilibrium temperature of 299 {+-} 19 K, which places the planet close to the habitable zone around the host star. This is the smallest planet found by Kepler to be orbiting in or near the habitable zone of a Sun-like star and represents an important step on the path to finding the first true Earth analog.

  2. Magnetic De-spinning of Space Objects

    Data.gov (United States)

    National Aeronautics and Space Administration — Objects in orbit about the earth rotate such that a service spacecraft cannot grapple to them. There are few techniques available to despin a space object without...

  3. NASA Advanced Concepts Office, Earth-To-Orbit Team Design Process and Tools

    Science.gov (United States)

    Waters, Eric D.; Garcia, Jessica; Threet, Grady E., Jr.; Phillips, Alan

    2013-01-01

    The Earth-to-Orbit Team (ETO) of the Advanced Concepts Office (ACO) at NASA Marshall Space Flight Center (MSFC) is considered the pre-eminent "go-to" group for pre-phase A and phase A concept definition. Over the past several years the ETO team has evaluated thousands of launch vehicle concept variations for a significant number of studies including agency-wide efforts such as the Exploration Systems Architecture Study (ESAS), Constellation, Heavy Lift Launch Vehicle (HLLV), Augustine Report, Heavy Lift Propulsion Technology (HLPT), Human Exploration Framework Team (HEFT), and Space Launch System (SLS). The ACO ETO Team is called upon to address many needs in NASA's design community; some of these are defining extremely large trade-spaces, evaluating advanced technology concepts which have not been addressed by a large majority of the aerospace community, and the rapid turn-around of highly time critical actions. It is the time critical actions, those often limited by schedule or little advanced warning, that have forced the five member ETO team to develop a design process robust enough to handle their current output level in order to meet their customer's needs. Based on the number of vehicle concepts evaluated over the past year this output level averages to four completed vehicle concepts per day. Each of these completed vehicle concepts includes a full mass breakdown of the vehicle to a tertiary level of subsystem components and a vehicle trajectory analysis to determine optimized payload delivery to specified orbital parameters, flight environments, and delta v capability. A structural analysis of the vehicle to determine flight loads based on the trajectory output, material properties, and geometry of the concept is also performed. Due to working in this fast-paced and sometimes rapidly changing environment, the ETO Team has developed a finely tuned process to maximize their delivery capabilities. The objective of this paper is to describe the interfaces

  4. Orbital Noise of the Earth Causes Intensity Fluctuation in the Geomagnetic Field

    Science.gov (United States)

    Liu, Han-Shou; Kolenkiewicz, R.; Wade, C., Jr.

    2003-01-01

    Orbital noise of Earth's obliquity can provide an insight into the core of the Earth that causes intensity fluctuations in the geomagnetic field. Here we show that noise spectrum of the obliquity frequency have revealed a series of frequency periods centered at 250-, 1OO-, 50-, 41-, 30-, and 26-kyr which are almost identical with the observed spectral peaks from the composite curve of 33 records of relative paleointensity spanning the past 800 kyr (Sint-800 data). A continuous record for the past two million years also reveals the presence of the major 100 kyr periodicity in obliquity noise and geomagnetic intensity fluctuations. These results of correlation suggest that obliquity noise may power the dynamo, located in the liquid outer core of the Earth, which generates the geomagnetic field.

  5. The development of a specialized processor for a space-based multispectral earth imager

    Science.gov (United States)

    Khedr, Mostafa E.

    2008-10-01

    This work was done in the Department of Computer Engineering, Lvov Polytechnic National University, Lvov, Ukraine, as a thesis entitled "Space Imager Computer System for Raw Video Data Processing" [1]. This work describes the synthesis and practical implementation of a specialized computer system for raw data control and processing onboard a satellite MultiSpectral earth imager. This computer system is intended for satellites with resolution in the range of one meter with 12-bit precession. The design is based mostly on general off-the-shelf components such as (FPGAs) plus custom designed software for interfacing with PC and test equipment. The designed system was successfully manufactured and now fully functioning in orbit.

  6. The history of the UV radiation climate of the earth--theoretical and space-based observations.

    Science.gov (United States)

    Cockell, C S; Horneck, G

    2001-04-01

    In the Archean era (3.8-2.5 Ga ago) the Earth probably lacked a protective ozone column. Using data obtained in the Earth's orbit on the inactivation of Bacillus subtilis spores we quantitatively estimate the potential biological effects of such an environment. We combine this practical data with theoretical calculations to propose a history of the potential UV stress on the surface of the Earth over time. The data suggest that an effective ozone column was established at a pO2 of approximately 5 x 10(-3) present atmospheric level. The improvement in the UV environment on the early Proterozoic Earth might have been a much more rapid event than has previously been supposed, with DNA damage rates dropping by two orders of magnitude in the space of just a few tens of millions of years. We postulate that a coupling between reduced UV stress and increased pO2 production could have contributed toward a positive feedback in the production of ozone in the early Proterozoic atmosphere. This would contribute to the apparent rapidity of the oxidation event. The data provide an evolutionary perspective on present-day Antarctic ozone depletion.

  7. Deep Space Gateway Science Opportunities

    Science.gov (United States)

    Quincy, C. D.; Charles, J. B.; Hamill, Doris; Sidney, S. C.

    2018-01-01

    The NASA Life Sciences Research Capabilities Team (LSRCT) has been discussing deep space research needs for the last two years. NASA's programs conducting life sciences studies - the Human Research Program, Space Biology, Astrobiology, and Planetary Protection - see the Deep Space Gateway (DSG) as affording enormous opportunities to investigate biological organisms in a unique environment that cannot be replicated in Earth-based laboratories or on Low Earth Orbit science platforms. These investigations may provide in many cases the definitive answers to risks associated with exploration and living outside Earth's protective magnetic field. Unlike Low Earth Orbit or terrestrial locations, the Gateway location will be subjected to the true deep space spectrum and influence of both galactic cosmic and solar particle radiation and thus presents an opportunity to investigate their long-term exposure effects. The question of how a community of biological organisms change over time within the harsh environment of space flight outside of the magnetic field protection can be investigated. The biological response to the absence of Earth's geomagnetic field can be studied for the first time. Will organisms change in new and unique ways under these new conditions? This may be specifically true on investigations of microbial communities. The Gateway provides a platform for microbiology experiments both inside, to improve understanding of interactions between microbes and human habitats, and outside, to improve understanding of microbe-hardware interactions exposed to the space environment.

  8. Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST)

    Science.gov (United States)

    Baldauf, Brian; Conti, Alberto

    2016-01-01

    The "Search for Life" via imaging of exoplanets is a mission that requires extremely stable telescopes with apertures in the 10 m to 20 m range. The High Definition Space Telescope (HDST) envisioned for this mission would have an aperture >10 m, which is a larger payload than what can be delivered to space using a single launch vehicle. Building and assembling the mirror segments enabling large telescopes will likely require multiple launches and assembly in space. Space-based telescopes with large apertures will require major changes to system architectures.The Optical Telescope Assembly (OTA) for HDST is a primary mission cost driver. Enabling and affordable solutions for this next generation of large aperture space-based telescope are needed.This paper reports on the concept for the Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST), which demonstrates on-orbit robotic and/or astronaut assembly of a precision optical telescope in space. It will also facilitate demonstration of active correction of phase and mirror shape. MODEST is proposed to be delivered to the ISS using standard Express Logistics Carriers (ELCs) and can mounted to one of a variety of ISS pallets. Post-assembly value includes space, ground, and environmental studies, and a testbed for new instruments. This demonstration program for next generation mirror technology provides significant risk reduction and demonstrates the technology in a six-mirror phased telescope. Other key features of the demonstration include the use of an active primary optical surface with wavefront feedback control that allows on-orbit optimization and demonstration of precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Carbon Fiber Reinforced Polymer that have excellent mechanical and thermal properties, e.g. high stiffness, high modulus, high thermal

  9. Spaceship earth: take your classroom into space

    NARCIS (Netherlands)

    Hartevelt, S.; van den Putte, W.; Wamsteker, J.; de Vet, S.; van Loon, J.J.W.A.; Celton, E.; Savage, N.D.L.

    2012-01-01

    Schools in Europe actively participated in the educational project "Spaceship Earth", part of ESA astronaut André Kuipers’ PromISSe mission. The initiative, conceptualized by the European Space Agency (ESA) and the Netherlands Space Office (NSO) also involved a unique collaboration of a team

  10. Design and Implementation of a Space Environment Simulation Toolbox for Small Satellites

    DEFF Research Database (Denmark)

    Amini, Rouzbeh; Larsen, Jesper A.; Izadi-Zamanabadi, Roozbeh

    This paper presents a developed toolbox for space environment model in SIMULINK that facilitates development and design of Attitude Determination and Control Systems (ADCS) for a Low Earth Orbit (LEO) spacecraft. The toolbox includes, among others, models of orbit propagators, disturbances, Earth...

  11. A standard library for modeling satellite orbits on a microcomputer

    Science.gov (United States)

    Beutel, Kenneth L.

    1988-03-01

    Introductory students of astrodynamics and the space environment are required to have a fundamental understanding of the kinematic behavior of satellite orbits. This thesis develops a standard library that contains the basic formulas for modeling earth orbiting satellites. This library is used as a basis for implementing a satellite motion simulator that can be used to demonstrate orbital phenomena in the classroom. Surveyed are the equations of orbital elements, coordinate systems and analytic formulas, which are made into a standard method for modeling earth orbiting satellites. The standard library is written in the C programming language and is designed to be highly portable between a variety of computer environments. The simulation draws heavily on the standards established by the library to produce a graphics-based orbit simulation program written for the Apple Macintosh computer. The simulation demonstrates the utility of the standard library functions but, because of its extensive use of the Macintosh user interface, is not portable to other operating systems.

  12. Rendezvous and Docking for Space Exploration

    Science.gov (United States)

    Machula, M. F.; Crain, T.; Sandhoo, G. S.

    2005-01-01

    To achieve the exploration goals, new approaches to exploration are being envisioned that include robotic networks, modular systems, pre-positioned propellants and in-space assembly in Earth orbit, Lunar orbit and other locations around the cosmos. A fundamental requirement for rendezvous and docking to accomplish in-space assembly exists in each of these locations. While existing systems and technologies can accomplish rendezvous and docking in low earth orbit, and rendezvous and docking with crewed systems has been successfully accomplished in low lunar orbit, our capability must extend toward autonomous rendezvous and docking. To meet the needs of the exploration vision in-space assembly requiring both crewed and uncrewed vehicles will be an integral part of the exploration architecture. This paper focuses on the intelligent application of autonomous rendezvous and docking technologies to meet the needs of that architecture. It also describes key technology investments that will increase the exploration program's ability to ensure mission success, regardless of whether the rendezvous are fully automated or have humans in the loop.

  13. Precipitation regions on the Earth of high energy electrons, injected by a point source moving along a circular Earth orbit

    Science.gov (United States)

    Kolesnikov, E. K.; Klyushnikov, G. N.

    2018-05-01

    In the paper we continue the study of precipitation regions of high-energy charged particles, carried out by the authors since 2002. In contrast to previous papers, where a stationary source of electrons was considered, it is assumed that the source moves along a low circular near-earth orbit with a constant velocity. The orbit position is set by the inclination angle of the orbital plane to the equatorial plane and the longitude of the ascending node. The total number of injected electrons is determined by the source strength and the number of complete revolutions that the source makes along the circumference. Construction of precipitation regions is produced using the computational algorithm based on solving of the system of ordinary differential equations. The features of the precipitation regions structure for the dipole approximation of the geomagnetic field and the symmetrical arrangement of the orbit relative to the equator are noted. The dependencies of the precipitation regions on different orbital parametres such as the incline angle, the ascending node position and kinetic energy of injected particles have been considered.

  14. From Science Reserves to Sustainable Multiple Uses beyond Earth orbit: Evaluating Issues on the Path towards Balanced Environmental Management on Planetary Bodies

    Science.gov (United States)

    Race, Margaret

    Over the past five decades, our understanding of space beyond Earth orbit has been shaped by a succession of mainly robotic missions whose technologies have enabled scientists to answer diverse science questions about celestial bodies across the solar system. For all that time, exploration has been guided by planetary protection policies and principles promulgated by COSPAR and based on provisions in Article IX of the Outer Space Treaty of 1967. Over time, implementation of the various COSPAR planetary protection policies have sought to avoid harmful forward and backward contamination in order to ensure the integrity of science findings, guide activities on different celestial bodies, and appropriately protect Earth whenever extraterrestrial materials have been returned. The recent increased interest in extending both human missions and commercial activities beyond Earth orbit have prompted discussions in various quarters about the need for updating policies and guidelines to ensure responsible, balanced space exploration and use by all parties, regardless whether activities are undertaken by governmental or non-governmental entities. Already, numerous researchers and workgroups have suggested a range of different ways to manage activities on celestial environments (e.g, wilderness parks, exclusion zones, special regions, claims, national research bases, environmental impact assessments, etc.). While the suggestions are useful in thinking about how to manage future space activities, they are not based on any systematically applied or commonly accepted criteria (scientific or otherwise). In addition, they are borrowed from terrestrial approaches for environmental protection, which may or may not have direct applications to space environments. As noted in a recent COSPAR-PEX workshop (GWU 2012), there are no clear definitions of issues such as harmful contamination, the environment to be protected, or what are considered reasonable activity or impacts for particular

  15. PCVs Estimation and their Impacts on Precise Orbit Determination of LEOs

    Science.gov (United States)

    Chunmei, Z.; WANG, X.

    2017-12-01

    In the last decade the precise orbit determination (POD) based on GNSS, such as GPS, has been considered as one of the efficient methods to derive orbits of Low Earth Orbiters (LEOs) that demand accuracy requirements. The Earth gravity field recovery and its related researches require precise dynamic orbits of LEOs. With the improvements of GNSS satellites' orbit and clock accuracy, the algorithm optimization and the refinement of perturbation force models, the antenna phase-center variations (PCVs) of space-borne GNSS receiver have become an increasingly important factor that affects POD accuracy. A series of LEOs such as HY-2, ZY-3 and FY-3 with homebred space-borne GNSS receivers have been launched in the past several years in China. Some of these LEOs load dual-mode GNSS receivers of GPS and BDS signals. The reliable performance of these space-borne receivers has been establishing an important foundation for the future launches of China gravity satellites. Therefore, we first evaluate the data quality of on-board GNSS measurement by examining integrity, multipath error, cycle slip ratio and other quality indices. Then we determine the orbits of several LEOs at different altitudes by the reduced dynamic orbit determination method. The corresponding ionosphere-free carrier phase post-fit residual time series are obtained. And then we establish the PCVs model by the ionosphere-free residual approach and analyze the effects of antenna phase-center variation on orbits. It is shown that orbit accuracy of LEO satellites is greatly improved after in-flight PCV calibration. Finally, focus on the dual-mode receiver of FY-3 satellite we analyze the quality of onboard BDS data and then evaluate the accuracy of the FY-3 orbit determined using only BDS measurement onboard. The accuracy of LEO satellites orbit based on BDS would be well improved with the global completion of BDS by 2020.

  16. Future earth orbit transportation systems/technology implications

    Science.gov (United States)

    Henry, B. Z.; Decker, J. P.

    1976-01-01

    Assuming Space Shuttle technology to be state-of-the-art, projected technological advances to improve the capabilities of single-stage-to-orbit (SSTO) derivatives are examined. An increase of about 30% in payload performance can be expected from upgrading the present Shuttle system through weight and drag reductions and improvements in the propellants and engines. The ODINEX (Optimal Design Integration Executive Computer Program) program has been used to explore design options. An advanced technology SSTO baseline system derived from ODINEX analysis has a conventional wing-body configuration using LOX/LH engines, three with two-position nozzles with expansion ratios of 40 and 200 and four with fixed nozzles with an expansion ratio of 40. Two assisted-takeoff approaches are under consideration in addition to a concept in which the orbital vehicle takes off empty using airbreathing propulsion and carries out a rendezvous with two large cryogenic tankers carrying propellant at an altitude of 6100 m. Further approaches under examination for propulsion, aerothermodynamic design, and design integration are described.

  17. Exo-Milankovitch Cycles. I. Orbits and Rotation States

    Science.gov (United States)

    Deitrick, Russell; Barnes, Rory; Quinn, Thomas R.; Armstrong, John; Charnay, Benjamin; Wilhelm, Caitlyn

    2018-02-01

    The obliquity of the Earth, which controls our seasons, varies by only ∼2.°5 over ∼40,000 years, and its eccentricity varies by only ∼0.05 over 100,000 years. Nonetheless, these small variations influence Earth’s ice ages. For exoplanets, however, variations can be significantly larger. Previous studies of the habitability of moonless Earth-like exoplanets have found that high obliquities, high eccentricities, and dynamical variations can extend the outer edge of the habitable zone by preventing runaway glaciation (snowball states). We expand upon these studies by exploring the orbital dynamics with a semianalytic model that allows us to map broad regions of parameter space. We find that, in general, the largest drivers of obliquity variations are secular spin–orbit resonances. We show how the obliquity varies in several test cases, including Kepler-62 f, across a wide range of orbital and spin parameters. These obliquity variations, alongside orbital variations, will have a dramatic impact on the climates of such planets.

  18. Meteoroid Orbits from Observations

    Science.gov (United States)

    Campbell-Brown, Margaret

    2018-04-01

    Millions of orbits of meteoroids have been measured over the last few decades, and they comprise the largest sample of orbits of solar system bodies which exists. The orbits of these objects can shed light on the distribution and evolution of comets and asteroids in near-Earth space (e.g. Neslusan et al. 2016). If orbits can be measured at sufficiently high resolution, individual meteoroids can be traced back to their parent bodies and, in principle, even to their ejection time (Rudawska et al. 2012). Orbits can be measured with multi-station optical observations or with radar observations.The most fundamental measured quantities are the speed of the meteor and the two angles of the radiant, or point in the sky from which the meteor appears to come. There are many methods used to determine these from observations, but not all produce the most accurate results (Egal et al. 2017). These three measured quantities, along with the time and location of the observation, are sufficient to obtain an orbit (see, e.g., Clark & Wiegert 2011), but the measurements must be corrected for the deceleration of the meteoroid in the atmosphere before it was detected, the rotation of the Earth, and the gravitational attraction of the Earth (including higher order moments if great precision is necessary).Once meteor orbits have been determined, studies of the age and origin of meteor showers (Bruzzone et al., 2015), the parent bodies of sporadic sources (Pokorny et al. 2014), and the dynamics of the meteoroid complex as a whole can be constrained.Bruzzone, J. S., Brown, P., Weryk, R., Campbell-Brown, M., 2015. MNRAS 446, 1625.Clark, D., Wiegert, P., 2011. M&PS 46, 1217.Egal, A., Gural, P., Vaubaillon, J., Colas, F., Thuillot, W., 2017. Icarus 294, 43.Neslusan, L., Vaubaillon, J., Hajdukova, M., 2016. A&A 589, id.A100.Pokorny, P., Vokrouhlicky, D., Nesvorny, D., Campbell-Brown, M., Brown, P., 2014. ApJ 789, id.25.Rudawska, R., Vaubaillon, J., Atreya, P., 2012. A&A 541, id.A2

  19. Space Debris Mitigation Guidelines

    Science.gov (United States)

    Johnson, Nicholas L.

    2011-01-01

    The purpose of national and international space debris mitigation guides is to promote the preservation of near-Earth space for applications and exploration missions far into the future. To accomplish this objective, the accumulation of objects, particularly in long-lived orbits, must be eliminated or curtailed.

  20. Space Debris and Observational Astronomy

    Science.gov (United States)

    Seitzer, Patrick

    2018-01-01

    Since the launch of Sputnik 1 in 1957, astronomers have faced an increasing number of artificial objects contaminating their images of the night sky. Currently almost 17000 objects larger than 10 cm are tracked and have current orbits in the public catalog. Active missions are only a small fraction of these objects. Most are inactive satellites, rocket bodies, and fragments of larger objects: all space debris. Several mega-constellations are planned which will increase this number by 20% or more in low Earth orbit (LEO). In terms of observational astronomy, this population of Earth orbiting objects has three implications: 1) the number of streaks and glints from spacecraft will only increase. There are some practical steps that can be taken to minimize the number of such streaks and glints in astronomical imaging data. 2) The risk to damage to orbiting astronomical telescopes will only increase, particularly those in LEO. 3) If you are working on a plan for an orbiting telescope project, then there are specific steps that must be taken to minimize space debris generation during the mission lifetime, and actions to safely dispose of the spacecraft at end of mission to prevent it from becoming space debris and a risk to other missions. These steps may involve sacrifices to mission performance and lifetime, but are essential in today's orbital environment.

  1. Deep space optical communication via relay satellite

    Science.gov (United States)

    Dolinar, S.; Vilnrotter, V.; Gagliardi, R.

    1981-01-01

    The application of optical communications for a deep space link via an earth-orbiting relay satellite is discussed. The system uses optical frequencies for the free-space channel and RF links for atmospheric transmission. The relay satellite is in geostationary orbit and contains the optics necessary for data processing and formatting. It returns the data to earth through the RF terrestrial link and also transmits an optical beacon to the satellite for spacecraft return pointing and for the alignment of the transmitting optics. Future work will turn to modulation and coding, pointing and tracking, and optical-RF interfacing.

  2. Analytic model for the long-term evolution of circular Earth satellite orbits including lunar node regression

    Science.gov (United States)

    Zhu, Ting-Lei; Zhao, Chang-Yin; Zhang, Ming-Jiang

    2017-04-01

    This paper aims to obtain an analytic approximation to the evolution of circular orbits governed by the Earth's J2 and the luni-solar gravitational perturbations. Assuming that the lunar orbital plane coincides with the ecliptic plane, Allan and Cook (Proc. R. Soc. A, Math. Phys. Eng. Sci. 280(1380):97, 1964) derived an analytic solution to the orbital plane evolution of circular orbits. Using their result as an intermediate solution, we establish an approximate analytic model with lunar orbital inclination and its node regression be taken into account. Finally, an approximate analytic expression is derived, which is accurate compared to the numerical results except for the resonant cases when the period of the reference orbit approximately equals the integer multiples (especially 1 or 2 times) of lunar node regression period.

  3. Novel Solar Sail Mission Concepts for High-Latitude Earth and Lunar Observation

    NARCIS (Netherlands)

    Heiligers, M.J.; Parker, Jeffrey S.; Macdonald, Malcolm

    2016-01-01

    This paper proposes the use of solar sail periodic orbits in the Earth-Moon system for ob-servation of the high-latitudes of the Earth and Moon. At the Earth, the high-latitudes will be crucial in answering questions concerning global climate change, monitoring space weather events and ensuring

  4. NASA's Earth Science Flight Program overview

    Science.gov (United States)

    Neeck, Steven P.; Volz, Stephen M.

    2011-11-01

    NASA's Earth Science Division (ESD) conducts pioneering work in Earth system science, the interdisciplinary view of Earth that explores the interaction among the atmosphere, oceans, ice sheets, land surface interior, and life itself that has enabled scientists to measure global and climate changes and to inform decisions by governments, organizations, and people in the United States and around the world. The ESD makes the data collected and results generated by its missions accessible to other agencies and organizations to improve the products and services they provide, including air quality indices, disaster management, agricultural yield projections, and aviation safety. In addition to four missions now in development and 14 currently operating on-orbit, the ESD is now developing the first tier of missions recommended by the 2007 Earth Science Decadal Survey and is conducting engineering studies and technology development for the second tier. Furthermore, NASA's ESD is planning implementation of a set of climate continuity missions to assure availability of key data sets needed for climate science and applications. These include a replacement for the Orbiting Carbon Observatory (OCO), OCO-2, planned for launch in 2013; refurbishment of the SAGE III atmospheric chemistry instrument to be hosted by the International Space Station (ISS) as early as 2014; and the Gravity Recovery and Climate Experiment Follow-On (GRACE FO) mission scheduled for launch in 2016. The new Earth Venture (EV) class of missions is a series of uncoupled, low to moderate cost, small to medium-sized, competitively selected, full orbital missions, instruments for orbital missions of opportunity, and sub-orbital projects.

  5. Dynamics and stability of a tethered centrifuge in low earth orbit

    Science.gov (United States)

    Quadrelli, B. M.; Lorenzini, E. C.

    1992-01-01

    The three-dimensional attitude dynamics of a spaceborne tethered centrifuge for artificial gravity experiments in low earth orbit is analyzed using two different methods. First, the tethered centrifuge is modeled as a dumbbell with a straight viscoelastic tether, point tip-masses, and sophisticated environmental models such as nonspherical gravity, thermal perturbations, and a dynamic atmospheric model. The motion of the centrifuge during spin-up, de-spin, and steady-rotation is then simulated. Second, a continuum model of the tether is developed for analyzing the stability of lateral tether oscillations. Results indicate that the maximum fluctuation about the 1-g radial acceleration level is less than 0.001 g; the time required for spin-up and de-spin is less than one orbit; and lateral oscillations are stable for any practical values of the system parameters.

  6. THE HABITABILITY AND DETECTION OF EARTH-LIKE PLANETS ORBITING COOL WHITE DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Fossati, L.; Haswell, C. A.; Patel, M. R.; Busuttil, R. [Department of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Bagnulo, S. [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom); Kowalski, P. M. [GFZ German Research Centre for Geosciences, Telegrafenberg, D-14473 Potsdam (Germany); Shulyak, D. V. [Institute of Astrophysics, Georg-August-University, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany); Sterzik, M. F., E-mail: l.fossati@open.ac.uk, E-mail: C.A.Haswell@open.ac.uk, E-mail: M.R.Patel@open.ac.uk, E-mail: r.busuttil@open.ac.uk, E-mail: sba@arm.ac.uk, E-mail: kowalski@gfz-potsdam.de, E-mail: denis.shulyak@gmail.com, E-mail: msterzik@eso.org [European Southern Observatory, Casilla 19001, Santiago 19 (Chile)

    2012-09-20

    Since there are several ways planets can survive the giant phase of the host star, we examine the habitability and detection of planets orbiting white dwarfs. As a white dwarf cools from 6000 K to 4000 K, a planet orbiting at 0.01 AU would remain in the continuous habitable zone (CHZ) for {approx}8 Gyr. We show that photosynthetic processes can be sustained on such planets. The DNA-weighted UV radiation dose for an Earth-like planet in the CHZ is less than the maxima encountered on Earth, and hence non-magnetic white dwarfs are compatible with the persistence of complex life. Polarization due to a terrestrial planet in the CHZ of a cool white dwarf (CWD) is 10{sup 2} (10{sup 4}) times larger than it would be in the habitable zone of a typical M-dwarf (Sun-like star). Polarimetry is thus a viable way to detect close-in rocky planets around white dwarfs. Multi-band polarimetry would also allow us to reveal the presence of a planet atmosphere, providing a first characterization. Planets in the CHZ of a 0.6 M{sub Sun} white dwarf will be distorted by Roche geometry, and a Kepler-11d analog would overfill its Roche lobe. With current facilities a super-Earth-sized atmosphereless planet is detectable with polarimetry around the brightest known CWD. Planned future facilities render smaller planets detectable, in particular by increasing the instrumental sensitivity in the blue.

  7. THE HABITABILITY AND DETECTION OF EARTH-LIKE PLANETS ORBITING COOL WHITE DWARFS

    International Nuclear Information System (INIS)

    Fossati, L.; Haswell, C. A.; Patel, M. R.; Busuttil, R.; Bagnulo, S.; Kowalski, P. M.; Shulyak, D. V.; Sterzik, M. F.

    2012-01-01

    Since there are several ways planets can survive the giant phase of the host star, we examine the habitability and detection of planets orbiting white dwarfs. As a white dwarf cools from 6000 K to 4000 K, a planet orbiting at 0.01 AU would remain in the continuous habitable zone (CHZ) for ∼8 Gyr. We show that photosynthetic processes can be sustained on such planets. The DNA-weighted UV radiation dose for an Earth-like planet in the CHZ is less than the maxima encountered on Earth, and hence non-magnetic white dwarfs are compatible with the persistence of complex life. Polarization due to a terrestrial planet in the CHZ of a cool white dwarf (CWD) is 10 2 (10 4 ) times larger than it would be in the habitable zone of a typical M-dwarf (Sun-like star). Polarimetry is thus a viable way to detect close-in rocky planets around white dwarfs. Multi-band polarimetry would also allow us to reveal the presence of a planet atmosphere, providing a first characterization. Planets in the CHZ of a 0.6 M ☉ white dwarf will be distorted by Roche geometry, and a Kepler-11d analog would overfill its Roche lobe. With current facilities a super-Earth-sized atmosphereless planet is detectable with polarimetry around the brightest known CWD. Planned future facilities render smaller planets detectable, in particular by increasing the instrumental sensitivity in the blue.

  8. Guiding Requirements for Designing Life Support System Architectures for Crewed Exploration Missions Beyond Low-Earth Orbit

    Science.gov (United States)

    Perry, Jay L.; Sargusingh, Miriam J.; Toomarian, Nikzad

    2016-01-01

    The National Aeronautics and Space Administration's (NASA) technology development roadmaps provide guidance to focus technological development in areas that enable crewed exploration missions beyond low-Earth orbit. Specifically, the technology area roadmap on human health, life support and habitation systems describes the need for life support system (LSS) technologies that can improve reliability and in-flight maintainability within a minimally-sized package while enabling a high degree of mission autonomy. To address the needs outlined by the guiding technology area roadmap, NASA's Advanced Exploration Systems (AES) Program has commissioned the Life Support Systems (LSS) Project to lead technology development in the areas of water recovery and management, atmosphere revitalization, and environmental monitoring. A notional exploration LSS architecture derived from the International Space has been developed and serves as the developmental basis for these efforts. Functional requirements and key performance parameters that guide the exploration LSS technology development efforts are presented and discussed. Areas where LSS flight operations aboard the ISS afford lessons learned that are relevant to exploration missions are highlighted.

  9. Learning More About Our Earth: An Exploration of NASA's Contributions to Earth Science Through Remote Sensing Technologies

    Science.gov (United States)

    Lindsay, Francis

    2017-01-01

    NASA is commonly known for its pioneering work in space exploration and the technological advancements that made access to space possible. NASA is now increasingly known for the agency's research and technologies that support the Earth sciences. This is a presentation focusing on NASA's Earth science efforts told mostly through the technological innovations NASA uses to achieve a greater understanding of the Earth, making it possible to explore the Earth as a system. Enabling this science is NASA's fleet of over two dozen Earth science spacecraft, supported by aircraft, ships and ground observations. NASA's Earth Observing System (EOS) is a coordinated series of polar-orbiting and low inclination satellites for long-term global observations of the land surface, biosphere, solid Earth, atmosphere, and oceans. With the launching of the three flagship satellite missions, Terra, Aqua and Aura, beginning in 1999, NASA's initial Mission to Planet Earth made it possible to measure aspects of the environment that touch the lives of every person around the world. NASA harnessing the unique space-based platform means, fortunately, no planet is better studied than the one we actually live on.

  10. FCAPD Protective Coating for Space Tethers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Alameda Applied Sciences Corporation (AASC) proposes to demonstrate extended service lifetime of space tethers in the Low Earth Orbit (LEO) environment by using...

  11. Review of current activities to model and measure the orbital debris environment in low-earth orbit

    Science.gov (United States)

    Reynolds, R. C.

    A very active orbital debris program is currently being pursued at the NASA/Johnson Space Center (JSC), with projects designed to better define the current environment, to project future environments, to model the processes contributing to or constraining the growth of debris in the environment, and to gather supporting data needed to improve the understanding of the orbital debris problem and the hazard it presents to spacecraft. This paper is a review of the activity being conducted at JSC, by NASA, Lockheed Engineering and Sciences Company, and other support contractors, and presents a review of current activity, results of current research, and a discussion of directions for future development.

  12. On the identification of substructure in phase space using orbital frequencies

    NARCIS (Netherlands)

    Gomez, Facundo A.; Helmi, Amina

    2010-01-01

    We study the evolution of satellite debris to establish the most suitable space to identify past merger events. We confirm that the space of orbital frequencies is very promising in this respect. In frequency space individual streams can be easily identified, and their separation provides a direct

  13. The Future of Space Astronomy.

    Science.gov (United States)

    Field, George B.

    1984-01-01

    Discusses various aspects of space astronomy, considering advantages, the space telescope and ground-based astronomy, an orbiting astrophysics facility, solar physics, and other areas. Indicates that earth-based astronomy will continue to be carried out there and space astronomy will be limited to observations that can be carried out only from…

  14. Achieving Climate Change Absolute Accuracy in Orbit

    Science.gov (United States)

    Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; hide

    2013-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high absolute radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high absolute accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.

  15. Earth observations from space: History, promise, and reality. Executive summary

    Science.gov (United States)

    1995-01-01

    In this report the Committee on Earth Studies (CES), a standing committee of the Space Studies Board (SSB) within the National Research Council (NRC), reviews the recent history (nominally from 1981 to 1995) of the U.S. earth observations programs that serve civilian needs. The principal observations programs examined are those of NASA and the National Oceanic and Atmospheric Administration (NOAA). The Air Force' s Defense Meteorological Satellite Program (DMSP) is discussed, but only from the perspective of its relationship to civil needs and the planned merger with the NOAA polar-orbiting system. The report also reviews the interfaces between the earth observations satellite programs and the major national and international environmental monitoring and research programs. The monitoring and research programs discussed are the U.S. Global Change Research Program (USGCRP), the International Geosphere-Biosphere Program (IGBP), the World Climate Research Program (WCRP), related international scientific campaigns, and operational programs for the sharing and application of environmental data. The purpose of this report is to provide a broad historical review and commentary based on the views of the CES members, with particular emphasis on tracing the lengthy record of advisory committee recommendations. Any individual topic could be the subject of an extended report in its own right. Indeed, extensive further reviews are already under way to that end. If the CES has succeeded in the task it has undertaken. This report will serve as a useful starting point for any such more intensive study. The report is divided into eight chapters: ( I ) an introduction, (2) the evolution of the MTPE, (3) its relationship to the USGCRP, (4) applications of earth observations data, (5) the role that smaller satellites can play in research and operational remote sensing, (6) earth system modeling and information systems, (7) a number of associated activities that contribute to the MTPE

  16. Programs Visualize Earth and Space for Interactive Education

    Science.gov (United States)

    2014-01-01

    Kevin Hussey and others at the Jet Propulsion Laboratory produced web applications to visualize all of the spacecraft in orbit around Earth and in the Solar System. Hussey worked with Milwaukee, Wisconsin-based The Elumenati to rewrite the programs, and after licensing them, the company started offering a version that can be viewed on spheres and dome theaters for schools, museums, science centers, and other institutions.

  17. Orbital mechanics and astrodynamics techniques and tools for space missions

    CERN Document Server

    Hintz, Gerald R

    2015-01-01

    This textbook covers fundamental and advanced topics in orbital mechanics and astrodynamics to expose the student to the basic dynamics of space flight. The engineers and graduate students who read this class-tested text will be able to apply their knowledge to mission design and navigation of space missions. Through highlighting basic, analytic and computer-based methods for designing interplanetary and orbital trajectories, this text provides excellent insight into astronautical techniques and tools. This book is ideal for graduate students in Astronautical or Aerospace Engineering and related fields of study, researchers in space industrial and governmental research and development facilities, as well as researchers in astronautics. This book also: ·       Illustrates all key concepts with examples ·       Includes exercises for each chapter ·       Explains concepts and engineering tools a student or experienced engineer can apply to mission design and navigation of space missions ·�...

  18. Wisconsin Earth and Space Science Education

    Science.gov (United States)

    Bilbrough, Larry (Technical Monitor); French, George

    2003-01-01

    The Wisconsin Earth and Space Science Education project successfilly met its objectives of creating a comprehensive online portfolio of science education curricular resources and providing a professional development program to increase educator competency with Earth and Space science content and teaching pedagogy. Overall, 97% of participants stated that their experience was either good or excellent. The favorable response of participant reactions to the professional development opportunities highlights the high quality of the professional development opportunity. The enthusiasm generated for using the curricular material in classroom settings was overwhelmingly positive at 92%. This enthusiasm carried over into actual classroom implementation of resources from the curricular portfolio, with 90% using the resources between 1-6 times during the school year. The project has had a positive impact on student learning in Wisconsin. Although direct measurement of student performance is not possible in a project of this kind, nearly 75% of participating teachers stated that they saw an increase in student performance in math and science as a result of using project resources. Additionally, nearly 75% of participants saw an increase in the enthusiasm of students towards math and science. Finally, some evidence exists that the professional development academies and curricular portfolio have been effective in changing educator behavior. More than half of all participants indicated that they have used more hands-on activities as a result of the Wisconsin Earth and Space Science Education project.

  19. Forward Technology Solar Cell Experiment First On-Orbit Data

    Science.gov (United States)

    Walters, R. J.; Garner, J. C.; Lam, S. N.; Vazquez, J. A.; Braun, W. R.; Ruth, R. E.; Warner, J. H.; Lorentzen, J. R.; Messenger, S. R.; Bruninga, R.; hide

    2007-01-01

    This paper presents first on orbit measured data from the Forward Technology Solar Cell Experiment (FTSCE). FTSCE is a space experiment housed within the 5th Materials on the International Space Station Experiment (MISSE-5). MISSE-5 was launched aboard the Shuttle return to flight mission (STS-114) on July 26, 2005 and deployed on the exterior of the International Space Station (ISS). The experiment will remain in orbit for nominally one year, after which it will be returned to Earth for post-flight testing and analysis. While on orbit, the experiment is designed to measure a 36 point current vs. voltage (IV) curve on each of the experimental solar cells, and the data is continuously telemetered to Earth. The experiment also measures the solar cell temperature and the orientation of the solar cells to the sun. A range of solar cell technologies are included in the experiment including state-of-the-art triple junction InGaP/GaAs/Ge solar cells from several vendors, thin film amorphous Si and CuIn(Ga)Se2 cells, and next-generation technologies like single-junction GaAs cells grown on Si wafers and metamorphic InGaP/InGaAs/Ge triple-junction cells. In addition to FTSCE, MISSE-5 also contains a Thin-Film Materials experiment. This is a passive experiment that will provide data on the effect of the space environment on more than 200 different materials. FTSCE was initially conceived in response to various on-orbit and ground test anomalies associated with space power systems. The Department of Defense (DoD) required a method of rapidly obtaining on orbit validation data for new space solar cell technologies, and NRL was tasked to devise an experiment to meet this requirement. Rapid access to space was provided by the MISSE Program which is a NASA Langley Research Center program. MISSE-5 is a completely self-contained experiment system with its own power generation and storage system and communications system. The communications system, referred to as PCSat, transmits

  20. Dynamics of space particles and spacecrafts passing by the atmosphere of the Earth.

    Science.gov (United States)

    Gomes, Vivian Martins; Prado, Antonio Fernando Bertachini de Almeida; Golebiewska, Justyna

    2013-01-01

    The present research studies the motion of a particle or a spacecraft that comes from an orbit around the Sun, which can be elliptic or hyperbolic, and that makes a passage close enough to the Earth such that it crosses its atmosphere. The idea is to measure the Sun-particle two-body energy before and after this passage in order to verify its variation as a function of the periapsis distance, angle of approach, and velocity at the periapsis of the particle. The full system is formed by the Sun, the Earth, and the particle or the spacecraft. The Sun and the Earth are in circular orbits around their center of mass and the motion is planar for all the bodies involved. The equations of motion consider the restricted circular planar three-body problem with the addition of the atmospheric drag. The initial conditions of the particle or spacecraft (position and velocity) are given at the periapsis of its trajectory around the Earth.

  1. Science Enabled by the Ares V: A Large Monolithic Telescope Placed at the Second Sun-Earth Lagrange Point

    Science.gov (United States)

    Hopkins, Randall C.; Stahl, H. Philip

    2007-01-01

    The payload mass and volume capabilities of the planned Ares V launch vehicle provide the science community with unprecedented opportunities to place large science payloads into low earth orbit and beyond. One example, the outcome of a recent study conducted at the NASA Marshall Space Flight Center, is a large, monolithic telescope with a primary mirror diameter of 6.2 meters placed into a halo orbit about the second Sun-Earth Lagrange point, or L2, approximately 1.5 million kin beyond Earth's orbit. Operating in the visible and ultraviolet regions of the electromagnetic spectrum, such a large telescope would allow astronomers to detect bio-signatures and characterize the atmospheres of transiting exoplanets, provide high resolution imaging three or more times better than the Hubble Space Telescope and the James Webb Space Telescope, and observe the ultraviolet light from warm baryonic matter.

  2. Earth Satellite Population Instability: Underscoring the Need for Debris Mitigation

    Science.gov (United States)

    Liou, Jer-chyi; Johnson, N. L.

    2006-01-01

    A recent study by NASA indicates that the implementation of international orbital debris mitigation measures alone will not prevent a significant increase in the artificial Earth satellite population, beginning in the second half of this century. Whereas the focus of the aerospace community for the past 25 years has been on the curtailment of the generation of long-lived orbital debris, active remediation of the current orbital debris population should now be reconsidered to help preserve near-Earth space for future generations. In particular, we show in this paper that even if launch operations were to cease today, the population of space debris would continue to grow. Further, proposed remediation techniques do not appear to offer a viable solution. We therefore recommend that, while the aerospace community maintains the current debris-limiting mission regulations and postmission disposal procedures, future emphasis should be placed on finding new remediation technologies for solving this growing problem. Since the launch of Sputnik 1, space activities have created an orbital debris environment that poses increasing impact risks to existing space systems, including human space flight and robotic missions (1, 2). Currently, more than 9,000 Earth orbiting man-made objects (including many breakup fragments), with a combined mass exceeding 5 million kilograms, are tracked by the US Space Surveillance Network and maintained in the US satellite catalog (3-5). Three accidental collisions between cataloged satellites during the period from late 1991 to early 2005 have already been documented (6), although fortunately none resulted in the creation of large, trackable debris clouds. Several studies conducted during 1991-2001 demonstrated, with assumed future launch rates, the unintended growth potential of the Earth satellite population, resulting from random, accidental collisions among resident space objects (7-13). In some low Earth orbit (LEO) altitude regimes where

  3. Preventing Commercial Colonialism and Retaining Sovereignty Over National Policy and Military Strategy in Space

    Science.gov (United States)

    2018-04-09

    of satellites and sub-orbital space tourism flights, to the almost fictional asteroid mining, hotels on the Moon, and settlements on Mars. In... tourism . However, it is likely that the Chinese military will protect Chinese commercial presence in space either through militarization of dual-use...include sub-orbital space tourism , crew changes for orbital facilities, and residential tourism in orbit around Earth and the Moon. Visions of manned

  4. Space Shuttle Orbiter - Leading edge structural design/analysis and material allowables

    Science.gov (United States)

    Johnson, D. W.; Curry, D. M.; Kelly, R. E.

    1986-01-01

    Reinforced Carbon-Carbon (RCC), a structural composite whose development was targeted for the high temperature reentry environments of reusable space vehicles, has successfully demonstrated that capability on the Space Shuttle Orbiter. Unique mechanical properties, particularly at elevated temperatures up to 3000 F, make this material ideally suited for the 'hot' regions of multimission space vehicles. Design allowable characterization testing, full-scale development and qualification testing, and structural analysis techniques will be presented herein that briefly chart the history of the RCC material from infancy to eventual multimission certification for the Orbiter. Included are discussions pertaining to the development of the design allowable data base, manipulation of the test data into usable forms, and the analytical verification process.

  5. Challenges for future space power systems

    International Nuclear Information System (INIS)

    Brandhorst, H.W. Jr.

    1989-01-01

    Forecasts of space power needs are presented. The needs fall into three broad categories: survival, self-sufficiency, and industrialization. The cost of delivering payloads to orbital locations and from Low Earth Orbit (LEO) to Mars are determined. Future launch cost reductions are predicted. From these projections the performances necessary for future solar and nuclear space power options are identified. The availability of plentiful cost effective electric power and of low cost access to space are identified as crucial factors in the future extension of human presence in space

  6. High-energy charged particle bursts in the near-Earth space as earthquake precursors

    Directory of Open Access Journals (Sweden)

    S. Yu. Aleksandrin

    2003-02-01

    Full Text Available The experimental data on high-energy charged particle fluxes, obtained in various near-Earth space experiments (MIR orbital station, METEOR-3, GAMMA and SAMPEX satellites were processed and analyzed with the goal to search for particle bursts. Particle bursts have been selected in every experiment considered. It was shown that the significant part of high-energy charged particle bursts correlates with seismic activity. Moreover, the particle bursts are observed several hours before strong earthquakes; L-shells of particle bursts and corresponding earthquakes are practically the same. Some features of a seismo-magnetosphere connection model, based on the interaction of electromagnetic emission of seismic origin and radiation belt particles, were considered. Key words. Ionospheric physics (energetic particles, trapped; energetic particles, precipitating; magnetosphere-ionosphere interactions

  7. A space parasol as a countermeasure against the greenhouse effect

    Science.gov (United States)

    Hudson, H. S.

    1991-01-01

    It is suggested that the deployment of a 'space parasol' at the L1 Langrangian point of the earth-sun system would serve to intercept some desired fraction of the solar radiant energy, thereby lessening the impact of the greenhouse effect. The parasol satellites are described and possible orbit configurations are discussed. Orbital possibilities include Low Earth Orbit, Geosynchronous orbit, and L1 which appears to be the best option. Structural strength, control, and use of extraterrestrial material in the construction of the parasol are discussed.

  8. MOM-E: Moon-Orbiting Mothership Explorer

    Science.gov (United States)

    Murphy, Gloria A.

    2010-01-01

    The National Aeronautics and Space Administration proposed that a new class of robotic space missions and spacecrafts be introduced to "ensure that future missions are safe, sustainable and affordable". Indeed, the United States space program aims for a return to manned space missions beyond Earth orbit, and robotic explorers are intended to pave the way. This vision requires that all future missions become less costly, provide a sustainable business plan, and increase in safety. Over the course of several fast feasibility studies that considered the 3 drivers above, the small-scale, consumer-driven Moon-Orbiting Mothership Explorer (MOM-E) mission was born. MOM-E's goals are to enable space exploration by offering a scaled down platform which carries multiple small space explorers to the Moon. Each payload will be dropped at their desired destination, offering a competitive price to customers. MOM-E's current scope of operations is limited to the Moon and will be used as a proof of concept mission. However, MOM-E is specifically designed with the idea that the platform is scalable.

  9. Simultaneous Laser Ranging and Communication from an Earth-Based Satellite Laser Ranging Station to the Lunar Reconnaissance Orbiter in Lunar Orbit

    Science.gov (United States)

    Sun, Xiaoli; Skillman, David R.; Hoffman, Evan D.; Mao, Dandan; McGarry, Jan F.; Neumann, Gregory A.; McIntire, Leva; Zellar, Ronald S.; Davidson, Frederic M.; Fong, Wai H.; hide

    2013-01-01

    We report a free space laser communication experiment from the satellite laser ranging (SLR) station at NASA Goddard Space Flight Center (GSFC) to the Lunar Reconnaissance Orbiter (LRO) in lunar orbit through the on board one-way Laser Ranging (LR) receiver. Pseudo random data and sample image files were transmitted to LRO using a 4096-ary pulse position modulation (PPM) signal format. Reed-Solomon forward error correction codes were used to achieve error free data transmission at a moderate coding overhead rate. The signal fading due to the atmosphere effect was measured and the coding gain could be estimated.

  10. Emigrating Beyond Earth Human Adaptation and Space Colonization

    CERN Document Server

    Smith, Cameron M

    2012-01-01

    For four million years humankind has been actively expanding geographically and in doing so has adapted to a wide variety of hostile environments. Now we are looking towards the ultimate adaptation - the colonization of space. Emigrating Beyond Earth illustrates that this is not a technocratic endeavor, but a natural continuation of human evolution; a journey not just for the engineer and rocket scientist, but for everyman. Based on the most current understanding of our universe, human adaptation and evolution, the authors explain why space colonization must be planned as an adaptation to, rather than the conquest of, space. Emigrating Beyond Earth argues that space colonization is an insurance policy for our species, and that it isn't about rockets and robots, it's about humans doing what we've been doing for four million years: finding new places and new ways to live. Applying a unique anthropological approach, the authors outline a framework for continued human space exploration and offer a glimpse of a po...

  11. TRAPPED PROTON FLUXES AT LOW EARTH ORBITS MEASURED BY THE PAMELA EXPERIMENT

    Energy Technology Data Exchange (ETDEWEB)

    Adriani, O.; Bongi, M. [Department of Physics and Astronomy, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy); Barbarino, G. C. [Department of Physics, University of Naples " Federico II," I-80126 Naples (Italy); Bazilevskaya, G. A. [Lebedev Physical Institute, RU-119991 Moscow (Russian Federation); Bellotti, R.; Bruno, A. [Department of Physics, University of Bari, I-70126 Bari (Italy); Boezio, M.; Bonvicini, V.; Carbone, R. [INFN, Sezione di Trieste, I-34149 Trieste (Italy); Bogomolov, E. A. [Ioffe Physical Technical Institute, RU-194021 St. Petersburg (Russian Federation); Bottai, S. [INFN, Sezione di Florence, I-50019 Sesto Fiorentino, Florence (Italy); Cafagna, F. [INFN, Sezione di Bari, I-70126 Bari (Italy); Campana, D. [INFN, Sezione di Naples, I-80126 Naples (Italy); Carlson, P. [KTH, Department of Physics, and the Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Centre, SE-10691 Stockholm (Sweden); Casolino, M.; De Donato, C.; De Santis, C.; De Simone, N.; Felice, V. Di [INFN, Sezione di Rome " Tor Vergata," I-00133 Rome (Italy); Castellini, G., E-mail: alessandro.bruno@ba.infn.it [IFAC, I-50019 Sesto Fiorentino, Florence (Italy); and others

    2015-01-20

    We report an accurate measurement of the geomagnetically trapped proton fluxes for kinetic energy above ∼70 MeV performed by the PAMELA mission at low Earth orbits (350 ÷ 610 km). Data were analyzed in the frame of the adiabatic theory of charged particle motion in the geomagnetic field. Flux properties were investigated in detail, providing a full characterization of the particle radiation in the South Atlantic Anomaly region, including locations, energy spectra, and pitch angle distributions. PAMELA results significantly improve the description of the Earth's radiation environment at low altitudes, placing important constraints on the trapping and interaction processes, and can be used to validate current trapped particle radiation models.

  12. Apparent rotation properties of space debris extracted from photometric measurements

    Science.gov (United States)

    Šilha, Jiří; Pittet, Jean-Noël; Hamara, Michal; Schildknecht, Thomas

    2018-02-01

    Knowledge about the rotation properties of space debris objects is essential for the active debris removal missions, accurate re-entry predictions and to investigate the long-term effects of the space environment on the attitude motion change. Different orbital regions and object's physical properties lead to different attitude states and their change over time. Since 2007 the Astronomical Institute of the University of Bern (AIUB) performs photometric measurements of space debris objects. To June 2016 almost 2000 light curves of more than 400 individual objects have been acquired and processed. These objects are situated in all orbital regions, from low Earth orbit (LEO), via global navigation systems orbits and high eccentricity orbit (HEO), to geosynchronous Earth orbit (GEO). All types of objects were observed including the non-functional spacecraft, rocket bodies, fragmentation debris and uncorrelated objects discovered during dedicated surveys. For data acquisition, we used the 1-meter Zimmerwald Laser and Astrometry Telescope (ZIMLAT) at the Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald, Switzerland. We applied our own method of phase-diagram reconstruction to extract the apparent rotation period from the light curve. Presented is the AIUB's light curve database and the obtained rotation properties of space debris as a function of object type and orbit.

  13. The relationship between orbital, earth-based, and sample data for lunar landing sites

    Science.gov (United States)

    Clark, P. E.; Hawke, B. R.; Basu, A.

    1990-01-01

    Results are reported of a detailed examination of data available for the Apollo lunar landing sites, including the Apollo orbital measurements of six major elements derived from XRF and gamma-ray instruments and geochemical parameters derived from earth-based spectral reflectivity data. Wherever orbital coverage for Apollo landing sites exist, the remote data were correlated with geochemical data derived from the soil sample averages for major geological units and the major rock components associated with these units. Discrepancies were observed between the remote and the soil-anlysis elemental concentration data, which were apparently due to the differences in the extent of exposure of geological units, and, hence, major rock eomponents, in the area sampled. Differences were observed in signal depths between various orbital experiments, which may provide a mechanism for explaining differences between the XRF and other landing-site data.

  14. Taiwan Space Programs

    Science.gov (United States)

    Liu, Jann-Yenq

    Taiwan space programs consist of FORMOSAT-1, -2, and -3, sounding rockets, and international cooperation. FORMOSAT-1, a low-earth-orbit (LEO) scientific experimental satellite, was launched on January 26, 1999. It circulates with an altitude of 600 km and 35 degree inclination around the Earth every 97 minutes, transmitting collected data to Taiwan's receiving stations approximately six times a day. The major mission of FORMOSAT-1 includes three scientific experiments for measuring the effects of ionospheric plasma and electrodynamics, taking the ocean color image and conducting Ka-band communication experiment. The FORMOSAT- 1 mission was ended by June 15, 2004. FORMOSAT-2, launched on May 21, 2004 onto the Sun-synchronous orbit located at 891 km above ground. The main mission of FORMOSAT-2 is to conduct remote sensing imaging over Taiwan and on terrestrial and oceanic regions of the entire earth. The images captured by FORMOSAT-2 during daytime can be used for land distribution, natural resources research, environmental protection, disaster prevention and rescue work etc. When the satellite travels to the eclipsed zone, it observes natural phenomena of lighting in the upper atmosphere. FORMOSAT-3 is an international collaboration project between Taiwan and the US to develop advanced technology for the real-time monitoring of the global climate. This project is also named Constellation Observing System for Meteorology, Ionosphere and Climate, or FORMOSAT-3/COSMIC for short. Six micro-satellites were launched on 15 April 2007 and eventually placed into six different orbits at 700 800 kilometer above the earth ground. These satellites orbit around the earth to form a LEO constellation that receives signals transmitted by the 24 US GPS satellites. The satellite observation covers the entire global atmosphere and ionosphere, providing over 2,500 global sounding data per day. These data distribute uniformly over the earth's atmosphere. The global climate information

  15. The BioSentinel Bioanalytical Microsystem: Characterizing DNA Radiation Damage in Living Organisms Beyond Earth Orbit

    Science.gov (United States)

    Ricco, A. J.; Hanel, R.; Bhattacharya, S.; Boone, T.; Tan, M.; Mousavi, A.; Rademacher, A.; Schooley, A.; Klamm, B.; Benton, J.; hide

    2016-01-01

    We will present details and initial lab test results from an integrated bioanalytical microsystem designed to conduct the first biology experiments beyond low Earth orbit (LEO) since Apollo 17 (1972). The 14-kg, 12x24x37-cm BioSentinel spacecraft (Figure 1) assays radiation-responsive yeast in its science payload by measuring DNA double-strand breaks (DSBs) repaired via homologous recombination, a mechanism common to all eukaryotes including humans. S. cerevisiae (brewer's yeast) in 288 microwells are provided with nutrient and optically assayed for growth and metabolism via 3-color absorptimetry monthly during the 18-month mission. BioSentinel is one of several secondary payloads to be deployed by NASA's Exploration Mission 1 (EM-1) launch vehicle into approximately 0.95 AU heliocentric orbit in July 2018; it will communicate with Earth from up to 100 million km.

  16. Results from On-Orbit Testing of the Fram Memory Test Experiment on the Fastsat Micro-Satellite

    Science.gov (United States)

    MacLeod, Todd C.; Sims, W. Herb; Varnavas, Kosta A.; Ho, Fat D.

    2011-01-01

    NASA is planning on going beyond Low Earth orbit with manned exploration missions. The radiation environment for most Low Earth orbit missions is harsher than at the Earth's surface but much less harsh than deep space. Development of new electronics is needed to meet the requirements of high performance, radiation tolerance, and reliability. The need for both Volatile and Non-volatile memory has been identified. Emerging Non-volatile memory technologies (FRAM, C-RAM,M-RAM, R-RAM, Radiation Tolerant FLASH, SONOS, etc.) need to be investigated for use in Space missions. An opportunity arose to fly a small memory experiment on a high inclination satellite (FASTSAT). An off-the-shelf 512K Ramtron FRAM was chosen to be tested in the experiment.

  17. On-Orbit Measurement of Next Generation Space Solar Cell Technology on the International Space Station

    Science.gov (United States)

    Wolford, David S.; Myers, Matthew G.; Prokop, Norman F.; Krasowski, Michael J.; Parker, David S.; Cassidy, Justin C.; Davies, William E.; Vorreiter, Janelle O.; Piszczor, Michael F.; McNatt, Jeremiah S.

    2015-01-01

    Measurement is essential for the evaluation of new photovoltaic (PV) technology for space solar cells. NASA Glenn Research Center (GRC) is in the process of measuring several solar cells in a supplemental experiment on NASA Goddard Space Flight Center's (GSFC) Robotic Refueling Mission's (RRM) Task Board 4 (TB4). Four industry and government partners have provided advanced PV devices for measurement and orbital environment testing. The experiment will be on-orbit for approximately 18 months. It is completely self-contained and will provide its own power and internal data storage. Several new cell technologies including four- junction (4J) Inverted Metamorphic Multijunction (IMM) cells will be evaluated and the results compared to ground-based measurements.

  18. The Initial Nine Space Settlements

    Science.gov (United States)

    Gale, Anita E.; Edwards, Richard P.

    2003-01-01

    The co-authors describe a chronology of space infrastructure development illustrating how each element of infrastructure enables development of subsequent more ambitious infrastructure. This is likened to the ``Southern California freeway phenomenon'', wherein a new freeway built in a remote area promotes establishment of gas stations, restaurants, hotels, housing, and eventually entire new communities. The chronology includes new launch vehicles, inter-orbit vehicles, multiple LEO space stations, lunar mining, on-orbit manufacturing, tourist destinations, and supporting technologies required to make it all happen. The space settlements encompassed by the chronology are in Earth orbit (L5 and L4), on the lunar surface, in Mars orbit, on the Martian surface, and in the asteroid belt. Each space settlement is justified with a business rationale for construction. This paper is based on materials developed for Space Settlement Design Competitions that enable high school students to experience the technical and management challenges of working on an industry proposal team.

  19. Orbits of the inner satellites of Neptune

    Science.gov (United States)

    Brozovic, Marina; Showalter, Mark R.; Jacobson, Robert Arthur; French, Robert S.; de Pater, Imke; Lissauer, Jack

    2018-04-01

    We report on the numerically integrated orbits of seven inner satellites of Neptune, including S/2004 N1, the last moon of Neptune to be discovered by the Hubble Space Telescope (HST). The dataset includes Voyager imaging data as well as the HST and Earth-based astrometric data. The observations span time period from 1989 to 2016. Our orbital model accounts for the equatorial bulge of Neptune, perturbations from the Sun and the planets, and perturbations from Triton. The initial orbital integration assumed that the satellites are massless, but the residuals improved significantly as the masses adjusted toward values that implied that the density of the satellites is in the realm of 1 g/cm3. We will discuss how the integrated orbits compare to the precessing ellipses fits, mean orbital elements, current orbital uncertainties, and the need for future observations.

  20. 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.

  1. The bistatic radar capabilities of the Medicina radiotelescopes in space debris detection and tracking

    Science.gov (United States)

    Montebugnoli, S.; Pupillo, G.; Salerno, E.; Pluchino, S.; di Martino, M.

    2010-03-01

    An accurate measurement of the position and trajectory of the space debris fragments is of primary importance for the characterization of the orbital debris environment. The Medicina Radioastronomical Station is a radio observation facility that is here proposed as receiving part of a ground-based space surveillance system for detecting and tracking space debris at different orbital regions (from Low Earth Orbits up to Geostationary Earth Orbits). The proposed system consists of two bistatic radars formed by the existing Medicina receiving antennas coupled with appropriate transmitters. This paper focuses on the current features and future technical development of the receiving part of the observational setup. Outlines of possible transmitting systems will also be given together with the evaluation of the observation strategies achievable with the proposed facilities.

  2. Radiation Environment at LEO in the frame of Space Monitoring Data Center at Moscow State University - recent, current and future missions

    Science.gov (United States)

    Myagkova, Irina; Kalegaev, Vladimir; Panasyuk, Mikhail; Svertilov, Sergey; Bogomolov, Vitaly; Bogomolov, Andrey; Barinova, Vera; Barinov, Oleg; Bobrovnikov, Sergey; Dolenko, Sergey; Mukhametdinova, Ludmila; Shiroky, Vladimir; Shugay, Julia

    2016-04-01

    Radiation Environment of Near-Earth space is one of the most important factors of space weather. Space Monitoring Data Center of Moscow State University provides operational control of radiation conditions at Low Earth's Orbits (LEO) of the near-Earth space using data of recent (Vernov, CORONAS series), current (Meteor-M, Electro-L series) and future (Lomonosov) space missions. Internet portal of Space Monitoring Data Center of Skobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University (SINP MSU) http://swx.sinp.msu.ru/ provides possibilities to control and analyze the space radiation conditions in the real time mode together with the geomagnetic and solar activity including hard X-ray and gamma- emission of solar flares. Operational data obtained from space missions at L1, GEO and LEO and from the Earth's magnetic stations are used to represent radiation and geomagnetic state of near-Earth environment. The models of space environment that use space measurements from different orbits were created. Interactive analysis and operational neural network forecast services are based on these models. These systems can automatically generate alerts on particle fluxes enhancements above the threshold values, both for SEP and relativistic electrons of outer Earth's radiation belt using data from GEO and LEO as input. As an example of LEO data we consider data from Vernov mission, which was launched into solar-synchronous orbit (altitude 640 - 83 0 km, inclination 98.4°, orbital period about 100 min) on July 8, 2014 and began to receive scientific information since July 20, 2014. Vernov mission have provided studies of the Earth's radiation belt relativistic electron precipitation and its possible connection with atmosphere transient luminous events, as well as the solar hard X-ray and gamma-emission measurements. Radiation and electromagnetic environment monitoring in the near-Earth Space, which is very important for space weather study, was also realised

  3. Edible Earth and Space Science Activities

    Science.gov (United States)

    Lubowich, D.; Shupla, C.

    2014-07-01

    In this workshop we describe using Earth and Space Science demonstrations with edible ingredients to increase student interest. We show how to use chocolate, candy, cookies, popcorn, bagels, pastries, Pringles, marshmallows, whipped cream, and Starburst candy for activities such as: plate tectonics, the interior structure of the Earth and Mars, radioactivity/radioactive dating of rocks and stars, formation of the planets, lunar phases, convection, comets, black holes, curvature of space, dark energy, and the expansion of the Universe. In addition to creating an experience that will help students remember specific concepts, edible activities can be used as a formative assessment, providing students with the opportunity to create something that demonstrates their understanding of the model. The students often eat the demonstrations. These demonstrations are an effective teaching tool for all ages, and can be adapted for cultural, culinary, and ethnic differences among the students.

  4. Low Earth Orbit Environmental Effects on Space Tether Materials

    Science.gov (United States)

    Finckernor, Miria M.; Gitlemeier, Keith A.; Hawk, Clark W.; Watts, Ed

    2005-01-01

    Atomic oxygen (AO) and ultraviolet (UV) radiation erode and embrittle most polymeric materials. This research was designed to test several different materials and coatings under consideration for their application to space tethers, for resistance to these effects. The samples were vacuum dehydrated, weighed and then exposed to various levels of AO or UV radiation at the NASA Marshall Space Flight Center. They were then re-weighed to determine mass loss due to atomic oxygen erosion, inspected for damage and tensile tested to determine strength loss. The experiments determined that the Photosil coating process, while affording some protection, damaged the tether materials worse than the AO exposure. TOR-LM also failed to fully protect the materials, especially from UV radiation. The POSS and nickel coatings did provide some protection to the tethers, which survived the entire test regime. M5 was tested, uncoated, and survived AO exposure, though its brittleness prevented any tensile testing.

  5. Laser Remediation of Threats Posed by Small Orbital Debris

    Science.gov (United States)

    Fork, Richard L.; Rogers, Jan R.; Hovater, Mary A.

    2012-01-01

    The continually increasing amount of orbital debris in near Earth space poses an increasing challenge to space situational awareness. Recent collisions of spacecraft caused abrupt increases in the density of both large and small debris in near Earth space. An especially challenging class of threats is that due to the increasing density of small (1 mm to 10 cm dimension) orbital debris. This small debris poses a serious threat since: (1) The high velocity enables even millimeter dimension debris to cause serious damage to vulnerable areas of space assets, e.g., detector windows; (2) The small size and large number of debris elements prevent adequate detection and cataloguing. We have identified solutions to this threat in the form of novel laser systems and novel ways of using these laser systems. While implementation of the solutions we identify is challenging we find approaches offering threat mitigation within time frames and at costs of practical interest. We base our analysis on the unique combination of coherent light specifically structured in both space and time and applied in novel ways entirely within the vacuum of space to deorbiting small debris. We compare and contrast laser based small debris removal strategies using ground based laser systems with strategies using space based laser systems. We find laser systems located and used entirely within space offer essential and decisive advantages over groundbased laser systems.

  6. Early Earth(s) Across Time and Space

    Science.gov (United States)

    Mojzsis, S.

    2014-04-01

    The geochemical and cosmochemical record of our solar system is the baseline for exploring the question: "when could life appear on a world similar to our own?" Data arising from direct analysis of the oldest terrestrial rocks and minerals from the first 500 Myr of Earth history - termed the Hadean Eon - inform us about the timing for the establishment of a habitable silicate world. Liquid water is the key medium for life. The origin of water, and its interaction with the crust as revealed in the geologic record, guides our exploration for a cosmochemically Earth-like planets. From the time of primary planetary accretion to the start of the continuous rock record on Earth at ca. 3850 million years ago, our planet experienced a waning bolide flux that partially or entirely wiped out surface rocks, vaporized oceans, and created transient serpentinizing atmospheres. Arguably, "Early Earths" across the galaxy may start off as ice planets due to feeble insolation from their young stars, occasionally punctuated by steam atmospheres generated by cataclysmic impacts. Alternatively, early global environments conducive to life spanned from a benign surface zone to deep into crustal rocks and sediments. In some scenarios, nascent biospheres benefit from the exogenous delivery of essential bio-elements via leftovers of accretion, and the subsequent establishment of planetary-scale hydrothermal systems. If what is now known about the early dynamical regime of the Earth serves as any measure of the potential habitability of worlds across space and time, several key boundary conditions emerge. These are: (i) availability and long-term stability of liquid water; (ii) presence of energy resources; (iii) accessibility of organic raw materials; (iv) adequate inventory of radioisotopes to drive internal heating; (v) gross compositional parameters such as mantle/core mass ratio, and (vi) P-T conditions at or near the surface suitable for sustaining biological activity. Life could

  7. Optimal Earth's reentry disposal of the Galileo constellation

    Science.gov (United States)

    Armellin, Roberto; San-Juan, Juan F.

    2018-02-01

    Nowadays there is international consensus that space activities must be managed to minimize debris generation and risk. The paper presents a method for the end-of-life (EoL) disposal of spacecraft in Medium Earth Orbit (MEO). The problem is formulated as a multiobjective optimisation one, which is solved with an evolutionary algorithm. An impulsive manoeuvre is optimised to reenter the spacecraft in Earth's atmosphere within 100 years. Pareto optimal solutions are obtained using the manoeuvre Δv and the time-to-reentry as objective functions to be minimised. To explore at the best the search space a semi-analytical orbit propagator, which can propagate an orbit for 100 years in few seconds, is adopted. An in-depth analysis of the results is carried out to understand the conditions leading to a fast reentry with minimum propellant. For this aim a new way of representing the disposal solutions is introduced. With a single 2D plot we are able to fully describe the time evolution of all the relevant orbital parameters as well as identify the conditions that enables the eccentricity build-up. The EoL disposal of the Galileo constellation is used as test case.

  8. Modeling Earth Albedo for Satellites in Earth Orbit

    DEFF Research Database (Denmark)

    Bhanderi, Dan; Bak, Thomas

    2005-01-01

    Many satellite are influences by the Earthøs albedo, though very few model schemes exist.in order to predict this phenomenon. Earth albedo is often treated as noise, or ignored completely. When applying solar cells in the attitude hardware, Earth albedo can cause the attitude estimate to deviate...... with as much as 20 deg. Digital Sun sensors with Earth albedo correction in hardware exist, but are expensive. In addition, albedo estimates are necessary in thermal calculations and power budgets. We present a modeling scheme base4d on Eartht reflectance, measured by NASA's Total Ozone Mapping Spectrometer......, in which the Earth Probe Satellite has recorded reflectivity data daily since mid 1996. The mean of these data can be used to calculate the Earth albedo given the positions of the satellite and the Sun. Our results show that the albedo varies highly with the solar angle to the satellite's field of view...

  9. Exploration of Near-Earth Objects from the Deep Space Gateway

    Science.gov (United States)

    Dunham, D. W.; Stakkestad, K.; Vedder, P.; McAdams, J.; Horsewood, J.; Genova, A. L.

    2018-02-01

    The paper will show how clever use of orbital dynamics can lower delta-V costs to enable scientifically interesting missions. The high-energy Deep Space Gateway orbits can be used to reach NEOs, a trans node for crews, or to deploy small sats. Examples are given.

  10. An analysis of the low-earth-orbit communications environment

    Science.gov (United States)

    Diersing, Robert Joseph

    Advances in microprocessor technology and availability of launch opportunities have caused interest in low-earth-orbit satellite based communications systems to increase dramatically during the past several years. In this research the capabilities of two low-cost, store-and-forward LEO communications satellites operating in the public domain are examined--PACSAT-1 (operated by the Radio Amateur Satellite Corporation) and UoSAT-3 (operated by the University of Surrey, England, Electrical Engineering Department). The file broadcasting and file transfer facilities are examined in detail and a simulation model of the downlink traffic pattern is developed. The simulator will aid the assessment of changes in design and implementation for other systems. The development of the downlink traffic simulator is based on three major parts. First, is a characterization of the low-earth-orbit operating environment along with preliminary measurements of the PACSAT-1 and UoSAT-3 systems including: satellite visibility constraints on communications, monitoring equipment configuration, link margin computations, determination of block and bit error rates, and establishing typical data capture rates for ground stations using computer-pointed directional antennas and fixed omni-directional antennas. Second, arrival rates for successful and unsuccessful file server connections are established along with transaction service times. Downlink traffic has been further characterized by measuring: frame and byte counts for all data-link layer traffic; 30-second interval average response time for all traffic and for file server traffic only; file server response time on a per-connection basis; and retry rates for information and supervisory frames. Finally, the model is verified by comparison with measurements of actual traffic not previously used in the model building process. The simulator is then used to predict operation of the PACSAT-1 satellite with modifications to the original design.

  11. Growing Minority Student Interest in Earth and Space Science with Suborbital and Space-related Investigations

    Science.gov (United States)

    Austin, S. A.

    2009-12-01

    Cubesat and related vehicles. The Cubesat extension benefits from specifications developed by Stanford University and California Polytechnical State University which provides low-profile, entry-level access for student-based science and engineering investigations in low-earth orbits and the availability of Commercial-Off-The-Shelf components including a Cubesat kit developed by Pumpkin, Inc. The programs have also benefited from partnerships with other universities including Montana State University, University of Vermont, University of Rhode Island and Cornell University. The programs are presently supported by funding from NSF Geoscience, the New York State Space Grant Consortium and a National Space Grant Minority Serving Institution Partnership award.

  12. The European Space Agency's FESTIP initiative

    Science.gov (United States)

    Burleson, Daphne

    1998-01-01

    In an effort to reduce the cost of access and open up new markets, the European Space Agency has begun a program called Future European Space Transportation Investigations Programme or FESTIP, in which reusable launcher concepts are being studied and developed. The ideal reusable launcher would be comparable to a normal aircraft in that it would be capable of taking off from many possible locations on Earth, enter the desired orbital plane, then accelerate to orbital velocity, release its payload, de-orbit, disperse its kinetic energy and land at the take-off base to be prepared for its next flight following a quick turnaround time. This ideal vehicle would be called the `single-stage-to-orbit reusable rocket launcher' or SSTO-RRL. All space launchers currently in use are staged to orbit and expendable, except the US Space Shuttle, and there is no SSTO-RRL in operation as yet. This paper will discuss the design options being studied by the European Space Agency (ESA) as well as their practical use in serving the space-launch market (FESTIP Workshop 1).

  13. The effect of lunarlike satellites on the orbital infrared light curves of Earth-analog planets.

    Science.gov (United States)

    Moskovitz, Nicholas A; Gaidos, Eric; Williams, Darren M

    2009-04-01

    We have investigated the influence of lunarlike satellites on the infrared orbital light curves of Earth-analog extrasolar planets. Such light curves will be obtained by NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions as a consequence of repeat observations to confirm the companion status of a putative planet and determine its orbit. We used an energy balance model to calculate disk-averaged infrared (bolometric) fluxes from planet-satellite systems over a full orbital period (one year). The satellites are assumed to lack an atmosphere, have a low thermal inertia like that of the Moon, and span a range of plausible radii. The planets are assumed to have thermal and orbital properties that mimic those of Earth, while their obliquities and orbital longitudes of inferior conjunction remain free parameters. Even if the gross thermal properties of the planet can be independently constrained (e.g., via spectroscopy or visible-wavelength detection of specular glint from a surface ocean), only the largest (approximately Mars-sized) lunarlike satellites can be detected by light curve data from a TPF-like instrument (i.e., one that achieves a photometric signal-to-noise ratio of 10 to 20 at infrared wavelengths). Nondetection of a lunarlike satellite can obfuscate the interpretation of a given system's infrared light curve so that it may resemble a single planet with high obliquity, different orbital longitude of vernal equinox relative to inferior conjunction, and in some cases drastically different thermal characteristics. If the thermal properties of the planet are not independently established, then the presence of a lunarlike satellite cannot be inferred from infrared data, which would thus demonstrate that photometric light curves alone can only be used for preliminary study, and the addition of spectroscopic data will be necessary.

  14. 78 FR 14920 - Earth Stations Aboard Aircraft Communicating With Fixed-Satellite Service Geostationary-Orbit...

    Science.gov (United States)

    2013-03-08

    ... Consumer and Governmental Affairs Bureau, Reference Information Center shall send a copy of this Report and... ground, ESAAs shall not be authorized for transmission at angles less than 5[deg] measured from the plane..., in the plane of the geostationary satellite orbit (GSO) as it appears at the particular earth station...

  15. Ground Contact Analysis for Korea’s Fictitious Lunar Orbiter Mission

    Directory of Open Access Journals (Sweden)

    Young-Joo Song

    2013-12-01

    Full Text Available In this research, the ground contact opportunity for the fictitious low lunar orbiter is analyzed to prepare for a future Korean lunar orbiter mission. The ground contact opportunity is basically derived from geometrical relations between the typical ground stations at the Earth, the relative positions of the Earth and Moon, and finally, the lunar orbiter itself. Both the cut-off angle and the orbiter’s Line of Sight (LOS conditions (weather orbiter is located at near or far side of the Moon seen from the Earth are considered to determine the ground contact opportunities. Four KOMPSAT Ground Stations (KGSs are assumed to be Korea’s future Near Earth Networks (NENs to support lunar missions, and world-wide separated Deep Space Networks (DSNs are also included during the contact availability analysis. As a result, it is concluded that about 138 times of contact will be made between the orbiter and the Daejeon station during 27.3 days of prediction time span. If these contact times are converted into contact duration, the duration is found to be about 8.55 days, about 31.31% of 27.3 days. It is discovered that selected four KGSs cannot provide continuous tracking of the lunar orbiter, meaning that international collaboration is necessary to track Korea’s future lunar orbiter effectively. Possible combinations of world-wide separated DSNs are also suggested to compensate for the lack of contact availability with only four KGSs, as with primary and backup station concepts. The provided algorithm can be easily modified to support any type of orbit around the Moon, and therefore, the presented results could aid further progress in the design field of Korea’s lunar orbiter missions.

  16. Our Future in Space

    Science.gov (United States)

    Impey, Chris David

    2017-06-01

    The Space Age is half a century old. Its early successes were driven by a fierce superpower rivalry between the Soviet Union and the United States, which tended to obscure the fact that exploration and risk-taking is built into human DNA. Decades after we last set foot on the Moon, and years after the Space Shuttle was retired, the space activity is finally leaving the doldrums. A vibrant private sector led by SpaceX, Blue Origins, and Virgin Galactic plans to launch supplies cheaply into Earth orbit and give anyone the chance of a sub-orbital joy ride. New materials are being developed that could lead to space elevators and transform the economics of space travel. Fighting gravity will always be difficult but engineers are rethinking rockets and developing new propulsion technologies. Permanent bases on the Moon and Mars are now within reach, and a new Space Race is brewing, with China ascendant. Medical advances might even allow us to reach for the stars. The talk will review the history and landmarks of the international space program, give a snapshot of the current dynamic situation, and plot the trajectory of the future of space travel. The time has come to envision our future off-Earth.

  17. Dynamics and design of space nets for orbital capture

    CERN Document Server

    Yang, Leping; Zhen, Ming; Liu, Haitao

    2017-01-01

    This book covers the topics of theoretical principles, dynamics model and algorithm, mission analysis, system design and experimental studies of space nets system, aiming to provide an initial framework in this field and serve as a ready reference for those interested. Space nets system represents a forefront field in future development of aerospace technologies. However, it involves new challenges and problems such as nonlinear and distorted nets structure, complex rigid flexible coupling dynamics, orbital transfer of space flexible composite and dynamics control. Currently, no comprehensive books on space nets dynamics and design are available, so potential readers can get to know the working mechanism, dynamics elements, and mission design of the space nets system from a Chinese perspective.

  18. Higher order sliding mode control of laser pointing for orbital debris mitigation

    Science.gov (United States)

    Palosz, Arthur

    This thesis explores the use of a space-based laser to clean up small orbital debris from near Earth space. This system's challenge is to quickly and precisely aim the laser beam at very small (laser beam onto the orbital debris. A Kalman Filter (KF) is designed to accurately track the orbital debris and generate a command signal for the controller. A second order Super Twisting Sliding Mode Controller (2-SMC) is designed to follow the command signal generated by the KF and to overcome the parametric uncertainties and external disturbances. The performance of the system is validated with a computer simulation created in MATLAB and Simulink.

  19. Combined Global Navigation Satellite Systems in the Space Service Volume

    Science.gov (United States)

    Force, Dale A.; Miller, James J.

    2013-01-01

    Besides providing position, velocity, and timing (PVT) for terrestrial users, the Global Positioning System (GPS) is also being used to provide PVT information for earth orbiting satellites. In 2006, F. H. Bauer, et. al., defined the Space Service Volume in the paper GPS in the Space Service Volume , presented at ION s 19th international Technical Meeting of the Satellite Division, and looked at GPS coverage for orbiting satellites. With GLONASS already operational, and the first satellites of the Galileo and Beidou/COMPASS constellations already in orbit, it is time to look at the use of the new Global Navigation Satellite Systems (GNSS) coming into service to provide PVT information for earth orbiting satellites. This presentation extends GPS in the Space Service Volume by examining the coverage capability of combinations of the new constellations with GPS GPS was first explored as a system for refining the position, velocity, and timing of other spacecraft equipped with GPS receivers in the early eighties. Because of this, a new GPS utility developed beyond the original purpose of providing position, velocity, and timing services for land, maritime, and aerial applications. GPS signals are now received and processed by spacecraft both above and below the GPS constellation, including signals that spill over the limb of the earth. Support of GPS space applications is now part of the system plan for GPS, and support of the Space Service Volume by other GNSS providers has been proposed to the UN International Committee on GNSS (ICG). GPS has been demonstrated to provide decimeter level position accuracy in real-time for satellites in low Earth orbit (centimeter level in non-real-time applications). GPS has been proven useful for satellites in geosynchronous orbit, and also for satellites in highly elliptical orbits. Depending on how many satellites are in view, one can keep time locked to the GNSS standard, and through that to Universal Time as long as at least one

  20. Considering the space environment

    International Nuclear Information System (INIS)

    Boudenot, J.C.; Fillon, T.; Barrillot, C.; Calvet, M.C.

    1999-01-01

    The high levels of radiation encountered in space and in the upper atmosphere can affect the onboard electronics in satellites, launch vehicles and aircraft. The main categories of radiation in space have been classified into four distinct types; radiation belts, solar flares, cosmic radiation and the solar wind. Most of the risk to modern electronic systems arises from heavy ions. In geostationary and low polar orbits, these originate mainly as protons from solar flares. In medium earth orbits, the main source is trapped protons and the South Atlantic anomaly. (authors)

  1. 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.

  2. Growth in the Number of SSN Tracked Orbital Objects

    Science.gov (United States)

    Stansbery, Eugene G.

    2004-01-01

    The number of objects in earth orbit tracked by the US Space Surveillance Network (SSN) has experienced unprecedented growth since March, 2003. Approximately 2000 orbiting objects have been added to the "Analyst list" of tracked objects. This growth is primarily due to the resumption of full power/full time operation of the AN/FPS-108 Cobra Dane radar located on Shemya Island, AK. Cobra Dane is an L-band (23-cm wavelength) phased array radar which first became operational in 1977. Cobra Dane was a "Collateral Sensor" in the SSN until 1994 when its communication link with the Space Control Center (SCC) was closed. NASA and the Air Force conducted tests in 1999 using Cobra Dane to detect and track small debris. These tests confirmed that the radar was capable of detecting and maintaining orbits on objects as small as 5-cm diameter. Subsequently, Cobra Dane was reconnected to the SSN and resumed full power/full time space surveillance operations on March 4, 2003. This paper will examine the new data and its implications to the understanding of the orbital debris environment and orbital safety.

  3. Space Debris Elimination (SpaDE)

    Data.gov (United States)

    National Aeronautics and Space Administration — The amount of debris in low Earth orbit (LEO) has increased rapidly over the last twenty years. This prevalence of debris increases the likelihood of cascading...

  4. Depolarization on Earth-space paths

    Science.gov (United States)

    1981-01-01

    Sources of depolarization effects on the propagation paths of orthogonally-polarized information channels are considered. The main sources of depolarization at millimeter wave frequencies are hydrometeor absorption and scattering in the troposphere. Terms are defined. Mathematical formulations for the effects of the propagation medium characteristics and antenna performance on signals in dual polarization Earth-space links are presented. Techniques for modeling rain and ice depolarization are discussed.

  5. Evaluation of thermal control coatings for use on solar dynamic radiators in low earth orbit

    Science.gov (United States)

    Dever, Joyce A.; Rodriguez, Elvin; Slemp, Wayne S.; Stoyack, Joseph E.

    1991-01-01

    Thermal control coatings with high thermal emittance and low solar absorptance are needed for Space Station Freedom (SSF) solar dynamic power module radiator (SDR) surfaces for efficient heat rejection. Additionally, these coatings must be durable to low earth orbital (LEO) environmental effects of atomic oxygen, ultraviolet radiation and deep thermal cycles which occur as a result of start-up and shut-down of the solar dynamic power system. Eleven candidate coatings were characterized for their solar absorptance and emittance before and after exposure to ultraviolet (UV) radiation (200 to 400 nm), vacuum UV (VUV) radiation (100 to 200 nm) and atomic oxygen. Results indicated that the most durable and best performing coatings were white paint thermal control coatings Z-93, zinc oxide pigment in potassium silicate binder, and YB-71, zinc orthotitanate pigment in potassium silicate binder. Optical micrographs of these materials exposed to the individual environmental effects of atomic oxygen and vacuum thermal cycling showed that no surface cracking occurred.

  6. Requirements for Designing Life Support System Architectures for Crewed Exploration Missions Beyond Low-Earth Orbit

    Science.gov (United States)

    Howard, David; Perry,Jay; Sargusingh, Miriam; Toomarian, Nikzad

    2016-01-01

    NASA's technology development roadmaps provide guidance to focus technological development on areas that enable crewed exploration missions beyond low-Earth orbit. Specifically, the technology area roadmap on human health, life support and habitation systems describes the need for life support system (LSS) technologies that can improve reliability and in-situ maintainability within a minimally-sized package while enabling a high degree of mission autonomy. To address the needs outlined by the guiding technology area roadmap, NASA's Advanced Exploration Systems (AES) Program has commissioned the Life Support Systems (LSS) Project to lead technology development in the areas of water recovery and management, atmosphere revitalization, and environmental monitoring. A notional exploration LSS architecture derived from the International Space has been developed and serves as the developmental basis for these efforts. Functional requirements and key performance parameters that guide the exploration LSS technology development efforts are presented and discussed. Areas where LSS flight operations aboard the ISS afford lessons learned that are relevant to exploration missions are highlighted.

  7. Space Technology for Reduction of Desert Areas on Earth and Weather Control

    Directory of Open Access Journals (Sweden)

    Constantin SANDU

    2018-03-01

    Full Text Available In precedent papers the authors presented the idea of a space system composed of two opposite parabolic mirrors (large and small having the same focal point. This system is able to concentrate solar power in a strong light beam having irradiance of hundreds or thousands of times stronger than the solar irradiance on Earth's orbit. The system can be placed on a Sun synchronous orbit around the Earth or on the Earth’s orbit around the Sun at a distance of several hundred km from ground. When the concentrated light beam is directed toward the Earth surface it can locally melt, vaporize or decomposes tones of ground in its elements. This is happening because when the ground is hit by the light beam, ground temperature can reach thousands of degrees Celsius. At such temperatures the matter is decomposed into constitutive elements. For example, the silicate oxides which are frequently found in the composition of desert ground are decomposed into oxygen and silicon. Similarly, other oxides release oxygen and other type of oxides or constitutive elements. A network of deep and large channels can be dug in this way in hot deserts as Sahara. When these channels are connected with the seas & oceans, a network of water channels is created in those deserts. In this way, the local climate of deserts will change because channel water is vaporized during daytime when air temperature reaches 50ºC and condenses during nighttime when air temperature is around 0ºC. Presence of clouds over the hot deserts can lead to a reduction of ground temperature and rain follows. The channel water can be desalinized for producing drinking water and for irrigation using simple equipment. In addition to these advantages, channel deserts can be a solution for melting of polar ice calottes and flooding of seaside areas that are inhabited areas. On the other hand, the system composed of two opposite mirrors can be used for strength decreasing or deviation of hurricanes and

  8. National Polar-orbiting Operational Environmental Satellite System (NPOESS) Design and Architecture

    Science.gov (United States)

    Hinnant, F.

    2008-12-01

    The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system - the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS will replace the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD and will provide continuity for the NASA Earth Observing System (EOS) with the launch of the NPOESS Preparatory Project (NPP). This poster will provide an overview of the NPOESS architecture, which includes four segments. The space segment includes satellites in two orbits that carry a suite of sensors to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the Earth, atmosphere, and near-Earth space environment. The NPOESS design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users through a Command, Control, and Communication Segment (C3S). The data processing for NPOESS is accomplished through an Interface Data Processing Segment (IDPS)/Field Terminal Segment (FTS) that processes NPOESS satellite data to provide environmental data products to NOAA and DoD processing centers operated by the United States government as well as to remote terminal users. The Launch Support Segment completes the four segments that make up NPOESS that will enhance the connectivity between research and operations and provide critical operational and scientific environmental measurements to military, civil, and scientific users until 2026.

  9. Near-Earth asteroids: Metals occurrence, extraction, and fabrication

    Science.gov (United States)

    Westfall, Richard

    Near-earth asteroids occur in three principle types of orbits: Amor, Apollo, and Aten. Amor asteroids make relatively close (within 0.3 AU) approaches to the earth's orbit, but do not actually overlap it. Apollo asteroids spend most of their time outside the earth's orbital path, but at some point of close approach to the sun, they cross the orbit of the earth. Aten asteroids are those whose orbits remain inside the earth's path for the majority of their time, with semi-major axes less than 0.1 AU. Near-earth orbit asteroids include: stones, stony-irons, irons, carbonaceous, and super-carbonaceous. Metals within these asteroids include: iron, nickel, cobalt, the platinum group, aluminum, titanium, and others. Focus is on the extraction of ferrous and platinum group metals from the stony-iron asteroids, and the iron asteroids. Extraction of the metal fraction can be accomplished through the use of tunnel-boring-machines (TBM) in the case of the stony-irons. The metals within the story-iron asteroids occur as dispersed granules, which can be separated from the stony fraction through magnetic and gaseous digestion separation techniques. The metal asteroids are processes by drilling and gaseous digestion or by gaseous digestion alone. Manufacturing of structures, housings, framing networks, pressure vessels, mirrors, and other products is accomplished through the chemical vapor deposition (CVD) of metal coating on advanced composites and on the inside of contour-defining inflatables (CDI). Metal coatings on advanced composites provide: resistance to degradation in the hostile environments of space; superior optical properties; superior heat dissipation; service as wear coatings; and service as evidential coatings. Metal coatings on the inside of CDI produce metal load-bearing products. Fibers such as graphite, kevlar, glass, ceramic, metal, etc., can be incorporated in the metal coatings on the inside of CDI producing metal matrix products which exhibit high strength

  10. A high-fidelity N-body ephemeris generator for satellites in Earth orbit

    Science.gov (United States)

    Simmons, David R.

    1991-10-01

    A program is currently used for mission planning called the Analytic Satellite Ephemeris Program (ASEP), which produces projected data for orbits that remain fairly close to Earth. Lunar and solar perturbations are taken into account in another program called GRAVE. This project is a revision of GRAVE which incorporates more flexible means of input for initial data, provides additional kinds of output information, and makes use of structured programming techniques to make the program more understandable and reliable. The computer program ORBIT was tested against tracking data for the first 313 days of operation of the CRRES satellite. A sample graph is given comparing the semi-major axis calculated by the program with the values supplied by NORAD. When calculated for points at which CRRES passes through the ascending node, the argument of perigee, the right ascension of the ascending node, and the mean anomaly all stay within about a degree of the corresponding values from NORAD; the inclination of the orbital plane is much closer. The program value of the eccentricity is in error by no more than 0.0002.

  11. Measuring the quality of public open space using Google Earth.

    Science.gov (United States)

    Taylor, Bronwen T; Fernando, Peter; Bauman, Adrian E; Williamson, Anna; Craig, Jonathan C; Redman, Sally

    2011-02-01

    Proximity to public open space, such as parks and other green spaces, has considerable health benefits, and people have been shown to be more likely to use such space for physical activity if it is of high quality. This paper describes a new remote-assessment approach that makes use of Google Earth Pro (the free version of this program is Google Earth) to provide rapid and inexpensive measurement of the quality of public open space. The aim of the study was to assess the correlation between assessments of the quality of public open space using (1) the remote method (making use of Google Earth Pro) and (2) direct observation with a well-established measure of quality, the Public Open Space Tool (POST). Fifty parks selected from the southwest part of Sydney, Australia, were assessed in 2009 with the remote method (using Google Earth Pro), and scores were compared with those obtained from direct observation of the same parks using POST. The time taken to conduct the assessments using each method was also recorded. Raters for each method were blind to scores obtained from using the other method. Analyses were conducted in 2009. The Spearman correlation coefficient between the quality scores obtained for the 50 parks using the remote method and direct observation was 0.9 (pspaces without the need for in-person visits, dramatically reducing the time required for environmental audits of public open space. Copyright © 2011 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  12. Power beaming providing a space power infrastructure

    International Nuclear Information System (INIS)

    Bamberger, J.A.; Coomes, E.P.

    1992-01-01

    This paper, based on two levels of technology maturity, applied the power beaming concept to four panned satellite constellations. The analysis shows that with currently available technology, power beaming can provide mass savings to constellations in orbits ranging from low-Earth orbit to geosynchronous orbit. Two constellations, space surveillance and tracking system and space-based radar, can be supported with current technology. The other two constellations, space-based laser array and boost surveillance and tracking system, will require power and transmission system improvements before their breakeven specific mass is achieved. A doubling of SP-100 conversion efficiency from 10 to 20% would meet or exceed breakeven for these constellations

  13. Spacecraft design project: Low Earth orbit communications satellite

    Science.gov (United States)

    Moroney, Dave; Lashbrook, Dave; Mckibben, Barry; Gardener, Nigel; Rivers, Thane; Nottingham, Greg; Golden, Bill; Barfield, Bill; Bruening, Joe; Wood, Dave

    1991-01-01

    This is the final product of the spacecraft design project completed to fulfill the academic requirements of the Spacecraft Design and Integration 2 course (AE-4871) taught at the U.S. Naval Postgraduate School. The Spacecraft Design and Integration 2 course is intended to provide students detailed design experience in selection and design of both satellite system and subsystem components, and their location and integration into a final spacecraft configuration. The design team pursued a design to support a Low Earth Orbiting (LEO) communications system (GLOBALSTAR) currently under development by the Loral Cellular Systems Corporation. Each of the 14 team members was assigned both primary and secondary duties in program management or system design. Hardware selection, spacecraft component design, analysis, and integration were accomplished within the constraints imposed by the 11 week academic schedule and the available design facilities.

  14. Earth in Space: A CD-ROM Version for Pre-College Teachers

    Science.gov (United States)

    Pedigo, P.

    2003-12-01

    Earth in Space, a magazine about the Earth and space sciences for pre-college science teachers, was published by AGU between 1987 and 2001 (9 issues each year). The goal of Earth in Space was to make research at the frontiers of the geosciences accessible to teachers and students and engage them in thinking about scientific careers. Each issue contained two or three recent research articles, rewritten for a high school level audience from the original version published in peer-reviewed AGU journals, which were supplemented with short news items and biographic information about the authors. As part of a 2003 summer internship with AGU, sponsored by the AGU Committee on Education and Human Resources (CEHR) and the American Institute of Physics, this collection of Earth in Space magazines was converted into an easily accessible electronic resource for K-12 teachers and students. Every issue was scanned into a PDF file. The entire collection of articles was cataloged in a database indexed to key topic terms (e.g., volcanoes, global climate change, space weather). A front-page was designed in order to facilitate rapid access to articles concerning specific topics within the Earth and space sciences of particular interest to high school students. A compact CD-ROM version of this resource will be distributed to science teachers at future meetings of the National Science Teachers Association and will be made available through AGU's Outreach and Research Support program.

  15. Space Weather Impacts to Conjunction Assessment: A NASA Robotic Orbital Safety Perspective

    Science.gov (United States)

    Ghrist, Richard; Ghrist, Richard; DeHart, Russel; Newman, Lauri

    2013-01-01

    National Aeronautics and Space Administration (NASA) recognizes the risk of on-orbit collisions from other satellites and debris objects and has instituted a process to identify and react to close approaches. The charter of the NASA Robotic Conjunction Assessment Risk Analysis (CARA) task is to protect NASA robotic (unmanned) assets from threats posed by other space objects. Monitoring for potential collisions requires formulating close-approach predictions a week or more in the future to determine analyze, and respond to orbital conjunction events of interest. These predictions require propagation of the latest state vector and covariance assuming a predicted atmospheric density and ballistic coefficient. Any differences between the predicted drag used for propagation and the actual drag experienced by the space objects can potentially affect the conjunction event. Therefore, the space environment itself, in particular how space weather impacts atmospheric drag, is an essential element to understand in order effectively to assess the risk of conjunction events. The focus of this research is to develop a better understanding of the impact of space weather on conjunction assessment activities: both accurately determining the current risk and assessing how that risk may change under dynamic space weather conditions. We are engaged in a data-- ]mining exercise to corroborate whether or not observed changes in a conjunction event's dynamics appear consistent with space weather changes and are interested in developing a framework to respond appropriately to uncertainty in predicted space weather. In particular, we use historical conjunction event data products to search for dynamical effects on satellite orbits from changing atmospheric drag. Increased drag is expected to lower the satellite specific energy and will result in the satellite's being 'later' than expected, which can affect satellite conjunctions in a number of ways depending on the two satellites' orbits

  16. Views from Space

    Science.gov (United States)

    Kitmacher, Gary H.

    2002-01-01

    Only in the last century have human beings flown in space and men and machines have explored the worlds of our solar system. Robots have gone to most of the our neighboring worlds, the valleys of Mars and the clouds and moons of Jupiter. Instruments like the Hubble Space Telescope have looked into deep space. Those of us on the earth have been able to participate as vicarious explorers through the records, and experiences and the photographs that have been returned. At the beginning of the space program hardly anyone thought of photographs from space as anything more than a branch of industrial photography. There were pictures of the spaceships, and launches and of astronauts in training, but these were all pictures taken on the ground. When John Glenn became America's first man in orbit, bringing a camera was an afterthought. An Ansco Autoset was purchased in a drug store and hastily modified so the astronaut could use it more easily while in his pressure suit. In 1962, everything that Glenn did was deemed an experiment. At the beginning of the program, no one knew for certain whether weightlessness would prevent a man from seeing, or from breathing, or from eating and swallowing. Photography was deemed nothing more than a recreational extra. Not only was little expected of those first pictures taken from space, but there was serious concern that taking pictures of other nations from orbit would be seen as an act of ill will and even one of war- as sovereign sensitive nations would resent having pictures taken by Americans orbiting overhead. A few years earlier, in 1957, in reaction to the Soviet launch of the first Sputnik satellite, scientists told congressman of the necessity of orbiting our own robot spacecraft-they predicted that one day we would take daily pictures of the world's weather. Congressman were incredulous. But space photography developed quickly. For security purposes, spy satellites took over many of the responsibilities we had depended upon

  17. Wireless Power Transmission Options for Space Solar Power

    Science.gov (United States)

    Potter, Seth; Davis, Dean; Born, Martin; Bayer, Martin; Howell, Joe; Mankins, John

    2008-01-01

    Space Solar Power (SSP), combined with Wireless Power Transmission (WPT), offers the far-term potential to solve major energy problems on Earth. In the long term, we aspire to beam energy to Earth from geostationary Earth orbit (GEO), or even further distances in space. In the near term, we can beam power over more moderate distances, but still stretch the limits of today s technology. In recent studies, a 100 kWe-class "Power Plug" Satellite and a 10 kWe-class Lunar Polar Solar Power outpost have been considered as the first steps in using these WPT options for SSP. Our current assessments include consideration of orbits, wavelengths, and structural designs to meet commercial, civilian government, and military needs. Notional transmitter and receiver sizes are considered for use in supplying 5 to 40 MW of power. In the longer term, lunar or asteroidal material can be used. By using SSP and WPT technology for near-term missions, we gain experience needed for sound decisions in designing and developing larger systems to send power from space to Earth.

  18. Armstrong Laboratory Space Visual Function Tester Program

    Science.gov (United States)

    Oneal, Melvin R.; Task, H. Lee; Gleason, Gerald A.

    1992-01-01

    Viewgraphs on space visual function tester program are presented. Many astronauts and cosmonauts have commented on apparent changes in their vision while on-orbit. Comments have included descriptions of earth features and objects that would suggest enhanced distance visual acuity. In contrast, some cosmonaut observations suggest a slight loss in their object discrimination during initial space flight. Astronauts have also mentioned a decreased near vision capability that did not recover to normal until return to earth. Duntley space vision experiment, USSR space vision experiments, and visual function testers are described.

  19. Low-Cost Propellant Launch to Earth Orbit from a Tethered Balloon

    Science.gov (United States)

    Wilcox, Brian H.

    2006-01-01

    Propellant will be more than 85% of the mass that needs to be lofted into Low Earth Orbit (LEO) in the planned program of Exploration of the Moon, Mars, and beyond. This paper describes a possible means for launching thousands of tons of propellant per year into LEO at a cost 15 to 30 times less than the current launch cost per kilogram. The basic idea is to mass-produce very simple, small and relatively low-performance rockets at a cost per kilogram comparable to automobiles, instead of the 25X greater cost that is customary for current launch vehicles that are produced in small quantities and which are manufactured with performance near the limits of what is possible. These small, simple rockets can reach orbit because they are launched above 95% of the atmosphere, where the drag losses even on a small rocket are acceptable, and because they can be launched nearly horizontally with very simple guidance based primarily on spin-stabilization. Launching above most of the atmosphere is accomplished by winching the rocket up a tether to a balloon. A fuel depot in equatorial orbit passes over the launch site on every orbit (approximately every 90 minutes). One or more rockets can be launched each time the fuel depot passes overhead, so the launch rate can be any multiple of 6000 small rockets per year, a number that is sufficient to reap the benefits of mass production.

  20. Thermal stresses in the space shuttle orbiter: Analysis versus test

    International Nuclear Information System (INIS)

    Grooms, H.R.; Gibson, W.F. Jr.; Benson, P.L.

    1984-01-01

    Significant temperature differences occur between the internal structure and the outer skin of the Space Shuttle Orbiter as it returns from space. These temperature differences cause important thermal stresses. A finite element model containing thousands of degrees of freedom is used to predict these stresses. A ground test was performed to verify the prediction method. The analysis and test results compare favorably. (orig.)

  1. Space Mobile Network: A Near Earth Communications and Navigation Architecture

    Science.gov (United States)

    Israel, David J.; Heckler, Gregory W.; Menrad, Robert J.

    2016-01-01

    This paper shares key findings of NASA's Earth Regime Network Evolution Study (ERNESt) team resulting from its 18-month effort to define a wholly new architecture-level paradigm for the exploitation of space by civil space and commercial sector organizations. Since the launch of Sputnik in October 1957 spaceflight missions have remained highly scripted activities from launch through disposal. The utilization of computer technology has enabled dramatic increases in mission complexity; but, the underlying premise that the diverse actions necessary to meet mission goals requires minute-by-minute scripting, defined weeks in advance of execution, for the life of the mission has remained. This archetype was appropriate for a "new frontier" but now risks overtly constraining the potential market-based opportunities for the innovation considered necessary to efficiently address the complexities associated with meeting communications and navigation requirements projected to be characteristics of the next era of space exploration: a growing number of missions in simultaneous execution, increased variance of mission types and growth in location/orbital regime diversity. The resulting ERNESt architectural cornerstone - the Space Mobile Network (SMN) - was envisioned as critical to creating an environment essential to meeting these future challenges in political, programmatic, technological and budgetary terms. The SMN incorporates technologies such as: Disruption Tolerant Networking (DTN) and optical communications, as well as new operations concepts such as User Initiated Services (UIS) to provide user services analogous to today's terrestrial mobile network user. Results developed in collaboration with NASA's Space Communications and Navigation (SCaN) Division and field centers are reported on. Findings have been validated via briefings to external focus groups and initial ground-based demonstrations. The SMN opens new niches for exploitation by the marketplace of mission

  2. 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

  3. Achievable space elevators for space transportation and starship acceleration

    Science.gov (United States)

    Pearson, Jerome

    1990-04-01

    Space elevator concepts for low-cost space launches are reviewed. Previous concepts suffered from requirements for ultra-high-strength materials, dynamically unstable systems, or from danger of collision with space debris. The use of magnetic grain streams solves these problems. Magnetic grain streams can support short space elevators for lifting payloads cheaply into Earth orbit, overcoming the material strength problem in building space elevators. Alternatively, the stream could support an international spaceport circling the Earth daily tens of miles above the equator, accessible to advanced aircraft. Mars could be equipped with a similar grain stream, using material from its moons Phobos and Deimos. Grain-stream arcs about the sun could be used for fast launches to the outer planets and for accelerating starships to near lightspeed for interstellar reconnaisance. Grain streams are essentially impervious to collisions, and could reduce the cost of space transportation by an order of magnitude.

  4. Handbook of space security policies, applications and programs

    CERN Document Server

    Hays, Peter; Robinson, Jana; Moura, Denis; Giannopapa, Christina

    2015-01-01

    Space Security involves the use of space (in particular communication, navigation, earth observation, and electronic intelligence satellites) for military and security purposes on earth and also the maintenance of space (in particular the earth orbits) as safe and secure areas for conducting peaceful activities. The two aspects can be summarized as "space for security on earth" and “the safeguarding of space for peaceful endeavors.” The Handbook will provide a sophisticated, cutting-edge resource on the space security policy portfolio and the associated assets, assisting fellow members of the global space community and other interested policy-making and academic audiences in keeping abreast of the current and future directions of this vital dimension of international space policy. The debate on coordinated space security measures, including relevant 'Transparency and Confidence-Building Measures,' remains at a relatively early stage of development. The book offers a comprehensive description of the variou...

  5. Atomic Oxygen Erosion Yield Prediction for Spacecraft Polymers in Low Earth Orbit

    Science.gov (United States)

    Banks, Bruce A.; Backus, Jane A.; Manno, Michael V.; Waters, Deborah L.; Cameron, Kevin C.; deGroh, Kim K.

    2009-01-01

    The ability to predict the atomic oxygen erosion yield of polymers based on their chemistry and physical properties has been only partially successful because of a lack of reliable low Earth orbit (LEO) erosion yield data. Unfortunately, many of the early experiments did not utilize dehydrated mass loss measurements for erosion yield determination, and the resulting mass loss due to atomic oxygen exposure may have been compromised because samples were often not in consistent states of dehydration during the pre-flight and post-flight mass measurements. This is a particular problem for short duration mission exposures or low erosion yield materials. However, as a result of the retrieval of the Polymer Erosion and Contamination Experiment (PEACE) flown as part of the Materials International Space Station Experiment 2 (MISSE 2), the erosion yields of 38 polymers and pyrolytic graphite were accurately measured. The experiment was exposed to the LEO environment for 3.95 years from August 16, 2001 to July 30, 2005 and was successfully retrieved during a space walk on July 30, 2005 during Discovery s STS-114 Return to Flight mission. The 40 different materials tested (including Kapton H fluence witness samples) were selected specifically to represent a variety of polymers used in space as well as a wide variety of polymer chemical structures. The MISSE 2 PEACE Polymers experiment used carefully dehydrated mass measurements, as well as accurate density measurements to obtain accurate erosion yield data for high-fluence (8.43 1021 atoms/sq cm). The resulting data was used to develop an erosion yield predictive tool with a correlation coefficient of 0.895 and uncertainty of +/-6.3 10(exp -25)cu cm/atom. The predictive tool utilizes the chemical structures and physical properties of polymers to predict in-space atomic oxygen erosion yields. A predictive tool concept (September 2009 version) is presented which represents an improvement over an earlier (December 2008) version.

  6. Do slow orbital periodicities appear in the record of earth's magnetic reversals?

    Science.gov (United States)

    Stothers, Richard B.

    1987-01-01

    Time-series spectral analysis has been performed on the dates of geomagnetic reversals of the last 20 Myr BP and earlier. Possible evidence is found from the presence of high spectral peaks for two very long periodicities, 0.4 Myr and 1.3 Myr, that may be associated with slow variations of the earth's orbital eccentricity as predicted by Berger. However, statistical significance tests and a number of other arguments do not confirm the two detections.

  7. TEST BED FOR THE SIMULATION OF MAGNETIC FIELD MEASUREMENTS OF LOW EARTH ORBIT SATELLITES

    Directory of Open Access Journals (Sweden)

    Alberto Gallina

    2018-03-01

    Full Text Available The paper presents a test bed designed to simulate magnetic environment experienced by a spacecraft on low Earth orbit. It consists of a spherical air bearing located inside a Helmholtz cage. The spherical air bearing is used for simulating microgravity conditions of orbiting bodies while the Helmholtz cage generates a controllable magnetic field resembling the one surrounding a satellite during its motion. Dedicated computer software is used to initially calculate the magnetic field on an established orbit. The magnetic field data is then translated into current values and transmitted to programmable power supplies energizing the cage. The magnetic field within the cage is finally measured by a test article mounted on the air bearing. The paper provides a description of the test bed and the test article design. An experimental test proves the good performance of the entire system.

  8. Precise Orbit Solution for Swarm Using Space-Borne GPS Data and Optimized Pseudo-Stochastic Pulses

    Directory of Open Access Journals (Sweden)

    Bingbing Zhang

    2017-03-01

    Full Text Available Swarm is a European Space Agency (ESA project that was launched on 22 November 2013, which consists of three Swarm satellites. Swarm precise orbits are essential to the success of the above project. This study investigates how well Swarm zero-differenced (ZD reduced-dynamic orbit solutions can be determined using space-borne GPS data and optimized pseudo-stochastic pulses under high ionospheric activity. We choose Swarm space-borne GPS data from 1–25 October 2014, and Swarm reduced-dynamic orbits are obtained. Orbit quality is assessed by GPS phase observation residuals and compared with Precise Science Orbits (PSOs released by ESA. Results show that pseudo-stochastic pulses with a time interval of 6 min and a priori standard deviation (STD of 10−2 mm/s in radial (R, along-track (T and cross-track (N directions are optimized to Swarm ZD reduced-dynamic precise orbit determination (POD. During high ionospheric activity, the mean Root Mean Square (RMS of Swarm GPS phase residuals is at 9–11 mm, Swarm orbit solutions are also compared with Swarm PSOs released by ESA and the accuracy of Swarm orbits can reach 2–4 cm in R, T and N directions. Independent Satellite Laser Ranging (SLR validation indicates that Swarm reduced-dynamic orbits have an accuracy of 2–4 cm. Swarm-B orbit quality is better than those of Swarm-A and Swarm-C. The Swarm orbits can be applied to the geomagnetic, geoelectric and gravity field recovery.

  9. Light-Curing Structural Tape for In-Space Repair, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has numerous requirements for in-space repair capabilities to aid future missions beyond earth orbit. A subset of these requirements is adhesive patch materials...

  10. Low earth orbit radiation dose distribution in a phantom head

    International Nuclear Information System (INIS)

    Konradi, A.; Badhwar, G.D.; Cash, B.L.; Hardy, K.A.

    1992-01-01

    In order to compare analytical methods with data obtained during exposure to space radiation, a phantom head instrumented with a large number of radiation detectors was flown on the Space Shuttle on three occasions: 8 August 1989 (STS-28), 28 February 1990 (STS-36), and 24 April 1990 (STS-31). The objective of this experiment was to obtain a measurement of the inhomogeneity in the dose distribution within a phantom head volume. The orbits of these missions were complementary-STS-28 and STS-36 had high inclination and low altitude, while STS-31 had a low inclination and high altitude. In the cases of STS-28 and STS-36, the main contribution to the radiation dose comes from galactic cosmic rays (GCR) with a minor to negligible part supplied by the inner belt through the South Atlantic Anomaly (SAA), and for STS-28 an even smaller one from a proton enhancement during a solar flare-associated proton event. For STS-31, the inner belt protons dominate and the GCR contribution is almost negligible. The internal dose distribution is consistent with the mass distribution of the orbiter and the self-shielding and physical location of the phantom head. (author)

  11. Challenges for future space power systems

    International Nuclear Information System (INIS)

    Brandhorst, H.W. Jr.

    1989-01-01

    The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. The key to success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience was made. These needs fall into three broad categories-survival, self sufficiency and industrialization. The cost of delivering payloads to orbital locations from low earth orbit (LEO) to Mars was determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options were made. These goals are largely dependent upon orbital location and energy storage needs

  12. Lunar base mission technology issues and orbital demonstration requirements on space station

    Science.gov (United States)

    Llewellyn, Charles P.; Weidman, Deene J.

    1992-01-01

    The International Space Station has been the object of considerable design, redesign, and alteration since it was originally proposed in early 1984. In the intervening years the station has slowly evolved to a specific design that was thoroughly reviewed by a large agency-wide Critical Evaluation Task Force (CETF). As space station designs continue to evolve, studies must be conducted to determine the suitability of the current design for some of the primary purposes for which the station will be used. This paper concentrates on the technology requirements and issues, the on-orbit demonstration and verification program, and the space station focused support required prior to the establishment of a permanently manned lunar base as identified in the National Commission on Space report. Technology issues associated with the on-orbit assembly and processing of the lunar vehicle flight elements are also discussed.

  13. Space nuclear power: a strategy for tomorrow

    International Nuclear Information System (INIS)

    Buden, D.; Angelo, J. Jr.

    1981-01-01

    Energy: reliable, portable, abundant and low cost will be a most critical factor, perhaps the sine qua non, for the unfolding of man's permanent presence in space. Space-based nuclear power, in turn, is a key technology for developing such space platforms and the transportation systems necessary to service them. A strategy for meeting space power requirements is the development of a 100-kW(e) nuclear reactor system for high earth orbit missions, transportation from Shuttle orbits to geosynchronous orbit, and for outer planet exploration. The component technology for this nuclear power plant is now underway at the Los Alamos National Laboratory. As permanent settlements are established on the Moon and in space, multimegawatt power plants will be needed. This would involve different technology similar to terrestrial nuclear power plants

  14. NASA's In-Space Manufacturing Project: A Roadmap for a Multimaterial Fabrication Laboratory in Space

    Science.gov (United States)

    Prater, Tracie; Werkheiser, Niki; Ledbetter, Frank

    2017-01-01

    Human space exploration to date has been limited to low Earth orbit and the moon. The International Space Station (ISS) provides a unique opportunity for NASA to partner with private industry for development and demonstration of the technologies needed to support exploration initiatives. One challenge that is critical to sustainable and safer exploration is the ability to manufacture and recycle materials in space. This paper provides an overview of NASA's in-space manufacturing (ISM) project, its past and current activities (2014-2017), and how technologies under development will ultimately culminate in a multimaterial fabrication laboratory ("ISM FabLab") to be deployed on the International Space Station in the early 2020s. ISM is a critical capability for the long endurance missions NASA seeks to undertake in the coming decades. An unanticipated failure that can be adapted for in low earth orbit, through a resupply launch or a return to earth, may instead result in a loss of mission while in transit to Mars. To have a suite of functional ISM capabilities that are compatible with NASA's exploration timeline, ISM must be equipped with the resources necessary to develop these technologies and deploy them for testing prior to the scheduled de-orbit of ISS in 2024. The presentation provides a broad overview of ISM projects activities culminating with the Fabrication Laboratory for ISS. In 2017, the in-space manufacturing project issued a broad agency announcement for this capability. Requirements of the Fabrication Laboratory as stated in the solicitation will be discussed. The FabLab will move NASA and private industry significantly closer to changing historical paradigms for human spaceflight where all materials used in space are launched from earth. While the current ISM FabLab will be tested on ISS, future systems are eventually intended for use in a deep space habitat or transit vehicle. The work of commercial companies funded under NASA's Small Business

  15. Nuclear power in space

    International Nuclear Information System (INIS)

    Aftergood, S.; Hafemeister, D.W.; Prilutsky, O.F.; Rodionov, S.N.; Primack, J.R.

    1991-01-01

    Nuclear reactors have provided energy for satellites-with nearly disastrous results. Now the US government is proposing to build nuclear-powered boosters to launch Star Wars defenses. These authors represent scientific groups that are opposed to the use of nuclear power in near space. The authors feel that the best course for space-borne reactors is to ban them from Earth orbit and use them in deep space

  16. The Space Station Freedom - International cooperation and innovation in space safety

    Science.gov (United States)

    Rodney, George A.

    1989-01-01

    The Space Station Freedom (SSF) being developed by the United States, European Space Agency (ESA), Japan, and Canada poses novel safety challenges in design, operations, logistics, and program management. A brief overview discloses many features that make SSF a radical departure from earlier low earth orbit (LEO) space stations relative to safety management: size and power levels; multiphase manned assembly; 30-year planned lifetime, with embedded 'hooks and scars' forevolution; crew size and skill-mix variability; sustained logistical dependence; use of man, robotics and telepresence for on-orbit maintenance of station and free-flyer systems; closed-environment recycling; use of automation and expert systems; long-term operation of collocated life-sciences and materials-science experiments, requiring control and segregation of hazardous and chemically incompatible materials; and materials aging in space.

  17. An atomic gravitational wave interferometric sensor in low earth orbit (AGIS-LEO)

    Science.gov (United States)

    Hogan, Jason M.; Johnson, David M. S.; Dickerson, Susannah; Kovachy, Tim; Sugarbaker, Alex; Chiow, Sheng-Wey; Graham, Peter W.; Kasevich, Mark A.; Saif, Babak; Rajendran, Surjeet; Bouyer, Philippe; Seery, Bernard D.; Feinberg, Lee; Keski-Kuha, Ritva

    2011-07-01

    We propose an atom interferometer gravitational wave detector in low Earth orbit (AGIS-LEO). Gravitational waves can be observed by comparing a pair of atom interferometers separated by a 30 km baseline. In the proposed configuration, one or three of these interferometer pairs are simultaneously operated through the use of two or three satellites in formation flight. The three satellite configuration allows for the increased suppression of multiple noise sources and for the detection of stochastic gravitational wave signals. The mission will offer a strain sensitivity of {<10^{-18}/sqrt{Hz}} in the 50mHz-10Hz frequency range, providing access to a rich scientific region with substantial discovery potential. This band is not currently addressed with the LIGO, VIRGO, or LISA instruments. We analyze systematic backgrounds that are relevant to the mission and discuss how they can be mitigated at the required levels. Some of these effects do not appear to have been considered previously in the context of atom interferometry, and we therefore expect that our analysis will be broadly relevant to atom interferometric precision measurements. Finally, we present a brief conceptual overview of shorter-baseline ({lesssim100 m}) atom interferometer configurations that could be deployed as proof-of-principle instruments on the International Space Station (AGIS-ISS) or an independent satellite.

  18. Folding and unfolding of large-size shell construction for application in Earth orbit

    Science.gov (United States)

    Kondyurin, Alexey; Pestrenina, Irena; Pestrenin, Valery; Rusakov, Sergey

    2016-07-01

    A future exploration of space requires a technology of large module for biological, technological, logistic and other applications in Earth orbits [1-3]. This report describes the possibility of using large-sized shell structures deployable in space. Structure is delivered to the orbit in the spaceship container. The shell is folded for the transportation. The shell material is either rigid plastic or multilayer prepreg comprising rigid reinforcements (such as reinforcing fibers). The unfolding process (bringing a construction to the unfolded state by loading the internal pressure) needs be considered at the presence of both stretching and bending deformations. An analysis of the deployment conditions (the minimum internal pressure bringing a construction from the folded state to the unfolded state) of large laminated CFRP shell structures is formulated in this report. Solution of this mechanics of deformable solids (MDS) problem of the shell structure is based on the following assumptions: the shell is made of components whose median surface has a reamer; in the separate structural element relaxed state (not stressed and not deformed) its median surface coincides with its reamer (this assumption allows choose the relaxed state of the structure correctly); structural elements are joined (sewn together) by a seam that does not resist rotation around the tangent to the seam line. The ways of large shell structures folding, whose median surface has a reamer, are suggested. Unfolding of cylindrical, conical (full and truncated cones), and large-size composite shells (cylinder-cones, cones-cones) is considered. These results show that the unfolding pressure of such large-size structures (0.01-0.2 atm.) is comparable to the deploying pressure of pneumatic parts (0.001-0.1 atm.) [3]. It would be possible to extend this approach to investigate the unfolding process of large-sized shells with ruled median surface or for non-developable surfaces. This research was

  19. Surviving space flight: case study on MELiSSA's CIII nitrifying compartment

    Science.gov (United States)

    Ilgrande, Chiara; Lasseur, Christophe; Mastroleo, Felice; Paille, Christel; Leys, Natalie; Morozova, Julia; Ilyin, Vyacheslav; Clauwaert, Peter; Christiaens, Marlies E. R.; Lindeboom, Ralph E. F.; Vlaeminck, Siegfried; Prat, Delphine; Arroyo, Jose M. C.; Conincx, Ilse; Van Hoey, Olivier; Roume, Hugo; Udert, Kai; Sas, Benedikt

    2016-07-01

    Space synthetic biology offers key opportunities for long-term space missions. Planets mining, terraformation, space medicine and Life Support technologies would all benefit from an integrative biological approach. However, space is a harsh environment for life: microgravity, temperature, UV and cosmic radiation can affect the health and functionality of microorganisms and plants, possibly preventing the optimal performance of the systems. The European Space Agency's Life Support System (MELiSSA) has been developed as a model for future long term Space missions and Space habitation. MELiSSA is a 5 compartment artificial ecosystem with microorganisms and higher, that aims at completely recycling gas, liquid and solid waste. In this study, the survival and functional activity after Lower Earth Orbit conditions of microbial nitrogen conversions, relevant for MELiSSA's CIII compartment, was tested. Synthetic communities containing Nitrosomonas europeae, Nitrosomonas ureae, Nitrobacter winogradskyi, Nitrospira moscoviensis and Cupriavidus pinatubonensis were exposed to the Lower Earth Orbit conditions of the International Space Station (ISS) for 7 days. Nitrosomonas europeae, Nitrobacter winogradskyi, Cupriavidus pinatubonensis, and three mixed communities (a urine nitrification sludge, a sludge containing aerobic ammonia oxidizing bacteria and anammox bacteria (OLAND), and an aquaculture sludge containing ammonia oxidizing archaea) were exposed to Lower Earth Orbit conditions for 44 days. Survival after both space flights was demonstrated because nitritation, nitratation, denitrification and anammox activity could be restored at a rate comparable to ground storage conditions. Our results validate the potential survival feasibility and suggest future space applications for N-related microorganisms.

  20. A journey from particle physics to outer space

    CERN Document Server

    2006-01-01

    Particle physics can take you a long way - even into space! Astronaut Christer Fuglesang recently jetted into orbit on his first space mission, 14 years after he left CERN to join the European Space Agency. Christer Fuglesang near the launch pad area at NASA's Kennedy Space Center, Florida, in preparation for the STS-116 mission. (photo: ESA, S.Corvaja)Christer Fuglesang in space (photo: NASA). In CERN's years of efforts to explore the fundamentals of the Universe, it has not yet sent anyone beyond planet Earth. On 10 December 2006, Christer Fuglesang boldly went where no CERN scientist had ever gone before. The 49-year-old ex-CERN physicist-turned-astronaut embarked on his first mission on board space shuttle Discovery. Originally from Stockholm, he also had the honour of being the first Swedish national in space. Christer Fuglesang is an astronaut with the European Space Agency (ESA), a partner of the International Space Station (ISS) - a research facility that is being assembled in orbit around the Earth...

  1. The Orbital Distribution of Earth-crossing Asteroids and Meteoroids

    Science.gov (United States)

    Benoit, P. H.; Sears, D. W. G.

    1993-07-01

    The relationship between meteorites and Earth-crossing asteroids and between individual meteorites and meteor showers has been the subject of debate for some time. Recently, links have been claimed between certain meteorites and meteoroid complexes [e.g., 1] and it has been suggested that some meteorites are members of orbital "streams" [2]. It is difficult to evaluate these ideas because of the lack of appropriate measureable properties in the meteorites themselves. Cosmic ray exposure ages provide one approach but most cosmogenic nuclides have large halflives and hence generally reflect the long term radiation exposure of the body rather than the short term orbital evolution leading up to Earth impact. Here we use natural thermoluminescence (TL) data to determine the "average" perihelion of ordinary chondrites among the modern falls over periods of time of less than 10^3-10^5 years prior to Earth impact. The level of natural TL of a meteorite (at a given glow curve temperature) is a function of buildup through radiation dose (which, in turn, is a function of depth or "shielding" and external cosmic ray flux) and decay through thermal draining [3]. The shallow TL vs. depth profile observed in lunar cores [4] can, after correction for irradiation geometry, be used to to calculate TL profiles in meteoroid-sized bodies. Our new calculations indicate a range of natural TL of only about 15% in large meteoroid-sized bodies and an even smaller range in smaller bodies. The "half-life" of TL is far greater than the solar/cosmic ray flux cycle and hence variations in the external flux over time are expected to have only very minor effects. It is thus possible to calculate an "irradiation temperature" for a meteorite using its natural TL level, which can be shown through decay calculations to largely reflect the perihelion of the meteoroid body. The time period over which this irradiation temperature is averaged is a function of the temperature (perihelion); the period is 1

  2. Mapping the earth's magnetic and gravity fields from space Current status and future prospects

    Science.gov (United States)

    Settle, M.; Taranik, J. V.

    1983-01-01

    The principal magnetic fields encountered by earth orbiting spacecraft include the main (core) field, external fields produced by electrical currents within the ionosphere and magnetosphere, and the crustal (anomaly) field generated by variations in the magnetization of the outermost portions of the earth. The first orbital field measurements which proved to be of use for global studies of crustal magnetization were obtained by a series of three satellites launched and operated from 1965 to 1971. Each of the satellites, known as a Polar Orbiting Geophysical Observatory (POGO), carried a rubidium vapor magnetometer. Attention is also given to Magsat launched in 1979, the scalar anomaly field derived from the Magsat measurements, satellite tracking studies in connection with gravity field surveys, radar altimetry, the belt of positive free air gravity anomalies situated along the edge of the Pacific Ocean basin, future technological capabilities, and information concerning data availability.

  3. Development of constraint algorithm for the number of electrons in molecular orbitals consisting mainly 4f atomic orbitals of rare-earth elements and its introduction to tight-binding quantum chemical molecular dynamics method

    International Nuclear Information System (INIS)

    Endou, Akira; Onuma, Hiroaki; Jung, Sun-ho

    2007-01-01

    Our original tight-binding quantum chemical molecular dynamics code, Colors', has been successfully applied to the theoretical investigation of complex materials including rare-earth elements, e.g., metal catalysts supported on a CeO 2 surface. To expand our code so as to obtain a good convergence for the electronic structure of a calculation system including a rare-earth element, we developed a novel algorithm to provide a constraint condition for the number of electrons occupying the selected molecular orbitals that mainly consist of 4f atomic orbitals of the rare-earth element. This novel algorithm was introduced in Colors. Using Colors, we succeeded in obtaining the classified electronic configurations of the 4f atomic orbitals of Ce 4+ and reduced Ce ions in a CeO 2 bulk model with one oxygen defect, which makes it difficult to obtain a good convergence using a conventional first-principles quantum chemical calculation code. (author)

  4. Center for the Utilization of Biological Engineering in Space (CUBES)

    Data.gov (United States)

    National Aeronautics and Space Administration — As NASA shifts its focus from low-Earth orbit to deep space missions, the agency is investing in the development of technologies that will allow long-duration...

  5. On the feasibility of studying the exospheres of Earth-like exoplanets by Lyman- α monitoring. Detectability constraints for nearby M stars

    Science.gov (United States)

    Castro, Ana I. Gómez de; Beitia-Antero, Leire; Ustamujic, Sabina

    2018-04-01

    Observations of the Earth's exosphere have unveiled an extended envelope of hydrogen reaching further than 10 Earth radii composed of atoms orbiting around the Earth. This large envelope increases significantly the opacity of the Earth to Lyman α (Ly α) photons coming from the Sun, to the point of making feasible the detection of the Earth's transit signature from 1.35 pc if pointing with an 8 meter primary mirror space telescope through a clean line of sight ( N H flux variability. We show that, in spite of the interstellar, heliospheric and astrospheric absorption, the transit signature in M5 V type stars would be detectable with a dedicated Ly α flux monitor implemented in a 4-8 m class space telescope. Such monitoring programs would enable measuring the robustness of planetary atmospheres under heavy space weather conditions like those produced by M-type stars. A 2-m class telescope, such as the World Space Observatory, would suffice to detect an Earth-like planet orbiting around Proxima Centauri, if there was such a planet or nearby M5 type stars.

  6. Strategic Implications of Human Exploration of Near-Earth Asteroids

    Science.gov (United States)

    Drake, Bret G.

    2011-01-01

    The current United States Space Policy [1] as articulated by the White House and later confirmed by the Congress [2] calls for [t]he extension of the human presence from low-Earth orbit to other regions of space beyond low-Earth orbit will enable missions to the surface of the Moon and missions to deep space destinations such as near-Earth asteroids and Mars. Human exploration of the Moon and Mars has been the focus of numerous exhaustive studies and planning, but missions to Near-Earth Asteroids (NEAs) has, by comparison, garnered relatively little attention in terms of mission and systems planning. This paper examines the strategic implications of human exploration of NEAs and how they can fit into the overall exploration strategy. This paper specifically addresses how accessible NEAs are in terms of mission duration, technologies required, and overall architecture construct. Example mission architectures utilizing different propulsion technologies such as chemical, nuclear thermal, and solar electric propulsion were formulated to determine resulting figures of merit including number of NEAs accessible, time of flight, mission mass, number of departure windows, and length of the launch windows. These data, in conjunction with what we currently know about these potential exploration targets (or need to know in the future), provide key insights necessary for future mission and strategic planning.

  7. Space sickness on earth

    Science.gov (United States)

    Nooij, S. A. E.; Bos, J. E.; Groen, E. L.; Bles, W.; Ockels, W. J.

    2007-09-01

    During the first days in space, i.e., after a transition from 1G to 0G, more than 50% of the astro- (and cosmonauts) suffer from the Space Adaptation Syndrome (SAS).The symptoms of SAS, like nausea and dizziness, are especially provoked by head movements. Astronauts have mentioned close similarities between the symptoms of SAS and the symptoms they experienced after a 1 hour centrifuge run on Earth, i.e., after a transition from 3G to 1G (denoted by Sickness Induced by Centrifugation, SIC). During several space missions, we related susceptibility to SAS and to SIC in 11 astronauts and found 4 of them being susceptible to both SIC and SAS, and 7 being not susceptible to SIC nor to SAS. This correspondence in susceptibility suggests that SIC and SAS share the same underlying mechanism. To further study this mechanism, several vestibular parameters have been investigated (e.g. postural stability, vestibularly driven eye movements, subjective vertical). We found some striking changes in individual cases that are possibly due to the centrifuge run. However, the variability between subjects generally is very large, making physiological links to SIC and SAS still hard to find.

  8. Bringing Space Weather Down to Earth

    Science.gov (United States)

    Reiff, P. H.; Sumners, C.

    2005-05-01

    Most of the public has no idea what Space Weather is, but a number of innovative programs, web sites, magazine articles, TV shows and planetarium shows have taken space weather from an unknown quantity to a much more visible field. This paper reviews new developments, including the new Space Weather journal, the very popular spaceweather.com website, new immersive planetarium shows that can go "on the road", and well-publicized Sun-Earth Day activities. Real-time data and reasonably accurate spaceweather forecasts are available from several websites, with many subscribers. Even the renaissance of amateur radio because of Homeland Security brings a new generation of learners to wonder what is going on in the Sun today. The NSF Center for Integrated Space Weather Modeling has a dedicated team to reach both the public and a greater diversity of new scientists.

  9. The search for life on Earth and other planets.

    Science.gov (United States)

    Gross, Michael

    2012-04-10

    As the NASA rover Curiosity approaches Mars on its quest to look for signs of past or present life there and sophisticated instruments like the space telescopes Kepler and CoRoT keep discovering additional, more Earth-like planets orbiting distant stars, science faces the question of how to spot life on other planets. Even here on Earth biotopes remain to be discovered and explored.

  10. Magnetic Actuator in Space and Application for High Precision Formation Flying

    National Research Council Canada - National Science Library

    Dargent, Thierry; Maini, Massimiliano

    2005-01-01

    Electromagnetic (EM) actuators in space applications are not a new idea but they are most of the time associated to low Earth orbit missions, where the on-board magnetic moment interacts with the Earth magnetic field...

  11. Nuclear reactor power for an electrically powered orbital transfer vehicle

    Science.gov (United States)

    Jaffe, L.; Beatty, R.; Bhandari, P.; Chow, E.; Deininger, W.; Ewell, R.; Fujita, T.; Grossman, M.; Kia, T.; Nesmith, B.

    1987-01-01

    To help determine the systems requirements for a 300-kWe space nuclear reactor power system, a mission and spacecraft have been examined which utilize electric propulsion and this nuclear reactor power for multiple transfers of cargo between low earth orbit (LEO) and geosynchronous earth orbit (GEO). A propulsion system employing ion thrusters and xenon propellant was selected. Propellant and thrusters are replaced after each sortie to GEO. The mass of the Orbital Transfer Vehicle (OTV), empty and dry, is 11,000 kg; nominal propellant load is 5000 kg. The OTV operates between a circular orbit at 925 km altitude, 28.5 deg inclination, and GEO. Cargo is brought to the OTV by Shuttle and an Orbital Maneuvering Vehicle (OMV); the OTV then takes it to GEO. The OTV can also bring cargo back from GEO, for transfer by OMV to the Shuttle. OTV propellant is resupplied and the ion thrusters are replaced by the OMV before each trip to GEO. At the end of mission life, the OTV's electric propulsion is used to place it in a heliocentric orbit so that the reactor will not return to earth. The nominal cargo capability to GEO is 6000 kg with a transit time of 120 days; 1350 kg can be transferred in 90 days, and 14,300 kg in 240 days. These capabilities can be considerably increased by using separate Shuttle launches to bring up propellant and cargo, or by changing to mercury propellant.

  12. Nuclear reactor power for an electrically powered orbital transfer vehicle

    International Nuclear Information System (INIS)

    Jaffe, L.; Beatty, R.; Bhandari, P.

    1987-01-01

    To help determine the systems requirements for a 300-kWe space nuclear reactor power system, a mission and spacecraft have been examined which utilize electric propulsion and this nuclear reactor power for multiple transfers of cargo between low Earth orbit (LEO) and geosynchronous Earth orbit (GEO). A propulsion system employing ion thrusters and xenon propellant was selected. Propellant and thrusters are replaced after each sortie to GEO. The mass of the Orbital Transfer Vehicle (OTV), empty and dry, is 11,000 kg; nominal propellant load is 5000 kg. The OTV operates between a circular orbit at 925 km altitude, 28.5 deg inclination, and GEO. Cargo is brought to the OTV by Shuttle and an Orbital Maneuvering Vehicle (OMV); the OTV then takes it to GEO. The OTV can also bring cargo back from GEO, for transfer by OMV to the Shuttle. OTV propellant is resupplied and the ion thrusters are replaced by the OMV before each trip to GEO. At the end of mission life, the OTV's electric propulsion is used to place it in a heliocentric orbit so that the reactor will not return to Earth. The nominal cargo capability to GEO is 6000 kg with a transit time of 120 days; 1350 kg can be transferred in 90 days, and 14,300 kg in 240 days. These capabilities can be considerably increased by using separate Shuttle launches to bring up propellant and cargo, or by changing to mercury propellant

  13. Study on Chinese space mutation breeding by integrating the earth with the space

    International Nuclear Information System (INIS)

    Wen Xianfang; Zhang Long; Dai Weixu; Li Chunhua

    2004-01-01

    This paper described the status of space mutation breeding in China. It emphasized that since 1978 Chinese Space scientists and agricultural biologists have send 50 kg seeds of more than 70 crops including cereals, cotton, oil, vegetable, fruit and pasture to the space using the facilities such as reture satellite 9 times, Shenzhou aircraft twice and high balloon 4 times, and 19 new varieties with high yield, high quality and disease-resistance, including five rice varieties, two wheat varieties, two cotton varieties, one sweat pepper, one tomato variety, one sesame variety, three water melon varieties, one lotus varieties and one ganaderma lucidum variety, have been bred though years of breeding at the Earth at more than 70 Chinese research institutes in 22 provinces. In addition more than 50 new lines and many other germ plasma resources have been obtained. Study on space breeding mechanism, such as biological effect of space induction, genetic variation by cell and molecular techniques and simulated study at the earth, has been conducted and some progresses have been achieved. Many space-breeding bases have been established in some provinces. Space varieties have been extended up to 270000 hectares, and some useful scientific achievements and social economic benefit had been made. The study of Chinese space mutation breading is going ahead in the world. The paper also introduced the contribution and results made by former three reture satellites in space science. Some basic parameters listed involved in study on space mutation breeding and the former three reture satellites. We also prospected the future of space mutation breeding. (authors)

  14. Radar Images of the Earth and the World Wide Web

    Science.gov (United States)

    Chapman, B.; Freeman, A.

    1995-01-01

    A perspective of NASA's Jet Propulsion Laboratory as a center of planetary exploration, and its involvement in studying the earth from space is given. Remote sensing, radar maps, land topography, snow cover properties, vegetation type, biomass content, moisture levels, and ocean data are items discussed related to earth orbiting satellite imaging radar. World Wide Web viewing of this content is discussed.

  15. Large-size deployable construction heated by solar irradiation in free space

    Science.gov (United States)

    Pestrenina, Irena; Kondyurin, Alexey; Pestrenin, Valery; Kashin, Nickolay; Naymushin, Alexey

    Large-size deployable construction in free space with subsequent direct curing was invented more than fifteen years ago (Briskman et al., 1997 and Kondyurin, 1998). It caused a lot of scientific problems, one of which is a possibility to use the solar energy for initiation of the curing reaction. This paper is devoted to investigate the curing process under sun irradiation during a space flight in Earth orbits. A rotation of the construction is considered. This motion can provide an optimal temperature distribution in the construction that is required for the polymerization reaction. The cylindrical construction of 80 m length with two hemispherical ends of 10 m radius is considered. The wall of the construction of 10 mm carbon fibers/epoxy matrix composite is irradiated by heat flux from the sun and radiates heat from the external surface by the Stefan- Boltzmann law. A stage of polymerization reaction is calculated as a function of temperature/time based on the laboratory experiments with certified composite materials for space exploitation. The curing kinetics of the composite is calculated for different inclination Low Earth Orbits (300 km altitude) and Geostationary Earth Orbit (40000 km altitude). The results show that • the curing process depends strongly on the Earth orbit and the rotation of the construction; • the optimal flight orbit and rotation can be found to provide the thermal regime that is sufficient for the complete curing of the considered construction. The study is supported by RFBR grant No.12-08-00970-a. 1. Briskman V., A.Kondyurin, K.Kostarev, V.Leontyev, M.Levkovich, A.Mashinsky, G.Nechitailo, T.Yudina, Polymerization in microgravity as a new process in space technology, Paper No IAA-97-IAA.12.1.07, 48th International Astronautical Congress, October 6-10, 1997, Turin Italy. 2. Kondyurin A.V., Building the shells of large space stations by the polymerisation of epoxy composites in open space, Int. Polymer Sci. and Technol., v.25, N4

  16. Low Earth orbit thermal control coatings exposure flight tests: A comparison of U.S. and Russian results. Report, 8 November-12 August 1993

    International Nuclear Information System (INIS)

    Tribble, A.C.; Lukins, R.; Watts, E.; Naumov, S.F.; Sergeev, V.K.

    1995-03-01

    Both the United States (US) and Russia have conducted a variety of space environment effects on materials (SEEM) flight experiments in recent years. A prime US example was the Long Duration Exposure Facility (LDEF), which spent 5 years and 9 months in low Earth orbit (LEO) from April 1984 to January 1990. A key Russian experiment was the Removable Cassette Container experiment, (RCC-1), flown on the Mir Orbital Station from 11 January 1990 to 26 April 1991. This paper evaluates the thermal control coating materials data generated by these two missions by comparing: environmental exposure conditions, functionality and chemistry of thermal control coating materials, and pre- and post-flight analysis of absorptance, emittance, and mass loss due to atomic oxygen erosion. It will be seen that there are noticeable differences in the US and Russian space environment measurements and models, which complicates comparisons of environments. The results of both flight experiments confirm that zinc oxide and zinc oxide orthotitanate white thermal control paints in metasilicate binders (Z93, YB71, TP-co-2, TP-co-11, and TP-co-12), are the most stable upon exposure to the space environment. It is also seen that Russian flight materials experience broadens to the use of silicone and acrylic resin binders while the US relies more heavily on polyurethane

  17. Sapphire: Canada's Answer to Space-Based Surveillance of Orbital Objects

    Science.gov (United States)

    Maskell, P.; Oram, L.

    The Canadian Department of National Defence is in the process of developing the Canadian Space Surveillance System (CSSS) as the main focus of the Surveillance of Space (SofS) Project. The CSSS consists of two major elements: the Sapphire System and the Sensor System Operations Centre (SSOC). The space segment of the Sapphire System is comprised of the Sapphire Satellite - an autonomous spacecraft with an electro-optical payload which will act as a contributing sensor to the United States (US) Space Surveillance Network (SSN). It will operate in a circular, sunsynchronous orbit at an altitude of approximately 750 kilometers and image a minimum of 360 space objects daily in orbits ranging from 6,000 to 40,000 kilometers in altitude. The ground segment of the Sapphire System is composed of a Spacecraft Control Center (SCC), a Satellite Processing and Scheduling Facility (SPSF), and the Sapphire Simulator. The SPSF will be responsible for data transmission, reception, and processing while the SCC will serve to control and monitor the Sapphire Satellite. Surveillance data will be received from Sapphire through two ground stations. Following processing by the SPSF, the surveillance data will then be forwarded to the SSOC. The SSOC will function as the interface between the Sapphire System and the US Joint Space Operations Center (JSpOC). The JSpOC coordinates input from various sensors around the world, all of which are a part of the SSN. The SSOC will task the Sapphire System daily and provide surveillance data to the JSpOC for correlation with data from other SSN sensors. This will include orbital parameters required to predict future positions of objects to be tracked. The SSOC receives daily tasking instructions from the JSpOC to determine which objects the Sapphire spacecraft is required to observe. The advantage of this space-based sensor over ground-based telescopes is that weather and time of day are not factors affecting observation. Thus, space-based optical

  18. Circular Orbit Target Capture Using Space Tether-Net System

    Directory of Open Access Journals (Sweden)

    Guang Zhai

    2013-01-01

    Full Text Available The space tether-net system for on-orbit capture is proposed in this paper. In order to research the dynamic behaviors during system deployment, both free and nonfree deployment dynamics in circular orbit are developed; the system motion with respect to Local Vertical and Local Horizontal frame is also researched with analysis and simulation. The results show that in the case of free deployment, the capture net follows curve trajectories due to the relative orbit dynamic perturbation, and the initial deployment velocities are planned by state transformation equations for static and floating target captures; in the case of non-free deployment, the system undergoes an altitude libration along the Local Vertical, and the analytical solutions that describe the attitude libration are obtained by using variable separation and integration. Finally, the dynamics of postdeployment system is also proved marginally stable if the critical initial conditions are satisfied.

  19. Implementation of small group discussion as a teaching method in earth and space science subject

    Science.gov (United States)

    Aryani, N. P.; Supriyadi

    2018-03-01

    In Physics Department Universitas Negeri Semarang, Earth and Space Science subject is included in the curriculum of the third year of physics education students. There are various models of teaching earth and space science subject such as textbook method, lecturer, demonstrations, study tours, problem-solving method, etc. Lectures method is the most commonly used of teaching earth and space science subject. The disadvantage of this method is the lack of two ways interaction between lecturers and students. This research used small group discussion as a teaching method in Earth and Space science. The purpose of this study is to identify the conditions under which an efficient discussion may be initiated and maintained while students are investigating properties of earth and space science subjects. The results of this research show that there is an increase in student’s understanding of earth and space science subject proven through the evaluation results. In addition, during the learning process, student’s activeness also increase.

  20. Earth's Trojan asteroid.

    Science.gov (United States)

    Connors, Martin; Wiegert, Paul; Veillet, Christian

    2011-07-27

    It was realized in 1772 that small bodies can stably share the same orbit as a planet if they remain near 'triangular points' 60° ahead of or behind it in the orbit. Such 'Trojan asteroids' have been found co-orbiting with Jupiter, Mars and Neptune. They have not hitherto been found associated with Earth, where the viewing geometry poses difficulties for their detection, although other kinds of co-orbital asteroid (horseshoe orbiters and quasi-satellites) have been observed. Here we report an archival search of infrared data for possible Earth Trojans, producing the candidate 2010 TK(7). We subsequently made optical observations which established that 2010 TK(7) is a Trojan companion of Earth, librating around the leading Lagrange triangular point, L(4). Its orbit is stable over at least ten thousand years.