WorldWideScience

Sample records for spacecraft safe landing

  1. Imaging Flash Lidar for Safe Landing on Solar System Bodies and Spacecraft Rendezvous and Docking

    Science.gov (United States)

    Amzajerdian, Farzin; Roback, Vincent E.; Bulyshev, Alexander E.; Brewster, Paul F.; Carrion, William A; Pierrottet, Diego F.; Hines, Glenn D.; Petway, Larry B.; Barnes, Bruce W.; Noe, Anna M.

    2015-01-01

    NASA has been pursuing flash lidar technology for autonomous, safe landing on solar system bodies and for automated rendezvous and docking. During the final stages of the landing from about 1 kilometer to 500 meters above the ground, the flash lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes. The onboard flight computer can then use the 3-D map of terrain to guide the vehicle to a safe location. As an automated rendezvous and docking sensor, the flash lidar can provide relative range, velocity, and bearing from an approaching spacecraft to another spacecraft or a space station. NASA Langley Research Center has developed and demonstrated a flash lidar sensor system capable of generating 16,000 pixels range images with 7 centimeters precision, at 20 Hertz frame rate, from a maximum slant range of 1800 m from the target area. This paper describes the lidar instrument and presents the results of recent flight tests onboard a rocket-propelled free-flyer vehicle (Morpheus) built by NASA Johnson Space Center. The flights were conducted at a simulated lunar terrain site, consisting of realistic hazard features and designated landing areas, built at NASA Kennedy Space Center specifically for this demonstration test. This paper also provides an overview of the plan for continued advancement of the flash lidar technology aimed at enhancing its performance to meet both landing and automated rendezvous and docking applications.

  2. Effects of Spacecraft Landings on the Moon

    Science.gov (United States)

    Metzger, Philip T.; Lane, John E.

    2013-01-01

    The rocket exhaust of spacecraft landing on the Moon causes a number of observable effects that need to be quantified, including: disturbance of the regolith and volatiles at the landing site; damage to surrounding hardware such as the historic Apollo sites through the impingement of high-velocity ejecta; and levitation of dust after engine cutoff through as-yet unconfirmed mechanisms. While often harmful, these effects also beneficially provide insight into lunar geology and physics. Some of the research results from the past 10 years is summarized and reviewed here.

  3. Autonomous spacecraft landing through human pre-attentive vision

    International Nuclear Information System (INIS)

    Schiavone, Giuseppina; Izzo, Dario; Simões, Luís F; De Croon, Guido C H E

    2012-01-01

    In this work, we exploit a computational model of human pre-attentive vision to guide the descent of a spacecraft on extraterrestrial bodies. Providing the spacecraft with high degrees of autonomy is a challenge for future space missions. Up to present, major effort in this research field has been concentrated in hazard avoidance algorithms and landmark detection, often by reference to a priori maps, ranked by scientists according to specific scientific criteria. Here, we present a bio-inspired approach based on the human ability to quickly select intrinsically salient targets in the visual scene; this ability is fundamental for fast decision-making processes in unpredictable and unknown circumstances. The proposed system integrates a simple model of the spacecraft and optimality principles which guarantee minimum fuel consumption during the landing procedure; detected salient sites are used for retargeting the spacecraft trajectory, under safety and reachability conditions. We compare the decisions taken by the proposed algorithm with that of a number of human subjects tested under the same conditions. Our results show how the developed algorithm is indistinguishable from the human subjects with respect to areas, occurrence and timing of the retargeting. (paper)

  4. Hazard avoidance via descent images for safe landing

    Science.gov (United States)

    Yan, Ruicheng; Cao, Zhiguo; Zhu, Lei; Fang, Zhiwen

    2013-10-01

    In planetary or lunar landing missions, hazard avoidance is critical for landing safety. Therefore, it is very important to correctly detect hazards and effectively find a safe landing area during the last stage of descent. In this paper, we propose a passive sensing based HDA (hazard detection and avoidance) approach via descent images to lower the landing risk. In hazard detection stage, a statistical probability model on the basis of the hazard similarity is adopted to evaluate the image and detect hazardous areas, so that a binary hazard image can be generated. Afterwards, a safety coefficient, which jointly utilized the proportion of hazards in the local region and the inside hazard distribution, is proposed to find potential regions with less hazards in the binary hazard image. By using the safety coefficient in a coarse-to-fine procedure and combining it with the local ISD (intensity standard deviation) measure, the safe landing area is determined. The algorithm is evaluated and verified with many simulated descent downward looking images rendered from lunar orbital satellite images.

  5. Vega-1 and Vega-2: vertical profiles of wind velocity according to Doppler measurements data at landing spacecrafts

    International Nuclear Information System (INIS)

    Kerzhanovich, V.V.; Antsibor, N.M.; Bakit'ko, R.V.

    1987-01-01

    Results of the measurements of the Venus atmosphere vertical motion using the ''Vega'' landing spacecrafts are presented. Signal emitted by the landing spacecraft transmitter was received by flying apparatus and retranslated to the Earth. The difference between the measured frequency of the retranslated signal and reference one (Doppler's shift) permitted to determine the velocity of the landing spacecraft with the accuracy of 2 cm/s with the pitch of 1 s

  6. GN and C Subsystem Concept for Safe Precision Landing of the Proposed Lunar MARE Robotic Science Mission

    Science.gov (United States)

    Carson, John M., III; Johnson, Andrew E.; Anderson, F. Scott; Condon, Gerald L.; Nguyen, Louis H.; Olansen, Jon B.; Devolites, Jennifer L.; Harris, William J.; Hines, Glenn D.; Lee, David E.; hide

    2016-01-01

    The Lunar MARE (Moon Age and Regolith Explorer) Discovery Mission concept targets delivery of a science payload to the lunar surface for sample collection and dating. The mission science is within a 100-meter radius region of smooth lunar maria terrain near Aristarchus crater. The location has several small, sharp craters and rocks that present landing hazards to the spacecraft. For successful delivery of the science payload to the surface, the vehicle Guidance, Navigation and Control (GN&C) subsystem requires safe and precise landing capability, so design infuses the NASA Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) and a gimbaled, throttleable LOX/LCH4 main engine. The ALHAT system implemented for Lunar MARE is a specialization of prototype technologies in work within NASA for the past two decades, including a passive optical Terrain Relative Navigation (TRN) sensor, a Navigation Doppler Lidar (NDL) velocity and range sensor, and a Lidar-based Hazard Detection (HD) sensor. The landing descent profile is from a retrograde orbit over lighted terrain with landing near lunar dawn. The GN&C subsystem with ALHAT capabilities will deliver the science payload to the lunar surface within a 20-meter landing ellipse of the target location and at a site having greater than 99% safety probability, which minimizes risk to safe landing and delivery of the MARE science payload to the intended terrain region.

  7. Simple Automatic File Exchange (SAFE) to Support Low-Cost Spacecraft Operation via the Internet

    Science.gov (United States)

    Baker, Paul; Repaci, Max; Sames, David

    1998-01-01

    Various issues associated with Simple Automatic File Exchange (SAFE) are presented in viewgraph form. Specific topics include: 1) Packet telemetry, Internet IP networks and cost reduction; 2) Basic functions and technical features of SAFE; 3) Project goals, including low-cost satellite transmission to data centers to be distributed via an Internet; 4) Operations with a replicated file protocol; 5) File exchange operation; 6) Ground stations as gateways; 7) Lessons learned from demonstrations and tests with SAFE; and 8) Feedback and future initiatives.

  8. Study on the Venus rock composition in the northern part of the Land Aphrodita at the Vega 2 landing spacecraft

    International Nuclear Information System (INIS)

    Surkov, Yu.A.; Moskaleva, L.P.; Shzheglov, O.P.; 9400005SU; AN SSSR, Moscow. Fizicheskij Inst.)

    1986-01-01

    A brief description is given of experiment on X-ray radiometric determination of the elemental composition of Venus rock carried out with the help of the landing spacecraft Vega 2. Preliminary data on the rock composition in the Northern part of the Land Aphrodita and geochemical interpretation of the studied rock character are given. The detailed analysis of the Venus rock composition with application of iterations according to the ITERA program (Surkov etalli 1983) and application of the data on content of natural raedioactive elements determined by the ''Vega-2'' station gamma spectrometer (Surkov and et alli). Show that in the northen part of the Land Aphrodita rock is close by its composition with rocks of anorthosite-norite-troctolite group, which are widely distributed on the Moon surface

  9. A new landing impact attenuation seat in manned spacecraft biologically-inspired by felids

    Directory of Open Access Journals (Sweden)

    Yu Hui

    2015-04-01

    Full Text Available When manned spacecraft comes back to the earth, it relies on the impact attenuation seat to protect astronauts from injuries during landing phase. Hence, the seat needs to transfer impact load, as small as possible, to the crew. However, there is little room left for traditional seat to improve further. Herein, a new seat system biologically-inspired by felids’ landing is proposed. Firstly, a series of experiments was carried out on cats and tigers, in which they were trained to jump down voluntarily from different heights. Based on the ground reaction forces combined with kinematics, the experiment indicated that felids’ landing after self-initial jump was a multi-step impact attenuation process and the new seat was inspired by this. Then the construction and work process of new seat were redesigned to realize the multi-step impact attenuation. The dynamic response of traditional and new seat is analyzed under the identical conditions and the results show that the new concept seat can significantly weaken the occupant overload in two directions compared with that of traditional seat. As a consequence, the risk of injury evaluated for spinal and head is also lowered, meaning a higher level of protection which is especially beneficial to the debilitated astronaut.

  10. Critical Spacecraft-to-Earth Communications for Mars Exploration Rover (MER) entry, descent and landing

    Science.gov (United States)

    Hurd, William J.; Estabrook, Polly; Racho, Caroline S.; Satorius, Edgar H.

    2002-01-01

    For planetary lander missions, the most challenging phase of the spacecraft to ground communications is during the entry, descent, and landing (EDL). As each 2003 Mars Exploration Rover (MER) enters the Martian atmosphere, it slows dramatically. The extreme acceleration and jerk cause extreme Doppler dynamics on the X-band signal received on Earth. When the vehicle slows sufficiently, the parachute is deployed, causing almost a step in deceleration. After parachute deployment, the lander is lowered beneath the parachute on a bridle. The swinging motion of the lander imparts high Doppler dynamics on the signal and causes the received signal strength to vary widely, due to changing antenna pointing angles. All this time, the vehicle transmits important health and status information that is especially critical if the landing is not successful. Even using the largest Deep Space Network antennas, the weak signal and high dynamics render it impossible to conduct reliable phase coherent communications. Therefore, a specialized form of frequency-shift-keying will be used. This paper describes the EDL scenario, the signal conditions, the methods used to detect and frequency-track the carrier and to detect the data modulation, and the resulting performance estimates.

  11. Changing pattern of landslide risk in Europe - The SafeLand project

    Science.gov (United States)

    Nadim, F.; Kalsnes, B.

    2012-04-01

    The need to protect people and property with a changing pattern of landslide hazard and risk caused by climate change and changes in demography, and the reality for societies in Europe to live with the risk associated with natural hazards, were the motives for the project SafeLand: "Living with landslide risk in Europe: Assessment, effects of global change, and risk management strategies." SafeLand is a large, integrating research project under the European Commission's 7th Framework Programme (FP7). The project started on 1 May 2009 and will end on 30 April 2012. It involves 27 partners from 12 European countries, and has international collaborators and advisers from China, India, USA, Japan and Hong Kong. SafeLand also involves 25 End-Users from 11 countries. SafeLand is coordinated by the International Centre for Geohazards (ICG) at Norwegian Geotechnical Institute in Norway. Further information on the SafeLand project can be found at its web site http://safeland-fp7.eu/. Main results achieved in SafeLand include: - Various guidelines related to landslide triggering processes and run-out modelling. - Development and testing of several empirical methods for predicting the characteristics of threshold rainfall events for triggering of precipitation-induced landslides, and development of an empirical model for assessing the changes in landslide frequency (hazard) as a function of changes in the demography and population density. - Guideline for landslide susceptibility, hazard and risk assessment and zoning. - New methodologies for physical and societal vulnerability assessment. - Identification of landslide hazard and risk hotspots for Europe. The results show clearly where areas with the largest landslide risk are located in Europe and the objective approach allows a ranking of the countries by exposed area and population. - Different regional and local climate model simulations over selected regions of Europe at spatial resolutions of 10x10 km and 2.8x2.8 km

  12. Flight Testing a Real-Time Hazard Detection System for Safe Lunar Landing on the Rocket-Powered Morpheus Vehicle

    Science.gov (United States)

    Trawny, Nikolas; Huertas, Andres; Luna, Michael E.; Villalpando, Carlos Y.; Martin, Keith E.; Carson, John M.; Johnson, Andrew E.; Restrepo, Carolina; Roback, Vincent E.

    2015-01-01

    The Hazard Detection System (HDS) is a component of the ALHAT (Autonomous Landing and Hazard Avoidance Technology) sensor suite, which together provide a lander Guidance, Navigation and Control (GN&C) system with the relevant measurements necessary to enable safe precision landing under any lighting conditions. The HDS consists of a stand-alone compute element (CE), an Inertial Measurement Unit (IMU), and a gimbaled flash LIDAR sensor that are used, in real-time, to generate a Digital Elevation Map (DEM) of the landing terrain, detect candidate safe landing sites for the vehicle through Hazard Detection (HD), and generate hazard-relative navigation (HRN) measurements used for safe precision landing. Following an extensive ground and helicopter test campaign, ALHAT was integrated onto the Morpheus rocket-powered terrestrial test vehicle in March 2014. Morpheus and ALHAT then performed five successful free flights at the simulated lunar hazard field constructed at the Shuttle Landing Facility (SLF) at Kennedy Space Center, for the first time testing the full system on a lunar-like approach geometry in a relevant dynamic environment. During these flights, the HDS successfully generated DEMs, correctly identified safe landing sites and provided HRN measurements to the vehicle, marking the first autonomous landing of a NASA rocket-powered vehicle in hazardous terrain. This paper provides a brief overview of the HDS architecture and describes its in-flight performance.

  13. Evaluation of MODIS Land Surface Temperature with In Situ Snow Surface Temperature from CREST-SAFE

    Science.gov (United States)

    Perez Diaz, C. L.; Lakhankar, T.; Romanov, P.; Munoz, J.; Khanbilvardi, R.; Yu, Y.

    2016-12-01

    This paper presents the procedure and results of a temperature-based validation approach for the Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) product provided by the National Aeronautics and Space Administration (NASA) Terra and Aqua Earth Observing System satellites using in situ LST observations recorded at the Cooperative Remote Sensing Science and Technology Center - Snow Analysis and Field Experiment (CREST-SAFE) during the years of 2013 (January-April) and 2014 (February-April). A total of 314 day and night clear-sky thermal images, acquired by the Terra and Aqua satellites, were processed and compared to ground-truth data from CREST-SAFE with a frequency of one measurement every 3 min. Additionally, this investigation incorporated supplementary analyses using meteorological CREST-SAFE in situ variables (i.e. wind speed, cloud cover, incoming solar radiation) to study their effects on in situ snow surface temperature (T-skin) and T-air. Furthermore, a single pixel (1km2) and several spatially averaged pixels were used for satellite LST validation by increasing the MODIS window size to 5x5, 9x9, and 25x25 windows for comparison. Several trends in the MODIS LST data were observed, including the underestimation of daytime values and nighttime values. Results indicate that, although all the data sets (Terra and Aqua, diurnal and nocturnal) showed high correlation with ground measurements, day values yielded slightly higher accuracy ( 1°C), both suggesting that MODIS LST retrievals are reliable for similar land cover classes and atmospheric conditions. Results from the CREST-SAFE in situ variables' analyses indicate that T-air is commonly higher than T-skin, and that a lack of cloud cover results in: lower T-skin and higher T-air minus T-skin difference (T-diff). Additionally, the study revealed that T-diff is inversely proportional to cloud cover, wind speed, and incoming solar radiation. Increasing the MODIS window size

  14. Bioprocessing of sewage sludge for safe recycling on agricultural land - BIOWASTE

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Jens Ejbye; Angelidaki, Irini; Christensen, Nina; Batstone, Damien John; Lyberatos, Gerasimos; Stamatelatou, Katerina; Lichtfouse, Eric; Elbisser, Brigitte; Rogers, Kayne; Sappin-Didier, Valerie; Dernaix, Laurence; Caria; Giovanni; Metzger, Laure; Borghi, Veronica; Montcada, Eloi

    2003-07-01

    Disposal and handling of sewage sludge are increasing problems in Europe due to the increasing quantities of the sewage sludge produced. A large amount of the sewage sludge contains small fractions of toxic chemicals, which results in problems with safe use of the sewage sludge on agricultural land. From an ecological and economical point of view, it would be essential to establish methodologies, which could allow sewage sludge to be reused as fertilizers on agricultural land. Energy efficient biotreatment processes of organic waste are, therefore, of crucial importance. BIOWASTE will offer an integrated study of this area. The typical composition of sewage sludge will be characterized with regard to key contaminating compounds. The following compounds will be in focus: Emulsifying agents such as nonylphenols and nonylphenol ethoxylates (NPE), polycyclic aromatic hydrocarbons (PAHs) derived from incomplete combustion processes and phthalates, which are used as additives in plastics and surfactants such as linear alkyl benzene sulfonate (LAS). Analytical techniques suitable for qualitative and quantitative evaluation of the chemical species involved in the processes under investigation will be determined. Bacteria that are able to degrade selected contaminating compounds under anaerobic and aerobic conditions will be isolated, characterized and bioaugmented for decontamination of sewage sludge through bioprocessing. Aerobic, anaerobic and combination of aerobic/anaerobic bioprocessing of sewage sludge will be applied. A mathematical model will be developed to describe the biodegradation processes of the contaminating compounds after establishing the kinetic parameters for degradation of contaminating compounds. The bioprocessed sewage sludge will be used in eco- and plant- toxicology tests to evaluate the impact of the xenobiotics on the environment. Methodologies will be developed and applied to assess the cleanliness of the bioprocessing as a safe method for waste

  15. An Evaluation of Ultra-High Pressure Regulator for Robotic Lunar Landing Spacecraft

    Science.gov (United States)

    Burnside, Christopher; Trinh, Huu; Pedersen, Kevin

    2011-01-01

    The Robotic Lunar Lander Development (RLLD) Project Office at NASA Marshall Space Flight Center (MSFC) has studied several lunar surface science mission concepts. These missions focus on spacecraft carrying multiple science instruments and power systems that will allow extended operations on the lunar surface. Initial trade studies of launch vehicle options for these mission concepts indicate that the spacecraft design will be significantly mass-constrained. To minimize mass and facilitate efficient packaging, the notional propulsion system for these landers has a baseline of an ultra-high pressure (10,000 psig) helium pressurization system that has been used on Defense missiles. The qualified regulator is capable of short duration use; however, the hardware has not been previously tested at NASA spacecraft requirements with longer duration. Hence, technical risks exist in using this missile-based propulsion component for spacecraft applications. A 10,000-psig helium pressure regulator test activity is being carried out as part of risk reduction testing for MSFC RLLD project. The goal of the test activity is to assess the feasibility of commercial off-the-shelf ultra-high pressure regulator by testing with a representative flight mission profile. Slam-start, gas blowdown, water expulsion, lock-up, and leak tests are also performed on the regulator to assess performance under various operating conditions. The preliminary test results indicated that the regulator can regulate helium to a stable outlet pressure of 740 psig within the +/- 5% tolerance band and maintain a lock-up pressure less than +5% for all tests conducted. Numerous leak tests demonstrated leakage less than 10-3 standard cubic centimeters per second (SCCS) for internal seat leakage at lock-up and less than10-5 SCCS for external leakage through the regulator ambient reference cavity. The successful tests have shown the potential for 10,000 psig helium systems in NASA spacecraft and have reduced risk

  16. Investigation of the THOR Anthropomorphic Test Device for Predicting Occupant Injuries during Spacecraft Launch Abort and Landing

    Directory of Open Access Journals (Sweden)

    Jeffrey T. Somers

    2014-03-01

    Full Text Available The objective of this study was to investigate new methods for predicting injury from expected spaceflight dynamic loads by leveraging a broader range of available information in injury biomechanics. Although all spacecraft designs were considered, the primary focus was the NASA Orion capsule, as the authors have the most knowledge and experience related to this design. The team defined a list of critical injuries and selected the Test Device for Human Occupant Restraint (THOR anthropomorphic test device (ATD as the basis for new standards and requirements. In addition, the team down selected the list of available injury metrics to the following: head injury criteria (HIC 15, kinematic rotational brain injury criteria (BRIC, neck axial tension and compression force, maximum chest deflection, lateral shoulder force and displacement, acetabular lateral force, thoracic spine axial compression force, ankle moments, and average distal forearm speed limits. The team felt that these metrics capture all of the injuries that might be expected by a seated crewmember during vehicle aborts and landings. Using previously determined injury risk levels for nominal and off-nominal landings, appropriate injury assessment reference values (IARVs were defined for each metric. Musculoskeletal deconditioning due to exposure to reduced gravity over time can affect injury risk during landing; therefore a deconditioning factor was applied to all IARVs. Although there are appropriate injury data for each anatomical region of interest, additional research is needed for several metrics to improve the confidence score.

  17. Safe use of metal-contaminated agricultural land by cultivation of energy maize (Zea mays)

    International Nuclear Information System (INIS)

    Van Slycken, S.; Witters, N.; Meers, E.; Peene, A.; Michels, E.; Adriaensen, K.; Ruttens, A.; Vangronsveld, J.; Du Laing, G.; Wierinck, I.; Van Dael, M.; Van Passel, S.; Tack, F.M.G.

    2013-01-01

    Production of food crops on trace element-contaminated agricultural lands in the Campine region (Belgium) can be problematic as legal threshold values for safe use of these crops can be exceeded. Conventional sanitation of vast areas is too expensive and alternatives need to be investigated. Zea mays on a trace element-contaminated soil in the region showed an average yield of 53 ± 10 Mg fresh or 20 ± 3 Mg dry biomass ha −1 . Whole plant Cd concentrations complied with legal threshold values for animal feed. Moreover, threshold values for use in anaerobic digestion were met. Biogas production potential did not differ between maize grown on contaminated and non-contaminated soils. Results suggested favorable perspectives for farmers to generate non-food crops profitably, although effective soil cleaning would be very slow. This demonstrates that a valuable and sustainable alternative use can be generated for moderately contaminated soils on which conventional agriculture is impaired. -- Highlights: •Zea mays on trace element-contaminated soil has an average yield of 20 ± 3 Mg DW ha −1 . •Whole plant Cd concentrations complied with legal threshold values for animal feed. •Biogas production did not differ from maize grown on non-contaminated soils. •Perspectives are favorable for farmers to generate non-food crops profitably. •Effective soil cleaning would be very slow. -- Energy maize cultivation constitutes a sustainable alternative use of trace element-contaminated agricultural soils

  18. Comparison of eye-safe solid state laser DIAL with passive gas filter correlation measurements from aircraft and spacecraft

    Science.gov (United States)

    Hess, Robert V.; Staton, Leo D.; Wallio, H. Andrew; Wang, Liang-Guo

    1992-01-01

    Differential Absorption Lidar (DIAL) using solid state Ti:sapphire lasers finds current application in the NASA/LASE Project for H2O vapor measurements in the approximately = 0.820 micron region for the lower and mid-troposphere and in potential future applications in planned measurements of the approximately = 0.940 micron region where both strong and weak absorption lines enables measurements throughout the troposphere and lower stratosphere. The challenge exists to perform measurements in the eye-safe greater than 1.5 micron region. A comparison between DIAL and passive Gas Filter Correlation Radiometer (GFCR) measurements is made. The essence of the differences in signal to noise ratio for DIAL and passive GFCR measurements is examined. The state of the art of lasers and optical parametric oscillators (OPO's) is discussed.

  19. Attenuation of stress waves in single and multi-layered structures. [mitigation of elastic and plastic stress waves during spacecraft landing

    Science.gov (United States)

    Yang, J. C. S.; Tsui, C. Y.

    1972-01-01

    Analytical and experimental studies were made of the attenuation of the stress waves during passage through single and multilayer structures. The investigation included studies on elastic and plastic stress wave propagation in the composites and those on shock mitigating material characteristics such as dynamic stress-strain relations and energy absorbing properties. The results of the studies are applied to methods for reducing the stresses imposed on a spacecraft during planetary or ocean landings.

  20. Probabilistic Surface Characterization for Safe Landing Hazard Detection and Avoidance (HDA)

    Science.gov (United States)

    Ivanov, Tonislav I. (Inventor); Huertas, Andres (Inventor); Johnson, Andrew E. (Inventor)

    2015-01-01

    Apparatuses, systems, computer programs and methods for performing hazard detection and avoidance for landing vehicles are provided. Hazard assessment takes into consideration the geometry of the lander. Safety probabilities are computed for a plurality of pixels in a digital elevation map. The safety probabilities are combined for pixels associated with one or more aim points and orientations. A worst case probability value is assigned to each of the one or more aim points and orientations.

  1. New complex fertilizer 'Suprodit' to obtain safe agricultural productions on contaminated lands.

    Science.gov (United States)

    Nikolaevich Ratnikov, Alexander; Sergeevich Anisimov, Vyacheslav; Nikoaevna Anisimova, Lidiya; Georgievich Sviridenko, Dmitry; Jurievna Balanova, Olesya

    2015-04-01

    ). The Cd accumulation by barley grain in sod-podzolic soil, contaminated with Cd6, Zn600, Cu390 mg/kg, when applying "SUPRODIT" was 2.5 times less than after industrial fertilizers (NPK and nitrophoska) application; the accumulation of Zn - 1.5 and 1.9 times less; the accumulation of Cu - 1.6 and 1.5 times less in comparison with NPK and nitrophoska, respectively. Applying of "SUPRODIT" constrain the accumulation of 137Cs in barley grain 1.2-1.3 times more efficiently than NPK and nitrophoska. Use "SUPRODIT" in technologies of cultivation of fodder crops on contaminated land in the districts of the Kaluga and Bryansk regions of the Russian Federation allow us to get a feed corresponding to acceptable levels on the content of 137Cs at a density of contamination 500-920 kBq/m2, which ensures that the milk will fit to corresponding maximum permissible concentration.

  2. SafeLand guidelines for landslide monitoring and early warning systems in Europe - Design and required technology

    Science.gov (United States)

    Bazin, S.

    2012-04-01

    Landslide monitoring means the comparison of landslide characteristics like areal extent, speed of movement, surface topography and soil humidity from different periods in order to assess landslide activity. An ultimate "universal" methodology for this purpose does not exist; every technology has its own advantages and disadvantages. End-users should carefully consider each one to select the methodologies that represent the best compromise between pros and cons, and are best suited for their needs. Besides monitoring technology, there are many factors governing the choice of an Early Warning System (EWS). A people-centred EWS necessarily comprises five key elements: (1) knowledge of the risks; (2) identification, monitoring, analysis and forecasting of the hazards; (3) operational centre; (4) communication or dissemination of alerts and warnings; and (5) local capabilities to respond to the warnings received. The expression "end-to-end warning system" is also used to emphasize that EWSs need to span all steps from hazard detection through to community response. The aim of the present work is to provide guidelines for establishing the different components for landslide EWSs. One of the main deliverables of the EC-FP7 SafeLand project addresses the technical and practical issues related to monitoring and early warning for landslides, and identifies the best technologies available in the context of both hazard assessment and design of EWSs. This deliverable targets the end-users and aims to facilitate the decision process by providing guidelines. For the purpose of sharing the globally accumulated expertise, a screening study was done on 14 EWSs from 8 different countries. On these bases, the report presents a synoptic view of existing monitoring methodologies and early-warning strategies and their applicability for different landslide types, scales and risk management steps. Several comprehensive checklists and toolboxes are also included to support informed

  3. Helicopter Flight Test of 3-D Imaging Flash LIDAR Technology for Safe, Autonomous, and Precise Planetary Landing

    Science.gov (United States)

    Roback, Vincent; Bulyshev, Alexander; Amzajerdian, Farzin; Reisse, Robert

    2013-01-01

    Two flash lidars, integrated from a number of cutting-edge components from industry and NASA, are lab characterized and flight tested for determination of maximum operational range under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project (in its fourth development and field test cycle) which is seeking to develop a guidance, navigation, and control (GN&C) and sensing system based on lidar technology capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The flash lidars incorporate pioneering 3-D imaging cameras based on Indium-Gallium-Arsenide Avalanche Photo Diode (InGaAs APD) and novel micro-electronic technology for a 128 x 128 pixel array operating at 30 Hz, high pulse-energy 1.06 micrometer Nd:YAG lasers, and high performance transmitter and receiver fixed and zoom optics. The two flash lidars are characterized on the NASA-Langley Research Center (LaRC) Sensor Test Range, integrated with other portions of the ALHAT GN&C system from partner organizations into an instrument pod at NASA-JPL, integrated onto an Erickson Aircrane Helicopter at NASA-Dryden, and flight tested at the Edwards AFB Rogers dry lakebed over a field of human-made geometric hazards during the summer of 2010. Results show that the maximum operational range goal of 1 km is met and exceeded up to a value of 1.2 km. In addition, calibrated 3-D images of several hazards are acquired in real-time for later reconstruction into Digital Elevation Maps (DEM's).

  4. Landing Safely on Mars

    Science.gov (United States)

    Merritt, Eileen; Shifflett, Elizabeth

    2012-01-01

    It can be difficult to teach students about objects in space that are far away and impossible to touch. The authors found that reading nonfiction trade books, modeling relationships using everyday objects, and synthesizing ideas through writing and drawing helped their students improve their understanding. An added benefit of the integration was…

  5. SAFE Newsletter

    OpenAIRE

    2013-01-01

    The Center of Excellence SAFE – “Sustainable Architecture for Finance in Europe” – is a cooperation of the Center for Financial Studies and Goethe University Frankfurt. It is funded by the LOEWE initiative of the State of Hessen (Landes-Offensive zur Entwicklung wissenschaftlich-ökonomischer Exzellenz). SAFE brings together more than 40 professors and just as many junior researchers who are all dedicated to conducting research in support of a sustainable financial architecture. The Center has...

  6. Guide to the safe design, construction and use of radioisotopic power generators for certain land and sea applications

    International Nuclear Information System (INIS)

    1970-01-01

    The increasing development and production of certain types of radioisotopic power generators has indicated the need for internationally acceptable recommendations to be formulated governing the health and safety aspects of their construction and use. Accordingly, a Joint IAEA/ENEA Working Group was set up in 1966 with the task of studying the health and safety problems associated with such devices. The Working Group met twice, in April and December 1967, and prepared a draft guide to the safe design, construction and use of radioisotopic power generators. This draft guide was circulated in September 1968 to IAEA and ENEA Member States for consideration, and the comments that were subsequently received have formed the basis of a re-examination of the draft text in June 1969 by a joint IAEA/ENEA group of consultants set up by the two Agencies to bring the draft guide to its final form. This guide is intended to facilitate the establishment of an adequate standard of safety in the design, construction, installation and use of radioisotopic power generators, and in their ultimate disposal. The immediate requirement is considered to be in relation to those generators which are in an advanced state of development and production and which are designed for use on land and on o r under the sea. The guide deals mainly with radioisotopic power generators in the power range from about one hundred milliwatts to some hundred watts. However, competent national authorities may adapt these guidelines to generators outside this power range. It has been decided at this stage to exclude consideration of miniature generators for medical use, in watches and in other devices available to the general public. Generators for use in space have also been excluded.

  7. Preliminary Results from the Joint Russian and US Field Test: Measurement of Sensorimotor and Cardiovascular Responses Immediately Following Landing of the Soyuz Spacecraft

    Science.gov (United States)

    Reschke, M. F.; Kozlovskaya, I. B.; Tomilovskaya, E. S.; Bloomberg, J. J.; Platts, S. H.; Rukavishnikov, I. V.; Fomina, E. V.; Stenger, M. B.; Lee, S. M. C.; Wood, S. J.; hide

    2013-01-01

    Ongoing collaborative research efforts between NASA's Neuroscience and Cardiovascular Laboratories, and the Institute of Biomedical Problems' (IBMP) Sensory-Motor and Countermeasures Laboratories have been measuring functional sensorimotor, cardiovascular and strength responses following bed rest, dry immersion, short duration (Space Shuttle) and long duration (Mir and International Space Station) space flights. While the unloading paradigms associated with dry immersion and bed rest have do serve as acceptable flight analogs, testing of crew responses following the long duration flights does not begin until a minimum of 24 hours after landing. As a result it is not possible to estimate the nonlinear trend of the early (testing at the time of landing and before the flight crews have left the landing site. By joint agreement this research effort has been identified as the functional Field Test (FT). For practical reasons the FT has been divided into two phases: the full FT and a preliminary pilot version (PFT) of the FT that is reduced in both length and scope. The primary goal of this research is to determine functional abilities in long duration space flight crews beginning as soon after landing as possible (test in conjunction with postural ataxia testing. In addition to the immediate post-landing collection of data for the full FT, postflight data will be acquired at a minimum of one to three more other times within the 24 hr following landing and continue until functional sensorimotor and cardiovascular responses have returned to preflight normative values. The PFT represents a single trial run comprised of jointly agreed tests from the full FT and relies heavily on IBMP's Sensory-Motor and Countermeasures Laboratories for content, and implementation. The PFT is currently scheduled for the September 2013 landing of the Soyuz spacecraft (34S). Testing will include: (1) a sit-to-stand test, (2) recovery from a fall where the crewmember begins in the prone

  8. Land

    NARCIS (Netherlands)

    C.A. Hunsberger (Carol); Tom P. Evans

    2012-01-01

    textabstractPressure on land resources has increased during recent years despite international goals to improve their management. The fourth Global Environment Outlook (UNEP 2007) highlighted the unprecedented land-use changes created by a burgeoning population, economic development and

  9. Utilizing Science to Ensure Safe Access to Cultural Resources on Public Lands: The Portland Native American Community and Traditional Gathering of Camas

    Science.gov (United States)

    Greene, C.

    2017-12-01

    Native Americans have been conducting and contributing to science for millenia. We have observed nature and passed on evidence-based Traditional Ecological Knowledge (TEK) from generation to generation. Prior to colonization, this knowledge enabled our people to live with ample nutritional resources. Our long-standing relationship to nature continues today in tribal, rural, and urban communities, yet access to cultural resources (traditional food and medicines) proves challenging due to modern land management practices. The Native American community and public land managers in Portland, Oregon are addressing this challenge through the restoration of cultural resources across the landscape. One focus in these efforts is the camas plant (Camssia quamash), which grows in wetland and prairie ecosystems. The harvested bulbs are traditionally pit roasted, converting the indigestible inulin into carbohydrates of high nutritional value. Access to local natural areas has been granted for Native American community members to gather camas, yet pesticide and herbicide application as land management practices have created uncertainty regarding the safety of ingesting the camas bulbs. The Native American community gathered camas bulbs in November 2015 for analysis, which resulted in glyphosate (pesticide) and triclopyr (herbicide). There are various factors which may influence the uptake of pesticide and herbicide residuals in camas which need further investigation, including pesticide/herbicide application details (date, location), preferential uptake of pesticide/herbicides in camas among the present plant community, the impact of pit roasting bulbs on residuals, and traditional land management practices like prescribed burning. Utilizing TEK and science to ensure safe access to cultural resources is paramount in preserving our cultures and enhancing the value of indigenous perspectives on land management practices and policies.

  10. Safe sex

    Science.gov (United States)

    ... sex; Sexually transmitted - safe sex; GC - safe sex; Gonorrhea - safe sex; Herpes - safe sex; HIV - safe sex; ... contact. STIs include: Chlamydia Genital herpes Genital warts Gonorrhea Hepatitis HIV HPV Syphilis STIs are also called ...

  11. lands

    Directory of Open Access Journals (Sweden)

    A.T. O'Geen

    2015-04-01

    Full Text Available Groundwater pumping chronically exceeds natural recharge in many agricultural regions in California. A common method of recharging groundwater — when surface water is available — is to deliberately flood an open area, allowing water to percolate into an aquifer. However, open land suitable for this type of recharge is scarce. Flooding agricultural land during fallow or dormant periods has the potential to increase groundwater recharge substantially, but this approach has not been well studied. Using data on soils, topography and crop type, we developed a spatially explicit index of the suitability for groundwater recharge of land in all agricultural regions in California. We identified 3.6 million acres of agricultural land statewide as having Excellent or Good potential for groundwater recharge. The index provides preliminary guidance about the locations where groundwater recharge on agricultural land is likely to be feasible. A variety of institutional, infrastructure and other issues must also be addressed before this practice can be implemented widely.

  12. Global opportunities in land and water use while staying within the safe (and just) operating space: quantifications of interactions and tradeoffs

    Science.gov (United States)

    Gerten, Dieter; Jägermeyr, Jonas; Heck, Vera

    2016-04-01

    Staying within the safe and just operating space as defined by multiple planetary boundaries will be a major challenge especially in view of anticipated future increases in food demand, the potential need for balancing climate change (e.g. through terrestrial carbon dioxide removal) and its impacts, and the water and land demand associated with these goals and measures. This presentation will show simulation results from a comprehensive model-based study on the global potentials of diverse crop management options considered as opportunities to stay within the planetary boundaries for human freshwater use and land-system change. The quantified on-farm options include rainwater harvesting, soil conservation and more efficient irrigation, all of which are designed to use neither more water nor more land for agriculture than is presently the case. Results show that irrigation efficiency improvements could save substantial amounts of water in many river basins (globally 48% of non-productive water consumption in an ambitious scenario), and if rerouted to irrigate neighbouring rainfed systems, could at the same time boost kilocalorie production by 26% globally. Low-tech solutions for small-scale farmers on water-limited croplands show the potential to increase rainfed yields to a similar extent. In combination, such ambitious yet achievable integrated water management strategies could increase global kcal production by 41% and close the water-related yield gap by 62%. Global climate change would have adverse effects on crop yields in many regions, but the improvements in water management quantified here could buffer such effects to a significant degree. Thus, a substantial amount of anticipated future needs for food production could be fulfilled without further approaching / transgressing planetary boundaries. In addition, it will be shown how large-scale biomass plantations for the purpose of terrestrial CO2 removal (climate engineering, potentially implemented should

  13. Disain dan Implementasi Kontrol PID Model Reference Adaptive Control untuk Automatic Safe Landing pada Pesawat UAV Quadcopter

    Directory of Open Access Journals (Sweden)

    Teddy Sudewo

    2012-09-01

    Full Text Available Pada fase penerbangan quadcopter, fase landing (pendaratan merupakan fase paling kritis, dimana resiko terjadi kecelakaan paling besar. Permasalahan tersebut muncul karena adanya beberapa kendala, seperti kendala pada struktur rangka pesawat yang kecil, peningkatan beban pada sayap pesawat serta pengaruh angin sehingga menyebabkan pesawat tidak stabil. Pada penelitian tugas akhir ini, didesain suatu sistem kontrol pada UAV quadcopter menggunakan kontrol PID dengan Model Reference Adaptive Control (MRAC. Sistem pengendalian berbasis MRAC menawarkan beberapa kelebihan untuk mengatasi karakteristik plant non-linear salah satunya quadcopter. MRAC merupakan kontrol adaptif dimana performansi keluaran sistem (proses akan mengikuti performansi keluaran model referensinya. Pada tugas akhir ini, model referensi sudah ditentukan diawal dan spesifikasinya tetap sehingga dapat langsung didisain mekanisme adaptasi dari MRAC. Parameter proses θ (a1,a2,b0,b1 diestimasi menggunakan metode Extended Least Square, parameter proses tersebut akan mentuning parameter kontroler (k0,k1,k2,k3 sehingga menghasilkan sinyal kontrol PID. Hasil pengujian menunjukkan bahwa ketika terjadi perubahan parameter pada plant, kontroler mampu memperbaiki respon agar tetap dapat mengikuti model referensinya dan dalam mengatasi gangguan metode adaptasi MRAC memiliki kemampuan yang baik dilihat dari waktu yang dibutuhkan yang relatif singkat.

  14. Land

    CSIR Research Space (South Africa)

    Audouin, M

    2007-01-01

    Full Text Available the factors contributing to desertification and practical measures necessary to combat desertification and mitigate the effect of drought. The priority issues reported on in this chapter are soil and veld degradation, and the loss of land for agricultural use....

  15. Spacecraft operations

    CERN Document Server

    Sellmaier, Florian; Schmidhuber, Michael

    2015-01-01

    The book describes the basic concepts of spaceflight operations, for both, human and unmanned missions. The basic subsystems of a space vehicle are explained in dedicated chapters, the relationship of spacecraft design and the very unique space environment are laid out. Flight dynamics are taught as well as ground segment requirements. Mission operations are divided into preparation including management aspects, execution and planning. Deep space missions and space robotic operations are included as special cases. The book is based on a course held at the German Space Operation Center (GSOC).

  16. How safe is safe?

    International Nuclear Information System (INIS)

    Hughes, C.F.; Flood, M.

    1996-01-01

    60 and 70 degree convexo-concave valve. Nine hundred and one valves were implanted in Australia. Twelve strut fractures were reported. Two other patients have been explanted and have demonstrated 'single leg separation'. This particular problem was only investigated when two patients died of a fractured valve in the same hospital on the same day. A retrospective study of all known patients in Australia has shown poor follow up, lack of knowledge and indeed lack of interest in device failure modes. Consequently, the Australian and New Zealand Heart Valve Registry was established to track all implanted valves and to notify physicians of any new information. This is perhaps the first device-specific register in Australia. The safety of individual devices is often not known by manufacturers, regulators and clinicians alike. No follow up is available and large volume long term studies are yet to be implemented for the majority of devices. Without such studies and without mandatory problem reporting, the relative safety of medical devices will continue to be measured by banner headlines, sensational TV 'grabs' and protracted law suits. At present, only schemes such as the Problem Reporting Scheme can tell us (albeit vaguely) 'how safe is safe'

  17. Spacecraft radiator systems

    Science.gov (United States)

    Anderson, Grant A. (Inventor)

    2012-01-01

    A spacecraft radiator system designed to provide structural support to the spacecraft. Structural support is provided by the geometric "crescent" form of the panels of the spacecraft radiator. This integration of radiator and structural support provides spacecraft with a semi-monocoque design.

  18. Aqueous extracts of a Mars analogue regolith that mimics the Phoenix landing site do not inhibit spore germination or growth of model spacecraft contaminants Bacillus subtilis 168 and Bacillus pumilus SAFR-032

    Science.gov (United States)

    Nicholson, Wayne L.; McCoy, Lashelle E.; Kerney, Krystal R.; Ming, Douglas W.; Golden, D. C.; Schuerger, Andrew C.

    2012-08-01

    Because Mars is a primary target for life detection and habitability assessment missions, its exploration is also by necessity a Planetary Protection issue. The recent finding of significant levels of perchlorate (ClO4-) in regolith sampled from the Phoenix landing site raises the question of its potential biotoxicity to putative indigenous martian life, microbial forward contaminants from Earth, or future human visitors. To address this issue, an analogue regolith was constructed based on regolith chemistry data from the Phoenix landing site. A Mars Aqueous Regolith Extract (MARE) was prepared from the Phoenix analogue regolith and analyzed by ion chromatography. The MARE contained (mg/L) the cations Na+ (1411 ± 181), Mg2+ (1051 ± 160), Ca2+ (832 ± 125), and K+ (261 ± 29), and the anions SO42-(5911±993), ClO4-(5316±1767), Cl(171±25) and F- (2.0 ± 0.4). Nitrogen-containing species NO3-(773±113) and NO2-(6.9±2.3) were also present as a result of regolith preparation procedures, but their relevance to Mars is at present unknown. The MARE was tested for potential toxic effects on two model spacecraft contaminants, the spore-forming bacteria Bacillus subtilis strain 168 and Bacillus pumilus strain SAFR-032. In B. subtilis, spore germination and initial vegetative growth (up to ˜5 h) was not inhibited in a rich complex medium prepared with the MARE, but growth after 5 h was significantly suppressed in medium prepared using the MARE. Both B. subtilis and B. pumilus exhibited significantly higher rates of spore germination and growth in the MARE vs. DW with no additions (likely due to endogenous spore nutrients), but germination and growth was further stimulated by addition of glucose and a combination of buffered inorganic salts (K2HPO4, KH2PO4, (NH4)2SO4, and MgSO4). The data indicate that the aqueous environment in the regolith from the Phoenix landing site containing high levels of perchlorate does not pose a significant barrier to growth of putative

  19. Safe Haven.

    Science.gov (United States)

    Bush, Gail

    2003-01-01

    Discusses school libraries as safe havens for teenagers and considers elements that foster that atmosphere, including the physical environment, lack of judgments, familiarity, leisure, and a welcoming nature. Focuses on the importance of relationships, and taking the time to listen to teens and encourage them. (LRW)

  20. Simulation and Spacecraft Design: Engineering Mars Landings.

    Science.gov (United States)

    Conway, Erik M

    2015-10-01

    A key issue in history of technology that has received little attention is the use of simulation in engineering design. This article explores the use of both mechanical and numerical simulation in the design of the Mars atmospheric entry phases of the Viking and Mars Pathfinder missions to argue that engineers used both kinds of simulation to develop knowledge of their designs' likely behavior in the poorly known environment of Mars. Each kind of simulation could be used as a warrant of the other's fidelity, in an iterative process of knowledge construction.

  1. Safe Grid

    Science.gov (United States)

    Chow, Edward T.; Stewart, Helen; Korsmeyer, David (Technical Monitor)

    2003-01-01

    The biggest users of GRID technologies came from the science and technology communities. These consist of government, industry and academia (national and international). The NASA GRID is moving into a higher technology readiness level (TRL) today; and as a joint effort among these leaders within government, academia, and industry, the NASA GRID plans to extend availability to enable scientists and engineers across these geographical boundaries collaborate to solve important problems facing the world in the 21 st century. In order to enable NASA programs and missions to use IPG resources for program and mission design, the IPG capabilities needs to be accessible from inside the NASA center networks. However, because different NASA centers maintain different security domains, the GRID penetration across different firewalls is a concern for center security people. This is the reason why some IPG resources are been separated from the NASA center network. Also, because of the center network security and ITAR concerns, the NASA IPG resource owner may not have full control over who can access remotely from outside the NASA center. In order to obtain organizational approval for secured remote access, the IPG infrastructure needs to be adapted to work with the NASA business process. Improvements need to be made before the IPG can be used for NASA program and mission development. The Secured Advanced Federated Environment (SAFE) technology is designed to provide federated security across NASA center and NASA partner's security domains. Instead of one giant center firewall which can be difficult to modify for different GRID applications, the SAFE "micro security domain" provide large number of professionally managed "micro firewalls" that can allow NASA centers to accept remote IPG access without the worry of damaging other center resources. The SAFE policy-driven capability-based federated security mechanism can enable joint organizational and resource owner approved remote

  2. Spacecraft Spin Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides the capability to correct unbalances of spacecraft by using dynamic measurement techniques and static/coupled measurements to provide products of...

  3. Sun Safe Mode Controller Design for LADEE

    Science.gov (United States)

    Fusco, Jesse C.; Swei, Sean S. M.; Nakamura, Robert H.

    2015-01-01

    This paper presents the development of sun safe controllers which are designed to keep the spacecraft power positive and thermally balanced in the event an anomaly is detected. Employed by NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE), the controllers utilize the measured sun vector and the spacecraft body rates for feedback control. To improve the accuracy of sun vector estimation, the least square minimization approach is applied to process the sensor data, which is proven to be effective and accurate. To validate the controllers, the LADEE spacecraft model engaging the sun safe mode was first simulated and then compared with the actual LADEE orbital fight data. The results demonstrated the applicability of the proposed sun safe controllers.

  4. Spacecraft Charge Monitor

    Science.gov (United States)

    Goembel, L.

    2003-12-01

    We are currently developing a flight prototype Spacecraft Charge Monitor (SCM) with support from NASA's Small Business Innovation Research (SBIR) program. The device will use a recently proposed high energy-resolution electron spectroscopic technique to determine spacecraft floating potential. The inspiration for the technique came from data collected by the Atmosphere Explorer (AE) satellites in the 1970s. The data available from the AE satellites indicate that the SCM may be able to determine spacecraft floating potential to within 0.1 V under certain conditions. Such accurate measurement of spacecraft charge could be used to correct biases in space plasma measurements. The device may also be able to measure spacecraft floating potential in the solar wind and in orbit around other planets.

  5. Radiation Effects on Spacecraft Structural Materials

    International Nuclear Information System (INIS)

    Wang, Jy-An J.; Ellis, Ronald J.; Hunter, Hamilton T.; Singleterry, Robert C. Jr.

    2002-01-01

    Research is being conducted to develop an integrated technology for the prediction of aging behavior for space structural materials during service. This research will utilize state-of-the-art radiation experimental apparatus and analysis, updated codes and databases, and integrated mechanical and radiation testing techniques to investigate the suitability of numerous current and potential spacecraft structural materials. Also included are the effects on structural materials in surface modules and planetary landing craft, with or without fission power supplies. Spacecraft structural materials would also be in hostile radiation environments on the surface of the moon and planets without appreciable atmospheres and moons around planets with large intense magnetic and radiation fields (such as the Jovian moons). The effects of extreme temperature cycles in such locations compounds the effects of radiation on structural materials. This paper describes the integrated methodology in detail and shows that it will provide a significant technological advance for designing advanced spacecraft. This methodology will also allow for the development of advanced spacecraft materials through the understanding of the underlying mechanisms of material degradation in the space radiation environment. Thus, this technology holds a promise for revolutionary advances in material damage prediction and protection of space structural components as, for example, in the development of guidelines for managing surveillance programs regarding the integrity of spacecraft components, and the safety of the aging spacecraft. (authors)

  6. Automating Trend Analysis for Spacecraft Constellations

    Science.gov (United States)

    Davis, George; Cooter, Miranda; Updike, Clark; Carey, Everett; Mackey, Jennifer; Rykowski, Timothy; Powers, Edward I. (Technical Monitor)

    2001-01-01

    Spacecraft trend analysis is a vital mission operations function performed by satellite controllers and engineers, who perform detailed analyses of engineering telemetry data to diagnose subsystem faults and to detect trends that may potentially lead to degraded subsystem performance or failure in the future. It is this latter function that is of greatest importance, for careful trending can often predict or detect events that may lead to a spacecraft's entry into safe-hold. Early prediction and detection of such events could result in the avoidance of, or rapid return to service from, spacecraft safing, which not only results in reduced recovery costs but also in a higher overall level of service for the satellite system. Contemporary spacecraft trending activities are manually intensive and are primarily performed diagnostically after a fault occurs, rather than proactively to predict its occurrence. They also tend to rely on information systems and software that are oudated when compared to current technologies. When coupled with the fact that flight operations teams often have limited resources, proactive trending opportunities are limited, and detailed trend analysis is often reserved for critical responses to safe holds or other on-orbit events such as maneuvers. While the contemporary trend analysis approach has sufficed for current single-spacecraft operations, it will be unfeasible for NASA's planned and proposed space science constellations. Missions such as the Dynamics, Reconnection and Configuration Observatory (DRACO), for example, are planning to launch as many as 100 'nanospacecraft' to form a homogenous constellation. A simple extrapolation of resources and manpower based on single-spacecraft operations suggests that trending for such a large spacecraft fleet will be unmanageable, unwieldy, and cost-prohibitive. It is therefore imperative that an approach to automating the spacecraft trend analysis function be studied, developed, and applied to

  7. Fractionated Spacecraft Architectures Seeding Study

    National Research Council Canada - National Science Library

    Mathieu, Charlotte; Weigel, Annalisa

    2006-01-01

    .... Models were developed from a customer-centric perspective to assess different fractionated spacecraft architectures relative to traditional spacecraft architectures using multi-attribute analysis...

  8. Spacecraft momentum control systems

    CERN Document Server

    Leve, Frederick A; Peck, Mason A

    2015-01-01

    The goal of this book is to serve both as a practical technical reference and a resource for gaining a fuller understanding of the state of the art of spacecraft momentum control systems, specifically looking at control moment gyroscopes (CMGs). As a result, the subject matter includes theory, technology, and systems engineering. The authors combine material on system-level architecture of spacecraft that feature momentum-control systems with material about the momentum-control hardware and software. This also encompasses material on the theoretical and algorithmic approaches to the control of space vehicles with CMGs. In essence, CMGs are the attitude-control actuators that make contemporary highly agile spacecraft possible. The rise of commercial Earth imaging, the advances in privately built spacecraft (including small satellites), and the growing popularity of the subject matter in academic circles over the past decade argues that now is the time for an in-depth treatment of the topic. CMGs are augmented ...

  9. Spacecraft Material Outgassing Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This compilation of outgassing data of materials intended for spacecraft use were obtained at the Goddard Space Flight Center (GSFC), utilizing equipment developed...

  10. Spacecraft Fire Safety Demonstration

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Spacecraft Fire Safety Demonstration project is to develop and conduct large-scale fire safety experiments on an International Space Station...

  11. Quick spacecraft charging primer

    International Nuclear Information System (INIS)

    Larsen, Brian Arthur

    2014-01-01

    This is a presentation in PDF format which is a quick spacecraft charging primer, meant to be used for program training. It goes into detail about charging physics, RBSP examples, and how to identify charging.

  12. Safe cycling!

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    The HSE Unit will be running a cycling safety campaign at the entrances to CERN's restaurants on 14, 15 and 16 May. Pop along to see if they can persuade you to get back in the saddle!   With summer on its way, you might feel like getting your bike out of winter storage. Well, the HSE Unit has come up with some original ideas to remind you of some of the most basic safety rules. This year, the prevention campaign will be focussing on three themes: "Cyclists and their equipment", "The bicycle on the road", and "Other road users". This is an opportunity to think about the condition of your bike as well as how you ride it. From 14 to 16 May, representatives of the Swiss Office of Accident Prevention and the Touring Club Suisse will join members of the HSE Unit at the entrances to CERN's restaurants to give you advice on safe cycling (see box). They will also be organising three activity stands where you can test your knowle...

  13. Deployable Brake for Spacecraft

    Science.gov (United States)

    Rausch, J. R.; Maloney, J. W.

    1987-01-01

    Aerodynamic shield that could be opened and closed proposed. Report presents concepts for deployable aerodynamic brake. Brake used by spacecraft returning from high orbit to low orbit around Earth. Spacecraft makes grazing passes through atmosphere to slow down by drag of brake. Brake flexible shield made of woven metal or ceramic withstanding high temperatures created by air friction. Stored until needed, then deployed by set of struts.

  14. Optical Landing Hazard Sensor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Visidyne proposes to investigate an active optical 3D imaging LADAR as the sensor for an automated Landing Hazard Avoidance system for spacecraft landing on the Moon...

  15. How safe is safe enough?

    International Nuclear Information System (INIS)

    Desnoyers, B.; Chanzy, Y.

    2004-01-01

    The IAEA Regulations for the Safe Transport of Radioactive Material, were historically established with the objective to reduce the probability that persons be exposed to unacceptable doses due to normal operation or accident situations during transport of radioactive material. Based on the International Basic Safety Standards for Protection against Ionizing Radiation (BSS), the definition, which was adopted for an unacceptable dose for an accident situation, is the excess of the maximum dose limits permissible in a single year for the occupational exposure of a worker in the BSS. Concerning the severity of accident situations, it has always be clearly stated that the objective of the tests for demonstrating ability to withstand accident conditions of transport was not to cover every accident condition, but solely most of them. The last available evaluations regarding the rate of accidents which are covered by the standardised accident conditions of transport defined in the IAEA Regulations give a range of about 80%, plus or minus 15% which depends on transport mode and studies. Consequently, slight variations in the capabilities of the packages to meet the specified performance would probably not have significant consequences on the protection level in case of accident. In the assessment of the compliance with the regulations, the tendency of experts, taking advantage of the enhanced performances of computer calculation codes, is to ask more and more calculations, with more and more accuracy, leading to more and more restrictions. Consequently, cost and delay are considerably increased without any evidence of an equivalent effect on the level of protection. This paper will initiate a reflection on the general objectives and principles when implementing the Regulations, in such a way that demonstrations remain cost effective, taking into account evolution of the techniques and a high level of safety

  16. Internet Technology on Spacecraft

    Science.gov (United States)

    Rash, James; Parise, Ron; Hogie, Keith; Criscuolo, Ed; Langston, Jim; Powers, Edward I. (Technical Monitor)

    2000-01-01

    The Operating Missions as Nodes on the Internet (OMNI) project has shown that Internet technology works in space missions through a demonstration using the UoSAT-12 spacecraft. An Internet Protocol (IP) stack was installed on the orbiting UoSAT-12 spacecraft and tests were run to demonstrate Internet connectivity and measure performance. This also forms the basis for demonstrating subsequent scenarios. This approach provides capabilities heretofore either too expensive or simply not feasible such as reconfiguration on orbit. The OMNI project recognized the need to reduce the risk perceived by mission managers and did this with a multi-phase strategy. In the initial phase, the concepts were implemented in a prototype system that includes space similar components communicating over the TDRS (space network) and the terrestrial Internet. The demonstration system includes a simulated spacecraft with sample instruments. Over 25 demonstrations have been given to mission and project managers, National Aeronautics and Space Administration (NASA), Department of Defense (DoD), contractor technologists and other decisions makers, This initial phase reached a high point with an OMNI demonstration given from a booth at the Johnson Space Center (JSC) Inspection Day 99 exhibition. The proof to mission managers is provided during this second phase with year 2000 accomplishments: testing the use of Internet technologies onboard an actual spacecraft. This was done with a series of tests performed using the UoSAT-12 spacecraft. This spacecraft was reconfigured on orbit at very low cost. The total period between concept and the first tests was only 6 months! On board software was modified to add an IP stack to support basic IP communications. Also added was support for ping, traceroute and network timing protocol (NTP) tests. These tests show that basic Internet functionality can be used onboard spacecraft. The performance of data was measured to show no degradation from current

  17. Mechanical Design of Spacecraft

    Science.gov (United States)

    1962-01-01

    In the spring of 1962, engineers from the Engineering Mechanics Division of the Jet Propulsion Laboratory gave a series of lectures on spacecraft design at the Engineering Design seminars conducted at the California Institute of Technology. Several of these lectures were subsequently given at Stanford University as part of the Space Technology seminar series sponsored by the Department of Aeronautics and Astronautics. Presented here are notes taken from these lectures. The lectures were conceived with the intent of providing the audience with a glimpse of the activities of a few mechanical engineers who are involved in designing, building, and testing spacecraft. Engineering courses generally consist of heavily idealized problems in order to allow the more efficient teaching of mathematical technique. Students, therefore, receive a somewhat limited exposure to actual engineering problems, which are typified by more unknowns than equations. For this reason it was considered valuable to demonstrate some of the problems faced by spacecraft designers, the processes used to arrive at solutions, and the interactions between the engineer and the remainder of the organization in which he is constrained to operate. These lecture notes are not so much a compilation of sophisticated techniques of analysis as they are a collection of examples of spacecraft hardware and associated problems. They will be of interest not so much to the experienced spacecraft designer as to those who wonder what part the mechanical engineer plays in an effort such as the exploration of space.

  18. Spacecraft Attitude Determination

    DEFF Research Database (Denmark)

    Bak, Thomas

    This thesis describes the development of an attitude determination system for spacecraft based only on magnetic field measurements. The need for such system is motivated by the increased demands for inexpensive, lightweight solutions for small spacecraft. These spacecraft demands full attitude...... determination based on simple, reliable sensors. Meeting these objectives with a single vector magnetometer is difficult and requires temporal fusion of data in order to avoid local observability problems. In order to guaranteed globally nonsingular solutions, quaternions are generally the preferred attitude...... is a detailed study of the influence of approximations in the modeling of the system. The quantitative effects of errors in the process and noise statistics are discussed in detail. The third contribution is the introduction of these methods to the attitude determination on-board the Ørsted satellite...

  19. The viking landing sites: selection and certification.

    Science.gov (United States)

    Masursky, H; Crabill, N L

    1976-08-27

    During the past several years the Viking project developed plans to use Viking orbiter instruments and Earth-based radar to certify the suitability of the landing sites selected as the safest and most scientifically rewarding using Mariner 9 data. During June and July 1976, the Earth-based radar and orbital spacecraft observations of some of the prime and backup sites were completed. The results of these combined observations indicated that the Viking 1 prime landing area in the Chryse region of Mars is geologically varied and possibly more hazardous than expected, and was not certifiable as a site for the Viking 1 landing. Consequently, the site certification effort had to be drastically modified and lengthened to search for a site that might be safe enough to attempt to land. The selected site considered at 47.5 degrees W, 22.4 degrees N represented a compromise between desirable characteristics observed with visual images and those inferred from Earth-based radar. It lies in the Chryse region about 900 kilometers northwest of the original site. Viking 1 landed successfully at this site on 20 July 1976.

  20. Revamping Spacecraft Operational Intelligence

    Science.gov (United States)

    Hwang, Victor

    2012-01-01

    The EPOXI flight mission has been testing a new commercial system, Splunk, which employs data mining techniques to organize and present spacecraft telemetry data in a high-level manner. By abstracting away data-source specific details, Splunk unifies arbitrary data formats into one uniform system. This not only reduces the time and effort for retrieving relevant data, but it also increases operational visibility by allowing a spacecraft team to correlate data across many different sources. Splunk's scalable architecture coupled with its graphing modules also provide a solid toolset for generating data visualizations and building real-time applications such as browser-based telemetry displays.

  1. Dips spacecraft integration issues

    International Nuclear Information System (INIS)

    Determan, W.R.; Harty, R.B.

    1988-01-01

    The Department of Energy, in cooperation with the Department of Defense, has recently initiated the dynamic isotope power system (DIPS) demonstration program. DIPS is designed to provide 1 to 10 kW of electrical power for future military spacecraft. One of the near-term missions considered as a potential application for DIPS was the boost surveillance and tracking system (BSTS). A brief review and summary of the reasons behind a selection of DIPS for BSTS-type missions is presented. Many of these are directly related to spacecraft integration issues; these issues will be reviewed in the areas of system safety, operations, survivability, reliability, and autonomy

  2. Addressing EO-1 Spacecraft Pulsed Plasma Thruster EMI Concerns

    Science.gov (United States)

    Zakrzwski, C. M.; Davis, Mitch; Sarmiento, Charles; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    The Pulsed Plasma Thruster (PPT) Experiment on the Earth Observing One (EO-1) spacecraft has been designed to demonstrate the capability of a new generation PPT to perform spacecraft attitude control. Results from PPT unit level radiated electromagnetic interference (EMI) tests led to concerns about potential interference problems with other spacecraft subsystems. Initial plans to address these concerns included firing the PPT at the spacecraft level both in atmosphere, with special ground support equipment. and in vacuum. During the spacecraft level tests, additional concerns where raised about potential harm to the Advanced Land Imager (ALI). The inadequacy of standard radiated emission test protocol to address pulsed electromagnetic discharges and the lack of resources required to perform compatibility tests between the PPT and an ALI test unit led to changes in the spacecraft level validation plan. An EMI shield box for the PPT was constructed and validated for spacecraft level ambient testing. Spacecraft level vacuum tests of the PPT were deleted. Implementation of the shield box allowed for successful spacecraft level testing of the PPT while eliminating any risk to the ALI. The ALI demonstration will precede the PPT demonstration to eliminate any possible risk of damage of ALI from PPT operation.

  3. Living Lands

    DEFF Research Database (Denmark)

    Christensen, Suna Møller

    2015-01-01

    , hunters attended to questions like safe-journeying on ice or the role of natural surroundings in children’s education, in ways revealing a relational perception of ‘nature’ and dissolving culture-nature dualisms. Hunters’ experiences in living the land afforded children a dwelling position from which...... to grow with the features of the land. Framed this way, ‘nature’ was regarded as part of the social world. I suggest that learning among Arctic hunters is social and twofold. First, we can learn how human-environment relations influence individual life trajectories. Secondly, ‘nature’ as part...

  4. Space environment studies for the SZ-4 spacecraft

    International Nuclear Information System (INIS)

    Ye Zonghai

    2004-01-01

    The space environment, especially the solar-terrestrial space environment, has close bearings on mankind's astronautical activities. An overview is presented of the space environment and safeguard services on the 'SZ' series of spacecraft, with special reference to the SZ-4 spacecraft. These include monitoring of the space environment on SZ-4, studies on its distribution, variation and effects on astronautical performance, as well as space environment forecasts for safe launching, normal operation and safe return of SZ-4. Current progress both in China and overseas is covered

  5. Special Semaphore Scheme for UHF Spacecraft Communications

    Science.gov (United States)

    Butman, Stanley; Satorius, Edgar; Ilott, Peter

    2006-01-01

    A semaphore scheme has been devised to satisfy a requirement to enable ultrahigh- frequency (UHF) radio communication between a spacecraft descending from orbit to a landing on Mars and a spacecraft, in orbit about Mars, that relays communications between Earth and the lander spacecraft. There are also two subsidiary requirements: (1) to use UHF transceivers, built and qualified for operation aboard the spacecraft that operate with residual-carrier binary phase-shift-keying (BPSK) modulation at a selectable data rate of 8, 32, 128, or 256 kb/s; and (2) to enable low-rate signaling even when received signals become so weak as to prevent communication at the minimum BPSK rate of 8 kHz. The scheme involves exploitation of Manchester encoding, which is used in conjunction with residual-carrier modulation to aid the carrier-tracking loop. By choosing various sequences of 1s, 0s, or 1s alternating with 0s to be fed to the residual-carrier modulator, one would cause the modulator to generate sidebands at a fundamental frequency of 4 or 8 kHz and harmonics thereof. These sidebands would constitute the desired semaphores. In reception, the semaphores would be detected by a software demodulator.

  6. Managing Cassini Safe Mode Attitude at Saturn

    Science.gov (United States)

    Burk, Thomas A.

    2010-01-01

    The Cassini spacecraft was launched on October 15, 1997 and arrived at Saturn on June 30, 2004. It has performed detailed observations and remote sensing of Saturn, its rings, and its satellites since that time. In the event safe mode interrupts normal orbital operations, Cassini has flight software fault protection algorithms to detect, isolate, and recover to a thermally safe and commandable attitude and then wait for further instructions from the ground. But the Saturn environment is complex, and safety hazards change depending on where Cassini is in its orbital trajectory around Saturn. Selecting an appropriate safe mode attitude that insures safe operation in the Saturn environment, including keeping the star tracker field of view clear of bright bodies, while maintaining a quiescent, commandable attitude, is a significant challenge. This paper discusses the Cassini safe table management strategy and the key criteria that must be considered, especially during low altitude flybys of Titan, in deciding what spacecraft attitude should be used in the event of safe mode.

  7. Spacecraft Thermal Management

    Science.gov (United States)

    Hurlbert, Kathryn Miller

    2009-01-01

    In the 21st century, the National Aeronautics and Space Administration (NASA), the Russian Federal Space Agency, the National Space Agency of Ukraine, the China National Space Administration, and many other organizations representing spacefaring nations shall continue or newly implement robust space programs. Additionally, business corporations are pursuing commercialization of space for enabling space tourism and capital business ventures. Future space missions are likely to include orbiting satellites, orbiting platforms, space stations, interplanetary vehicles, planetary surface missions, and planetary research probes. Many of these missions will include humans to conduct research for scientific and terrestrial benefits and for space tourism, and this century will therefore establish a permanent human presence beyond Earth s confines. Other missions will not include humans, but will be autonomous (e.g., satellites, robotic exploration), and will also serve to support the goals of exploring space and providing benefits to Earth s populace. This section focuses on thermal management systems for human space exploration, although the guiding principles can be applied to unmanned space vehicles as well. All spacecraft require a thermal management system to maintain a tolerable thermal environment for the spacecraft crew and/or equipment. The requirements for human rating and the specified controlled temperature range (approximately 275 K - 310 K) for crewed spacecraft are unique, and key design criteria stem from overall vehicle and operational/programatic considerations. These criteria include high reliability, low mass, minimal power requirements, low development and operational costs, and high confidence for mission success and safety. This section describes the four major subsystems for crewed spacecraft thermal management systems, and design considerations for each. Additionally, some examples of specialized or advanced thermal system technologies are presented

  8. Traveling Safely with Medicines

    Science.gov (United States)

    ... Medications Safely My Medicine List How to Administer Traveling Safely with Medicines Planes, trains, cars – even boats ... your trip, ask your pharmacist about how to travel safely with your medicines. Make sure that you ...

  9. Spacecraft navigation at Mars using earth-based and in situ radio tracking techniques

    Science.gov (United States)

    Thurman, S. W.; Edwards, C. D.; Kahn, R. D.; Vijayaraghavan, A.; Hastrup, R. C.; Cesarone, R. J.

    1992-08-01

    A survey of earth-based and in situ radiometric data types and results from a number of studies investigating potential radio navigation performance for spacecraft approaching/orbiting Mars and for landed spacecraft and rovers on the surface of Mars are presented. The performance of Doppler, ranging and interferometry earth-based data types involving single or multiple spacecraft is addressed. This evaluation is conducted with that of in situ data types, such as Doppler and ranging measurements between two spacecraft near Mars, or between a spacecraft and one or more surface radio beacons.

  10. The Stardust spacecraft arrives at KSC

    Science.gov (United States)

    1998-01-01

    After arrival at the Shuttle Landing Facility in the early morning hours, the crated Stardust spacecraft waits to be unloaded from the aircraft. Built by Lockheed Martin Astronautics near Denver, Colo., for the Jet Propulsion Laboratory (JPL) NASA, the spacecraft Stardust will use a unique medium called aerogel to capture comet particles flying off the nucleus of comet Wild 2 in January 2004, plus collect interstellar dust for later analysis. Stardust will be launched aboard a Boeing Delta 7426 rocket from Complex 17, Cape Canaveral Air Station, targeted for Feb. 6, 1999. The collected samples will return to Earth in a re- entry capsule to be jettisoned from Stardust as it swings by in January 2006.

  11. Multiple spacecraft configuration designs for coordinated flight missions

    Science.gov (United States)

    Fumenti, Federico; Theil, Stephan

    2018-06-01

    Coordinated flight allows the replacement of a single monolithic spacecraft with multiple smaller ones, based on the principle of distributed systems. According to the mission objectives and to ensure a safe relative motion, constraints on the relative distances need to be satisfied. Initially, differential perturbations are limited by proper orbit design. Then, the induced differential drifts can be properly handled through corrective maneuvers. In this work, several designs are surveyed, defining the initial configuration of a group of spacecraft while counteracting the differential perturbations. For each of the investigated designs, focus is placed upon the number of deployable spacecraft and on the possibility to ensure safe relative motion through station keeping of the initial configuration, with particular attention to the required Δ V budget and the constraints violations.

  12. Guidance and control of swarms of spacecraft

    Science.gov (United States)

    Morgan, Daniel James

    using computer simulations. The swarm-keeping problem can be solved by placing the spacecraft on J2-invariant relative orbits, which prevent collisions and minimize the drift of the swarm over hundreds of orbits using a single burn. These orbits are achieved by energy matching the spacecraft to the reference orbit. Additionally, these conditions can be repeatedly applied to minimize the drift of the swarm when atmospheric drag has a large effect (orbits with an altitude under 500 km). The swarm reconfiguration is achieved using two steps: trajectory optimization and assignment. The trajectory optimization problem can be written as a nonlinear, optimal control problem. This optimal control problem is discretized, decoupled, and convexified so that the individual femtosats can efficiently solve the optimization. Sequential convex programming is used to generate the control sequences and trajectories required to safely and efficiently transfer a spacecraft from one position to another. The sequence of trajectories is shown to converge to a Karush-Kuhn-Tucker point of the nonconvex problem. In the case where many of the spacecraft are interchangeable, a variable-swarm, distributed auction algorithm is used to determine the assignment of spacecraft to target positions. This auction algorithm requires only local communication and all of the bidding parameters are stored locally. The assignment generated using this auction algorithm is shown to be near optimal and to converge in a finite number of bids. Additionally, the bidding process is used to modify the number of targets used in the assignment so that the reconfiguration can be achieved even when there is a disconnected communication network or a significant loss of agents. Once the assignment is achieved, the trajectory optimization can be run using the terminal positions determined by the auction algorithm. To implement these algorithms in real time a model predictive control formulation is used. Model predictive

  13. Spacecraft exploration of asteroids

    International Nuclear Information System (INIS)

    Veverka, J.; Langevin, Y.; Farquhar, R.; Fulchignoni, M.

    1989-01-01

    After two decades of spacecraft exploration, we still await the first direct investigation of an asteroid. This paper describes how a growing international interest in the solar system's more primitive bodies should remedy this. Plans are under way in Europe for a dedicated asteroid mission (Vesta) which will include multiple flybys with in situ penetrator studies. Possible targets include 4 Vesta, 8 Flora and 46 Hestia; launch its scheduled for 1994 or 1996. In the United States, NASA plans include flybys of asteroids en route to outer solar system targets

  14. Spacecraft rendezvous and docking

    DEFF Research Database (Denmark)

    Jørgensen, John Leif

    1999-01-01

    The phenomenons and problems encountered when a rendezvous manoeuvre, and possible docking, of two spacecrafts has to be performed, have been the topic for numerous studies, and, details of a variety of scenarios has been analysed. So far, all solutions that has been brought into realization has...... been based entirely on direct human supervision and control. This paper describes a vision-based system and methodology, that autonomously generates accurate guidance information that may assist a human operator in performing the tasks associated with both the rendezvous and docking navigation...

  15. Toward autonomous spacecraft

    Science.gov (United States)

    Fogel, L. J.; Calabrese, P. G.; Walsh, M. J.; Owens, A. J.

    1982-01-01

    Ways in which autonomous behavior of spacecraft can be extended to treat situations wherein a closed loop control by a human may not be appropriate or even possible are explored. Predictive models that minimize mean least squared error and arbitrary cost functions are discussed. A methodology for extracting cyclic components for an arbitrary environment with respect to usual and arbitrary criteria is developed. An approach to prediction and control based on evolutionary programming is outlined. A computer program capable of predicting time series is presented. A design of a control system for a robotic dense with partially unknown physical properties is presented.

  16. Osiris-REx Spacecraft Current Status and Forward Plans

    Science.gov (United States)

    Messenger, Scott; Lauretta, Dante S.; Connolly, Harold C., Jr.

    2017-01-01

    The NASA New Frontiers OSIRIS-REx spacecraft executed a flawless launch on September 8, 2016 to begin its 23-month journey to near-Earth asteroid (101955). The primary objective of the OSIRIS-REx mission is to collect and return to Earth a pristine sample of regolith from the asteroid surface. The sampling event will occur after a two-year period of remote sensing that will ensure a high probability of successful sampling of a region on the asteroid surface having high science value and within well-defined geological context. The OSIRIS-REx instrument payload includes three high-resolution cameras (OCAMS), a visible and near-infrared spectrometer (OVIRS), a thermal imaging spectrometer (OTES), an X-ray imaging spectrometer (REXIS), and a laser altimeter (OLA). As the spacecraft follows its nominal outbound-cruise trajectory, the propulsion, power, communications, and science instruments have undergone basic functional tests, with no major issues. Outbound cruise science investigations include a search for Earth Trojan asteroids as the spacecraft approaches the Sun-Earth L4 Lagrangian point in February 2017. Additional instrument checkouts and calibrations will be carried out during the Earth gravity assist maneuver in September 2017. During the Earth-moon flyby, visual and spectral images will be acquired to validate instrument command sequences planned for Bennu remote sensing. The asteroid Bennu remote sensing campaign will yield high resolution maps of the temperature and thermal inertia, distributions of major minerals and concentrations of organic matter across the asteroid surface. A high resolution 3d shape model including local surface slopes and a high-resolution gravity field will also be determined. Together, these data will be used to generate four separate maps that will be used to select the sampling site(s). The Safety map will identify hazardous and safe operational regions on the asteroid surface. The Deliverability map will quantify the accuracy

  17. Safe Kids Worldwide

    Science.gov (United States)

    ... Blog Videos Newsletter facebook twitter instagram pinterest gplus youtube Search Menu Why It Matters Who We Are What We Do Find Your Safe Kids Safe Kids Day Main menu Keeping All Kids Safe Safety Tips Get Involved 4 Star Charity Donate Text Burns and Scalds 4 tips ...

  18. Small Spacecraft for Planetary Science

    Science.gov (United States)

    Baker, John; Castillo-Rogez, Julie; Bousquet, Pierre-W.; Vane, Gregg; Komarek, Tomas; Klesh, Andrew

    2016-07-01

    As planetary science continues to explore new and remote regions of the Solar system with comprehensive and more sophisticated payloads, small spacecraft offer the possibility for focused and more affordable science investigations. These small spacecraft or micro spacecraft (attitude control and determination, capable computer and data handling, and navigation are being met by technologies currently under development to be flown on CubeSats within the next five years. This paper will discuss how micro spacecraft offer an attractive alternative to accomplish specific science and technology goals and what relevant technologies are needed for these these types of spacecraft. Acknowledgements: Part of this work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology under contract to NASA. Government sponsorship acknowledged.

  19. Printed Spacecraft Separation System

    Energy Technology Data Exchange (ETDEWEB)

    Dehoff, Ryan R [ORNL; Holmans, Walter [Planetary Systems Corporation

    2016-10-01

    In this project Planetary Systems Corporation proposed utilizing additive manufacturing (3D printing) to manufacture a titanium spacecraft separation system for commercial and US government customers to realize a 90% reduction in the cost and energy. These savings were demonstrated via “printing-in” many of the parts and sub-assemblies into one part, thus greatly reducing the labor associated with design, procurement, assembly and calibration of mechanisms. Planetary Systems Corporation redesigned several of the components of the separation system based on additive manufacturing principles including geometric flexibility and the ability to fabricate complex designs, ability to combine multiple parts of an assembly into a single component, and the ability to optimize design for specific mechanical property targets. Shock absorption was specifically targeted and requirements were established to attenuate damage to the Lightband system from shock of initiation. Planetary Systems Corporation redesigned components based on these requirements and sent the designs to Oak Ridge National Laboratory to be printed. ORNL printed the parts using the Arcam electron beam melting technology based on the desire for the parts to be fabricated from Ti-6Al-4V based on the weight and mechanical performance of the material. A second set of components was fabricated from stainless steel material on the Renishaw laser powder bed technology due to the improved geometric accuracy, surface finish, and wear resistance of the material. Planetary Systems Corporation evaluated these components and determined that 3D printing is potentially a viable method for achieving significant cost and savings metrics.

  20. Spectra and spacecraft

    Science.gov (United States)

    Moroz, V. I.

    2001-02-01

    In June 1999, Dr. Regis Courtin, Associate Editor of PSS, suggested that I write an article for the new section of this journal: "Planetary Pioneers". I hesitated , but decided to try. One of the reasons for my doubts was my primitive English, so I owe the reader an apology for this in advance. Writing took me much more time than I supposed initially, I have stopped and again returned to manuscript many times. My professional life may be divided into three main phases: pioneering work in ground-based IR astronomy with an emphasis on planetary spectroscopy (1955-1970), studies of the planets with spacecraft (1970-1989), and attempts to proceed with this work in difficult times. I moved ahead using the known method of trials and errors as most of us do. In fact, only a small percentage of efforts led to some important results, a sort of dry residue. I will try to describe below how has it been in my case: what may be estimated as the most important, how I came to this, what was around, etc.

  1. "Same Room, Safe Place".

    Science.gov (United States)

    Keene Woods, Nikki

    2017-04-01

    There are many different professional stances on safe sleep and then there is the reality of caring for a newborn. There is a debate among professionals regarding safe sleep recommendations. The continum of recommendations vary from the American Academy of Pediatrics (AAP) Safe Sleep Guidelines to the bed-sharing recommendations from the Mother-Baby Behavioral Sleep Laboratory. The lack of consistent and uniform safe sleep recommendations from health professionals has been confusing for families but has more recently raised a real professional ethical dilemma. Despite years of focused safe sleep community education and interventions, sleep-related infant deaths are on the rise in many communities. This commentary calls for a united safe sleep message from all health professionals to improve health for mothers and infants most at-risk, "Same Room, Safe Place."

  2. Curiosity's Autonomous Surface Safing Behavior Design

    Science.gov (United States)

    Neilson, Tracy A.; Manning, Robert M.

    2013-01-01

    The safing routines on all robotic deep-space vehicles are designed to put the vehicle in a power and thermally safe configuration, enabling communication with the mission operators on Earth. Achieving this goal is made a little more difficult on Curiosity because the power requirements for the core avionics and the telecommunication equipment exceed the capability of the single power source, the Multi-Mission Radioisotope Thermoelectric Generator. This drove the system design to create an operational mode, called "sleep mode", where the vehicle turns off most of the loads in order to charge the two Li-ion batteries. The system must keep the vehicle safe from over-heat and under-heat conditions, battery cell failures, under-voltage conditions, and clock failures, both while the computer is running and while the system is sleeping. The other goal of a safing routine is to communicate. On most spacecraft, this simply involves turning on the receiver and transmitter continuously. For Curiosity, Earth is above the horizon only a part of the day for direct communication to the Earth, and the orbiter overpass opportunities only occur a few times a day. The design must robustly place the Rover in a communicable condition at the correct time. This paper discusses Curiosity's autonomous safing behavior and describes how the vehicle remains power and thermally safe while sleeping, as well as a description of how the Rover communicates with the orbiters and Earth at specific times.

  3. Optimal trajectories of aircraft and spacecraft

    Science.gov (United States)

    Miele, A.

    1990-01-01

    Work done on algorithms for the numerical solutions of optimal control problems and their application to the computation of optimal flight trajectories of aircraft and spacecraft is summarized. General considerations on calculus of variations, optimal control, numerical algorithms, and applications of these algorithms to real-world problems are presented. The sequential gradient-restoration algorithm (SGRA) is examined for the numerical solution of optimal control problems of the Bolza type. Both the primal formulation and the dual formulation are discussed. Aircraft trajectories, in particular, the application of the dual sequential gradient-restoration algorithm (DSGRA) to the determination of optimal flight trajectories in the presence of windshear are described. Both take-off trajectories and abort landing trajectories are discussed. Take-off trajectories are optimized by minimizing the peak deviation of the absolute path inclination from a reference value. Abort landing trajectories are optimized by minimizing the peak drop of altitude from a reference value. Abort landing trajectories are optimized by minimizing the peak drop of altitude from a reference value. The survival capability of an aircraft in a severe windshear is discussed, and the optimal trajectories are found to be superior to both constant pitch trajectories and maximum angle of attack trajectories. Spacecraft trajectories, in particular, the application of the primal sequential gradient-restoration algorithm (PSGRA) to the determination of optimal flight trajectories for aeroassisted orbital transfer are examined. Both the coplanar case and the noncoplanar case are discussed within the frame of three problems: minimization of the total characteristic velocity; minimization of the time integral of the square of the path inclination; and minimization of the peak heating rate. The solution of the second problem is called nearly-grazing solution, and its merits are pointed out as a useful

  4. Spacecraft Charging and the Microwave Anisotropy Probe Spacecraft

    Science.gov (United States)

    Timothy, VanSant J.; Neergaard, Linda F.

    1998-01-01

    The Microwave Anisotropy Probe (MAP), a MIDEX mission built in partnership between Princeton University and the NASA Goddard Space Flight Center (GSFC), will study the cosmic microwave background. It will be inserted into a highly elliptical earth orbit for several weeks and then use a lunar gravity assist to orbit around the second Lagrangian point (L2), 1.5 million kilometers, anti-sunward from the earth. The charging environment for the phasing loops and at L2 was evaluated. There is a limited set of data for L2; the GEOTAIL spacecraft measured relatively low spacecraft potentials (approx. 50 V maximum) near L2. The main area of concern for charging on the MAP spacecraft is the well-established threat posed by the "geosynchronous region" between 6-10 Re. The launch in the autumn of 2000 will coincide with the falling of the solar maximum, a period when the likelihood of a substorm is higher than usual. The likelihood of a substorm at that time has been roughly estimated to be on the order of 20% for a typical MAP mission profile. Because of the possibility of spacecraft charging, a requirement for conductive spacecraft surfaces was established early in the program. Subsequent NASCAP/GEO analyses for the MAP spacecraft demonstrated that a significant portion of the sunlit surface (solar cell cover glass and sunshade) could have nonconductive surfaces without significantly raising differential charging. The need for conductive materials on surfaces continually in eclipse has also been reinforced by NASCAP analyses.

  5. Safe havens in Europe

    DEFF Research Database (Denmark)

    Paldam, Martin

    2013-01-01

    Eleven safe havens exist in Europe providing offshore banking and low taxes. Ten of these states are very small while Switzerland is moderately small. All 11 countries are richer than their large neighbors. It is shown that causality is from small to safe haven to wealth, and that theoretically...... equilibriums are likely to exist where a certain regulation is substantially lower in a small country than in its big neighbor. This generates a large capital inflow to the safe havens. The pool of funds that may reach the safe havens is shown to be huge. It is far in excess of the absorptive capacity...... of the safe havens, but it still explains, why they are rich. Microstates offer a veil of anonymity to funds passing through, and Switzerland offers safe storage of funds....

  6. Spacecraft Environmental Interactions Technology, 1983

    Science.gov (United States)

    1985-01-01

    State of the art of environment interactions dealing with low-Earth-orbit plasmas; high-voltage systems; spacecraft charging; materials effects; and direction of future programs are contained in over 50 papers.

  7. Gravity Probe B spacecraft description

    International Nuclear Information System (INIS)

    Bennett, Norman R; Burns, Kevin; Katz, Russell; Kirschenbaum, Jon; Mason, Gary; Shehata, Shawky

    2015-01-01

    The Gravity Probe B spacecraft, developed, integrated, and tested by Lockheed Missiles and Space Company and later Lockheed Martin Corporation, consisted of structures, mechanisms, command and data handling, attitude and translation control, electrical power, thermal control, flight software, and communications. When integrated with the payload elements, the integrated system became the space vehicle. Key requirements shaping the design of the spacecraft were: (1) the tight mission timeline (17 months, 9 days of on-orbit operation), (2) precise attitude and translational control, (3) thermal protection of science hardware, (4) minimizing aerodynamic, magnetic, and eddy current effects, and (5) the need to provide a robust, low risk spacecraft. The spacecraft met all mission requirements, as demonstrated by dewar lifetime meeting specification, positive power and thermal margins, precision attitude control and drag-free performance, reliable communications, and the collection of more than 97% of the available science data. (paper)

  8. Intelligent spacecraft module

    Science.gov (United States)

    Oungrinis, Konstantinos-Alketas; Liapi, Marianthi; Kelesidi, Anna; Gargalis, Leonidas; Telo, Marinela; Ntzoufras, Sotiris; Paschidi, Mariana

    2014-12-01

    The paper presents the development of an on-going research project that focuses on a human-centered design approach to habitable spacecraft modules. It focuses on the technical requirements and proposes approaches on how to achieve a spatial arrangement of the interior that addresses sufficiently the functional, physiological and psychosocial needs of the people living and working in such confined spaces that entail long-term environmental threats to human health and performance. Since the research perspective examines the issue from a qualitative point of view, it is based on establishing specific relationships between the built environment and its users, targeting people's bodily and psychological comfort as a measure toward a successful mission. This research has two basic branches, one examining the context of the system's operation and behavior and the other in the direction of identifying, experimenting and formulating the environment that successfully performs according to the desired context. The latter aspect is researched upon the construction of a scaled-model on which we run series of tests to identify the materiality, the geometry and the electronic infrastructure required. Guided by the principles of sensponsive architecture, the ISM research project explores the application of the necessary spatial arrangement and behavior for a user-centered, functional interior where the appropriate intelligent systems are based upon the existing mechanical and chemical support ones featured on space today, and especially on the ISS. The problem is set according to the characteristics presented at the Mars500 project, regarding the living quarters of six crew-members, along with their hygiene, leisure and eating areas. Transformable design techniques introduce spatial economy, adjustable zoning and increased efficiency within the interior, securing at the same time precise spatial orientation and character at any given time. The sensponsive configuration is

  9. A Sampling Based Approach to Spacecraft Autonomous Maneuvering with Safety Specifications

    Science.gov (United States)

    Starek, Joseph A.; Barbee, Brent W.; Pavone, Marco

    2015-01-01

    This paper presents a methods for safe spacecraft autonomous maneuvering that leverages robotic motion-planning techniques to spacecraft control. Specifically the scenario we consider is an in-plan rendezvous of a chaser spacecraft in proximity to a target spacecraft at the origin of the Clohessy Wiltshire Hill frame. The trajectory for the chaser spacecraft is generated in a receding horizon fashion by executing a sampling based robotic motion planning algorithm name Fast Marching Trees (FMT) which efficiently grows a tree of trajectories over a set of probabillistically drawn samples in the state space. To enforce safety the tree is only grown over actively safe samples for which there exists a one-burn collision avoidance maneuver that circularizes the spacecraft orbit along a collision-free coasting arc and that can be executed under potential thrusters failures. The overall approach establishes a provably correct framework for the systematic encoding of safety specifications into the spacecraft trajectory generations process and appears amenable to real time implementation on orbit. Simulation results are presented for a two-fault tolerant spacecraft during autonomous approach to a single client in Low Earth Orbit.

  10. Are Detox Diets Safe?

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Are Detox Diets Safe? KidsHealth / For Teens / Are Detox Diets ... seguras las dietas de desintoxicación? What Is a Detox Diet? The name sounds reassuring — everyone knows that ...

  11. Chernobyl new safe confinement

    International Nuclear Information System (INIS)

    Dodd, L.

    2011-01-01

    The author presents the new safe confinement that will be commissioned at Unit 4 of the Chernobyl NPP in 2015. The confinement will ensure that Chernobyl Unit 4 will be placed in an environmentally safe condition for at least next 100 years. The article highlights the current work status, future perspectives and the feasibility of confinement concept [ru

  12. Asymptotically Safe Dark Matter

    DEFF Research Database (Denmark)

    Sannino, Francesco; Shoemaker, Ian M.

    2015-01-01

    We introduce a new paradigm for dark matter (DM) interactions in which the interaction strength is asymptotically safe. In models of this type, the coupling strength is small at low energies but increases at higher energies, and asymptotically approaches a finite constant value. The resulting...... searches are the primary ways to constrain or discover asymptotically safe dark matter....

  13. Artist concept of Galileo spacecraft

    Science.gov (United States)

    1988-01-01

    Galileo spacecraft is illustrated in artist concept. Gallileo, named for the Italian astronomer, physicist and mathematician who is credited with construction of the first complete, practical telescope in 1620, will make detailed studies of Jupiter. A cooperative program with the Federal Republic of Germany the Galileo mission will amplify information acquired by two Voyager spacecraft in their brief flybys. Galileo is a two-element system that includes a Jupiter-orbiting observatory and an entry probe. Jet Propulsion Laboratory (JPL) is Galileo project manager and builder of the main spacecraft. Ames Research Center (ARC) has responsibility for the entry probe, which was built by Hughes Aircraft Company and General Electric. Galileo will be deployed from the payload bay (PLB) of Atlantis, Orbiter Vehicle (OV) 104, during mission STS-34.

  14. Safe Sleep for Babies

    Science.gov (United States)

    ... 5 MB] Read the MMWR Science Clips Safe Sleep for Babies Eliminating hazards Recommend on Facebook Tweet ... Page Problem Every year, there are thousands of sleep-related deaths among babies. View large image and ...

  15. Safe operating envelope

    Energy Technology Data Exchange (ETDEWEB)

    Oliva, N [Ontario Hydro, Toronto, ON (Canada)

    1997-12-01

    Safe Operating Envelope is described representing: The outer bound of plant conditions within which day-to-day plant operation must be maintained in order to comply with regulatory requirements, associated safety design criteria and corporate nuclear safety goals. Figs.

  16. The first safe country

    Directory of Open Access Journals (Sweden)

    Raffaela Puggioni

    2012-06-01

    Full Text Available The Dublin II Regulation makes the first safe country of refuge solelyresponsible for refugees and asylum seekers. In the case of Italy, thefirst responsible country has not been acting responsibly.

  17. Buying & Using Medicine Safely

    Science.gov (United States)

    ... Reducers Safe Daily Use of Aspirin Medication Health Fraud Resources for You FDA Consumer Updates (Drugs) Page ... feeds Follow FDA on Twitter Follow FDA on Facebook View FDA videos on YouTube View FDA photos ...

  18. Karate: Keep It Safe.

    Science.gov (United States)

    Jordan, David

    1981-01-01

    Safety guidelines for each phase of a karate practice session are presented to provide an accident-free and safe environment for teaching karate in a physical education or traditional karate training program. (JMF)

  19. Safe operating envelope

    International Nuclear Information System (INIS)

    Oliva, N.

    1997-01-01

    Safe Operating Envelope is described representing: The outer bound of plant conditions within which day-to-day plant operation must be maintained in order to comply with regulatory requirements, associated safety design criteria and corporate nuclear safety goals. Figs

  20. Safe driving for teens

    Science.gov (United States)

    Driving and teenagers; Teens and safe driving; Automobile safety - teenage drivers ... months before taking friends as passengers. Teenage-related driving deaths occur more often in certain conditions. OTHER SAFETY TIPS FOR TEENS Reckless driving is still a ...

  1. Removing Hair Safely

    Science.gov (United States)

    ... For Consumers Home For Consumers Consumer Updates Removing Hair Safely Share Tweet Linkedin Pin it More sharing ... related to common methods of hair removal. Laser Hair Removal In this method, a laser destroys hair ...

  2. Medications: Using Them Safely

    Science.gov (United States)

    ... to Safely Give Ibuprofen Childproofing and Preventing Household Accidents Medicines for Diabetes Complementary and Alternative Medicine How Do Pain Relievers Work? What Medicines Are and What They Do Medicines ...

  3. DroidSafe

    Science.gov (United States)

    2016-12-01

    Massachusetts Avenue, Build E19-750 Cambridge , MA 02139-4307 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS...Activity objects illustrating the challenges of points-to and information flow analysis...measure how many malicious flows Droid- Safe was able to detect). As these results illustrate , DroidSafe implements an analysis of unprece- dented

  4. Safe biodegradable fluorescent particles

    Science.gov (United States)

    Martin, Sue I [Berkeley, CA; Fergenson, David P [Alamo, CA; Srivastava, Abneesh [Santa Clara, CA; Bogan, Michael J [Dublin, CA; Riot, Vincent J [Oakland, CA; Frank, Matthias [Oakland, CA

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  5. Training for spacecraft technical analysts

    Science.gov (United States)

    Ayres, Thomas J.; Bryant, Larry

    1989-01-01

    Deep space missions such as Voyager rely upon a large team of expert analysts who monitor activity in the various engineering subsystems of the spacecraft and plan operations. Senior teammembers generally come from the spacecraft designers, and new analysts receive on-the-job training. Neither of these methods will suffice for the creation of a new team in the middle of a mission, which may be the situation during the Magellan mission. New approaches are recommended, including electronic documentation, explicit cognitive modeling, and coached practice with archived data.

  6. Guidance, navigation, and control subsystem for the EOS-AM spacecraft

    Science.gov (United States)

    Linder, David M.; Tolek, Joseph T.; Lombardo, John

    1992-01-01

    This paper presents the preliminary design of the Guidance, Navigation, and Control (GN&C) subsystem for the EOS-AM spacecraft and specifically focuses on the GN&C Normal Mode design. First, a brief description of the EOS-AM science mission, instruments, and system-level spacecraft design is provided. Next, an overview of the GN&C subsystem functional and performance requirements, hardware, and operating modes is presented. Then, the GN&C Normal Mode attitude determination, attitude control, and navigation systems are detailed. Finally, descriptions of the spacecraft's overall jitter performance and Safe Mode are provided.

  7. Results from active spacecraft potential control on the Geotail spacecraft

    International Nuclear Information System (INIS)

    Schmidt, R.; Arends, H.; Pedersen, A.

    1995-01-01

    A low and actively controlled electrostatic potential on the outer surfaces of a scientific spacecraft is very important for accurate measurements of cold plasma electrons and ions and the DC to low-frequency electric field. The Japanese/NASA Geotail spacecraft carriers as part of its scientific payload a novel ion emitter for active control of the electrostatic potential on the surface of the spacecraft. The aim of the ion emitter is to reduce the positive surface potential which is normally encountered in the outer magnetosphere when the spacecraft is sunlit. Ion emission clamps the surface potential to near the ambient plasma potential. Without emission control, Geotail has encountered plasma conditions in the lobes of the magnetotail which resulted in surface potentials of up to about +70 V. The ion emitter proves to be able to discharge the outer surfaces of the spacecraft and is capable of keeping the surface potential stable at about +2 V. This potential is measured with respect to one of the electric field probes which are current biased and thus kept at a potential slightly above the ambient plasma potential. The instrument uses the liquid metal field ion emission principle to emit indium ions. The ion beam energy is about 6 keV and the typical total emission current amounts to about 15 μA. Neither variations in the ambient plasma conditions nor operation of two electron emitters on Geotail produce significant variations of the controlled surface potential as long as the resulting electron emission currents remain much smaller than the ion emission current. Typical results of the active potential control are shown, demonstrating the surface potential reduction and its stability over time. 25 refs., 5 figs

  8. Charging in the environment of large spacecraft

    International Nuclear Information System (INIS)

    Lai, S.T.

    1993-01-01

    This paper discusses some potential problems of spacecraft charging as a result of interactions between a large spacecraft, such as the Space Station, and its environment. Induced electric field, due to VXB effect, may be important for large spacecraft at low earth orbits. Differential charging, due to different properties of surface materials, may be significant when the spacecraft is partly in sunshine and partly in shadow. Triple-root potential jump condition may occur because of differential charging. Sudden onset of severe differential charging may occur when an electron or ion beam is emitted from the spacecraft. The beam may partially return to the ''hot spots'' on the spacecraft. Wake effects, due to blocking of ambient ion trajectories, may result in an undesirable negative potential region in the vicinity of a large spacecraft. Outgassing and exhaust may form a significant spacecraft induced environment; ionization may occur. Spacecraft charging and discharging may affect the electronic components on board

  9. Airborne particulate matter in spacecraft

    Science.gov (United States)

    1988-01-01

    Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

  10. Safe Disposal of Pesticides

    Science.gov (United States)

    ... Toxics Environmental Information by Location Greener Living Health Land, Waste, and Cleanup Lead Mold Pesticides Radon Science ... or www.earth911.com . Think before disposing of extra pesticides and containers: Never reuse empty pesticide containers. ...

  11. Small Spacecraft Constellation Concept for Mars Atmospheric Radio Occultations

    Science.gov (United States)

    Asmar, S. W.; Mannucci, A. J.; Ao, C. O.; Kobayashi, M. M.; Lazio, J.; Marinan, A.; Massone, G.; McCandless, S. E.; Preston, R. A.; Seubert, J.; Williamson, W.

    2017-12-01

    First demonstrated in 1965 when Mariner IV flew by Mars and determined the salient features of its atmosphere, radio occultation experiments have been carried out on numerous planetary missions with great discoveries. These experiments utilize the now classic configuration of a signal from a single planetary spacecraft to Earth receiving stations, where the science data are acquired. The Earth science community advanced the technique to utilizing a constellation of spacecraft with the radio occultation links between the spacecraft, enabled by the infrastructure of the Global Positioning System. With the advent of small and less costly spacecraft, such as planetary CubeSats and other variations, such as the anticipated innovative Mars Cube One mission, crosslinks among small spacecraft can be used to study other planets in the near future. Advantages of this type of experiment include significantly greater geographical coverage, which could reach global coverage over a few weeks with a small number of spacecraft. Repeatability of the global coverage can lead to examining temperature-pressure profiles and ionospheric electron density profiles, on daily, seasonal, annual, or other time scales of interest. The higher signal-to-noise ratio for inter-satellite links, compared to a link to Earth, decreases the design demands on the instrumentation (smaller antennas and transmitters, etc.). After an actual Mars crosslink demonstration, this concept has been in development using Mars as a possible target. Scientific objectives, delivery methods, operational scenarios and end-to-end configuration have been documented. Science objectives include determining the state and variability of the lower Martian atmosphere, which has been an identified as a high priority objective by the Mars Exploration Program Analysis Group, particularly as it relates to entry, descent, and landing and ascent for future crewed and robotic missions. This paper will present the latest research on the

  12. Safeness of radiological machinery

    International Nuclear Information System (INIS)

    Yokoyama, Shun

    1979-01-01

    The human factors affecting the safeness of radiological machinery, which are often very big and complicated machines, are described from the stand point of handling. 20 to 50% of the troubles on equipments seem to be caused by men. This percentage will become even higher in highly developed equipments. Human factors have a great influence on the safeness of radiological equipments. As the human factors, there are sensory factors and knowledge factors as well as psychological factors, and the combination of these factors causes mishandling and danger. Medical services at present are divided in various areas, and consist of the teamwork of the people in various professions. Good human relationship, education and control are highly required to secure the safeness. (Kobatake, H.)

  13. LANDSAFE: LANDING SITE RISK ANALYSIS SOFTWARE FRAMEWORK

    Directory of Open Access Journals (Sweden)

    R. Schmidt

    2012-08-01

    Full Text Available The European Space Agency (ESA is planning a Lunar Lander mission in the 2018 timeframe that will demonstrate precise soft landing at the polar regions of the Moon. To ensure a safe and successful landing a careful risk analysis has to be carried out. This is comprised of identifying favorable target areas and evaluating the surface conditions in these areas. Features like craters, boulders, steep slopes, rough surfaces and shadow areas have to be identified in order to assess the risk associated to a landing site in terms of a successful touchdown and subsequent surface operation of the lander. In addition, global illumination conditions at the landing site have to be simulated and analyzed. The Landing Site Risk Analysis software framework (LandSAfe is a system for the analysis, selection and certification of safe landing sites on the lunar surface. LandSAfe generates several data products including high resolution digital terrain models (DTMs, hazard maps, illumination maps, temperature maps and surface reflectance maps which assist the user in evaluating potential landing site candidates. This paper presents the LandSAfe system and describes the methods and products of the different modules. For one candidate landing site on the rim of Shackleton crater at the south pole of the Moon a high resolution DTM is showcased.

  14. Reduced Gravity Landing Research Vehicle Design

    OpenAIRE

    Isert, Sarah

    2011-01-01

    Human and robotic missions beyond low earth orbit (LEO) are key components of NASA's currently emerging strategy for space exploration. These missions will inevitably include humancrewed lunar and planetary surface landings. Trips to near-earth asteroids are also in the incipient planning stages. A permanent presence on the surface of an extra terrestrial body like Mars or the Moon will require many landings by both human-crewed and robotic spacecraft. Planetary and lunar surface landings ...

  15. Model predictive control for spacecraft rendezvous in elliptical orbit

    Science.gov (United States)

    Li, Peng; Zhu, Zheng H.

    2018-05-01

    This paper studies the control of spacecraft rendezvous with attitude stable or spinning targets in an elliptical orbit. The linearized Tschauner-Hempel equation is used to describe the motion of spacecraft and the problem is formulated by model predictive control. The control objective is to maximize control accuracy and smoothness simultaneously to avoid unexpected change or overshoot of trajectory for safe rendezvous. It is achieved by minimizing the weighted summations of control errors and increments. The effects of two sets of horizons (control and predictive horizons) in the model predictive control are examined in terms of fuel consumption, rendezvous time and computational effort. The numerical results show the proposed control strategy is effective.

  16. Keeping Food Safe

    Centers for Disease Control (CDC) Podcasts

    2009-05-27

    This CDC Kidtastics podcast discusses things kids and parents can do to help prevent illness by keeping food safe.  Created: 5/27/2009 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 5/27/2009.

  17. Effective and Safe Ships

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Amdahl, Jørgen; Rutgersson, Olle

    1996-01-01

    A Joint Nordic Research project "Effecive and Safe Ships" is presented. The project is aiming to develop methods and tools for quantitative evaluation fo ship safety. This report is the report of the preliminary phase where the plan for the main project is developed. The objectives of the project...

  18. Are EU Banks Safe?

    NARCIS (Netherlands)

    R.J. Theissen (Roel)

    2013-01-01

    markdownabstract__Abstract__ What exactly are the rules banks are subject to, and are they fit for purpose? These are the two questions addressed in this book ‘Are EU banks safe?’ and its descriptive companion book ‘EU banking supervision’. The full rulebook on banks is difficult to find

  19. Quick Spacecraft Thermal Analysis Tool, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — For spacecraft design and development teams concerned with cost and schedule, the Quick Spacecraft Thermal Analysis Tool (QuickSTAT) is an innovative software suite...

  20. The safe home project.

    Science.gov (United States)

    Arphorn, Sara; Jiraniratisai, Sopaphan; Rungtakul, Rungsri; Phutta, Nikom

    2011-12-01

    The Thai Health Promotion Foundation supported the Improvement of Quality of Life of Informal Workers project in Ban Luang District, Amphur Photaram, Ratchaburi Province. There were many informal workers in Ban Luang District. Sweet-crispy fish producers in Ban Luang were the largest group among the sweet-crispy fish producers in Thailand. This project was aimed at improving living and working conditions of informal workers, with a focus on the sweet-crispy fish group. Good practices of improved living and working conditions were used to help informal workers build safe, healthy and productive work environments. These informal workers often worked in substandard conditions and were exposed to various hazards in the working area. These hazards included risk of exposure to hot work environment, ergonomics-related injuries, chemical hazards, electrical hazards etc. Ergonomics problems were commonly in the sweet-crispy fish group. Unnatural postures such as prolonged sitting were performed dominantly. One hundred and fifty informal workers participated in this project. Occupational health volunteers were selected to encourage occupational health and safety in four groups of informal workers in 2009. The occupational health volunteers trained in 2008 were farmers, beauty salon workers and doll makers. The occupational health and safety knowledge is extended to a new informal worker group: sweet-crispy fish producer, in 2009. The occupational health and safety training for sweet-crispy fish group is conducted by occupational health volunteers. The occupational health volunteers increased their skills and knowledge assist in to make safe home and safe community through participatory oriented training. The improvement of living and working condition is conducted by using a modified WISH, Work Improvement for Safe Home, checklist. The plans of improvement were recorded. The informal workers showed improvement mostly on material handling and storage. The safe uses and safe

  1. Multiple spacecraft Michelson stellar interferometer

    Science.gov (United States)

    Stachnik, R. V.; Arnold, D.; Melroy, P.; Mccormack, E. F.; Gezari, D. Y.

    1984-01-01

    Results of an orbital analysis and performance assessment of SAMSI (Spacecraft Array for Michelson Spatial Interferometry) are presented. The device considered includes two one-meter telescopes in orbits which are identical except for slightly different inclinations; the telescopes achieve separations as large as 10 km and relay starlight to a central station which has a one-meter optical delay line in one interferometer arm. It is shown that a 1000-km altitude, zero mean inclination orbit affords natural scanning of the 10-km baseline with departures from optical pathlength equality which are well within the corrective capacity of the optical delay line. Electric propulsion is completely adequate to provide the required spacecraft motions, principally those needed for repointing. Resolution of 0.00001 arcsec and magnitude limits of 15 to 20 are achievable.

  2. Spacecraft Tests of General Relativity

    Science.gov (United States)

    Anderson, John D.

    1997-01-01

    Current spacecraft tests of general relativity depend on coherent radio tracking referred to atomic frequency standards at the ground stations. This paper addresses the possibility of improved tests using essentially the current system, but with the added possibility of a space-borne atomic clock. Outside of the obvious measurement of the gravitational frequency shift of the spacecraft clock, a successor to the suborbital flight of a Scout D rocket in 1976 (GP-A Project), other metric tests would benefit most directly by a possible improved sensitivity for the reduced coherent data. For purposes of illustration, two possible missions are discussed. The first is a highly eccentric Earth orbiter, and the second a solar-conjunction experiment to measure the Shapiro time delay using coherent Doppler data instead of the conventional ranging modulation.

  3. Attitude Fusion Techniques for Spacecraft

    DEFF Research Database (Denmark)

    Bjarnø, Jonas Bækby

    Spacecraft platform instability constitutes one of the most significant limiting factors in hyperacuity pointing and tracking applications, yet the demand for accurate, timely and reliable attitude information is ever increasing. The PhD research project described within this dissertation has...... served to investigate the solution space for augmenting the DTU μASC stellar reference sensor with a miniature Inertial Reference Unit (IRU), thereby obtaining improved bandwidth, accuracy and overall operational robustness of the fused instrument. Present day attitude determination requirements are met...... of the instrument, and affecting operations during agile and complex spacecraft attitude maneuvers. As such, there exists a theoretical foundation for augmenting the high frequency performance of the μASC instrument, by harnessing the complementary nature of optical stellar reference and inertial sensor technology...

  4. Autonomous spacecraft rendezvous and docking

    Science.gov (United States)

    Tietz, J. C.; Almand, B. J.

    A storyboard display is presented which summarizes work done recently in design and simulation of autonomous video rendezvous and docking systems for spacecraft. This display includes: photographs of the simulation hardware, plots of chase vehicle trajectories from simulations, pictures of the docking aid including image processing interpretations, and drawings of the control system strategy. Viewgraph-style sheets on the display bulletin board summarize the simulation objectives, benefits, special considerations, approach, and results.

  5. Nonlinearity-induced spacecraft tumbling

    International Nuclear Information System (INIS)

    Amos, A.K.

    1994-01-01

    An existing tumbling criterion for the dumbbell satellite in planar librations is reexamined and modified to reflect a recently identified tumbling mode associated with the horizontal attitude orientation. It is shown that for any initial attitude there exists a critical angular rate below which the motion is oscillatory and harmonic and beyond which a continuous tumbling will ensue. If the angular rate is at the critical value the spacecraft drifts towards the horizontal attitude from which a spontaneous periodic tumbling occurs

  6. Worldwide Spacecraft Crew Hatch History

    Science.gov (United States)

    Johnson, Gary

    2009-01-01

    The JSC Flight Safety Office has developed this compilation of historical information on spacecraft crew hatches to assist the Safety Tech Authority in the evaluation and analysis of worldwide spacecraft crew hatch design and performance. The document is prepared by SAIC s Gary Johnson, former NASA JSC S&MA Associate Director for Technical. Mr. Johnson s previous experience brings expert knowledge to assess the relevancy of data presented. He has experience with six (6) of the NASA spacecraft programs that are covered in this document: Apollo; Skylab; Apollo Soyuz Test Project (ASTP), Space Shuttle, ISS and the Shuttle/Mir Program. Mr. Johnson is also intimately familiar with the JSC Design and Procedures Standard, JPR 8080.5, having been one of its original developers. The observations and findings are presented first by country and organized within each country section by program in chronological order of emergence. A host of reference sources used to augment the personal observations and comments of the author are named within the text and/or listed in the reference section of this document. Careful attention to the selection and inclusion of photos, drawings and diagrams is used to give visual association and clarity to the topic areas examined.

  7. Integrating standard operating procedures with spacecraft automation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Spacecraft automation has the potential to assist crew members and spacecraft operators in managing spacecraft systems during extended space missions. Automation can...

  8. Large Field Photogrammetry Techniques in Aircraft and Spacecraft Impact Testing

    Science.gov (United States)

    Littell, Justin D.

    2010-01-01

    The Landing and Impact Research Facility (LandIR) at NASA Langley Research Center is a 240 ft. high A-frame structure which is used for full-scale crash testing of aircraft and rotorcraft vehicles. Because the LandIR provides a unique capability to introduce impact velocities in the forward and vertical directions, it is also serving as the facility for landing tests on full-scale and sub-scale Orion spacecraft mass simulators. Recently, a three-dimensional photogrammetry system was acquired to assist with the gathering of vehicle flight data before, throughout and after the impact. This data provides the basis for the post-test analysis and data reduction. Experimental setups for pendulum swing tests on vehicles having both forward and vertical velocities can extend to 50 x 50 x 50 foot cubes, while weather, vehicle geometry, and other constraints make each experimental setup unique to each test. This paper will discuss the specific calibration techniques for large fields of views, camera and lens selection, data processing, as well as best practice techniques learned from using the large field of view photogrammetry on a multitude of crash and landing test scenarios unique to the LandIR.

  9. Guidance and Navigation for Rendezvous and Proximity Operations with a Non-Cooperative Spacecraft at Geosynchronous Orbit

    Science.gov (United States)

    Barbee, Brent William; Carpenter, J. Russell; Heatwole, Scott; Markley, F. Landis; Moreau, Michael; Naasz, Bo J.; VanEepoel, John

    2010-01-01

    The feasibility and benefits of various spacecraft servicing concepts are currently being assessed, and all require that the servicer spacecraft perform rendezvous, proximity, and capture operations with the target spacecraft to be serviced. Many high-value spacecraft, which would be logical targets for servicing from an economic point of view, are located in geosynchronous orbit, a regime in which autonomous rendezvous and capture operations are not commonplace. Furthermore, existing GEO spacecraft were not designed to be serviced. Most do not have cooperative relative navigation sensors or docking features, and some servicing applications, such as de-orbiting of a non-functional spacecraft, entail rendezvous and capture with a spacecraft that may be non-functional or un-controlled. Several of these challenges have been explored via the design of a notional mission in which a nonfunctional satellite in geosynchronous orbit is captured by a servicer spacecraft and boosted into super-synchronous orbit for safe disposal. A strategy for autonomous rendezvous, proximity operations, and capture is developed, and the Orbit Determination Toolbox (ODTBX) is used to perform a relative navigation simulation to assess the feasibility of performing the rendezvous using a combination of angles-only and range measurements. Additionally, a method for designing efficient orbital rendezvous sequences for multiple target spacecraft is utilized to examine the capabilities of a servicer spacecraft to service multiple targets during the course of a single mission.

  10. Protection of surface assets on Mars from wind blown jettisoned spacecraft components

    Science.gov (United States)

    Paton, Mark

    2017-07-01

    Jettisoned Entry, Descent and Landing System (EDLS) hardware from landing spacecraft have been observed by orbiting spacecraft, strewn over the Martian surface. Future Mars missions that land spacecraft close to prelanded assets will have to use a landing architecture that somehow minimises the possibility of impacts from these jettisoned EDLS components. Computer modelling is used here to investigate the influence of wind speed and direction on the distribution of EDLS components on the surface. Typical wind speeds encountered in the Martian Planetary Boundary Layer (PBL) were found to be of sufficient strength to blow items having a low ballistic coefficient, i.e. Hypersonic Inflatable Aerodynamic Decelerators (HIADs) or parachutes, onto prelanded assets even when the lander itself touches down several kilometres away. Employing meteorological measurements and careful characterisation of the Martian PBL, e.g. appropriate wind speed probability density functions, may then benefit future spacecraft landings, increase safety and possibly help reduce the delta v budget for Mars landers that rely on aerodynamic decelerators.

  11. Safe use of nanomaterials

    CERN Multimedia

    2013-01-01

    The use of nanomaterials  is on the increase worldwide, including at CERN. The HSE Unit has established a safety guideline to inform you of the main requirements for the safe handling and disposal of nanomaterials at CERN.   A risk assessment tool has also been developed which guides the user through the process of evaluating the risk for his or her activity. Based on the calculated risk level, the tool provides a list of recommended control measures.   We would therefore like to draw your attention to: Safety Guideline C-0-0-5 - Safe handling and disposal of nanomaterials; and Safety Form C-0-0-2 - Nanomaterial Risk Assessment   You can consult all of CERN’s safety rules and guidelines here. Please contact the HSE Unit for any questions you may have.   The HSE Unit

  12. Plutonium safe handling

    International Nuclear Information System (INIS)

    Tvehlov, Yu.

    2000-01-01

    The abstract, prepared on the basis of materials of the IAEA new leadership on the plutonium safe handling and its storage (the publication no. 9 in the Safety Reports Series), aimed at presenting internationally acknowledged criteria on the radiation danger evaluation and summarizing the experience in the safe management of great quantities of plutonium, accumulated in the nuclear states, is presented. The data on the weapon-class and civil plutonium, the degree of its danger, the measures for provision of its safety, including the data on accident radiation consequences with the fission number 10 18 , are presented. The recommendations, making it possible to eliminate the super- criticality danger, as well as ignition and explosion, to maintain the tightness of the facility, aimed at excluding the radioactive contamination and the possibility of internal irradiation, to provide for the plutonium security, physical protection and to reduce irradiation are given [ru

  13. Development of Large-Scale Spacecraft Fire Safety Experiments

    DEFF Research Database (Denmark)

    Ruff, Gary A.; Urban, David L.; Fernandez-Pello, A. Carlos

    2013-01-01

    exploration missions outside of low-earth orbit and accordingly, more complex in terms of operations, logistics, and safety. This will increase the challenge of ensuring a fire-safe environment for the crew throughout the mission. Based on our fundamental uncertainty of the behavior of fires in low...... of the spacecraft fire safety risk. The activity of this project is supported by an international topical team of fire experts from other space agencies who conduct research that is integrated into the overall experiment design. The large-scale space flight experiment will be conducted in an Orbital Sciences...

  14. Spacecraft Jitter Attenuation Using Embedded Piezoelectric Actuators

    Science.gov (United States)

    Belvin, W. Keith

    1995-01-01

    Remote sensing from spacecraft requires precise pointing of measurement devices in order to achieve adequate spatial resolution. Unfortunately, various spacecraft disturbances induce vibrational jitter in the remote sensing instruments. The NASA Langley Research Center has performed analysis, simulations, and ground tests to identify the more promising technologies for minimizing spacecraft pointing jitter. These studies have shown that the use of smart materials to reduce spacecraft jitter is an excellent match between a maturing technology and an operational need. This paper describes the use of embedding piezoelectric actuators for vibration control and payload isolation. In addition, recent advances in modeling, simulation, and testing of spacecraft pointing jitter are discussed.

  15. Radioisotopic heater units warm an interplanetary spacecraft

    International Nuclear Information System (INIS)

    Franco-Ferreira, E.A.

    1998-01-01

    The Cassini orbiter and Huygens probe, which were successfully launched on October 15, 1997, constitute NASA's last grand-scale interplanetary mission of this century. The mission, which consists of a four-year, close-up study of Saturn and its moons, begins in July 2004 with Cassini's 60 orbits of Saturn and about 33 fly-bys of the large moon Titan. The Huygens probe will descend and land on Titan. Investigations will include Saturn's atmosphere, its rings and its magnetosphere. The atmosphere and surface of Titan and other icy moons also will be characterized. Because of the great distance of Saturn from the sun, some of the instruments and equipment on both the orbiter and the probe require external heaters to maintain their temperature within normal operating ranges. These requirements are met by Light Weight Radioisotope Heater Units (LWRHUs) designed, fabricated and safety tested at Los Alamos National Laboratory, New Mexico. An improved gas tungsten arc welding procedure lowered costs and decreased processing time for heat units for the Cassini spacecraft

  16. Safe Laser Beam Propagation for Interplanetary Links

    Science.gov (United States)

    Wilson, Keith E.

    2011-01-01

    Ground-to-space laser uplinks to Earth–orbiting satellites and deep space probes serve both as a beacon and an uplink command channel for deep space probes and Earth-orbiting satellites. An acquisition and tracking point design to support a high bandwidth downlink from a 20-cm optical terminal on an orbiting Mars spacecraft typically calls for 2.5 kW of 1030-nm uplink optical power in 40 micro-radians divergent beams.2 The NOHD (nominal ocular hazard distance) of the 1030nm uplink is in excess of 2E5 km, approximately half the distance to the moon. Recognizing the possible threat of high power laser uplinks to the flying public and to sensitive Earth-orbiting satellites, JPL developed a three-tiered system at its Optical Communications Telescope Laboratory (OCTL) to ensure safe laser beam propagation through navigational and near-Earth space.

  17. Spacecraft Design Thermal Control Subsystem

    Science.gov (United States)

    Miyake, Robert N.

    2008-01-01

    The Thermal Control Subsystem engineers task is to maintain the temperature of all spacecraft components, subsystems, and the total flight system within specified limits for all flight modes from launch to end-of-mission. In some cases, specific stability and gradient temperature limits will be imposed on flight system elements. The Thermal Control Subsystem of "normal" flight systems, the mass, power, control, and sensing systems mass and power requirements are below 10% of the total flight system resources. In general the thermal control subsystem engineer is involved in all other flight subsystem designs.

  18. Escola segura Safe school

    Directory of Open Access Journals (Sweden)

    Edson Ferreira Liberal

    2005-11-01

    Full Text Available OBJETIVO: Revisão das estratégias para tornar o ambiente escolar seguro. Inicialmente os autores contextualizam a violência e os acidentes no ambiente escolar e fazem recomendações, baseadas em dados da literatura, para a implantação de escolas seguras. FONTE DE DADOS: Artigos publicados entre 1993 e 2005 na base de dados MEDLINE. Dados nacionais epidemiológicos e da literatura também foram pesquisados. SÍNTESE DOS DADOS: Há evidência crescente de que a intervenção tem múltiplos componentes. O foco político é a prática em educação em saúde com o envolvimento de toda a comunidade. O norte dessas intervenções é ajudar estudantes e toda a comunidade a adotar um comportamento seguro e saudável. As escolas estão assumindo um envolvimento crescente na promoção da saúde, prevenção de doenças e prevenção de trauma. Nesse contexto de prevenção de causas externas de morbimortalidade, é importante reconhecer o risco ambiental, locais e comportamentos de risco como favoráveis ao trauma e à violência, além de um novo conceito de acidentes como algo que possa ser evitado. CONCLUSÃO: A implementação da escola segura representa uma nova direção promissora para o trabalho preventivo baseado na escola. É importante notar que uma escola segura deve intervir não meramente na sua estrutura física, mas também torná-la tão segura quanto possível, trabalhando com a comunidade escolar por meio de educação em saúde, discutindo principalmente o comportamento saudável.OBJECTIVE: To review the strategies to make school a safe environment. The paper first addresses the social context of accidents and violence in the school environment, and makes recommendations, based on the literature data, for the implementation of safe schools. SOURCE OF DATA: Articles published between 1993 and 2005 in the MEDLINE database. Brazilian epidemiological and literature data have also been searched. SUMMARY OF THE FINDINGS: There is

  19. Safe motherhood at risk?

    Science.gov (United States)

    Thompson, A

    1996-12-01

    Health professionals' negative attitudes toward clients often exacerbate the problems women face in terms of health status and access to health care. Thus, the health professionals can themselves be obstacles to women seeking the health care they need. A key challenge to midwives, in addition to providing technically competent services, is gaining insight into the people for whom they are responsible so that childbirth traditions are treated with respect and women are offered dignity. Safe motherhood requires intersectoral collaboration. Many innovative approaches to safe motherhood are based on the community's participation in planning services that meet the needs of women. Other approaches are based on decentralization of services. For example, a large university teaching hospital in Lusaka, Zambia, set up birthing centers around the city to take the pressure off the hospital. Midwives head up these centers, which are close to the women's homes. Decentralization of delivery services has improved the physical and emotional outcomes for mothers and newborns. Midwives must be prepared to articulate concerns about inequalities and deficiencies in the health care system in order to persuade the government to change. Women, including midwives, need to form multidisciplinary alliances to work together to effect change. The front-line workers in maternity care are midwives. They should adopt the following strategies to become even more effective in their efforts to make motherhood safer. They should listen to what women say about their needs. They should scale services to a manageable, human scale. They should learn the skills to become politically active advocates. They should work with other midwives, women, leaders, and other professional groups. Motherhood can be safe when women have more control over their own decision making, the education to liberate themselves to make their own decisions, and access to skilled care.

  20. Spacecraft-to-Earth Communications for Juno and Mars Science Laboratory Critical Events

    Science.gov (United States)

    Soriano, Melissa; Finley, Susan; Jongeling, Andre; Fort, David; Goodhart, Charles; Rogstad, David; Navarro, Robert

    2012-01-01

    Deep Space communications typically utilize closed loop receivers and Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK). Critical spacecraft events include orbit insertion and entry, descent, and landing.---Low gain antennas--> low signal -to-noise-ratio.---High dynamics such as parachute deployment or spin --> Doppler shift. During critical events, open loop receivers and Multiple Frequency Shift Keying (MFSK) used. Entry, Descent, Landing (EDL) Data Analysis (EDA) system detects tones in real-time.

  1. Inherently safe reactors

    International Nuclear Information System (INIS)

    Maartensson, Anders

    1992-01-01

    A rethinking of nuclear reactor safety has created proposals for new designs based on inherent and passive safety principles. Diverging interpretations of these concepts can be found. This article reviews the key features of proposed advanced power reactors. An evaluation is made of the degree of inherent safety for four different designs: the AP-600, the PIUS, the MHTGR and the PRISM. The inherent hazards of today's most common reactor principles are used as reference for the evaluation. It is concluded that claims for the new designs being inherently, naturally or passively safe are not substantiated by experience. (author)

  2. Benefits of Spacecraft Level Vibration Testing

    Science.gov (United States)

    Gordon, Scott; Kern, Dennis L.

    2015-01-01

    NASA-HDBK-7008 Spacecraft Level Dynamic Environments Testing discusses the approaches, benefits, dangers, and recommended practices for spacecraft level dynamic environments testing, including vibration testing. This paper discusses in additional detail the benefits and actual experiences of vibration testing spacecraft for NASA Goddard Space Flight Center (GSFC) and Jet Propulsion Laboratory (JPL) flight projects. JPL and GSFC have both similarities and differences in their spacecraft level vibration test approach: JPL uses a random vibration input and a frequency range usually starting at 5 Hz and extending to as high as 250 Hz. GSFC uses a sine sweep vibration input and a frequency range usually starting at 5 Hz and extending only to the limits of the coupled loads analysis (typically 50 to 60 Hz). However, both JPL and GSFC use force limiting to realistically notch spacecraft resonances and response (acceleration) limiting as necessary to protect spacecraft structure and hardware from exceeding design strength capabilities. Despite GSFC and JPL differences in spacecraft level vibration test approaches, both have uncovered a significant number of spacecraft design and workmanship anomalies in vibration tests. This paper will give an overview of JPL and GSFC spacecraft vibration testing approaches and provide a detailed description of spacecraft anomalies revealed.

  3. Hybrid spacecraft attitude control system

    Directory of Open Access Journals (Sweden)

    Renuganth Varatharajoo

    2016-02-01

    Full Text Available The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.

  4. Safe handling of tritium

    International Nuclear Information System (INIS)

    1991-01-01

    The main objective of this publication is to provide practical guidance and recommendations on operational radiation protection aspects related to the safe handling of tritium in laboratories, industrial-scale nuclear facilities such as heavy-water reactors, tritium removal plants and fission fuel reprocessing plants, and facilities for manufacturing commercial tritium-containing devices and radiochemicals. The requirements of nuclear fusion reactors are not addressed specifically, since there is as yet no tritium handling experience with them. However, much of the material covered is expected to be relevant to them as well. Annex III briefly addresses problems in the comparatively small-scale use of tritium at universities, medical research centres and similar establishments. However, the main subject of this publication is the handling of larger quantities of tritium. Operational aspects include designing for tritium safety, safe handling practice, the selection of tritium-compatible materials and equipment, exposure assessment, monitoring, contamination control and the design and use of personal protective equipment. This publication does not address the technologies involved in tritium control and cleanup of effluents, tritium removal, or immobilization and disposal of tritium wastes, nor does it address the environmental behaviour of tritium. Refs, figs and tabs

  5. Vitamins, Are They Safe?

    Directory of Open Access Journals (Sweden)

    Hadi Hamishehkar

    2016-12-01

    Full Text Available The consumption of a daily multivitamin among people all over the world is dramatically increasing in recent years. Most of the people believe that if vitamins are not effective, at least they are safe. However, the long term health consequences of vitamins consumption are unknown. This study aimed to assess the side effects and possible harmful and detrimental properties of vitamins and to discuss whether vitamins can be used as safe health products or dietary supplements. We performed a MEDLINE/PubMed, EMBASE, Scopus and Google Scholar search and assessed reference lists of the included studies which were published from 1993 through 2015. The studies, with an emphasis on RCTs (randomized controlled clinical trials, were reviewed. As some vitamins such as fat-soluble vitamins (vitamin A, vitamin D, vitamin E, and also some of the water-soluble vitamins like folic acid may cause adverse events and some like vitamin C is widely taken assuming that it has so many benefits and no harm, we included relevant studies with negative or undesired results regarding the effect of these vitamins on health. Our recommendation is that taking high-dose supplements of vitamins A, E, D, C, and folic acid is not always effective for prevention of disease, and it can even be harmful to the health.

  6. Cool and Safe: Multiplicity in Safe Innovation at Unilever

    Science.gov (United States)

    Penders, Bart

    2011-01-01

    This article presents the making of a safe innovation: the application of ice structuring protein (ISP) in edible ices. It argues that safety is not the absence of risk but is an active accomplishment; innovations are not "made safe afterward" but "safe innovations are made". Furthermore, there are multiple safeties to be accomplished in the…

  7. A Stochastic Model for the Landing Dispersion of Hazard Detection and Avoidance Capable Flight Systems

    Science.gov (United States)

    Witte, L.

    2014-06-01

    To support landing site assessments for HDA-capable flight systems and to facilitate trade studies between the potential HDA architectures versus the yielded probability of safe landing a stochastic landing dispersion model has been developed.

  8. Estimating Torque Imparted on Spacecraft Using Telemetry

    Science.gov (United States)

    Lee, Allan Y.; Wang, Eric K.; Macala, Glenn A.

    2013-01-01

    There have been a number of missions with spacecraft flying by planetary moons with atmospheres; there will be future missions with similar flybys. When a spacecraft such as Cassini flies by a moon with an atmosphere, the spacecraft will experience an atmospheric torque. This torque could be used to determine the density of the atmosphere. This is because the relation between the atmospheric torque vector and the atmosphere density could be established analytically using the mass properties of the spacecraft, known drag coefficient of objects in free-molecular flow, and the spacecraft velocity relative to the moon. The density estimated in this way could be used to check results measured by science instruments. Since the proposed methodology could estimate disturbance torque as small as 0.02 N-m, it could also be used to estimate disturbance torque imparted on the spacecraft during high-altitude flybys.

  9. Computer simulation of spacecraft/environment interaction

    International Nuclear Information System (INIS)

    Krupnikov, K.K.; Makletsov, A.A.; Mileev, V.N.; Novikov, L.S.; Sinolits, V.V.

    1999-01-01

    This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language

  10. Computer simulation of spacecraft/environment interaction

    CERN Document Server

    Krupnikov, K K; Mileev, V N; Novikov, L S; Sinolits, V V

    1999-01-01

    This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language.

  11. 14 CFR 25.1515 - Landing gear speeds.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear, as...

  12. Optimal Autonomous Spacecraft Resiliency Maneuvers Using Metaheuristics

    Science.gov (United States)

    2014-09-15

    This work was accepted for published by the American Institute of Aeronautics and Astronautics (AIAA) Journal of Spacecraft and Rockets in July 2014...publication in the AIAA Journal of Spacecraft and Rockets . Chapter 5 introduces an impulsive maneuvering strategy to deliver a spacecraft to its final...upon arrival r2 and v2 , respectively. The variable T2 determines the time of flight needed to make the maneuver, and the variable θ2 determines the

  13. Mars Exploration Rovers Landing Dispersion Analysis

    Science.gov (United States)

    Knocke, Philip C.; Wawrzyniak, Geoffrey G.; Kennedy, Brian M.; Desai, Prasun N.; Parker, TImothy J.; Golombek, Matthew P.; Duxbury, Thomas C.; Kass, David M.

    2004-01-01

    Landing dispersion estimates for the Mars Exploration Rover missions were key elements in the site targeting process and in the evaluation of landing risk. This paper addresses the process and results of the landing dispersion analyses performed for both Spirit and Opportunity. The several contributors to landing dispersions (navigation and atmospheric uncertainties, spacecraft modeling, winds, and margins) are discussed, as are the analysis tools used. JPL's MarsLS program, a MATLAB-based landing dispersion visualization and statistical analysis tool, was used to calculate the probability of landing within hazardous areas. By convolving this with the probability of landing within flight system limits (in-spec landing) for each hazard area, a single overall measure of landing risk was calculated for each landing ellipse. In-spec probability contours were also generated, allowing a more synoptic view of site risks, illustrating the sensitivity to changes in landing location, and quantifying the possible consequences of anomalies such as incomplete maneuvers. Data and products required to support these analyses are described, including the landing footprints calculated by NASA Langley's POST program and JPL's AEPL program, cartographically registered base maps and hazard maps, and flight system estimates of in-spec landing probabilities for each hazard terrain type. Various factors encountered during operations, including evolving navigation estimates and changing atmospheric models, are discussed and final landing points are compared with approach estimates.

  14. Safe pill-dispensing.

    Science.gov (United States)

    Testa, Massimiliano; Pollard, John

    2007-01-01

    Each patient is supplied with a smart-card containing a Radio Frequency IDentification (RFID) chip storing a unique identification code. The patient places the Smart-card on a pill-dispenser unit containing an RFID reader. The RFID chip is read and the code sent to a Base-station via a wireless Bluetooth link. A database containing both patient details and treatment information is queried at the Base-station using the RFID as the search key. The patient's treatment data (i.e., drug names, quantities, time, etc.) are retrieved and sent back to the pill-dispenser unit via Bluetooth. Appropriate quantities of the required medications are automatically dispensed, unless the patient has already taken his/her daily dose. Safe, confidential communication and operation is ensured.

  15. A safe workplace

    International Nuclear Information System (INIS)

    Rittsel, Hans; Andersson, Bengt A.

    1993-01-01

    Full text: The video 'A safe workplace' has been produced by ABB Atom in order to create a tool for showing different target audiences that ABB Atom Nuclear Fuel Production Plant is a safe workplace and to 'de-mystify' nuclear fuel production. The main target audiences are visitor groups and employees of the company, but the video also qualifies for use as an information tool for other target groups who ask for a proper explanation of the way nuclear fuel is produced. The summarized content of the video is as follows: All individual steps of the production process are described with focus on the safety, quality and environmental requirements. The first part shows the delivery of UF 6 (uranium hexafluoride) to the plant and the following process for the conversion to UO 2 (uranium dioxide). The conversion method used is wet conversion that includes evaporation, precipitation, filtration, washing, reduction and stabilization. The next part is a description of the fuel pellet manufacture including uranium oxide blending, pellet pressing, sintering, grinding and a final visual inspection. A separate part, describing the manufacture of fuel pellets with a burnable neutron absorber, is included. The third part shows how to produce fuel rods and complete assemblies. Some of the moments of quality supervision that support the entire manufacturing process are also shown. The last part of the video comprises a brief description of the manufacture of fuel channels and other reactor core components like control rods. The video is produced with a Swedish spoken narrative. The playing time is 15 minutes. The video will be delivered with a text printed in English and copies reproduced in the PAL/VHS system may be ordered from ABB Atom Communication Dept. telefax no +4621-11 41 90, at the price of USD 100.- or SEK 750.- each. (author)

  16. Strategies for safe motherhood.

    Science.gov (United States)

    Chatterjee, A

    1995-02-01

    The Safe Motherhood Initiative was launched in 1988 as a global effort to halve maternal mortality and morbidity by the year 2000. The program uses a combination of health and nonhealth strategies to emphasize the need for maternal health services, extend family planning services, and improve the status of women. The maternal mortality rate (per 100,000 live births) is 390 for the world, 20-30 for developed countries, 450 for developing countries, and 420 for Asia. This translates into 308,000 maternal deaths in Asia, of which 100,000 occur in India. The direct causes of maternal mortality include sepsis, hemorrhage, eclampsia, and ruptured uterus. Indirect causes occur when associated medical conditions, such as anemia and jaundice, are exacerbated by pregnancy. Underlying causes are ineffective health services, inadequate obstetric care, unregulated fertility, infections, illiteracy, early marriage, poverty, malnutrition, and ignorance. India's Child Survival and Safe Motherhood Program seeks to achieve immediate improvements by improving health care. Longterm improvements will occur as nutrition, income, education, and the status of women improve. Improvements in health care will occur in through the provision of 1) essential obstetric care for all women (which will be essentially designed for low-risk women), 2) early detection of complications during pregnancy and labor, and 3) emergency services. Services will be provided to pregnant women at their door by field staff, at a first referral hospital, perhaps at maternity villages where high risk cases can be housed in the latter part of their pregnancies, and through the continual accessibility of government vehicles. In addition, family planning services will be improved so that fertility regulation can have its expected beneficial effect on the maternal mortality rate. The professional health organizations in India will also play a vital role in the success of this effort to reduce maternal mortality.

  17. Ulysses spacecraft control and monitoring system

    Science.gov (United States)

    Hamer, P. A.; Snowden, P. J.

    1991-01-01

    The baseline Ulysses spacecraft control and monitoring system (SCMS) concepts and the converted SCMS, residing on a DEC/VAX 8350 hardware, are considered. The main functions of the system include monitoring and displaying spacecraft telemetry, preparing spacecraft commands, producing hard copies of experimental data, and archiving spacecraft telemetry. The SCMS system comprises over 20 subsystems ranging from low-level utility routines to the major monitoring and control software. These in total consist of approximately 55,000 lines of FORTRAN source code and 100 VMS command files. The SCMS major software facilities are described, including database files, telemetry processing, telecommanding, archiving of data, and display of telemetry.

  18. Operationally Responsive Spacecraft Subsystem, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Saber Astronautics proposes spacecraft subsystem control software which can autonomously reconfigure avionics for best performance during various mission conditions....

  19. Land Cover

    Data.gov (United States)

    Kansas Data Access and Support Center — The Land Cover database depicts 10 general land cover classes for the State of Kansas. The database was compiled from a digital classification of Landsat Thematic...

  20. Mulighedernes land?

    DEFF Research Database (Denmark)

    Munck Petersen, Rikke

    2001-01-01

    Kommentar om arbejde med det åbne land i forlængelse af konfencen "Mulighedernes land" og vigtigheden af at landskabsarkitekter går aktivt ind i debatten og arbejdet med landskabets forandring i Danmark.......Kommentar om arbejde med det åbne land i forlængelse af konfencen "Mulighedernes land" og vigtigheden af at landskabsarkitekter går aktivt ind i debatten og arbejdet med landskabets forandring i Danmark....

  1. Safe percutaneous suprapubic catheterisation.

    Science.gov (United States)

    Goyal, N K; Goel, A; Sankhwar, S N

    2012-11-01

    We describe our technique of percutaneous suprapubic catheter insertion with special reference to steps that help to avoid common complications of haematuria and catheter misplacement. The procedure is performed using a stainless steel reusable trocar under local infiltrative anaesthesia, usually at the bedside. After clinical confirmation of a full bladder, the trocar is advanced into the bladder through a skin incision. Once the bladder is entered, the obturator is removed and the assistant inserts a Foley catheter followed by rapid balloon inflation. Slight traction is applied to the catheter for about five minutes. Patients with previous lower abdominal surgery, an inadequately distended bladder or acute pelvic trauma do not undergo suprapubic catheterisation using this method. The procedure was performed in 72 men (mean age: 42.4 years, range: 18-78 years) with urinary retention with a palpable bladder. The average duration of the procedure was less than five minutes. No complications were noted in any of the patients. Trocar suprapubic catheter insertion is a safe and effective bedside procedure for emergency bladder drainage and can be performed by resident surgeons. The common complications associated with the procedure can be avoided with a few careful steps.

  2. Making Our Food Safe

    International Nuclear Information System (INIS)

    Madsen, Michael

    2013-01-01

    Full text: As civilization has progressed societies have strived to make food safer; from using fire to cook our food, and boiling our water to make it safe to drink, advances in technology have helped kill microorganisms that can make food unsafe. The FAO/IAEA Joint Division helps provide technical assistance to Member States that want to implement irradiation technology in making their food safer. Food and waterborne diarrhoeal diseases are estimated to kill roughly 2.2 million people annually, of which 1.9 million are children. Irradiating some of the foods we eat can save many of these lives by reducing the risk of food poisoning and killing the organisms that cause disease. Irradiation works by treating food with a small dose of ionizing radiation, this radiation disrupts the bacteria’s DNA and cell membranes structure stopping the organism from reproducing or functioning, but does not make the food radioactive. It can be applied to a variety of foods from spices and seasonings, to fruits and vegetables and is similar to pasteurization, but without the need for high temperatures that might impair food quality. (author)

  3. Safe Handling of Radioisotopes

    International Nuclear Information System (INIS)

    1958-01-01

    Under its Statute the International Atomic Energy Agency is empowered to provide for the application of standards of safety for protection against radiation to its own operations and to operations making use of assistance provided by it or with which it is otherwise directly associated. To this end authorities receiving such assistance are required to observe relevant health and safety measures prescribed by the Agency. As a first step, it has been considered an urgent task to provide users of radioisotopes with a manual of practice for the safe handling of these substances. Such a manual is presented here and represents the first of a series of manuals and codes to be issued by the Agency. It has been prepared after careful consideration of existing national and international codes of radiation safety, by a group of international experts and in consultation with other international bodies. At the same time it is recommended that the manual be taken into account as a basic reference document by Member States of the Agency in the preparation of national health and safety documents covering the use of radioisotopes.

  4. OPINION: Safe exponential manufacturing

    Science.gov (United States)

    Phoenix, Chris; Drexler, Eric

    2004-08-01

    In 1959, Richard Feynman pointed out that nanometre-scale machines could be built and operated, and that the precision inherent in molecular construction would make it easy to build multiple identical copies. This raised the possibility of exponential manufacturing, in which production systems could rapidly and cheaply increase their productive capacity, which in turn suggested the possibility of destructive runaway self-replication. Early proposals for artificial nanomachinery focused on small self-replicating machines, discussing their potential productivity and their potential destructiveness if abused. In the light of controversy regarding scenarios based on runaway replication (so-called 'grey goo'), a review of current thinking regarding nanotechnology-based manufacturing is in order. Nanotechnology-based fabrication can be thoroughly non-biological and inherently safe: such systems need have no ability to move about, use natural resources, or undergo incremental mutation. Moreover, self-replication is unnecessary: the development and use of highly productive systems of nanomachinery (nanofactories) need not involve the construction of autonomous self-replicating nanomachines. Accordingly, the construction of anything resembling a dangerous self-replicating nanomachine can and should be prohibited. Although advanced nanotechnologies could (with great difficulty and little incentive) be used to build such devices, other concerns present greater problems. Since weapon systems will be both easier to build and more likely to draw investment, the potential for dangerous systems is best considered in the context of military competition and arms control.

  5. Aflatoxins & Safe Storage

    Directory of Open Access Journals (Sweden)

    Philippe eVillers

    2014-04-01

    Full Text Available The paper examines both field experience and research on the prevention of the exponential growth of aflatoxins during multi-month post harvest storage in hot, humid countries. The approach described is the application of modern safe storage methods using flexible, Ultra Hermetic™ structures that create an unbreatheable atmosphere through insect and microorganism respiration alone, without use of chemicals, fumigants, or pumps. Laboratory and field data are cited and specific examples are given describing the uses of Ultra Hermetic storage to prevent the growth of aflatoxins with their significant public health consequences. Also discussed is the presently limited quantitative information on the relative occurrence of excessive levels of aflatoxin (>20 ppb before versus after multi-month storage of such crops as maize, rice and peanuts when under high humidity, high temperature conditions and, consequently, the need for further research to determine the frequency at which excessive aflatoxin levels are reached in the field versus after months of post-harvest storage. The significant work being done to reduce aflatoxin levels in the field is mentioned, as well as its probable implications on post harvest storage. Also described is why, with some crops such as peanuts, using Ultra Hermetic storage may require injection of carbon dioxide or use of an oxygen absorber as an accelerant. The case of peanuts is discussed and experimental data is described.

  6. TTEthernet for Integrated Spacecraft Networks

    Science.gov (United States)

    Loveless, Andrew

    2015-01-01

    Aerospace projects have traditionally employed federated avionics architectures, in which each computer system is designed to perform one specific function (e.g. navigation). There are obvious downsides to this approach, including excessive weight (from so much computing hardware), and inefficient processor utilization (since modern processors are capable of performing multiple tasks). There has therefore been a push for integrated modular avionics (IMA), in which common computing platforms can be leveraged for different purposes. This consolidation of multiple vehicle functions to shared computing platforms can significantly reduce spacecraft cost, weight, and design complexity. However, the application of IMA principles introduces significant challenges, as the data network must accommodate traffic of mixed criticality and performance levels - potentially all related to the same shared computer hardware. Because individual network technologies are rarely so competent, the development of truly integrated network architectures often proves unreasonable. Several different types of networks are utilized - each suited to support a specific vehicle function. Critical functions are typically driven by precise timing loops, requiring networks with strict guarantees regarding message latency (i.e. determinism) and fault-tolerance. Alternatively, non-critical systems generally employ data networks prioritizing flexibility and high performance over reliable operation. Switched Ethernet has seen widespread success filling this role in terrestrial applications. Its high speed, flexibility, and the availability of inexpensive commercial off-the-shelf (COTS) components make it desirable for inclusion in spacecraft platforms. Basic Ethernet configurations have been incorporated into several preexisting aerospace projects, including both the Space Shuttle and International Space Station (ISS). However, classical switched Ethernet cannot provide the high level of network

  7. Spacecraft command and control using expert systems

    Science.gov (United States)

    Norcross, Scott; Grieser, William H.

    1994-01-01

    This paper describes a product called the Intelligent Mission Toolkit (IMT), which was created to meet the changing demands of the spacecraft command and control market. IMT is a command and control system built upon an expert system. Its primary functions are to send commands to the spacecraft and process telemetry data received from the spacecraft. It also controls the ground equipment used to support the system, such as encryption gear, and telemetry front-end equipment. Add-on modules allow IMT to control antennas and antenna interface equipment. The design philosophy for IMT is to utilize available commercial products wherever possible. IMT utilizes Gensym's G2 Real-time Expert System as the core of the system. G2 is responsible for overall system control, spacecraft commanding control, and spacecraft telemetry analysis and display. Other commercial products incorporated into IMT include the SYBASE relational database management system and Loral Test and Integration Systems' System 500 for telemetry front-end processing.

  8. Results of Large-Scale Spacecraft Flammability Tests

    Science.gov (United States)

    Ferkul, Paul; Olson, Sandra; Urban, David L.; Ruff, Gary A.; Easton, John; T'ien, James S.; Liao, Ta-Ting T.; Fernandez-Pello, A. Carlos; Torero, Jose L.; Eigenbrand, Christian; hide

    2017-01-01

    For the first time, a large-scale fire was intentionally set inside a spacecraft while in orbit. Testing in low gravity aboard spacecraft had been limited to samples of modest size: for thin fuels the longest samples burned were around 15 cm in length and thick fuel samples have been even smaller. This is despite the fact that fire is a catastrophic hazard for spaceflight and the spread and growth of a fire, combined with its interactions with the vehicle cannot be expected to scale linearly. While every type of occupied structure on earth has been the subject of full scale fire testing, this had never been attempted in space owing to the complexity, cost, risk and absence of a safe location. Thus, there is a gap in knowledge of fire behavior in spacecraft. The recent utilization of large, unmanned, resupply craft has provided the needed capability: a habitable but unoccupied spacecraft in low earth orbit. One such vehicle was used to study the flame spread over a 94 x 40.6 cm thin charring solid (fiberglasscotton fabric). The sample was an order of magnitude larger than anything studied to date in microgravity and was of sufficient scale that it consumed 1.5 of the available oxygen. The experiment which is called Saffire consisted of two tests, forward or concurrent flame spread (with the direction of flow) and opposed flame spread (against the direction of flow). The average forced air speed was 20 cms. For the concurrent flame spread test, the flame size remained constrained after the ignition transient, which is not the case in 1-g. These results were qualitatively different from those on earth where an upward-spreading flame on a sample of this size accelerates and grows. In addition, a curious effect of the chamber size is noted. Compared to previous microgravity work in smaller tunnels, the flame in the larger tunnel spread more slowly, even for a wider sample. This is attributed to the effect of flow acceleration in the smaller tunnels as a result of hot

  9. Submarines, spacecraft and exhaled breath.

    Science.gov (United States)

    Pleil, Joachim D; Hansel, Armin

    2012-03-01

    Foreword The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled breath. What may have escaped our notice is a complementary field of research that explores the creation and maintenance of artificial atmospheres practised by the submarine air monitoring and air purification (SAMAP) community. SAMAP is comprised of manufacturers, researchers and medical professionals dealing with the engineering and instrumentation to support human life in submarines and spacecraft (including shuttlecraft and manned rockets, high-altitude aircraft, and the International Space Station (ISS)). Here, the immediate concerns are short-term survival and long-term health in fairly confined environments where one cannot simply 'open the window' for fresh air. As such, one of the main concerns is air monitoring and the main sources of contamination are CO(2) and other constituents of human exhaled breath. Since the inaugural meeting in 1994 in Adelaide, Australia, SAMAP meetings have been held every two or three years alternating between the North American and European continents. The meetings are organized by Dr Wally Mazurek (a member of IABR) of the Defense Systems Technology Organization (DSTO) of Australia, and individual meetings are co-hosted by the navies of the countries in which they are held. An overriding focus at SAMAP is life support (oxygen availability and carbon dioxide removal). Certainly, other air constituents are also important; for example, the closed environment of a submarine or the ISS can build up contaminants from consumer products, cooking, refrigeration, accidental fires, propulsion and atmosphere maintenance. However, the most immediate concern is sustaining human metabolism: removing exhaled CO(2) and replacing metabolized O(2). Another

  10. Foot Pedals for Spacecraft Manual Control

    Science.gov (United States)

    Love, Stanley G.; Morin, Lee M.; McCabe, Mary

    2010-01-01

    Fifty years ago, NASA decided that the cockpit controls in spacecraft should be like the ones in airplanes. But controls based on the stick and rudder may not be best way to manually control a vehicle in space. A different method is based on submersible vehicles controlled with foot pedals. A new pilot can learn the sub's control scheme in minutes and drive it hands-free. We are building a pair of foot pedals for spacecraft control, and will test them in a spacecraft flight simulator.

  11. Enabling Advanced Automation in Spacecraft Operations with the Spacecraft Emergency Response System

    Science.gov (United States)

    Breed, Julie; Fox, Jeffrey A.; Powers, Edward I. (Technical Monitor)

    2001-01-01

    True autonomy is the Holy Grail of spacecraft mission operations. The goal of launching a satellite and letting it manage itself throughout its useful life is a worthy one. With true autonomy, the cost of mission operations would be reduced to a negligible amount. Under full autonomy, any problems (no matter the severity or type) that may arise with the spacecraft would be handled without any human intervention via some combination of smart sensors, on-board intelligence, and/or smart automated ground system. Until the day that complete autonomy is practical and affordable to deploy, incremental steps of deploying ever-increasing levels of automation (computerization of once manual tasks) on the ground and on the spacecraft are gradually decreasing the cost of mission operations. For example, NASA's Goddard Space Flight Center (NASA-GSFC) has been flying spacecraft with low cost operations for several years. NASA-GSFC's SMEX (Small Explorer) and MIDEX (Middle Explorer) missions have effectively deployed significant amounts of automation to enable the missions to fly predominately in 'light-out' mode. Under light-out operations the ground system is run without human intervention. Various tools perform many of the tasks previously performed by the human operators. One of the major issues in reducing human staff in favor of automation is the perceived increased in risk of losing data, or even losing a spacecraft, because of anomalous conditions that may occur when there is no one in the control center. When things go wrong, missions deploying advanced automation need to be sure that anomalous conditions are detected and that key personal are notified in a timely manner so that on-call team members can react to those conditions. To ensure the health and safety of its lights-out missions, NASA-GSFC's Advanced Automation and Autonomy branch (Code 588) developed the Spacecraft Emergency Response System (SERS). The SERS is a Web-based collaborative environment that enables

  12. Safe Minimum Internal Temperature Chart

    Science.gov (United States)

    ... Internal Temperature Chart Safe steps in food handling, cooking, and storage are essential in preventing foodborne illness. You can't see, smell, or taste harmful bacteria that may cause illness. In every step of food preparation, follow the four guidelines to keep food safe: ...

  13. More than a Safe Space

    Science.gov (United States)

    Sadowski, Michael

    2016-01-01

    Over the past three decades, much of the conversation about LGBTQ students in schools has centered on safety--anti-bullying policies, the "safe space" of gay-straight alliances, and "safe zones" marked by rainbow-colored stickers on classroom doors. In this article, Michael Sadowski argues that it's time to move beyond safety…

  14. Staying Safe in the Water

    Centers for Disease Control (CDC) Podcasts

    In this podcast, Dr. Julie Gilchrist, a pediatrician and medical epidemiologist from CDC’s Injury Center, talks about staying safe in the water. Tips are for all audiences, with a focus on preventing drownings and keeping children safe in and around the pool, lake, or ocean.

  15. Spacecraft and propulsion technician error

    Science.gov (United States)

    Schultz, Daniel Clyde

    Commercial aviation and commercial space similarly launch, fly, and land passenger vehicles. Unlike aviation, the U.S. government has not established maintenance policies for commercial space. This study conducted a mixed methods review of 610 U.S. space launches from 1984 through 2011, which included 31 failures. An analysis of the failure causal factors showed that human error accounted for 76% of those failures, which included workmanship error accounting for 29% of the failures. With the imminent future of commercial space travel, the increased potential for the loss of human life demands that changes be made to the standardized procedures, training, and certification to reduce human error and failure rates. Several recommendations were made by this study to the FAA's Office of Commercial Space Transportation, space launch vehicle operators, and maintenance technician schools in an effort to increase the safety of the space transportation passengers.

  16. Safe Anesthesia For Every Tot

    DEFF Research Database (Denmark)

    Weiss, Markus; Vutskits, Laszlo; Hansen, Tom G

    2015-01-01

    PURPOSE OF REVIEW: The term 'safe use of anesthesia in children is ill-defined and requires definition of and focus on the 'safe conduct of pediatric anesthesia'. RECENT FINDINGS: The Safe Anesthesia For Every Tot initiative (www.safetots.org) has been set up during the last year to focus...... on the safe conduct of pediatric anesthesia. This initiative aims to provide guidance on markers of quality anesthesia care. The introduction and implementation of national regulations of 'who, where, when and how' are required and will result in an improved perioperative outcome in vulnerable children....... The improvement of teaching, training, education and supervision of the safe conduct of pediatric anesthesia are the main goals of the safetots.org initiative. SUMMARY: This initiative addresses the well known perioperative risks in young children, perioperative causes for cerebral morbidity as well as gaps...

  17. Air Purification in Closed Environments: An Overview of Spacecraft Systems

    Science.gov (United States)

    Perry, Jay L.; LeVan, Douglas; Crumbley, Robert (Technical Monitor)

    2002-01-01

    The primary goal for a collective protection system and a spacecraft environmental control and life support system (ECLSS) are strikingly similar. Essentially both function to provide the occupants of a building or vehicle with a safe, habitable environment. The collective protection system shields military and civilian personnel from short-term exposure to external threats presented by toxic agents and industrial chemicals while an ECLSS sustains astronauts for extended periods within the hostile environment of space. Both have air quality control similarities with various aircraft and 'tight' buildings. This paper reviews basic similarities between air purification system requirements for collective protection and an ECLSS that define surprisingly common technological challenges and solutions. Systems developed for air revitalization on board spacecraft are discussed along with some history on their early development as well as a view of future needs. Emphasis is placed upon two systems implemented by the National Aeronautics and Space Administration (NASA) onboard the International Space Station (ISS): the trace contaminant control system (TCCS) and the molecular sieve-based carbon dioxide removal assembly (CDRA). Over its history, the NASA has developed and implemented many life support systems for astronauts. As the duration, complexity, and crew size of manned missions increased from minutes or hours for a single astronaut during Project Mercury to days and ultimately months for crews of 3 or more during the Apollo, Skylab, Shuttle, and ISS programs, these systems have become more sophisticated. Systems aboard spacecraft such as the ISS have been designed to provide long-term environmental control and life support. Challenges facing the NASA's efforts include minimizing mass, volume, and power for such systems, while maximizing their safety, reliability, and performance. This paper will highlight similarities and differences among air purification systems

  18. Distributed Autonomous Control of Multiple Spacecraft During Close Proximity Operations

    National Research Council Canada - National Science Library

    McCamish, Shawn B

    2007-01-01

    This research contributes to multiple spacecraft control by developing an autonomous distributed control algorithm for close proximity operations of multiple spacecraft systems, including rendezvous...

  19. Spacecraft Swarm Coordination and Planning Tool, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Fractionated spacecraft architectures to distribute mission performance from a single, monolithic satellite across large number of smaller spacecraft, for missions...

  20. Spacecraft Cabin Particulate Monitor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We have built and tested an optical extinction monitor for the detection of spacecraft cabin particulates. This sensor sensitive to particle sizes ranging from a few...

  1. SSTI- Lewis Spacecraft Nickel-Hydrogen Battery

    Science.gov (United States)

    Tobias, R. F.

    1997-01-01

    Topics considered include: NASA-Small Spacecraft Technology Initiative (SSTI) objectives, SSTI-Lewis overview, battery requirement, two cells Common Pressure Vessel (CPV) design summary, CPV electric performance, battery design summary, battery functional description, battery performance.

  2. Spacecraft Cabin Particulate Monitor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design, build and test an optical extinction monitor for the detection of spacecraft cabin particulates. This monitor will be sensitive to particle...

  3. Automated constraint checking of spacecraft command sequences

    Science.gov (United States)

    Horvath, Joan C.; Alkalaj, Leon J.; Schneider, Karl M.; Spitale, Joseph M.; Le, Dang

    1995-01-01

    Robotic spacecraft are controlled by onboard sets of commands called "sequences." Determining that sequences will have the desired effect on the spacecraft can be expensive in terms of both labor and computer coding time, with different particular costs for different types of spacecraft. Specification languages and appropriate user interface to the languages can be used to make the most effective use of engineering validation time. This paper describes one specification and verification environment ("SAVE") designed for validating that command sequences have not violated any flight rules. This SAVE system was subsequently adapted for flight use on the TOPEX/Poseidon spacecraft. The relationship of this work to rule-based artificial intelligence and to other specification techniques is discussed, as well as the issues that arise in the transfer of technology from a research prototype to a full flight system.

  4. Computational Model for Spacecraft/Habitat Volume

    Data.gov (United States)

    National Aeronautics and Space Administration — Please note that funding to Dr. Simon Hsiang, a critical co-investigator for the development of the Spacecraft Optimization Layout and Volume (SOLV) model, was...

  5. Industry perspectives on Plug-& -Play Spacecraft Avionics

    Science.gov (United States)

    Franck, R.; Graven, P.; Liptak, L.

    This paper describes the methodologies and findings from an industry survey of awareness and utility of Spacecraft Plug-& -Play Avionics (SPA). The survey was conducted via interviews, in-person and teleconference, with spacecraft prime contractors and suppliers. It focuses primarily on AFRL's SPA technology development activities but also explores the broader applicability and utility of Plug-& -Play (PnP) architectures for spacecraft. Interviews include large and small suppliers as well as large and small spacecraft prime contractors. Through these “ product marketing” interviews, awareness and attitudes can be assessed, key technical and market barriers can be identified, and opportunities for improvement can be uncovered. Although this effort focuses on a high-level assessment, similar processes can be used to develop business cases and economic models which may be necessary to support investment decisions.

  6. Spacecraft Multiple Array Communication System Performance Analysis

    Science.gov (United States)

    Hwu, Shian U.; Desilva, Kanishka; Sham, Catherine C.

    2010-01-01

    The Communication Systems Simulation Laboratory (CSSL) at the NASA Johnson Space Center is tasked to perform spacecraft and ground network communication system simulations, design validation, and performance verification. The CSSL has developed simulation tools that model spacecraft communication systems and the space and ground environment in which the tools operate. In this paper, a spacecraft communication system with multiple arrays is simulated. Multiple array combined technique is used to increase the radio frequency coverage and data rate performance. The technique is to achieve phase coherence among the phased arrays to combine the signals at the targeting receiver constructively. There are many technical challenges in spacecraft integration with a high transmit power communication system. The array combining technique can improve the communication system data rate and coverage performances without increasing the system transmit power requirements. Example simulation results indicate significant performance improvement can be achieved with phase coherence implementation.

  7. Automating a spacecraft electrical power system using expert systems

    Science.gov (United States)

    Lollar, L. F.

    1991-01-01

    Since Skylab, Marshall Space Flight Center (MSFC) has recognized the need for large electrical power systems (EPS's) in upcoming Spacecraft. The operation of the spacecraft depends on the EPS. Therefore, it must be efficient, safe, and reliable. In 1978, as a consequence of having to supply a large number of EPS personnel to monitor and control Skylab, the Electrical power Branch of MSFC began the autonomously managed power system (AMPS) project. This project resulted in the assembly of a 25-kW high-voltage dc test facility and provided the means of getting man out of the loop as much as possible. AMPS includes several embedded controllers which allow a significant level of autonomous operation. More recently, the Electrical Division at MSFC has developed the space station module power management and distribution (SSM/PMAD) breadboard to investigate managing and distributing power in the Space Station Freedom habitation and laboratory modules. Again, the requirement for a high level of autonomy for the efficient operation over the lifetime of the station and for the benefits of enhanced safety has been demonstrated. This paper describes the two breadboards and the hierarchical approach to automation which was developed through these projects.

  8. Spacecraft Attitude Tracking and Maneuver Using Combined Magnetic Actuators

    Science.gov (United States)

    Zhou, Zhiqiang

    2010-01-01

    The accuracy of spacecraft attitude control using magnetic actuators only is low and on the order of 0.4-5 degrees. The key reason is that the magnetic torque is two-dimensional and it is only in the plane perpendicular to the magnetic field vector. In this paper novel attitude control algorithms using the combination of magnetic actuators with Reaction Wheel Assembles (RWAs) or other types of actuators, such as thrusters, are presented. The combination of magnetic actuators with one or two RWAs aligned with different body axis expands the two-dimensional control torque to three-dimensional. The algorithms can guarantee the spacecraft attitude and rates to track the commanded attitude precisely. A design example is presented for Nadir pointing, pitch and yaw maneuvers. The results show that precise attitude tracking can be reached and the attitude control accuracy is comparable with RWAs based attitude control. The algorithms are also useful for the RWAs based attitude control. When there are only one or two workable RWAs due to RWA failures, the attitude control system can switch to the control algorithms for the combined magnetic actuators with the RWAs without going to the safe mode and the control accuracy can be maintained.

  9. Spacecraft Attitude Tracking and Maneuver Using Combined Magnetic Actuators

    Science.gov (United States)

    Zhou, Zhiqiang

    2012-01-01

    A paper describes attitude-control algorithms using the combination of magnetic actuators with reaction wheel assemblies (RWAs) or other types of actuators such as thrusters. The combination of magnetic actuators with one or two RWAs aligned with different body axis expands the two-dimensional control torque to three-dimensional. The algorithms can guarantee the spacecraft attitude and rates to track the commanded attitude precisely. A design example is presented for nadir-pointing, pitch, and yaw maneuvers. The results show that precise attitude tracking can be reached and the attitude- control accuracy is comparable with RWA-based attitude control. When there are only one or two workable RWAs due to RWA failures, the attitude-control system can switch to the control algorithms for the combined magnetic actuators with the RWAs without going to the safe mode, and the control accuracy can be maintained. The attitude-control algorithms of the combined actuators are derived, which can guarantee the spacecraft attitude and rates to track the commanded values precisely. Results show that precise attitude tracking can be reached, and the attitude-control accuracy is comparable with 3-axis wheel control.

  10. Method for Producing Launch/Landing Pads and Structures Project

    Science.gov (United States)

    Mueller, Robert P. (Compiler)

    2015-01-01

    Current plans for deep space exploration include building landing-launch pads capable of withstanding the rocket blast of much larger spacecraft that that of the Apollo days. The proposed concept will develop lightweight launch and landing pad materials from in-situ materials, utilizing regolith to produce controllable porous cast metallic foam brickstiles shapes. These shapes can be utilized to lay a landing launch platform, as a construction material or as more complex parts of mechanical assemblies.

  11. Formation of disintegration particles in spacecraft recorders

    International Nuclear Information System (INIS)

    Kurnosova, L.V.; Fradkin, M.I.; Razorenov, L.A.

    1986-01-01

    Experiments performed on the spacecraft Salyut 1, Kosmos 410, and Kosmos 443 enable us to record the disintegration products of particles which are formed in the material of the detectors on board the spacecraft. The observations were made by means of a delayed coincidence method. We have detected a meson component and also a component which is apparently associated with the generation of radioactive isotopes in the detectors

  12. Power requirements for commercial communications spacecraft

    Science.gov (United States)

    Billerbeck, W. J.

    1985-01-01

    Historical data on commercial spacecraft power systems are presented and their power requirements to the growth of satellite communications channel usage are related. Some approaches for estimating future power requirements of this class of spacecraft through the year 2000 are proposed. The key technology drivers in satellite power systems are addressed. Several technological trends in such systems are described, focusing on the most useful areas for research and development of major subsystems, including solar arrays, energy storage, and power electronics equipment.

  13. A Reconfigurable Testbed Environment for Spacecraft Autonomy

    Science.gov (United States)

    Biesiadecki, Jeffrey; Jain, Abhinandan

    1996-01-01

    A key goal of NASA's New Millennium Program is the development of technology for increased spacecraft on-board autonomy. Achievement of this objective requires the development of a new class of ground-based automony testbeds that can enable the low-cost and rapid design, test, and integration of the spacecraft autonomy software. This paper describes the development of an Autonomy Testbed Environment (ATBE) for the NMP Deep Space I comet/asteroid rendezvous mission.

  14. A design for a reusable water-based spacecraft known as the spacecoach

    CERN Document Server

    McConnell, Brian

    2016-01-01

     Based on components already in existence, this manual details a reference design for an interplanetary spacecraft that is simple, durable, fully reusable and comprised mostly of water. Using such an accessible material leads to a spacecraft architecture that is radically simpler, safer and cheaper than conventional capsule based designs. If developed, the potential affordability of the design will substantially open all of the inner solar system to human exploration. A spacecraft that is comprised mostly of water will be much more like a living cell or a terrarium than a conventional rocket and capsule design. It will use water for many purposes before it is superheated in electric engines for propulsion, purposes which include radiation shielding, heat management, basic life support, crew consumption and comfort. The authors coined the term "spacecoaches" to describe them, as an allusion to the Prairie Schooners of the Old West, which were simple, rugged, and could live off the land.

  15. Standardizing the information architecture for spacecraft operations

    Science.gov (United States)

    Easton, C. R.

    1994-01-01

    This paper presents an information architecture developed for the Space Station Freedom as a model from which to derive an information architecture standard for advanced spacecraft. The information architecture provides a way of making information available across a program, and among programs, assuming that the information will be in a variety of local formats, structures and representations. It provides a format that can be expanded to define all of the physical and logical elements that make up a program, add definitions as required, and import definitions from prior programs to a new program. It allows a spacecraft and its control center to work in different representations and formats, with the potential for supporting existing spacecraft from new control centers. It supports a common view of data and control of all spacecraft, regardless of their own internal view of their data and control characteristics, and of their communications standards, protocols and formats. This information architecture is central to standardizing spacecraft operations, in that it provides a basis for information transfer and translation, such that diverse spacecraft can be monitored and controlled in a common way.

  16. Attitude Estimation in Fractionated Spacecraft Cluster Systems

    Science.gov (United States)

    Hadaegh, Fred Y.; Blackmore, James C.

    2011-01-01

    An attitude estimation was examined in fractioned free-flying spacecraft. Instead of a single, monolithic spacecraft, a fractionated free-flying spacecraft uses multiple spacecraft modules. These modules are connected only through wireless communication links and, potentially, wireless power links. The key advantage of this concept is the ability to respond to uncertainty. For example, if a single spacecraft module in the cluster fails, a new one can be launched at a lower cost and risk than would be incurred with onorbit servicing or replacement of the monolithic spacecraft. In order to create such a system, however, it is essential to know what the navigation capabilities of the fractionated system are as a function of the capabilities of the individual modules, and to have an algorithm that can perform estimation of the attitudes and relative positions of the modules with fractionated sensing capabilities. Looking specifically at fractionated attitude estimation with startrackers and optical relative attitude sensors, a set of mathematical tools has been developed that specify the set of sensors necessary to ensure that the attitude of the entire cluster ( cluster attitude ) can be observed. Also developed was a navigation filter that can estimate the cluster attitude if these conditions are satisfied. Each module in the cluster may have either a startracker, a relative attitude sensor, or both. An extended Kalman filter can be used to estimate the attitude of all modules. A range of estimation performances can be achieved depending on the sensors used and the topology of the sensing network.

  17. Physical Properties of the MER and Beagle II Landing Sites on Mars

    Science.gov (United States)

    Jakosky, B. M.; Pelkey, S. M.; Mellon, M. T.; Putzig, N.; Martinez-Alonso, S.; Murphy, N.; Hynek, B.

    2003-12-01

    The ESA Beagle II and the NASA Mars Exploration Rover spacecraft are scheduled to land on the martian surface in December 2003 and January 2004, respectively. Mission operations and success depends on the physical properties of the surfaces on which they land. Surface structural characteristics such as the abundances of loose, unconsolidated fine material, of fine material that has been cemented into a duricrust, and of rocks affect the ability to safely land and to successfully sample and traverse the surface. Also, physical properties affect surface and atmospheric temperatures, which affect lander and rover functionality. We are in the process of analyzing surface temperature information for these sites, derived from MGS TES and Odyssey THEMIS daytime and nighttime measurements. Our approach is to: (i) remap thermal inertia using TES data at ~3-km resolution, to obtain the most complete coverage possible; (ii) interpret physical properties from TES coverage in conjunction with other remote-sensing data sets; (iii) map infrared brightness using daytime and nighttime THEMIS data at 100-m resolution, and do qualitative analysis of physical properties and processes; and (iv) derive thermal inertia from THEMIS nighttime data in conjunction with daytime albedo measurements derived from TES, THEMIS, and MOC observations. In addition, we will use measured temperatures and derived thermal inertia to predict surface temperatures for the periods of the missions.

  18. Approximation of attainable landing area of a moon lander by reachability analysis

    OpenAIRE

    Arslantas, Yunus; Oehlschlägel, Thimo; Sagliano, Marco; Theil, Stephan; Braxmaier, Claus

    2014-01-01

    Developments in space technology have paved the way for more challenging missions which require advanced guidance and control algorithms for safely and autonomously landing on celestial bodies. Instant determination of hazards, automatic guidance during landing maneuvers and likelihood maximization of safe landing are of paramount importance

  19. PRIORITY DIRECTIONS OF PROVISION OF STABLE LAND USE

    Directory of Open Access Journals (Sweden)

    L. Hun’ko

    2016-10-01

    Full Text Available The conditions of stable land use are highlighted in this article. The question of the territory of agricultural enterprises is considered as well. The characteristic of the type of land use is given here. The recommendations are shown on the formation of ecologically safe types of land use. In the terms of new land relations is important to resolve the issue of land use regulation to with stand landscapes against adverse natural and anthropogenic influences. The main instrument of the state, which aims to provide an ecologically permissible and economically effective land use, land use is as an important component of land relations. Planning should include a system of legal, technical, economic and environmental activities that will ensure the preservation, restoration and rational use of land and other natural resources for the benefit of the whole society. Keywords: land use, land management, stable development, landscape, soil erosion, protection of land.

  20. Internal Acoustics of the ISS and Other Spacecraft

    Science.gov (United States)

    Allen, Christopher S.

    2017-01-01

    It is important to control the acoustic environment inside spacecraft and space habitats to protect for astronaut communications, alarm audibility, and habitability, and to reduce astronauts' risk for sleep disturbance, and hear-ing loss. But this is not an easy task, given the various design trade-offs, and it has been difficult, historically, to achieve. Over time it has been found that successful control of spacecraft acoustic levels is achieved by levying firm requirements at the system-level, using a systems engineering approach for design and development, and then validating these requirements with acoustic testing. In the systems engineering method, the system-level requirements must be flowed down to sub-systems and component noise sources, using acoustic analysis and acoustic modelling to develop allocated requirements for the sub-systems and components. Noise controls must also be developed, tested, and implemented so the sub-systems and components can achieve their allocated limits. It is also important to have management support for acoustics efforts to maintain their priority against the various trade-offs, including mass, volume, power, cost, and schedule. In this extended abstract and companion presentation, the requirements, approach, and results for controlling acoustic levels in most US spacecraft since Apollo will be briefly discussed. The approach for controlling acoustic levels in the future US space vehicle, Orion Multipurpose Crew Vehicle (MPCV), will also be briefly discussed. These discussions will be limited to the control of continuous noise inside the space vehicles. Other types of noise, such as launch, landing, and abort noise, intermittent noise, Extra-Vehicular Activity (EVA) noise, emergency operations/off-nominal noise, noise exposure, and impulse noise are important, but will not be discussed because of time limitations.

  1. Large-Scale Spacecraft Fire Safety Tests

    Science.gov (United States)

    Urban, David; Ruff, Gary A.; Ferkul, Paul V.; Olson, Sandra; Fernandez-Pello, A. Carlos; T'ien, James S.; Torero, Jose L.; Cowlard, Adam J.; Rouvreau, Sebastien; Minster, Olivier; hide

    2014-01-01

    An international collaborative program is underway to address open issues in spacecraft fire safety. Because of limited access to long-term low-gravity conditions and the small volume generally allotted for these experiments, there have been relatively few experiments that directly study spacecraft fire safety under low-gravity conditions. Furthermore, none of these experiments have studied sample sizes and environment conditions typical of those expected in a spacecraft fire. The major constraint has been the size of the sample, with prior experiments limited to samples of the order of 10 cm in length and width or smaller. This lack of experimental data forces spacecraft designers to base their designs and safety precautions on 1-g understanding of flame spread, fire detection, and suppression. However, low-gravity combustion research has demonstrated substantial differences in flame behavior in low-gravity. This, combined with the differences caused by the confined spacecraft environment, necessitates practical scale spacecraft fire safety research to mitigate risks for future space missions. To address this issue, a large-scale spacecraft fire experiment is under development by NASA and an international team of investigators. This poster presents the objectives, status, and concept of this collaborative international project (Saffire). The project plan is to conduct fire safety experiments on three sequential flights of an unmanned ISS re-supply spacecraft (the Orbital Cygnus vehicle) after they have completed their delivery of cargo to the ISS and have begun their return journeys to earth. On two flights (Saffire-1 and Saffire-3), the experiment will consist of a flame spread test involving a meter-scale sample ignited in the pressurized volume of the spacecraft and allowed to burn to completion while measurements are made. On one of the flights (Saffire-2), 9 smaller (5 x 30 cm) samples will be tested to evaluate NASAs material flammability screening tests

  2. The trajectory prediction of spacecraft by grey method

    International Nuclear Information System (INIS)

    Wang, Qiyue; Wang, Zhongyu; Zhang, Zili; Wang, Yanqing; Zhou, Weihu

    2016-01-01

    The real-time and high-precision trajectory prediction of a moving object is a core technology in the field of aerospace engineering. The real-time monitoring and tracking technology are also significant guarantees of aerospace equipment. A dynamic trajectory prediction method called grey dynamic filter (GDF) which combines the dynamic measurement theory and grey system theory is proposed. GDF can use coordinates of the current period to extrapolate coordinates of the following period. At meantime, GDF can also keep the instantaneity of measured coordinates by the metabolism model. In this paper the optimal model length of GDF is firstly selected to improve the prediction accuracy. Then the simulation for uniformly accelerated motion and variably accelerated motion is conducted. The simulation results indicate that the mean composite position error of GDF prediction is one-fifth to that of Kalman filter (KF). By using a spacecraft landing experiment, the prediction accuracy of GDF is compared with the KF method and the primitive grey method (GM). The results show that the motion trajectory of spacecraft predicted by GDF is much closer to actual trajectory than the other two methods. The mean composite position error calculated by GDF is one-eighth to KF and one-fifth to GM respectively. (paper)

  3. The safe road transport system approach

    Directory of Open Access Journals (Sweden)

    Vollpracht Hans-Joachim

    2016-07-01

    Full Text Available More than 1,24 million people die each year on the worlds roads and between 20 to 50 million suffer from nonfatal injuries. The UN Road Safety Collaboration Meetings under the leadership of WHO developed the Programme for the Decade of Actions for road safety taking nations into the responsibility of improving their accident figures by the five pillars of a national Road Safety Policy, safer Roads, safer Vehicles, safer Road Users and Post Crash Care. It is this Safe System Approach that takes into consideration the land use, infrastructure and transport planning, road user’s abilities and limitations and the close cooperation of all governmental and none governmental stakeholders involved.

  4. Indoor Tanning Is Not Safe

    Science.gov (United States)

    ... the sun is by using these tips for skin cancer prevention. Indoor tanning is not a safe way to get vitamin ... to previous findings on the association between indoor tanning and skin cancer. Only a small number of people reported ...

  5. Alcohol use and safe drinking

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001944.htm Alcohol use and safe drinking To use the sharing features on this page, please enable JavaScript. Alcohol use involves drinking beer, wine, or hard liquor. ...

  6. Dukovany NPP - Safely 16 TERA

    International Nuclear Information System (INIS)

    Vlcek, J.

    2008-01-01

    In this presentation increasing of power output of the Dukovany NPP is reviewed. To operate all Dukovany Units safely with the perspective of long-term operation (LTO) of 50 - 60 years it is proposed.

  7. Safe drinking during cancer treatment

    Science.gov (United States)

    ... ency/patientinstructions/000060.htm Drinking water safely during cancer treatment To use the sharing features on this page, please enable JavaScript. During and right after your cancer treatment, your body may not be able to protect ...

  8. Safe handling of radiation sources

    International Nuclear Information System (INIS)

    Abd Nasir Ibrahim; Azali Muhammad; Ab Razak Hamzah; Abd Aziz Mohamed; Mohammad Pauzi Ismail

    2004-01-01

    This chapter discussed the subjects related to the safe handling of radiation sources: type of radiation sources, method of use: transport within premises, transport outside premises; Disposal of Gamma Sources

  9. REQUIREMENTS FOR IMAGE QUALITY OF EMERGENCY SPACECRAFTS

    Directory of Open Access Journals (Sweden)

    A. I. Altukhov

    2015-05-01

    Full Text Available The paper deals with the method for formation of quality requirements to the images of emergency spacecrafts. The images are obtained by means of remote sensing of near-earth space orbital deployment in the visible range. of electromagnetic radiation. The method is based on a joint taking into account conditions of space survey, characteristics of surveillance equipment, main design features of the observed spacecrafts and orbital inspection tasks. Method. Quality score is the predicted linear resolution image that gives the possibility to create a complete view of pictorial properties of the space image obtained by electro-optical system from the observing satellite. Formulation of requirements to the numerical value of this indicator is proposed to perform based on the properties of remote sensing system, forming images in the conditions of outer space, and the properties of the observed emergency spacecraft: dimensions, platform construction of the satellite, on-board equipment placement. For method implementation the authors have developed a predictive model of requirements to a linear resolution for images of emergency spacecrafts, making it possible to select the intervals of space shooting and get the satellite images required for quality interpretation. Main results. To verify the proposed model functionality we have carried out calculations of the numerical values for the linear resolution of the image, ensuring the successful task of determining the gross structural damage of the spacecrafts and identifying changes in their spatial orientation. As input data were used with dimensions and geometric primitives corresponding to the shape of deemed inspected spacecrafts: Resurs-P", "Canopus-B", "Electro-L". Numerical values of the linear resolution images have been obtained, ensuring the successful task solution for determining the gross structural damage of spacecrafts.

  10. Towards Safe Robotic Surgical Systems

    DEFF Research Database (Denmark)

    Sloth, Christoffer; Wisniewski, Rafael

    2015-01-01

    a controller for motion compensation in beating-heart surgery, and prove that it is safe, i.e., the surgical tool is kept within an allowable distance and orientation of the heart. We solve the problem by simultaneously finding a control law and a barrier function. The motion compensation system is simulated...... from several initial conditions to demonstrate that the designed control system is safe for every admissible initial condition....

  11. Safe use of ionizing radiations

    Energy Technology Data Exchange (ETDEWEB)

    1973-01-01

    Based on the ''Code of Practice for the protection of persons against ionizing radiations arising from medical and dental use'' (CIS 74-423), this handbook shows how hospital staff can avoid exposing themselves and others to these hazards. It is designed particularly for junior and student nurses. Contents: ionizing radiations, their types and characteristics; their uses and dangers; basic principles in their safe use; safe use in practice; explanation of terms.

  12. Staying Safe in the Water

    Centers for Disease Control (CDC) Podcasts

    2008-05-15

    In this podcast, Dr. Julie Gilchrist, a pediatrician and medical epidemiologist from CDC’s Injury Center, talks about staying safe in the water. Tips are for all audiences, with a focus on preventing drownings and keeping children safe in and around the pool, lake, or ocean.  Created: 5/15/2008 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 5/19/2008.

  13. Federal Lands

    Data.gov (United States)

    Department of Homeland Security — This map layer consists of federally owned or administered lands of theUnited States, Puerto Rico, and the U.S. Virgin Islands. Only areas of 640 acres or more are...

  14. Land Research

    Science.gov (United States)

    EPA is working to develop methods and guidance to manage and clean up contaminated land, groundwater and nutrient pollution as well as develop innovative approaches to managing materials and waste including energy recovery.

  15. Modeling the fundamental characteristics and processes of the spacecraft functioning

    Science.gov (United States)

    Bazhenov, V. I.; Osin, M. I.; Zakharov, Y. V.

    1986-01-01

    The fundamental aspects of modeling of spacecraft characteristics by using computing means are considered. Particular attention is devoted to the design studies, the description of physical appearance of the spacecraft, and simulated modeling of spacecraft systems. The fundamental questions of organizing the on-the-ground spacecraft testing and the methods of mathematical modeling were presented.

  16. Vapor-Compression Heat Pumps for Operation Aboard Spacecraft

    Science.gov (United States)

    Ruemmele, Warren; Ungar, Eugene; Cornwell, John

    2006-01-01

    Vapor-compression heat pumps (including both refrigerators and heat pumps) of a proposed type would be capable of operating in microgravity and would be safe to use in enclosed environments like those of spacecraft. The designs of these pumps would incorporate modifications of, and additions to, vapor-compression cycles of heat pumps now used in normal Earth gravitation, in order to ensure efficiency and reliability during all phases of operation, including startup, shutdown, nominal continuous operation, and peak operation. Features of such a design might include any or all of the following: (1) Configuring the compressor, condenser, evaporator, valves, capillary tubes (if any), and controls to function in microgravitation; (2) Selection of a working fluid that satisfies thermodynamic requirements and is safe to use in a closed crew compartment; (3) Incorporation of a solenoid valve and/or a check valve to prevent influx of liquid to the compressor upon startup (such influx could damage the compressor); (4) Use of a diode heat pipe between the cold volume and the evaporator to limit the influx of liquid to the compressor upon startup; and (5) Use of a heated block to vaporize any liquid that arrives at the compressor inlet.

  17. Robust Spacecraft Component Detection in Point Clouds

    Directory of Open Access Journals (Sweden)

    Quanmao Wei

    2018-03-01

    Full Text Available Automatic component detection of spacecraft can assist in on-orbit operation and space situational awareness. Spacecraft are generally composed of solar panels and cuboidal or cylindrical modules. These components can be simply represented by geometric primitives like plane, cuboid and cylinder. Based on this prior, we propose a robust automatic detection scheme to automatically detect such basic components of spacecraft in three-dimensional (3D point clouds. In the proposed scheme, cylinders are first detected in the iteration of the energy-based geometric model fitting and cylinder parameter estimation. Then, planes are detected by Hough transform and further described as bounded patches with their minimum bounding rectangles. Finally, the cuboids are detected with pair-wise geometry relations from the detected patches. After successive detection of cylinders, planar patches and cuboids, a mid-level geometry representation of the spacecraft can be delivered. We tested the proposed component detection scheme on spacecraft 3D point clouds synthesized by computer-aided design (CAD models and those recovered by image-based reconstruction, respectively. Experimental results illustrate that the proposed scheme can detect the basic geometric components effectively and has fine robustness against noise and point distribution density.

  18. Robust Spacecraft Component Detection in Point Clouds.

    Science.gov (United States)

    Wei, Quanmao; Jiang, Zhiguo; Zhang, Haopeng

    2018-03-21

    Automatic component detection of spacecraft can assist in on-orbit operation and space situational awareness. Spacecraft are generally composed of solar panels and cuboidal or cylindrical modules. These components can be simply represented by geometric primitives like plane, cuboid and cylinder. Based on this prior, we propose a robust automatic detection scheme to automatically detect such basic components of spacecraft in three-dimensional (3D) point clouds. In the proposed scheme, cylinders are first detected in the iteration of the energy-based geometric model fitting and cylinder parameter estimation. Then, planes are detected by Hough transform and further described as bounded patches with their minimum bounding rectangles. Finally, the cuboids are detected with pair-wise geometry relations from the detected patches. After successive detection of cylinders, planar patches and cuboids, a mid-level geometry representation of the spacecraft can be delivered. We tested the proposed component detection scheme on spacecraft 3D point clouds synthesized by computer-aided design (CAD) models and those recovered by image-based reconstruction, respectively. Experimental results illustrate that the proposed scheme can detect the basic geometric components effectively and has fine robustness against noise and point distribution density.

  19. Spacecraft Internal Acoustic Environment Modeling

    Science.gov (United States)

    Chu, SShao-sheng R.; Allen, Christopher S.

    2009-01-01

    carried out by acquiring octave band microphone data simultaneously at ten fixed locations throughout the mockup. SPLs (Sound Pressure Levels) predicted by our SEA model match well with measurements for our CM mockup, with a more complicated shape. Additionally in FY09, background NC noise (Noise Criterion) simulation and MRT (Modified Rhyme Test) were developed and performed in the mockup to determine the maximum noise level in CM habitable volume for fair crew voice communications. Numerous demonstrations of simulated noise environment in the mockup and associated SIL (Speech Interference Level) via MRT were performed for various communities, including members from NASA and Orion prime-/sub-contractors. Also, a new HSIR (Human-Systems Integration Requirement) for limiting pre- and post-landing SIL was proposed.

  20. Attitude coordination for spacecraft formation with multiple communication delays

    Directory of Open Access Journals (Sweden)

    Guo Yaohua

    2015-04-01

    Full Text Available Communication delays are inherently present in information exchange between spacecraft and have an effect on the control performance of spacecraft formation. In this work, attitude coordination control of spacecraft formation is addressed, which is in the presence of multiple communication delays between spacecraft. Virtual system-based approach is utilized in case that a constant reference attitude is available to only a part of the spacecraft. The feedback from the virtual systems to the spacecraft formation is introduced to maintain the formation. Using backstepping control method, input torque of each spacecraft is designed such that the attitude of each spacecraft converges asymptotically to the states of its corresponding virtual system. Furthermore, the backstepping technique and the Lyapunov–Krasovskii method contribute to the control law design when the reference attitude is time-varying and can be obtained by each spacecraft. Finally, effectiveness of the proposed methodology is illustrated by the numerical simulations of a spacecraft formation.

  1. Developing Sustainable Spacecraft Water Management Systems

    Science.gov (United States)

    Thomas, Evan A.; Klaus, David M.

    2009-01-01

    It is well recognized that water handling systems used in a spacecraft are prone to failure caused by biofouling and mineral scaling, which can clog mechanical systems and degrade the performance of capillary-based technologies. Long duration spaceflight applications, such as extended stays at a Lunar Outpost or during a Mars transit mission, will increasingly benefit from hardware that is generally more robust and operationally sustainable overtime. This paper presents potential design and testing considerations for improving the reliability of water handling technologies for exploration spacecraft. Our application of interest is to devise a spacecraft wastewater management system wherein fouling can be accommodated by design attributes of the management hardware, rather than implementing some means of preventing its occurrence.

  2. Embedded Thermal Control for Spacecraft Subsystems Miniaturization

    Science.gov (United States)

    Didion, Jeffrey R.

    2014-01-01

    Optimization of spacecraft size, weight and power (SWaP) resources is an explicit technical priority at Goddard Space Flight Center. Embedded Thermal Control Subsystems are a promising technology with many cross cutting NSAA, DoD and commercial applications: 1.) CubeSatSmallSat spacecraft architecture, 2.) high performance computing, 3.) On-board spacecraft electronics, 4.) Power electronics and RF arrays. The Embedded Thermal Control Subsystem technology development efforts focus on component, board and enclosure level devices that will ultimately include intelligent capabilities. The presentation will discuss electric, capillary and hybrid based hardware research and development efforts at Goddard Space Flight Center. The Embedded Thermal Control Subsystem development program consists of interrelated sub-initiatives, e.g., chip component level thermal control devices, self-sensing thermal management, advanced manufactured structures. This presentation includes technical status and progress on each of these investigations. Future sub-initiatives, technical milestones and program goals will be presented.

  3. Low power arcjet system spacecraft impacts

    Science.gov (United States)

    Pencil, Eric J.; Sarmiento, Charles J.; Lichtin, D. A.; Palchefsky, J. W.; Bogorad, A. L.

    1993-01-01

    Potential plume contamination of spacecraft surfaces was investigated by positioning spacecraft material samples relative to an arcjet thruster. Samples in the simulated solar array region were exposed to the cold gas arcjet plume for 40 hrs to address concerns about contamination by backstreaming diffusion pump oil. Except for one sample, no significant changes were measured in absorptance and emittance within experimental error. Concerns about surface property degradation due to electrostatic discharges led to the investigation of the discharge phenomenon of charged samples during arcjet ignition. Short duration exposure of charged samples demonstrated that potential differences are consistently and completely eliminated within the first second of exposure to a weakly ionized plume. The spark discharge mechanism was not the discharge phenomenon. The results suggest that the arcjet could act as a charge control device on spacecraft.

  4. Relativistic Spacecraft Propelled by Directed Energy

    Science.gov (United States)

    Kulkarni, Neeraj; Lubin, Philip; Zhang, Qicheng

    2018-04-01

    Achieving relativistic flight to enable extrasolar exploration is one of the dreams of humanity and the long-term goal of our NASA Starlight program. We derive a relativistic solution for the motion of a spacecraft propelled by radiation pressure from a directed energy (DE) system. Depending on the system parameters, low-mass spacecraft can achieve relativistic speeds, thus enabling interstellar exploration. The diffraction of the DE system plays an important role and limits the maximum speed of the spacecraft. We consider “photon recycling” as a possible method to achieving higher speeds. We also discuss recent claims that our previous work on this topic is incorrect and show that these claims arise from an improper treatment of causality.

  5. Numerical Analysis of Magnetic Sail Spacecraft

    International Nuclear Information System (INIS)

    Sasaki, Daisuke; Yamakawa, Hiroshi; Usui, Hideyuki; Funaki, Ikkoh; Kojima, Hirotsugu

    2008-01-01

    To capture the kinetic energy of the solar wind by creating a large magnetosphere around the spacecraft, magneto-plasma sail injects a plasma jet into a strong magnetic field produced by an electromagnet onboard the spacecraft. The aim of this paper is to investigate the effect of the IMF (interplanetary magnetic field) on the magnetosphere of magneto-plasma sail. First, using an axi-symmetric two-dimensional MHD code, we numerically confirm the magnetic field inflation, and the formation of a magnetosphere by the interaction between the solar wind and the magnetic field. The expansion of an artificial magnetosphere by the plasma injection is then simulated, and we show that the magnetosphere is formed by the interaction between the solar wind and the magnetic field expanded by the plasma jet from the spacecraft. This simulation indicates the size of the artificial magnetosphere becomes smaller when applying the IMF.

  6. LAND REFORM IN UKRAINE: HISTORIOGRAPHICAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Barantsov B.

    2016-05-01

    Full Text Available Modern land reform, that continues in Ukraine since the beginning of the 90-th of ХХ century, is a logical result of the functioning of society and the state.. It’s prerequisites becames, especially full monopolization of state on ownership of land; absence of payment for land as one of the means of ensuring the rational use of lands; absence on workers motivation for intensive work on the land, etc.. These and other preconditions contributed to soil degradation, production of agricultural products with exceeding of maximum allowable concentrations of pollutants, development of diseases, undermine the gene pool of nature and man. Mentioned reasons determined the goal and objectives of modern land reform, which were originally set out in the preamble to the Resolution of the Verkhovna Rada of Ukraine from December 18, 1990 «On Land Reform» with following changes and additions, and in the implementation of the land-reformation measures gained more complete content. Conducted analysis shows that land reform in Ukraine leads to a change of ownership of land, contributes to solving problems of citizens by land plots, enactment of payment for land usecreation of conditions for the development of land market. Thus changing land relations, is formed legal and regulatory framework of land reform and land market. However, positive developments in the implementation of land reform to end of the 90-th years have not led to a radical and effective upgrade of agricultural production, recovery of investment processes in other branches of industry, improving of welfare of the population. Land reform measures didn’t receive adequate financial support. The ultimate goal - an economically-effective and environmentally safe use of land in Ukraine - has not been achieved. Further reforming of land relations contributed to the adoption in October 2001 of the Land Code of Ukraine in the new edition that created the legal principles of land reform. Since it

  7. Autonomous Spacecraft Communication Interface for Load Planning

    Science.gov (United States)

    Dever, Timothy P.; May, Ryan D.; Morris, Paul H.

    2014-01-01

    Ground-based controllers can remain in continuous communication with spacecraft in low Earth orbit (LEO) with near-instantaneous communication speeds. This permits near real-time control of all of the core spacecraft systems by ground personnel. However, as NASA missions move beyond LEO, light-time communication delay issues, such as time lag and low bandwidth, will prohibit this type of operation. As missions become more distant, autonomous control of manned spacecraft will be required. The focus of this paper is the power subsystem. For present missions, controllers on the ground develop a complete schedule of power usage for all spacecraft components. This paper presents work currently underway at NASA to develop an architecture for an autonomous spacecraft, and focuses on the development of communication between the Mission Manager and the Autonomous Power Controller. These two systems must work together in order to plan future load use and respond to unanticipated plan deviations. Using a nominal spacecraft architecture and prototype versions of these two key components, a number of simulations are run under a variety of operational conditions, enabling development of content and format of the messages necessary to achieve the desired goals. The goals include negotiation of a load schedule that meets the global requirements (contained in the Mission Manager) and local power system requirements (contained in the Autonomous Power Controller), and communication of off-plan disturbances that arise while executing a negotiated plan. The message content is developed in two steps: first, a set of rapid-prototyping "paper" simulations are preformed; then the resultant optimized messages are codified for computer communication for use in automated testing.

  8. Inherently safe light water reactors

    International Nuclear Information System (INIS)

    Ise, Takeharu

    1987-01-01

    Today's large nuclear power reactors of world-wise use have been designed based on the philosophy. It seems that recent less electricity demand rates, higher capital cost and the TMI accident let us acknowledge relative small and simplified nuclear plants with safer features, and that Chernobyl accident in 1983 underlines the needs of intrinsic and passive safety characteristics. In such background, several inherently safe reactor concepts have been presented abroad and domestically. First describing 'Can inherently safe reactors be designed,' then I introduce representative reactor concepts of inherently safe LWRs advocated abroad so far. All of these innovative reactors employ intrinsic and passive features in their design, as follows: (1) PIUS, an acronym for Process Inherent Ultimate Safety, or an integral PWR with passive heat sink and passive shutdown mechanism, advocated by ASEA-ATOM of Sweden. (2) MAP(Minimum Attention Plant), or a self-pressurized, natural circulation integral PWR, promoted by CE Inc. of the U.S. (3) TPS(TRIGA Power System), or a compact PWR with passive heat sink and inherent fuel characteristics of large prompt temperature coefficient, prompted by GA Technologies Inc. of the U.S. (4) PIUS-BWR, or an inherently safe BWR employing passively actuated fluid valves, in competition with PIUS, prompted by ORNL of the U.S. Then, I will describe the domestic trends in Japan and the innovative inherently safe LWRs presented domestically so far. (author)

  9. Operational Philosophy Concerning Manned Spacecraft Cabin Leaks

    Science.gov (United States)

    DeSimpelaere, Edward

    2011-01-01

    The last thirty years have seen the Space Shuttle as the prime United States spacecraft for manned spaceflight missions. Many lessons have been learned about spacecraft design and operation throughout these years. Over the next few decades, a large increase of manned spaceflight in the commercial sector is expected. This will result in the exposure of commercial crews and passengers to many of the same risks crews of the Space Shuttle have encountered. One of the more dire situations that can be encountered is the loss of pressure in the habitable volume of the spacecraft during on orbit operations. This is referred to as a cabin leak. This paper seeks to establish a general cabin leak response philosophy with the intent of educating future spacecraft designers and operators. After establishing a relative definition for a cabin leak, the paper covers general descriptions of detection equipment, detection methods, and general operational methods for management of a cabin leak. Subsequently, all these items are addressed from the perspective of the Space Shuttle Program, as this will be of the most value to future spacecraft due to similar operating profiles. Emphasis here is placed upon why and how these methods and philosophies have evolved to meet the Space Shuttle s needs. This includes the core ideas of: considerations of maintaining higher cabin pressures vs. lower cabin pressures, the pros and cons of a system designed to feed the leak with gas from pressurized tanks vs. using pressure suits to protect against lower cabin pressures, timeline and consumables constraints, re-entry considerations with leaks of unknown origin, and the impact the International Space Station (ISS) has had to the standard Space Shuttle cabin leak response philosophy. This last item in itself includes: procedural management differences, hardware considerations, additional capabilities due to the presence of the ISS and its resource, and ISS docking/undocking considerations with a

  10. Testing programs for the Multimission Modular Spacecraft

    Science.gov (United States)

    Greenwell, T. J.

    1978-01-01

    The Multimission Modular Spacecraft (MMS) provides a standard spacecraft bus to a user for a variety of space missions ranging from near-earth to synchronous orbits. The present paper describes the philosophy behind the MMS module test program and discusses the implementation of the test program. It is concluded that the MMS module test program provides an effective and comprehensive customer buy-off at the subsystem contractor's plant, is an optimum approach for checkout of the subsystems prior to use for on-orbit servicing in the Shuttle Cargo Bay, and is a cost-effective technique for environmental testing.

  11. Robust Parametric Control of Spacecraft Rendezvous

    Directory of Open Access Journals (Sweden)

    Dake Gu

    2014-01-01

    Full Text Available This paper proposes a method to design the robust parametric control for autonomous rendezvous of spacecrafts with the inertial information with uncertainty. We consider model uncertainty of traditional C-W equation to formulate the dynamic model of the relative motion. Based on eigenstructure assignment and model reference theory, a concise control law for spacecraft rendezvous is proposed which could be fixed through solving an optimization problem. The cost function considers the stabilization of the system and other performances. Simulation results illustrate the robustness and effectiveness of the proposed control.

  12. Spacecraft charging: incoming and outgoing electrons

    CERN Document Server

    Lai, Shu T.

    2013-04-22

    This paper presents an overview of the roles played by incoming and outgoing electrons in spacecraft surface and stresses the importance of surface conditions for spacecraft charging. The balance between the incoming electron current from the ambient plasma and the outgoing currents of secondary electrons, backscattered electrons, and photoelectrons from the surfaces determines the surface potential. Since surface conditions significantly affect the outgoing currents, the critical temperature and the surface potential are also significantly affected. As a corollary, high level differential charging of adjacent surfaces with very different surface conditions is a space hazard.

  13. Event-triggered attitude control of spacecraft

    Science.gov (United States)

    Wu, Baolin; Shen, Qiang; Cao, Xibin

    2018-02-01

    The problem of spacecraft attitude stabilization control system with limited communication and external disturbances is investigated based on an event-triggered control scheme. In the proposed scheme, information of attitude and control torque only need to be transmitted at some discrete triggered times when a defined measurement error exceeds a state-dependent threshold. The proposed control scheme not only guarantees that spacecraft attitude control errors converge toward a small invariant set containing the origin, but also ensures that there is no accumulation of triggering instants. The performance of the proposed control scheme is demonstrated through numerical simulation.

  14. The spacecraft encounters of Comet Halley

    Science.gov (United States)

    Asoka Mendis, D.; Tsurutani, Bruce T.

    1986-01-01

    The characteristics of the Comet Halley spacecraft 'fleet' (VEGA 1 and VEGA 2, Giotto, Suisei, and Sakigake) are presented. The major aims of these missions were (1) to discover and characterize the nucleus, (2) to characterize the atmosphere and ionosphere, (3) to characterize the dust, and (4) to characterize the nature of the large-scale comet-solar wind interaction. While the VEGA and Giotto missions were designed to study all four areas, Suisei addressed the second and fourth. Sakigake was designed to study the solar wind conditions upstream of the comet. It is noted that NASA's Deep Space Network played an important role in spacecraft tracking.

  15. Land use

    International Nuclear Information System (INIS)

    Rickard, W.H.; Rogers, L.E.

    1977-01-01

    Justification for large land holdings at the Hanford Reservation has centered around a need for security and also as a buffer zone in the event of accidents. In recent years the importance of these large land holdings have become nationally recognized as highly desirable locations for ecological research concerning the function and structure of terrestrial ecosystems and as places to investigate the response of terrestrial ecosystems to long-term man-imposed environmental stresses. Carefully selected and protected land areas exist on the 110 square mile Arid Land Ecology Reserve (ALE) at Hanford. The projects described here provide supporting research for several applied projects that deal with environmental impact and land restoration. Information gained from this research has wide use and applicability to all kinds of energy technologies centered in the semi-arid shrub-steppe region of the northwestern United States. Ecological information reported includes: biotic characterization, including description of major habitats and endangered or threatened species; performances of native plant species, including determination of growth habits, nutrient requirements, and productivity; and, mineral cycling, including particularly the estimation of availability and behavior of airborne deposits to green plants

  16. Prospects for inherently safe reactors

    International Nuclear Information System (INIS)

    Barkenbus, J.N.

    1988-01-01

    Public fears over nuclear safety have led some within the nuclear community to investigate the possibility of producing inherently safe nuclear reactors; that is, reactors that are transparently incapable of producing a core melt. While several promising designs of such reactors have been produced, support for large-scale research and development efforts has not been forthcoming. The prospects for commercialization of inherently safe reactors, therefore, are problematic; possible events such as further nuclear reactor accidents and superpower summits, could alter the present situation significantly. (author)

  17. Is nuclear power safe enough

    Energy Technology Data Exchange (ETDEWEB)

    Andresen, A F [Institutt for Atomenergi, Kjeller (Norway)

    1979-01-01

    The lecture formed a commentary on the report of the Norwegian Government's Commission on Nuclear power Safety which was published in October 1978. It was introductorily pointed out that 'safe' and 'safety' are not in themselves meaningful terms and that the probability of an occurrence is the real measure. The main items in the Commission's report have been core meltdown, releases during reprocessing, waste disposal, plutonium diversion and environmental impacts. The 21 members of the Commission were unanimous in 7 of the 8 chapters. In chapter 2, 'Summary and Conclusions', 3 members dissented from the majority opinion, that, subject to certain conditions, nuclear power was a safe and acceptable source of energy.

  18. Safe and Liquid Mortgage Bonds

    DEFF Research Database (Denmark)

    Dick-Nielsen, Jens; Gyntelberg, Jacob; Lund, Jesper

    This paper shows that strict match pass-through funding of covered bonds provides safe and liquid mortgage bonds. Despite a 30% drop in house prices during the 2008 global crisis Danish mortgage bonds remained as liquid as most European government bonds. The Danish pass-through system effectively...... eliminates credit risk from the investor's perspective. Similar to other safe bonds, funding liquidity becomes the main driver of mortgage bond liquidity and this creates commonality in liquidity across markets and countries. These findings have implications for how to design a robust mortgage bond system...

  19. Modeling the Complex Dynamics of Landscape Development: Applications for Land Management

    National Research Council Canada - National Science Library

    Istanbulluoglu, Erkan; Flores, Homero; Bras, Rafael L

    2004-01-01

    .... Thus, remedial soil and land conservation plans are vitally important to stabilize erosion and use the land more safely for Army activities while complying with environmental regulations and standards...

  20. Software for Engineering Simulations of a Spacecraft

    Science.gov (United States)

    Shireman, Kirk; McSwain, Gene; McCormick, Bernell; Fardelos, Panayiotis

    2005-01-01

    Spacecraft Engineering Simulation II (SES II) is a C-language computer program for simulating diverse aspects of operation of a spacecraft characterized by either three or six degrees of freedom. A functional model in SES can include a trajectory flight plan; a submodel of a flight computer running navigational and flight-control software; and submodels of the environment, the dynamics of the spacecraft, and sensor inputs and outputs. SES II features a modular, object-oriented programming style. SES II supports event-based simulations, which, in turn, create an easily adaptable simulation environment in which many different types of trajectories can be simulated by use of the same software. The simulation output consists largely of flight data. SES II can be used to perform optimization and Monte Carlo dispersion simulations. It can also be used to perform simulations for multiple spacecraft. In addition to its generic simulation capabilities, SES offers special capabilities for space-shuttle simulations: for this purpose, it incorporates submodels of the space-shuttle dynamics and a C-language version of the guidance, navigation, and control components of the space-shuttle flight software.

  1. How Spacecraft Fly Spaceflight Without Formulae

    CERN Document Server

    Swinerd, Graham

    2009-01-01

    About half a century ago a small satellite, Sputnik 1, was launched. The satellite did very little other than to transmit a radio signal to announce its presence in orbit. However, this humble beginning heralded the dawn of the Space Age. Today literally thousands of robotic spacecraft have been launched, many of which have flown to far-flung regions of the Solar System carrying with them the human spirit of scientific discovery and exploration. Numerous other satellites have been launched in orbit around the Earth providing services that support our technological society on the ground. How Spacecraft Fly: Spaceflight Without Formulae by Graham Swinerd focuses on how these spacecraft work. The book opens with a historical perspective of how we have come to understand our Solar System and the Universe. It then progresses through orbital flight, rocket science, the hostile environment within which spacecraft operate, and how they are designed. The concluding chapters give a glimpse of what the 21st century may ...

  2. Microgravity Flammability Experiments for Spacecraft Fire Safety

    DEFF Research Database (Denmark)

    Legros, Guillaume; Minster, Olivier; Tóth, Balazs

    2012-01-01

    As fire behaviour in manned spacecraft still remains poorly understood, an international topical team has been created to design a validation experiment that has an unprecedented large scale for a microgravity flammability experiment. While the validation experiment is being designed for a re-sup...

  3. Parameter Estimation of Spacecraft Fuel Slosh Model

    Science.gov (United States)

    Gangadharan, Sathya; Sudermann, James; Marlowe, Andrea; Njengam Charles

    2004-01-01

    Fuel slosh in the upper stages of a spinning spacecraft during launch has been a long standing concern for the success of a space mission. Energy loss through the movement of the liquid fuel in the fuel tank affects the gyroscopic stability of the spacecraft and leads to nutation (wobble) which can cause devastating control issues. The rate at which nutation develops (defined by Nutation Time Constant (NTC can be tedious to calculate and largely inaccurate if done during the early stages of spacecraft design. Pure analytical means of predicting the influence of onboard liquids have generally failed. A strong need exists to identify and model the conditions of resonance between nutation motion and liquid modes and to understand the general characteristics of the liquid motion that causes the problem in spinning spacecraft. A 3-D computerized model of the fuel slosh that accounts for any resonant modes found in the experimental testing will allow for increased accuracy in the overall modeling process. Development of a more accurate model of the fuel slosh currently lies in a more generalized 3-D computerized model incorporating masses, springs and dampers. Parameters describing the model include the inertia tensor of the fuel, spring constants, and damper coefficients. Refinement and understanding the effects of these parameters allow for a more accurate simulation of fuel slosh. The current research will focus on developing models of different complexity and estimating the model parameters that will ultimately provide a more realistic prediction of Nutation Time Constant obtained through simulation.

  4. Spacecraft 3D Augmented Reality Mobile App

    Science.gov (United States)

    Hussey, Kevin J.; Doronila, Paul R.; Kumanchik, Brian E.; Chan, Evan G.; Ellison, Douglas J.; Boeck, Andrea; Moore, Justin M.

    2013-01-01

    The Spacecraft 3D application allows users to learn about and interact with iconic NASA missions in a new and immersive way using common mobile devices. Using Augmented Reality (AR) techniques to project 3D renditions of the mission spacecraft into real-world surroundings, users can interact with and learn about Curiosity, GRAIL, Cassini, and Voyager. Additional updates on future missions, animations, and information will be ongoing. Using a printed AR Target and camera on a mobile device, users can get up close with these robotic explorers, see how some move, and learn about these engineering feats, which are used to expand knowledge and understanding about space. The software receives input from the mobile device's camera to recognize the presence of an AR marker in the camera's field of view. It then displays a 3D rendition of the selected spacecraft in the user's physical surroundings, on the mobile device's screen, while it tracks the device's movement in relation to the physical position of the spacecraft's 3D image on the AR marker.

  5. Accelerated life testing of spacecraft subsystems

    Science.gov (United States)

    Wiksten, D.; Swanson, J.

    1972-01-01

    The rationale and requirements for conducting accelerated life tests on electronic subsystems of spacecraft are presented. A method for applying data on the reliability and temperature sensitivity of the parts contained in a sybsystem to the selection of accelerated life test parameters is described. Additional considerations affecting the formulation of test requirements are identified, and practical limitations of accelerated aging are described.

  6. Rotational Motion Control of a Spacecraft

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Kulczycki, P.

    2001-01-01

    The paper adopts the energy shaping method to control of rotational motion. A global representation of the rigid body motion is given in the canonical form by a quaternion and its conjugate momenta. A general method for motion control on a cotangent bundle to the 3-sphere is suggested. The design...... algorithm is validated for three-axis spacecraft attitude control...

  7. Rotational motion control of a spacecraft

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Kulczycki, P.

    2003-01-01

    The paper adopts the energy shaping method to control of rotational motion. A global representation of the rigid body motion is given in the canonical form by a quaternion and its conjugate momenta. A general method for motion control on a cotangent bundle to the 3-sphere is suggested. The design...... algorithm is validated for three-axis spacecraft attitude control. Udgivelsesdato: APR...

  8. Small Spacecraft Technology Initiative Education Program

    Science.gov (United States)

    1995-01-01

    A NASA engineer with the Commercial Remote Sensing Program (CRSP) at Stennis Space Center works with students from W.P. Daniels High School in New Albany, Miss., through NASA's Small Spacecraft Technology Initiative Program. CRSP is teaching students to use remote sensing to locate a potential site for a water reservoir to offset a predicted water shortage in the community's future.

  9. Spacecraft Attitude Control in Hamiltonian Framework

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2000-01-01

    The objective of this paper is to give a design scheme for attitude control algorithms of a generic spacecraft. Along with the system model formulated in the Hamilton's canonical form the algorithm uses information about a required potential energy and a dissipative term. The control action...

  10. Streamlined Modeling for Characterizing Spacecraft Anomalous Behavior

    Science.gov (United States)

    Klem, B.; Swann, D.

    2011-09-01

    Anomalous behavior of on-orbit spacecraft can often be detected using passive, remote sensors which measure electro-optical signatures that vary in time and spectral content. Analysts responsible for assessing spacecraft operational status and detecting detrimental anomalies using non-resolved imaging sensors are often presented with various sensing and identification issues. Modeling and measuring spacecraft self emission and reflected radiant intensity when the radiation patterns exhibit a time varying reflective glint superimposed on an underlying diffuse signal contribute to assessment of spacecraft behavior in two ways: (1) providing information on body component orientation and attitude; and, (2) detecting changes in surface material properties due to the space environment. Simple convex and cube-shaped spacecraft, designed to operate without protruding solar panel appendages, may require an enhanced level of preflight characterization to support interpretation of the various physical effects observed during on-orbit monitoring. This paper describes selected portions of the signature database generated using streamlined signature modeling and simulations of basic geometry shapes apparent to non-imaging sensors. With this database, summarization of key observable features for such shapes as spheres, cylinders, flat plates, cones, and cubes in specific spectral bands that include the visible, mid wave, and long wave infrared provide the analyst with input to the decision process algorithms contained in the overall sensing and identification architectures. The models typically utilize baseline materials such as Kapton, paints, aluminum surface end plates, and radiators, along with solar cell representations covering the cylindrical and side portions of the spacecraft. Multiple space and ground-based sensors are assumed to be located at key locations to describe the comprehensive multi-viewing aspect scenarios that can result in significant specular reflection

  11. Lifetime of a spacecraft around a synchronous system of asteroids using a dipole model

    Science.gov (United States)

    dos Santos, Leonardo Barbosa Torres; de Almeida Prado, Antonio F. Bertachini; Sanchez, Diogo Merguizo

    2017-11-01

    Space missions allow us to expand our knowledge about the origin of the solar system. It is believed that asteroids and comets preserve the physical characteristics from the time that the solar system was created. For this reason, there was an increase of missions to asteroids in the past few years. To send spacecraft to asteroids or comets is challenging, since these objects have their own characteristics in several aspects, such as size, shape, physical properties, etc., which are often only discovered after the approach and even after the landing of the spacecraft. These missions must be developed with sufficient flexibility to adjust to these parameters, which are better determined only when the spacecraft reaches the system. Therefore, conducting a dynamic investigation of a spacecraft around a multiple asteroid system offers an extremely rich environment. Extracting accurate information through analytical approaches is quite challenging and requires a significant number of restrictive assumptions. For this reason, a numerical approach to the dynamics of a spacecraft in the vicinity of a binary asteroid system is offered in this paper. In the present work, the equations of the Restricted Synchronous Four-Body Problem (RSFBP) are used to model a binary asteroid system. The main objective of this work is to construct grids of initial conditions, which relates semi-major axis and eccentricity, in order to quantify the lifetime of a spacecraft when released close to the less massive body of the binary system (modeled as a rotating mass dipole). We performed an analysis of the lifetime of the spacecraft considering several mass ratios of a binary system of asteroids and investigating the behavior of a spacecraft in the vicinity of this system. We analyze direct and retrograde orbits. This study investigated orbits that survive for at least 500 orbital periods of the system (which is approximately one year), then not colliding or escaping from the system during this

  12. Benefits of a Single-Person Spacecraft for Weightless Operations

    Science.gov (United States)

    Griffin, Brand Norman

    2012-01-01

    Historically, less than 20 percent of crew time related to extravehicular activity (EVA) is spent on productive external work. For planetary operations space suits are still the logical choice; however for safe and rapid access to the weightless environment, spacecraft offer compelling advantages. FlexCraft, a concept for a single-person spacecraft, enables any-time access to space for short or long excursions by different astronauts. For the International Space Station (ISS), going outside is time-consuming, requiring pre-breathing, donning a fitted space suit, and pumping down an airlock. For each ISS EVA this is between 12.5 and 16 hours. FlexCraft provides immediate access to space because it operates with the same cabin atmosphere as its host. Furthermore, compared to the space suit pure oxygen environment, a mixed gas atmosphere lowers the fire risk and allows use of conventional materials and systems. For getting to the worksite, integral propulsion replaces hand-over-hand translation or having another crew member operate the robotic arm. This means less physical exertion and more time at the work site. Possibly more important, in case of an emergency, FlexCraft can return from the most distant point on ISS in less than a minute. The one-size-fits-all FlexCraft means no on-orbit inventory of parts or crew time required to fit all astronauts. With a shirtsleeve cockpit, conventional displays and controls are used, there is no suit trauma and because the work is not strenuous, no rest days are required. Furthermore, there is no need to collect hand tools because manipulators are equipped with force multiplying end-effectors that can deliver the precise torque for the job. FlexCraft is an efficient solution for asteroid exploration allowing all crew to use one vehicle with no risk of contamination. And, because FlexCraft is a vehicle, its design offers better radiation and micro-meteoroid protection than space suits.

  13. Safe-haven CDS Premia

    DEFF Research Database (Denmark)

    Klingler, Sven; Lando, David

    We argue that Credit Default Swap (CDS) premia for safe-haven sovereigns, like Germany and the United States, are driven to a large extent by regulatory requirements under which derivatives dealing banks have an incentive to buy CDS to hedge counterparty credit risk of their counterparties. We...

  14. Thermodynamics of asymptotically safe theories

    DEFF Research Database (Denmark)

    Rischke, Dirk H.; Sannino, Francesco

    2015-01-01

    We investigate the thermodynamic properties of a novel class of gauge-Yukawa theories that have recently been shown to be completely asymptotically safe, because their short-distance behaviour is determined by the presence of an interacting fixed point. Not only do all the coupling constants freeze...

  15. How Safe Are Our Libraries?

    Science.gov (United States)

    St. Lifer, Evan

    1994-01-01

    Addresses issues of safety and security in libraries. Topics discussed include keeping library collections safe; patron behavioral problems; factoring loss into the budget; staff theft; access versus security; apathy regarding library crime; a need for a unified security apparatus; preventive measures; staff and patron safety; and a…

  16. Safe disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Hooker, P.; Metcalfe, R.; Milodowski, T.; Holliday, D.

    1997-01-01

    A high degree of international cooperation has characterized the two studies reported here which aim to address whether radioactive waste can be disposed of safely. Using hydrogeochemical and mineralogical surveying techniques earth scientists from the British Geological Survey have sought to identify and characterise suitable disposal sites. Aspects of the studies are explored emphasising their cooperative nature. (UK)

  17. Staying Safe on the Water

    Centers for Disease Control (CDC) Podcasts

    2008-06-05

    In this podcast for all audiences, Dr. Julie Gilchrist from CDC's Injury Center outlines tips for safe boating.  Created: 6/5/2008 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 6/8/2008.

  18. Safe transport of radioactive material

    International Nuclear Information System (INIS)

    1994-01-01

    Delivering radioactive material to where it is needed is a vital service to industry and medicine. Millions of packages are shipped all over the world by all modes of transport. The shipments pass through public places and must meet stringent safety requirements. This video explains how radioactive material is safely transported and describes the rules that carriers and handlers must follow

  19. Working safely with ionising radiation

    International Nuclear Information System (INIS)

    McDowell, D.J.

    1990-01-01

    A small leaflet provides information on working safely with ionizing radiation. Topics covered include the types of radiation, radiological units, external radiation, contamination and internal radiation, methods of protection form radiation, radiation monitors, protective clothing for contamination, personal dosemeters, radiation dose limits for classified workers and finally the Ionising Radiations Regulations 1985. (UK)

  20. On the spacecraft attitude stabilization in the orbital frame

    Directory of Open Access Journals (Sweden)

    Antipov Kirill A.

    2012-01-01

    Full Text Available The paper deals with spacecraft in the circular near-Earth orbit. The spacecraft interacts with geomagnetic field by the moments of Lorentz and magnetic forces. The octupole approximation of the Earth’s magnetic field is accepted. The spacecraft electromagnetic parameters, namely the electrostatic charge moment of the first order and the eigen magnetic moment are the controlled quasiperiodic functions. The control algorithms for the spacecraft electromagnetic parameters, which allows to stabilize the spacecraft attitude position in the orbital frame are obtained. The stability of the spacecraft stabilized orientation is proved both analytically and by PC computations.

  1. Surface Properties and Characteristics of Mars Landing Sites from Remote Sensing Data and Ground Truth

    Science.gov (United States)

    Golombek, M. P.; Haldemann, A. F.; Simpson, R. A.; Furgason, R. L.; Putzig, N. E.; Huertas, A.; Arvidson, R. E.; Heet, T.; Bell, J. F.; Mellon, M. T.; McEwen, A. S.

    2008-12-01

    Surface characteristics at the six sites where spacecraft have successfully landed on Mars can be related favorably to their signatures in remotely sensed data from orbit and from the Earth. Comparisons of the rock abundance, types and coverage of soils (and their physical properties), thermal inertia, albedo, and topographic slope all agree with orbital remote sensing estimates and show that the materials at the landing sites can be used as ground truth for the materials that make up most of the equatorial and mid- to moderately high-latitude regions of Mars. The six landing sites sample two of the three dominant global thermal inertia and albedo units that cover ~80% of the surface of Mars. The Viking, Spirit, Mars Pathfinder, and Phoenix landing sites are representative of the moderate to high thermal inertia and intermediate to high albedo unit that is dominated by crusty, cloddy, blocky or frozen soils (duricrust that may be layered) with various abundances of rocks and bright dust. The Opportunity landing site is representative of the moderate to high thermal inertia and low albedo surface unit that is relatively dust free and composed of dark eolian sand and/or increased abundance of rocks. Rock abundance derived from orbital thermal differencing techniques in the equatorial regions agrees with that determined from rock counts at the surface and varies from ~3-20% at the landing sites. The size-frequency distributions of rocks >1.5 m diameter fully resolvable in HiRISE images of the landing sites follow exponential models developed from lander measurements of smaller rocks and are continuous with these rock distributions indicating both are part of the same population. Interpretation of radar data confirms the presence of load bearing, relatively dense surfaces controlled by the soil type at the landing sites, regional rock populations from diffuse scattering similar to those observed directly at the sites, and root-mean-squared slopes that compare favorably

  2. Application of Space Environmental Observations to Spacecraft Pre-Launch Engineering and Spacecraft Operations

    Science.gov (United States)

    Barth, Janet L.; Xapsos, Michael

    2008-01-01

    This presentation focuses on the effects of the space environment on spacecraft systems and applying this knowledge to spacecraft pre-launch engineering and operations. Particle radiation, neutral gas particles, ultraviolet and x-rays, as well as micrometeoroids and orbital debris in the space environment have various effects on spacecraft systems, including degradation of microelectronic and optical components, physical damage, orbital decay, biasing of instrument readings, and system shutdowns. Space climate and weather must be considered during the mission life cycle (mission concept, mission planning, systems design, and launch and operations) to minimize and manage risk to both the spacecraft and its systems. A space environment model for use in the mission life cycle is presented.

  3. LANDSAFE: LANDING SITE RISK ANALYSIS SOFTWARE FRAMEWORK

    OpenAIRE

    Schmidt, Ralph; Bostelmann, Jonas; Cornet, Yves; Heipke, Christian; Philippe, Christian; Poncelet, Nadia; de Rosa, Diego; Vandeloise, Yannick

    2012-01-01

    The European Space Agency (ESA) is planning a Lunar Lander mission in the 2018 timeframe that will demonstrate precise soft landing at the polar regions of the Moon. To ensure a safe and successful landing a careful risk analysis has to be carried out. This is comprised of identifying favorable target areas and evaluating the surface conditions in these areas. Features like craters, boulders, steep slopes, rough surfaces and shadow areas have to be identified in order to assess the risk assoc...

  4. DOD Recovery personnel and NASA technicians inspect Friendship 7 spacecraft

    Science.gov (United States)

    1964-01-01

    Department of Defense Recovery personnel and spacecraft technicians from NASA adn McDonnell Aircraft Corp., inspect Astronaut John Glenn's Mercury spacecraft, Friendship 7, following its return to Cape Canaveral after recovery in the Atlantic Ocean.

  5. High-Performance Fire Detector for Spacecraft, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The danger from fire aboard spacecraft is immediate with only moments for detection and suppression. Spacecraft are unique high-value systems where the cost of...

  6. Ensuring a Safe Technological Revolution

    Science.gov (United States)

    2016-12-01

    much lower, and the performance gained can dramatically reduce life -cycle costs. Validated cost data are scarce, and accurate AM cost models need to be...reduce costs, minimize obsolescence issues and improve both capability and readi- ness across the entire life cycle of naval systems—including both the...of naval weapon systems. The Navy is actively engaging its various communi- ties to align needs and ensure that AM can be safely acceler- ated and

  7. Transfer pricing and safe harbours

    Directory of Open Access Journals (Sweden)

    Veronika Solilová

    2013-01-01

    Full Text Available Transfer prices are significant for both taxpayers and tax administrations because they determine in large part taxable profits of associated enterprises in different tax jurisdictions. Moreover, in the context of taxation, transfer prices must be complied with the arm’s length principle. However, Multinational Enterprises have been faced daily by conflicting rules and approaches to applying the arm’s length principle, burdensome documentation requirements, inconsistent audit standards and unpredictable competent authority outcomes. Therefore, the Committee on Fiscal Affairs launched another project on the administrative aspects of transfer pricing in 2010. On 16 May 2013 as a partial solution of this project was approved by the OECD Council the Revised Section E on Safe Harbours in Chapter IV of the Transfer Pricing Guidelines for Multinational Enterprises and Tax Authorities. The paper is focused on significant changes of newly approved chapter IV of the Transfer Pricing Guidelines for Multinational Enterprises and Tax Authorities, further on analysis of practice in this area, on advantages and disadvantages of safe harbours for taxpayers and competent authorities with aim to suggest recommendations on use of safe harbours in the Czech Republic.

  8. Space tribology: its role in spacecraft mechanisms

    International Nuclear Information System (INIS)

    Roberts, E W

    2012-01-01

    The subject of tribology encompasses the friction, wear and lubrication of mechanical components such as bearings and gears. Tribological practices are aimed at ensuring that such components operate with high efficiency (low friction) and achieve long lives. On spacecraft mechanisms the route to achieving these goals brings its own unique challenges. This review describes the problems posed by the space environment, the types of tribological component used on spacecraft and the approaches taken to their lubrication. It is shown that in many instances lubrication needs can be met by synthetic oils having exceedingly low volatilities, but that at temperature extremes the only means of reducing friction and wear is by solid lubrication. As the demands placed on space engineering increase, innovatory approaches will be needed to solve future tribological problems. The direction that future developments might take is anticipated and discussed.

  9. MIDN: A spacecraft Micro-dosimeter mission

    International Nuclear Information System (INIS)

    Pisacane, V. L.; Ziegler, J. F.; Nelson, M. E.; Caylor, M.; Flake, D.; Heyen, L.; Youngborg, E.; Rosenfeld, A. B.; Cucinotta, F.; Zaider, M.; Dicello, J. F.

    2006-01-01

    MIDN (Micro-dosimetry instrument) is a payload on the MidSTAR-I spacecraft (Midshipman Space Technology Applications Research) under development at the United States Naval Academy. MIDN is a solid-state system being designed and constructed to measure Micro-dosimetric spectra to determine radiation quality factors for space environments. Radiation is a critical threat to the health of astronauts and to the success of missions in low-Earth orbit and space exploration. The system will consist of three separate sensors, one external to the spacecraft, one internal and one embedded in polyethylene. Design goals are mass <3 kg and power <2 W. The MidSTAR-I mission in 2006 will provide an opportunity to evaluate a preliminary version of this system. Its low power and mass makes it useful for the International Space Station and manned and unmanned interplanetary missions as a real-time system to assess and alert astronauts to enhanced radiation environments. (authors)

  10. Galileo spacecraft power management and distribution system

    International Nuclear Information System (INIS)

    Detwiler, R.C.; Smith, R.L.

    1990-01-01

    It has been twelve years since two Voyager spacecraft began the direct route to the outer planets. In October 1989 a single Galileo spacecraft started the return to Jupiter. Conceived as a simple Voyager look-alike, the Galileo power management and distribution (PMAD) system has undergone many iterations in configuration. Major changes to the PMAD resulted from dual spun slip ring limitations, variations in launch vehicle thrust capabilities, and launch delays. Lack of an adequate launch vehicle for an interplanetary mission of Galileo's size has resulted in an extremely long flight duration. A Venus-Earth-Earth Gravity Assist (VEEGA) tour, vital to attain the required energy, results in a 6 year trip to Jupiter and its moons. This paper provides a description of the Galileo PMAD and documents the design drivers that established the final as-built hardware

  11. Improved techniques for predicting spacecraft power

    International Nuclear Information System (INIS)

    Chmielewski, A.B.

    1987-01-01

    Radioisotope Thermoelectric Generators (RTGs) are going to supply power for the NASA Galileo and Ulysses spacecraft now scheduled to be launched in 1989 and 1990. The duration of the Galileo mission is expected to be over 8 years. This brings the total RTG lifetime to 13 years. In 13 years, the RTG power drops more than 20 percent leaving a very small power margin over what is consumed by the spacecraft. Thus it is very important to accurately predict the RTG performance and be able to assess the magnitude of errors involved. The paper lists all the error sources involved in the RTG power predictions and describes a statistical method for calculating the tolerance

  12. Data combinations accounting for LISA spacecraft motion

    International Nuclear Information System (INIS)

    Shaddock, Daniel A.; Tinto, Massimo; Estabrook, Frank B.; Armstrong, J.W.

    2003-01-01

    The laser interferometer space antenna is an array of three spacecraft in an approximately equilateral triangle configuration which will be used as a low-frequency gravitational wave detector. We present here new generalizations of the Michelson- and Sagnac-type time-delay interferometry data combinations. These combinations cancel laser phase noise in the presence of different up and down propagation delays in each arm of the array, and slowly varying systematic motion of the spacecraft. The gravitational wave sensitivities of these generalized combinations are the same as previously computed for the stationary cases, although the combinations are now more complicated. We introduce a diagrammatic representation to illustrate that these combinations are actually synthesized equal-arm interferometers

  13. Close-Range Photogrammetry & Next Generation Spacecraft

    Science.gov (United States)

    Pappa, Richard S.

    2002-01-01

    NASA is focusing renewed attention on the topic of large, ultra-lightweight space structures, also known as 'gossamer' spacecraft. Nearly all of the details of the giant spacecraft are still to be worked out. But it's already clear that one of the most challenging aspects will be developing techniques to align and control these systems after they are deployed in space. A critical part of this process is creating new ground test methods to measure gossamer structures under stationary, deploying and vibrating conditions for validation of corresponding analytical predictions. In addressing this problem, I considered, first of all, the possibility of simply using conventional displacement or vibration sensor that could provide spatial measurements. Next, I turned my attention to photogrammetry, a method of determining the spatial coordinates of objects using photographs. The success of this research and development has convinced me that photogrammetry is the most suitable method to solve the gossamer measurement problem.

  14. Large Scale Experiments on Spacecraft Fire Safety

    DEFF Research Database (Denmark)

    Urban, David L.; Ruff, Gary A.; Minster, Olivier

    2012-01-01

    -based microgravity facilities or has been limited to very small fuel samples. Still, the work conducted to date has shown that fire behaviour in low-gravity is very different from that in normal-gravity, with differences observed for flammability limits, ignition delay, flame spread behaviour, flame colour and flame......Full scale fire testing complemented by computer modelling has provided significant knowhow about the risk, prevention and suppression of fire in terrestrial systems (cars, ships, planes, buildings, mines, and tunnels). In comparison, no such testing has been carried out for manned spacecraft due...... to the complexity, cost and risk associ-ated with operating a long duration fire safety experiment of a relevant size in microgravity. Therefore, there is currently a gap in knowledge of fire behaviour in spacecraft. The entire body of low-gravity fire research has either been conducted in short duration ground...

  15. Evaluation of Ultrafiltration for Spacecraft Water Reuse

    Science.gov (United States)

    Pickering, Karen D.; Wiesner, Mark R.

    2001-01-01

    Ultrafiltration is examined for use as the first stage of a primary treatment process for spacecraft wastewater. It is hypothesized that ultrafiltration can effectively serve as pretreatment for a reverse osmosis system, removing the majority of organic material in a spacecraft wastewater. However, it is believed that the interaction between the membrane material and the surfactant found in the wastewater will have a significant impact on the fouling of the ultrafiltration membrane. In this study, five different ultrafiltration membrane materials are examined for the filtration of wastewater typical of that expected to be produced onboard the International Space Station. Membranes are used in an unstirred batch cell. Flux, organic carbon rejection, and recovery from fouling are measured. The results of this evaluation will be used to select the most promising membranes for further study.

  16. FORTE spacecraft vibration mitigation. Final report

    International Nuclear Information System (INIS)

    Maly, J.R.

    1996-02-01

    This report documents work that was performed by CSA Engineering, Inc., for Los Alamos National Laboratory (LANL), to reduce vibrations of the FORTE spacecraft by retrofitting damped structural components into the spacecraft structure. The technical objective of the work was reduction of response at the location of payload components when the structure is subjected to the dynamic loading associated with launch and proto-qualification testing. FORTE is a small satellite that will be placed in orbit in 1996. The structure weighs approximately 425 lb, and is roughly 80 inches high and 40 inches in diameter. It was developed and built by LANL in conjunction with Sandia National Laboratories Albuquerque for the United States Department of Energy. The FORTE primary structure was fabricated primarily with graphite epoxy, using aluminum honeycomb core material for equipment decks and solar panel substrates. Equipment decks were bonded and bolted through aluminum mounting blocks to adjoining structure

  17. Redundancy for electric motors in spacecraft applications

    Science.gov (United States)

    Smith, Robert J.; Flew, Alastair R.

    1986-01-01

    The parts of electric motors which should be duplicated in order to provide maximum reliability in spacecraft application are identified. Various common types of redundancy are described. The advantages and disadvantages of each are noted. The principal types are illustrated by reference to specific examples. For each example, constructional details, basic performance data and failure modes are described, together with a discussion of the suitability of particular redundancy techniques to motor types.

  18. Research on spacecraft electrical power conversion

    Science.gov (United States)

    Wilson, T. G.

    1983-01-01

    The history of spacecraft electrical power conversion in literature, research and practice is reviewed. It is noted that the design techniques, analyses and understanding which were developed make today's contribution to power computers and communication installations. New applications which require more power, improved dynamic response, greater reliability, and lower cost are outlined. The switching mode approach in electronic power conditioning is discussed. Technical aspects of the research are summarized.

  19. Schema for Spacecraft-Command Dictionary

    Science.gov (United States)

    Laubach, Sharon; Garcia, Celina; Maxwell, Scott; Wright, Jesse

    2008-01-01

    An Extensible Markup Language (XML) schema was developed as a means of defining and describing a structure for capturing spacecraft command- definition and tracking information in a single location in a form readable by both engineers and software used to generate software for flight and ground systems. A structure defined within this schema is then used as the basis for creating an XML file that contains command definitions.

  20. Additive Manufacturing: Ensuring Quality for Spacecraft Applications

    Science.gov (United States)

    Swanson, Theodore; Stephenson, Timothy

    2014-01-01

    Reliable manufacturing requires that material properties and fabrication processes be well defined in order to insure that the manufactured parts meet specified requirements. While this issue is now relatively straightforward for traditional processes such as subtractive manufacturing and injection molding, this capability is still evolving for AM products. Hence, one of the principal challenges within AM is in qualifying and verifying source material properties and process control. This issue is particularly critical for applications in harsh environments and demanding applications, such as spacecraft.

  1. Wheel speed management control system for spacecraft

    Science.gov (United States)

    Goodzeit, Neil E. (Inventor); Linder, David M. (Inventor)

    1991-01-01

    A spacecraft attitude control system uses at least four reaction wheels. In order to minimize reaction wheel speed and therefore power, a wheel speed management system is provided. The management system monitors the wheel speeds and generates a wheel speed error vector. The error vector is integrated, and the error vector and its integral are combined to form a correction vector. The correction vector is summed with the attitude control torque command signals for driving the reaction wheels.

  2. The Manned Spacecraft Center and medical technology

    Science.gov (United States)

    Johnston, R. S.; Pool, S. L.

    1974-01-01

    A number of medically oriented research and hardware development programs in support of manned space flights have been sponsored by NASA. Blood pressure measuring systems for use in spacecraft are considered. In some cases, complete new bioinstrumentation systems were necessary to accomplish a specific physiological study. Plans for medical research during the Skylab program are discussed along with general questions regarding space-borne health service systems and details concerning the Health Services Support Control Center.

  3. Artificial Intelligence and Spacecraft Power Systems

    Science.gov (United States)

    Dugel-Whitehead, Norma R.

    1997-01-01

    This talk will present the work which has been done at NASA Marshall Space Flight Center involving the use of Artificial Intelligence to control the power system in a spacecraft. The presentation will include a brief history of power system automation, and some basic definitions of the types of artificial intelligence which have been investigated at MSFC for power system automation. A video tape of one of our autonomous power systems using co-operating expert systems, and advanced hardware will be presented.

  4. THE FUTURE OF SPACECRAFT NUCLEAR PROPULSION

    OpenAIRE

    Jansen, Frank

    2014-01-01

    This paper summarizes the advantages of space nuclear power and propulsion systems. It describes the actual status of international power level dependent spacecraft nuclear propulsion missions, especially the high power EU-Russian MEGAHIT study including the Russian Megawatt-Class Nuclear Power Propulsion System, the NASA GRC project and the low and medium power EU DiPoP study. Space nuclear propulsion based mission scenarios of these studies are sketched as well.

  5. Spacecraft early design validation using formal methods

    International Nuclear Information System (INIS)

    Bozzano, Marco; Cimatti, Alessandro; Katoen, Joost-Pieter; Katsaros, Panagiotis; Mokos, Konstantinos; Nguyen, Viet Yen; Noll, Thomas; Postma, Bart; Roveri, Marco

    2014-01-01

    The size and complexity of software in spacecraft is increasing exponentially, and this trend complicates its validation within the context of the overall spacecraft system. Current validation methods are labor-intensive as they rely on manual analysis, review and inspection. For future space missions, we developed – with challenging requirements from the European space industry – a novel modeling language and toolset for a (semi-)automated validation approach. Our modeling language is a dialect of AADL and enables engineers to express the system, the software, and their reliability aspects. The COMPASS toolset utilizes state-of-the-art model checking techniques, both qualitative and probabilistic, for the analysis of requirements related to functional correctness, safety, dependability and performance. Several pilot projects have been performed by industry, with two of them having focused on the system-level of a satellite platform in development. Our efforts resulted in a significant advancement of validating spacecraft designs from several perspectives, using a single integrated system model. The associated technology readiness level increased from level 1 (basic concepts and ideas) to early level 4 (laboratory-tested)

  6. Determination of Realistic Fire Scenarios in Spacecraft

    Science.gov (United States)

    Dietrich, Daniel L.; Ruff, Gary A.; Urban, David

    2013-01-01

    This paper expands on previous work that examined how large a fire a crew member could successfully survive and extinguish in the confines of a spacecraft. The hazards to the crew and equipment during an accidental fire include excessive pressure rise resulting in a catastrophic rupture of the vehicle skin, excessive temperatures that burn or incapacitate the crew (due to hyperthermia), carbon dioxide build-up or accumulation of other combustion products (e.g. carbon monoxide). The previous work introduced a simplified model that treated the fire primarily as a source of heat and combustion products and sink for oxygen prescribed (input to the model) based on terrestrial standards. The model further treated the spacecraft as a closed system with no capability to vent to the vacuum of space. The model in the present work extends this analysis to more realistically treat the pressure relief system(s) of the spacecraft, include more combustion products (e.g. HF) in the analysis and attempt to predict the fire spread and limiting fire size (based on knowledge of terrestrial fires and the known characteristics of microgravity fires) rather than prescribe them in the analysis. Including the characteristics of vehicle pressure relief systems has a dramatic mitigating effect by eliminating vehicle overpressure for all but very large fires and reducing average gas-phase temperatures.

  7. Probing interferometric parallax with interplanetary spacecraft

    Science.gov (United States)

    Rodeghiero, G.; Gini, F.; Marchili, N.; Jain, P.; Ralston, J. P.; Dallacasa, D.; Naletto, G.; Possenti, A.; Barbieri, C.; Franceschini, A.; Zampieri, L.

    2017-07-01

    We describe an experimental scenario for testing a novel method to measure distance and proper motion of astronomical sources. The method is based on multi-epoch observations of amplitude or intensity correlations between separate receiving systems. This technique is called Interferometric Parallax, and efficiently exploits phase information that has traditionally been overlooked. The test case we discuss combines amplitude correlations of signals from deep space interplanetary spacecraft with those from distant galactic and extragalactic radio sources with the goal of estimating the interplanetary spacecraft distance. Interferometric parallax relies on the detection of wavefront curvature effects in signals collected by pairs of separate receiving systems. The method shows promising potentialities over current techniques when the target is unresolved from the background reference sources. Developments in this field might lead to the construction of an independent, geometrical cosmic distance ladder using a dedicated project and future generation instruments. We present a conceptual overview supported by numerical estimates of its performances applied to a spacecraft orbiting the Solar System. Simulations support the feasibility of measurements with a simple and time-saving observational scheme using current facilities.

  8. On-orbit supervisor for controlling spacecraft

    Science.gov (United States)

    Vandervoort, Richard J.

    1992-07-01

    Spacecraft systems of the 1990's and beyond will be substantially more complex than their predecessors. They will have demanding performance requirements and will be expected to operate more autonomously. This underscores the need for innovative approaches to Fault Detection, Isolation and Recovery (FDIR). A hierarchical expert system is presented that provides on-orbit supervision using intelligent FDIR techniques. Each expert system in the hierarchy supervises the operation of a local set of spacecraft functions. Spacecraft operational goals flow top down while responses flow bottom up. The expert system supervisors have a fairly high degree of autonomy. Bureaucratic responsibilities are minimized to conserve bandwidth and maximize response time. Data for FDIR can be acquired local to an expert and from other experts. By using a blackboard architecture for each supervisor, the system provides a great degree of flexibility in implementing the problem solvers for each problem domain. In addition, it provides for a clear separation between facts and knowledge, leading to an efficient system capable of real time response.

  9. Delamination Assessment Tool for Spacecraft Composite Structures

    Science.gov (United States)

    Portela, Pedro; Preller, Fabian; Wittke, Henrik; Sinnema, Gerben; Camanho, Pedro; Turon, Albert

    2012-07-01

    Fortunately only few cases are known where failure of spacecraft structures due to undetected damage has resulted in a loss of spacecraft and launcher mission. However, several problems related to damage tolerance and in particular delamination of composite materials have been encountered during structure development of various ESA projects and qualification testing. To avoid such costly failures during development, launch or service of spacecraft, launcher and reusable launch vehicles structures a comprehensive damage tolerance verification approach is needed. In 2009, the European Space Agency (ESA) initiated an activity called “Delamination Assessment Tool” which is led by the Portuguese company HPS Lda and includes academic and industrial partners. The goal of this study is the development of a comprehensive damage tolerance verification approach for launcher and reusable launch vehicles (RLV) structures, addressing analytical and numerical methodologies, material-, subcomponent- and component testing, as well as non-destructive inspection. The study includes a comprehensive review of current industrial damage tolerance practice resulting from ECSS and NASA standards, the development of new Best Practice Guidelines for analysis, test and inspection methods and the validation of these with a real industrial case study. The paper describes the main findings of this activity so far and presents a first iteration of a Damage Tolerance Verification Approach, which includes the introduction of novel analytical and numerical tools at an industrial level. This new approach is being put to the test using real industrial case studies provided by the industrial partners, MT Aerospace, RUAG Space and INVENT GmbH

  10. SMART-1: the first spacecraft of the future

    Science.gov (United States)

    2003-09-01

    gather high-value scientific and technological data. Another innovation lies in the industrial policy applied to this mission. SMART-1 is a good example of an ESA mission in which a comparatively small company such as the Swedish Space Corporation (SSC) has been selected as prime contractor. “The experience of SSC in highly successful projects at national level was a key factor in the decision, as was ESA's goal of fostering a balanced industrial landscape in Europe,” says Niels Jensen of ESA’s Directorate of Industrial Matters and Technology Programmes. The magic of ion engines Solar-electric propulsion, one of the main technologies to be tested by SMART-1, is a new technique that uses 'ion engines'. These work by expelling a continuous beam of charged particles --ions-- at the back of the engine, which produces a thrust in the opposite direction and therefore pushes the spacecraft forward. The energy to feed the engine comes from the solar panels, hence the name 'solar-electric propulsion'. Engineers have been working on ion engines for decades, but only recently have obstacles such as the lack of power availability from a spacecraft’s solar panels been overcome. Recent missions have been using ion thrusters mainly for attitude control and orbit station keeping. In the recent case of ESA’s telecommunication satellite Artemis, the onboard availability of ion thrusters was actually what allowed the mission to be rescued. Having been left by the launcher on an unplanned orbit, Artemis was slowly - but safely - brought up to its final working orbit by the power of its ion engines, initially designed for orbit maintenance only. Starting with SMART-1, the first European spacecraft to use an ion engine as its main propulsion system, the amazing advantages of this method can now be fully exploited. Ion engines are very efficient: they deliver about ten times as much impulse per kilogram of propellant used. This gives a substantial reduction in the mass of the fuel

  11. Space Environments and Spacecraft Effects Organization Concept

    Science.gov (United States)

    Edwards, David L.; Burns, Howard D.; Miller, Sharon K.; Porter, Ron; Schneider, Todd A.; Spann, James F.; Xapsos, Michael

    2012-01-01

    The National Aeronautics and Space Administration (NASA) is embarking on a course to expand human presence beyond Low Earth Orbit (LEO) while also expanding its mission to explore the solar system. Destinations such as Near Earth Asteroids (NEA), Mars and its moons, and the outer planets are but a few of the mission targets. Each new destination presents an opportunity to increase our knowledge of the solar system and the unique environments for each mission target. NASA has multiple technical and science discipline areas specializing in specific space environments disciplines that will help serve to enable these missions. To complement these existing discipline areas, a concept is presented focusing on the development of a space environments and spacecraft effects (SENSE) organization. This SENSE organization includes disciplines such as space climate, space weather, natural and induced space environments, effects on spacecraft materials and systems and the transition of research information into application. This space environment and spacecraft effects organization will be composed of Technical Working Groups (TWG). These technical working groups will survey customers and users, generate products, and provide knowledge supporting four functional areas: design environments, engineering effects, operational support, and programmatic support. The four functional areas align with phases in the program mission lifecycle and are briefly described below. Design environments are used primarily in the mission concept and design phases of a program. Engineering effects focuses on the material, component, sub-system and system-level selection and the testing to verify design and operational performance. Operational support provides products based on real time or near real time space weather to mission operators to aid in real time and near-term decision-making. The programmatic support function maintains an interface with the numerous programs within NASA, other federal

  12. Large Scale Experiments on Spacecraft Fire Safety

    Science.gov (United States)

    Urban, David; Ruff, Gary A.; Minster, Olivier; Fernandez-Pello, A. Carlos; Tien, James S.; Torero, Jose L.; Legros, Guillaume; Eigenbrod, Christian; Smirnov, Nickolay; Fujita, Osamu; hide

    2012-01-01

    Full scale fire testing complemented by computer modelling has provided significant knowhow about the risk, prevention and suppression of fire in terrestrial systems (cars, ships, planes, buildings, mines, and tunnels). In comparison, no such testing has been carried out for manned spacecraft due to the complexity, cost and risk associated with operating a long duration fire safety experiment of a relevant size in microgravity. Therefore, there is currently a gap in knowledge of fire behaviour in spacecraft. The entire body of low-gravity fire research has either been conducted in short duration ground-based microgravity facilities or has been limited to very small fuel samples. Still, the work conducted to date has shown that fire behaviour in low-gravity is very different from that in normal gravity, with differences observed for flammability limits, ignition delay, flame spread behaviour, flame colour and flame structure. As a result, the prediction of the behaviour of fires in reduced gravity is at present not validated. To address this gap in knowledge, a collaborative international project, Spacecraft Fire Safety, has been established with its cornerstone being the development of an experiment (Fire Safety 1) to be conducted on an ISS resupply vehicle, such as the Automated Transfer Vehicle (ATV) or Orbital Cygnus after it leaves the ISS and before it enters the atmosphere. A computer modelling effort will complement the experimental effort. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew removes the need for strict containment of combustion products. This will facilitate the possibility of examining fire behaviour on a scale that is relevant to spacecraft fire safety and will provide unique data for fire model validation. This unprecedented opportunity will expand the understanding of the fundamentals of fire behaviour in spacecraft. The experiment is being

  13. How safe are nuclear plants? How safe should they be?

    International Nuclear Information System (INIS)

    Kouts, H.

    1988-01-01

    It has become customary to think about safety of nuclear plants in terms of risk as defined by the WASH-1400 study that some of the implications for the non-specialist escape our attention. Yet it is known that a rational program to understand safety, to identify unsafe events, and to use this kind of information or analysis to improve safety, requires us to use the methods of quantitative risk assessment. How this process can be made more understandable to a broader group of nontechnical people and how can a wider acceptance of the results of the process be developed have been questions under study and are addressed in this report. These are questions that have been struggled with for some time in the world of nuclear plant safety. The Nuclear Regulatory Commission examined them for several years as it moved toward developing a position on safety goals for nuclear plants, a requirement that had been assigned it by Congress. Opinion was sought from a broad spectrum of individuals, within the field of nuclear power and outside it, on the topic that was popularly called, ''How safe is safe enough?'' Views were solicited on the answer to the question and also on the way the answer should be framed when it was adopted. This report discusses the public policy and its implementation

  14. Rotary MR Damper for Launch/Landing Load Isolation and Resistive Crew Exercise for Exploration Spaceflight Missions

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop a rotary MR (magneto rheologic) Damper to integrate into exploration spacecraft crew seats to be used as an exercise device and launch/landing load isolation...

  15. NASA Officials in MCC to decide whether to land Apollo 16 or cancel landing

    Science.gov (United States)

    1972-01-01

    NASA Officials gather around a console in the Mission Operations Control Room (MOCR) in the Mission Control Center (MCC) prior to the making of a decision whether to land Apollo 16 on the moon or to abort the landing. Seated, left to right, are Dr. Christopher C. Kraft Jr., Director of the Manned Spacecraft Center (MSC), and Brig. Gen. James A. McDivitt (USAF), Manager, Apollo Spacecraft Program Office, MSC; and standing, left to right, are Dr. Rocco A. Petrone, Apollo Program Director, Office Manned Space Flight (OMSF), NASA HQ.; Capt. John K. Holcolmb (U.S. Navy, Ret.), Director of Apollo Operations, OMSF; Sigurd A. Sjoberg, Deputy Director, MSC; Capt. Chester M. Lee (U.S. Navy, Ret.), Apollo Mission Director, OMSF; Dale D. Myers, NASA Associate Administrator for Manned Space Flight; and Dr. George M. Low, NASA Deputy Administrator.

  16. Advanced engineering software for in-space assembly and manned planetary spacecraft

    Science.gov (United States)

    Delaquil, Donald; Mah, Robert

    1990-01-01

    Meeting the objectives of the Lunar/Mars initiative to establish safe and cost-effective extraterrestrial bases requires an integrated software/hardware approach to operational definitions and systems implementation. This paper begins this process by taking a 'software-first' approach to systems design, for implementing specific mission scenarios in the domains of in-space assembly and operations of the manned Mars spacecraft. The technological barriers facing implementation of robust operational systems within these two domains are discussed, and preliminary software requirements and architectures that resolve these barriers are provided.

  17. Material Optimization of Carbon/Epoxy Composite Rotor for Spacecraft Energy Storage

    Directory of Open Access Journals (Sweden)

    R Varatharajoo

    2016-09-01

    Full Text Available An investigation to optimize the carbon/epoxy composite rotor is performed for the spacecraft energy storage application. A highspeed multi-layer rotor design is proposed and different composite materials are tested to achieve the most suitable recipe. First, the analytical rotor evaluation is performed to establish a reliable numerical rotor model. Then, finite element analysis (FEA is employed in order to optimise the multi-layer composite rotor design. Subsequently, the modal analysis is carried out to determine the rotor natural frequencies and mode shapes for a safe operational regime below 50, 000 rpm.

  18. Contemporary state of spacecraft/environment interaction research

    CERN Document Server

    Novikov, L S

    1999-01-01

    Various space environment effects on spacecraft materials and equipment, and the reverse effects of spacecrafts and rockets on space environment are considered. The necessity of permanent updating and perfection of our knowledge on spacecraft/environment interaction processes is noted. Requirements imposed on models of space environment in theoretical and experimental researches of various aspects of the spacecraft/environment interaction problem are formulated. In this field, main problems which need to be solved today and in the nearest future are specified. The conclusion is made that the joint analysis of both aspects of spacecraft/environment interaction problem promotes the most effective solution of the problem.

  19. Spacecraft Charging: Hazard Causes, Hazard Effects, Hazard Controls

    Science.gov (United States)

    Koontz, Steve.

    2018-01-01

    Spacecraft flight environments are characterized both by a wide range of space plasma conditions and by ionizing radiation (IR), solar ultraviolet and X-rays, magnetic fields, micrometeoroids, orbital debris, and other environmental factors, all of which can affect spacecraft performance. Dr. Steven Koontz's lecture will provide a solid foundation in the basic engineering physics of spacecraft charging and charging effects that can be applied to solving practical spacecraft and spacesuit engineering design, verification, and operations problems, with an emphasis on spacecraft operations in low-Earth orbit, Earth's magnetosphere, and cis-Lunar space.

  20. Small intrinsically safe reactor implications

    International Nuclear Information System (INIS)

    Wakabayashi, Hiroaki

    1985-01-01

    Reviewing the history of nuclear power, it is found that peaceful uses of nuclear power are children of the war-like atom. Importance of special growth in a shielded environment is emphasized to exploit fully the advantages of nuclear power. Nuclear power reactors must be safe for their assimilation into society from the points of view of both technology and social psychology. ISR/ISER is identified as a missing link in the development of nuclear power reactors from this perspective and advocated for international development and utilization, being unleashed from the concerns of politicization, safety, and proliferation

  1. Mifrenz: Safe email for children

    Directory of Open Access Journals (Sweden)

    Tim Hunt

    Full Text Available Products currently available for monitoring children\\'s email usage are either considered to encourage dubious ethical behaviour or are time consuming for parents to administer. This paper describes the development of a new email client application for children called Mifrenz. This new application gives parents the ability to let their children safely use email, with the minimum of intervention. It was developed using mostly free software and also with the desire to provide real first hand programming examples to demonstrate to students.

  2. Type-safe pattern combinators

    DEFF Research Database (Denmark)

    Rhiger, Morten

    2009-01-01

    Macros still haven't made their way into typed higher-order programming languages such as Haskell and Standard ML. Therefore, to extend the expressiveness of Haskell or Standard ML, one must express new linguistic features in terms of functions that fit within the static type systems of these lan...... of these languages. This is particularly challenging when introducing features that span across multiple types and that bind variables. We address this challenge by developing, in a step by step manner, mechanisms for encoding patterns and pattern matching in Haskell in a type-safe way....

  3. STS-95: Post Landing and Crew Walkaround of the Orbiter at the Shuttle Landing Facility

    Science.gov (United States)

    1998-01-01

    After landing, the STS-95 crew (Commander Curtis L. Brown, Pilot Steven W. Lindsey, Mission Specialists Scott E. Parazynski, Stephen K. Robinson, Pedro Duque, Payload Specialists Chiaki Mukai and the legendary John H. Glenn) descend from the Space Shuttle. Commander Brown congratulates the crew and team photos are taken. The crew does a walkaround inspection of the spacecraft, then boards the bus for departure from the facility.

  4. SHARP - Automated monitoring of spacecraft health and status

    Science.gov (United States)

    Atkinson, David J.; James, Mark L.; Martin, R. G.

    1990-01-01

    Briefly discussed here are the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory (JPL). Some of the difficulties associated with the existing technology used in mission operations are highlighted. A new automated system based on artificial intelligence technology is described which seeks to overcome many of these limitations. The system, called the Spacecraft Health Automated Reasoning Prototype (SHARP), is designed to automate health and status analysis for multi-mission spacecraft and ground data systems operations. The system has proved to be effective for detecting and analyzing potential spacecraft and ground systems problems by performing real-time analysis of spacecraft and ground data systems engineering telemetry. Telecommunications link analysis of the Voyager 2 spacecraft was the initial focus for evaluation of the system in real-time operations during the Voyager spacecraft encounter with Neptune in August 1989.

  5. SHARP: Automated monitoring of spacecraft health and status

    Science.gov (United States)

    Atkinson, David J.; James, Mark L.; Martin, R. Gaius

    1991-01-01

    Briefly discussed here are the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory (JPL). Some of the difficulties associated with the existing technology used in mission operations are highlighted. A new automated system based on artificial intelligence technology is described which seeks to overcome many of these limitations. The system, called the Spacecraft Health Automated Reasoning Prototype (SHARP), is designed to automate health and status analysis for multi-mission spacecraft and ground data systems operations. The system has proved to be effective for detecting and analyzing potential spacecraft and ground systems problems by performing real-time analysis of spacecraft and ground data systems engineering telemetry. Telecommunications link analysis of the Voyager 2 spacecraft was the initial focus for evaluation of the system in real-time operations during the Voyager spacecraft encounter with Neptune in August 1989.

  6. Research-Based Monitoring, Prediction, and Analysis Tools of the Spacecraft Charging Environment for Spacecraft Users

    Science.gov (United States)

    Zheng, Yihua; Kuznetsova, Maria M.; Pulkkinen, Antti A.; Maddox, Marlo M.; Mays, Mona Leila

    2015-01-01

    The Space Weather Research Center (http://swrc. gsfc.nasa.gov) at NASA Goddard, part of the Community Coordinated Modeling Center (http://ccmc.gsfc.nasa.gov), is committed to providing research-based forecasts and notifications to address NASA's space weather needs, in addition to its critical role in space weather education. It provides a host of services including spacecraft anomaly resolution, historical impact analysis, real-time monitoring and forecasting, tailored space weather alerts and products, and weekly summaries and reports. In this paper, we focus on how (near) real-time data (both in space and on ground), in combination with modeling capabilities and an innovative dissemination system called the integrated Space Weather Analysis system (http://iswa.gsfc.nasa.gov), enable monitoring, analyzing, and predicting the spacecraft charging environment for spacecraft users. Relevant tools and resources are discussed.

  7. Selecting reasonable future land use scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Allred, W.E.; Smith, R.W. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1995-12-31

    This paper examines a process to help select the most reasonable future land use scenarios for hazardous waste and/or low-level radioactive waste disposal sites. The process involves evaluating future land use scenarios by applying selected criteria currently used by commercial mortgage companies to determine the feasibility of obtaining a loan for purchasing such land. The basis for the process is that only land use activities for which a loan can be obtained will be considered. To examine the process, a low-level radioactive waste site, the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory, is used as an example. The authors suggest that the process is a very precise, comprehensive, and systematic (common sense) approach for determining reasonable future use of land. Implementing such a process will help enhance the planning, decisionmaking, safe management, and cleanup of present and future disposal facilities.

  8. Selecting reasonable future land use scenarios

    International Nuclear Information System (INIS)

    Allred, W.E.; Smith, R.W.

    1995-01-01

    This paper examines a process to help select the most reasonable future land use scenario for hazardous waste and/or low-level radioactive waste disposal sites. The process involves evaluating future land use scenarios ab applying selected criteria currently used by commercial mortgage companies to determine the feasibility of obtaining a loan for purchasing such land. The basis for the process is that only land use activities for which a loan can be obtained well be considered. To examine the process, a low-level radioactive waste site, the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory, is used as an example. The authors suggest that the process is a very precise, comprehensive, and systematic approach for determining reasonable future use of land. Implementing such a process will help enhance the planning, decisionmaking, safe management, and cleanup of present and future disposal facilities

  9. Selecting reasonable future land use scenarios

    International Nuclear Information System (INIS)

    Allred, W.E.; Smith, R.W.

    1995-01-01

    This paper examines a process to help select the most reasonable future land use scenarios for hazardous waste and/or low-level radioactive waste disposal sites. The process involves evaluating future land use scenarios by applying selected criteria currently used by commercial mortgage companies to determine the feasibility of obtaining a loan for purchasing such land. The basis for the process is that only land use activities for which a loan can be obtained will be considered. To examine the process, a low-level radioactive waste site, the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory, is used as an example. The authors suggest that the process is a very precise, comprehensive, and systematic (common sense) approach for determining reasonable future use of land. Implementing such a process will help enhance the planning, decisionmaking, safe management, and cleanup of present and future disposal facilities

  10. Safe transport of radioactive material

    International Nuclear Information System (INIS)

    1990-01-01

    Recently the Agency redefined its policy for education and training in radiation safety. The emphasis is now on long-term strategic planning of general education and training programmes. In line with this general policy the Agency's Standing Advisory Group for the Safe Transport of Radioactive Material (SAGSTRAM) in its 7th meeting (April 1989) agreed that increased training activity should be deployed in the area of transport. SAGSTRAM specifically recommended the development of a standard training programme on this subject area, including audio-visual aids, in order to assist Member States in the implementation of the Agency's Regulations for the Safe Transport of Radioactive Material. This training programme should be substantiated by a biennial training course which is thought to be held either as an Interregional or a Regional Course depending on demand. This training manual, issued as a first publication in the Training Course Series, represents the basic text material for future training courses in transport safety. The topic areas covered by this training manual and most of the texts have been developed from the course material used for the 1987 Bristol Interregional Course on Transport Safety. The training manual is intended to give guidance to the lecturers of a course and will be provided to the participants for retention. Refs, figs and tabs

  11. Safe Driving After Propofol Sedation.

    Science.gov (United States)

    Summerlin-Grady, Lee; Austin, Paul N; Gabaldon, Dion A

    2017-10-01

    Propofol is a short-acting medication with fast cognitive and psychomotor recovery. However, patients are usually instructed not to drive a motor vehicle for 24 hours after receiving propofol. The purpose of this article was to review the evidence examining when it is safe to drive after receiving propofol for sedation for diagnostic and surgical procedures. This is a systematic review of the literature. A search of the literature was conducted using Google Scholar, PubMed, and the Cochrane Library for the time period 1990 to 2015. Two randomized controlled trials and two observational studies met the inclusion criteria. Using a simulator, investigators examined driving ability of subjects who received modest doses (about 100 mg) of propofol for endoscopic procedures and surveyed subjects who drove immediately after discharge. There were methodological concerns with the studies such as small sample sizes, modest doses of propofol, and three of the four studies were done in Japan by the same group of investigators limiting generalizability. This limited research suggests that it may be safe for patients to drive sooner than 24 hours after receiving propofol. However, large multicenter trials using heterogenous samples using a range of propofol doses are needed to support an evidence-based revision to the current discharge guidelines for patients receiving propofol. Copyright © 2016 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

  12. Keeping you safe by making machine tools safe

    CERN Multimedia

    2012-01-01

    CERN’s third safety objective for 2012 concerns the safety of equipment - and machine tools in particular.   There are three prerequisites for ensuring that a machine tool can be used safely: ·      the machine tool must comply with Directive 2009/104/EC, ·      the layout of the workshop must be compliant, and ·      everyone who uses the machine tool must be trained. Provided these conditions are met, the workshop head can grant authorisation to use the machine tool. To fulfil this objective, an inventory of the machine tools must be drawn up and the people responsible for them identified. The HSE Unit's Safety Inspection Service produces compliance reports for the machine tools. In order to meet the third objective set by the Director-General, the section has doubled its capacity to carry out inspections: ...

  13. Cluster PEACE observations of electrons of spacecraft origin

    Directory of Open Access Journals (Sweden)

    S. Szita

    2001-09-01

    Full Text Available The two PEACE (Plasma Electron And Current Experiment sensors on board each Cluster spacecraft sample the electron velocity distribution across the full 4 solid angle and the energy range 0.7 eV to 26 keV with a time resolution of 4 s. We present high energy and angular resolution 3D observations of electrons of spacecraft origin in the various environments encountered by the Cluster constellation, including a lunar eclipse interval where the spacecraft potential was reduced but remained positive, and periods of ASPOC (Active Spacecraft POtential Control operation which reduced the spacecraft potential. We demonstrate how the spacecraft potential may be found from a gradient change in the PEACE low energy spectrum, and show how the observed spacecraft electrons are confined by the spacecraft potential. We identify an intense component of the spacecraft electrons with energies equivalent to the spacecraft potential, the arrival direction of which is seen to change when ASPOC is switched on. Another spacecraft electron component, observed in the sunward direction, is reduced in the eclipse but unaffected by ASPOC, and we believe this component is produced in the analyser by solar UV. We find that PEACE anodes with a look direction along the spacecraft surfaces are more susceptible to spacecraft electron contamination than those which look perpendicular to the surface, which justifies the decision to mount PEACE with its field-of-view radially outward rather than tangentially.Key words. Magnetosheric physics (general or miscellaneous Space plasma physics (spacecraft sheaths, wakes, charging

  14. Electromagnetic Dissociation and Spacecraft Electronics Damage

    Science.gov (United States)

    Norbury, John W.

    2016-01-01

    When protons or heavy ions from galactic cosmic rays (GCR) or solar particle events (SPE) interact with target nuclei in spacecraft, there can be two different types of interactions. The more familiar strong nuclear interaction often dominates and is responsible for nuclear fragmentation in either the GCR or SPE projectile nucleus or the spacecraft target nucleus. (Of course, the proton does not break up, except possibly to produce pions or other hadrons.) The less familiar, second type of interaction is due to the very strong electromagnetic fields that exist when two charged nuclei pass very close to each other. This process is called electromagnetic dissociation (EMD) and primarily results in the emission of neutrons, protons and light ions (isotopes of hydrogen and helium). The cross section for particle production is approximately defined as the number of particles produced in nucleus-nucleus collisions or other types of reactions. (There are various kinematic and other factors which multiply the particle number to arrive at the cross section.) Strong, nuclear interactions usually dominate the nuclear reactions of most interest that occur between GCR and target nuclei. However, for heavy nuclei (near Fe and beyond) at high energy the EMD cross section can be much larger than the strong nuclear interaction cross section. This paper poses a question: Are there projectile or target nuclei combinations in the interaction of GCR or SPE where the EMD reaction cross section plays a dominant role? If the answer is affirmative, then EMD mechanisms should be an integral part of codes that are used to predict damage to spacecraft electronics. The question can become more fine-tuned and one can ask about total reaction cross sections as compared to double differential cross sections. These issues will be addressed in the present paper.

  15. Spacecraft fabrication and test MODIL. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Saito, T.T.

    1994-05-01

    This report covers the period from October 1992 through the close of the project. FY 92 closed out with the successful briefing to industry and with many potential and important initiatives in the spacecraft arena. Due to the funding uncertainties, we were directed to proceed as if our funding would be approximately the same as FY 92 ($2M), but not to make any major new commitments. However, the MODIL`s FY 93 funding was reduced to $810K and we were directed to concentrate on the cryocooler area. The cryocooler effort completed its demonstration project. The final meetings with the cryocooler fabricators were very encouraging as we witnessed the enthusiastic reception of technology to help them reduce fabrication uncertainties. Support of the USAF Phillips Laboratory cryocooler program was continued including kick-off meetings for the Prototype Spacecraft Cryocooler (PSC). Under Phillips Laboratory support, Gill Cruz visited British Aerospace and Lucas Aerospace in the United Kingdom to assess their manufacturing capabilities. In the Automated Spacecraft & Assembly Project (ASAP), contracts were pursued for the analysis by four Brilliant Eyes prime contractors to provide a proprietary snap shot of their current status of Integrated Product Development. In the materials and structure thrust the final analysis was completed of the samples made under the contract (``Partial Automation of Matched Metal Net Shape Molding of Continuous Fiber Composites``) to SPARTA. The Precision Technologies thrust funded the Jet Propulsion Laboratory to prepare a plan to develop a Computer Aided Alignment capability to significantly reduce the time for alignment and even possibly provide real time and remote alignment capability of systems in flight.

  16. Spacecraft computer technology at Southwest Research Institute

    Science.gov (United States)

    Shirley, D. J.

    1993-01-01

    Southwest Research Institute (SwRI) has developed and delivered spacecraft computers for a number of different near-Earth-orbit spacecraft including shuttle experiments and SDIO free-flyer experiments. We describe the evolution of the basic SwRI spacecraft computer design from those weighing in at 20 to 25 lb and using 20 to 30 W to newer models weighing less than 5 lb and using only about 5 W, yet delivering twice the processing throughput. Because of their reduced size, weight, and power, these newer designs are especially applicable to planetary instrument requirements. The basis of our design evolution has been the availability of more powerful processor chip sets and the development of higher density packaging technology, coupled with more aggressive design strategies in incorporating high-density FPGA technology and use of high-density memory chips. In addition to reductions in size, weight, and power, the newer designs also address the necessity of survival in the harsh radiation environment of space. Spurred by participation in such programs as MSTI, LACE, RME, Delta 181, Delta Star, and RADARSAT, our designs have evolved in response to program demands to be small, low-powered units, radiation tolerant enough to be suitable for both Earth-orbit microsats and for planetary instruments. Present designs already include MIL-STD-1750 and Multi-Chip Module (MCM) technology with near-term plans to include RISC processors and higher-density MCM's. Long term plans include development of whole-core processors on one or two MCM's.

  17. Soyuz Spacecraft Transported to Launch Pad

    Science.gov (United States)

    2003-01-01

    The Soyuz TMA-3 spacecraft and its booster rocket (rear view) is shown on a rail car for transport to the launch pad where it was raised to a vertical launch position at the Baikonur Cosmodrome, Kazakhstan on October 16, 2003. Liftoff occurred on October 18th, transporting a three man crew to the International Space Station (ISS). Aboard were Michael Foale, Expedition-8 Commander and NASA science officer; Alexander Kaleri, Soyuz Commander and flight engineer, both members of the Expedition-8 crew; and European Space agency (ESA) Astronaut Pedro Duque of Spain. Photo Credit: 'NASA/Bill Ingalls'

  18. Fault Detection and Isolation for Spacecraft

    DEFF Research Database (Denmark)

    Jensen, Hans-Christian Becker; Wisniewski, Rafal

    2002-01-01

    This article realizes nonlinear Fault Detection and Isolation for actuators, given there is no measurement of the states in the actuators. The Fault Detection and Isolation of the actuators is instead based on angular velocity measurement of the spacecraft and knowledge about the dynamics...... of the satellite. The algorithms presented in this paper are based on a geometric approach to achieve nonlinear Fault Detection and Isolation. The proposed algorithms are tested in a simulation study and the pros and cons of the algorithms are discussed....

  19. Aircraft, ships, spacecraft, nuclear plants and quality

    International Nuclear Information System (INIS)

    Patrick, M.G.

    1984-05-01

    A few quality assurance programs outside the purview of the Nuclear Regulatory Commission were studied to identify features or practices which the NRC could use to enhance its program for assuring quality in the design and construction of nuclear power plants. The programs selected were: the manufacture of large commercial transport aircraft, regulated by the Federal Aviation Administration; US Navy shipbuilding; commercial shipbuilding regulated by the Maritime Administration and the US Coast Guard; Government-owned nuclear plants under the Department of Energy; spacecraft under the National Aeronautics and Space Administration; and the construction of nuclear power plants in Canada, West Germany, France, Japan, Sweden, and the United Kingdom

  20. SSS-A spacecraft and experiment description.

    Science.gov (United States)

    Longanecker, G. W.; Hoffman, R. A.

    1973-01-01

    The scientific objectives of the Explorer-45 mission are discussed. The primary objective is the study of the ring current responsible for the main phase of magnetic storms. Closely associated with this objective is the determination of the relationship between magnetic storms, substorms, and the acceleration of charged particles in the magnetosphere. Further objectives are the measurement of a wide range of proton, electron and alpha-particle energies, and studies of wave-particle interactions responsible for particle transport and loss in the inner magnetosphere. The orbital parameters, the spacecraft itself, and some of its unique features, such as the data handling system, which is programmable from the ground, are described.

  1. Silicon Schottky Diode Safe Operating Area

    Science.gov (United States)

    Casey, Megan C.; Campola, Michael J.; Lauenstein, Jean-Marie; Wilcox, Edward P.; Phan, Anthony M.; LaBel, Kenneth A.

    2016-01-01

    Vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage is studied. Devices tested include optoelectronics, digital, analog, linear bipolar devices, and hybrid devices.

  2. Climate change, land use and land surveyors

    OpenAIRE

    van der Molen, P.; Mitchell, D.

    2016-01-01

    Research reveals that the land sector is a major emitter of greenhouse gases. But the land sector has also potential to reduce emissions. Different from other emission sectors like energy and transport, the land sector (in particular the rural area including forests) has the potential to also remove greenhouse gases from the atmosphere through sequestration and storage. This requires land use, land use change and forestry to be managed with respect to climate change goals. Carbon storage has ...

  3. Dementia - keeping safe in the home

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000031.htm Dementia - keeping safe in the home To use the ... make sure the homes of people who have dementia are safe for them. Safety Tips for the ...

  4. Breastfeeding FAQs: Safely Storing Breast Milk

    Science.gov (United States)

    ... Search English Español Breastfeeding FAQs: Safely Storing Breast Milk KidsHealth / For Parents / Breastfeeding FAQs: Safely Storing Breast ... may have. How do I store my breast milk? You can freeze and/or refrigerate your pumped ( ...

  5. Working safely with electronics racks

    CERN Document Server

    Simon Baird, HSE Unit Head

    2016-01-01

    Think of CERN and you’ll probably think of particle accelerators and detectors. These are the tools of the trade in particle physics, but behind them are the racks of electronics that include power supplies, control systems and data acquisition networks.   Inside an electronics rack: danger could be lurking if the rack is not powered off. In routine operation, these are no more harmful than the home entertainment system in your living room. But unscrew the cover and it’s a different matter. Even after following appropriate training, and with formal authorisation from your group leader or equivalent to carry out electrical work or any work in the vicinity of electrical hazards, and even with extensive experience of carrying out such operations, it’s important to incorporate safe working practices into your routine. At CERN, before the racks of electronics reach their operational configurations for the accelerators and detectors, they play a vital role in test set-ups ...

  6. Workshop on Developing Safe Software

    International Nuclear Information System (INIS)

    Lawrence, J.D.

    1994-11-01

    The Workshop on Developing Safe Software was held July 22--23, 1992, at the Hotel del Coronado, San Diego, California. The purpose of the workshop was to have four world experts discuss among themselves software safety issues which are of interest to the US Nuclear Regulatory Commission. These issues concern the development of software systems for use in nuclear power plant protection systems. The workshop comprised four sessions. Wednesday morning, July 22, consisted of presentations from each of the four panel members. On Wednesday afternoon, the panel members went through a list of possible software development techniques and commented on them. The Thursday morning, July 23, session consisted of an extended discussion among the panel members and the observers from the NRC. A final session on Thursday afternoon consisted of a discussion among the NRC observers as to what was learned from the workshop

  7. Workshop on developing safe software

    International Nuclear Information System (INIS)

    Lawrence, J.D.

    1992-01-01

    The Workshop on Developing Safe Software was held July 22--23 at the Hotel del Coronado, San Diego, California. The purpose of the workshop was to have four world experts discuss among themselves software safety issues which are of interest to the U. S. Nuclear Regulatory Commission (NRC). These issues concern the development of software systems for use in nuclear power plant protection systems. The workshop comprised four sessions. Wednesday morning, July 22, consisted of presentations from each of the four panel members. On Wednesday afternoon, the panel members went through a list of possible software development techniques and commented on them. The Thursday morning, July 23, session consisted of an extended discussion among the panel members and the observers from the NRC. A final session on Thursday afternoon consisted of a discussion among the NRC observers as to what was teamed from the workshop

  8. The Difference Safe Spaces Make

    Directory of Open Access Journals (Sweden)

    Kendric Coleman

    2016-05-01

    Full Text Available In the last decade, lesbian, gay, bisexual, and transgender (LGBT students have become very visible at Historically Black Colleges and Universities (HBCUs, but this visibility is not reflected in some colleges’ student programs and activities. Only a few notable HBCUs, such as Howard University and Spelman College, have made a concerted effort. Acknowledging that the LGBT community is significant and exists, and fostering such support, comes up against a steep wall of religious tradition and doctrines, and conservative administrations. It is imperative that HBCUs address LGBT issues and create and support a safe space for students to articulate their identity. Meanwhile, many LGBT students on these campuses find voice and understanding in Black scholars and writers such as Audre Lorde’s Zami: A New Spelling of My Name and Charles Michael Smith’s Fighting Words: Personal Essays by Black Gay Men.

  9. Safe Distribution of Declarative Processes

    DEFF Research Database (Denmark)

    Hildebrandt, Thomas; Mukkamala, Raghava Rao; Slaats, Tijs

    2011-01-01

    of projections that covers a DCR Graph that the network of synchronously communicating DCR Graphs given by the projections is bisimilar to the original global process graph. We exemplify the distribution technique on a process identified in a case study of an cross-organizational case management system carried...... process model generalizing labelled prime event structures to a systems model able to finitely represent ω-regular languages. An operational semantics given as a transition semantics between markings of the graph allows DCR Graphs to be conveniently used as both specification and execution model....... The technique for distribution is based on a new general notion of projection of DCR Graphs relative to a subset of labels and events identifying the set of external events that must be communicated from the other processes in the network in order for the distribution to be safe.We prove that for any vector...

  10. Spark-safe power source

    Energy Technology Data Exchange (ETDEWEB)

    Mester, I M; Konushkin, N A; Nevozinskiy, A K; Rubinshteyn, B Sh; Serov, V I; Vasnev, M A

    1981-01-01

    A shortcoming of the known power sources is their low reliability. The purpose of the invention is to improve the reliability of the device. This is achieved because the spark-safe power source is equipped with a by-passing transistor and potentiometer, and also a generator of control interruptions in the circuit, an I-element, first separating transformer, control block, second separating transformer whose secondary winding has a relay winding whose contacts are connected to the load circuit are connected in series. The generator of control separations of the circuit is connected to the base of the by-passing transistor and to the power source outlet, the potentiometer is connected in series to the main thyristor. The middle point of the potentiometer is connected to the second inlet of the I-element.

  11. Safe injection procedures, injection practices, and needlestick ...

    African Journals Online (AJOL)

    Results: Safe injection procedures regarding final waste disposal were sufficiently adopted, while measures regarding disposable injection equipment, waste containers, hand hygiene, as well as injection practices were inadequately carried out. Lack of job aid posters that promote safe injection and safe disposal of ...

  12. Developing Safe Schools Partnerships with Law Enforcement

    Science.gov (United States)

    Rosiak, John

    2009-01-01

    Safe schools are the concern of communities throughout the world. If a school is safe, and if children feel safe, students "are better able to learn. But what are the steps to make" this happen? First, it is important to understand the problem: What are the threats to school safety? These include crime-related behaviors that find their way to…

  13. Small Rocket/Spacecraft Technology (SMART) Platform

    Science.gov (United States)

    Esper, Jaime; Flatley, Thomas P.; Bull, James B.; Buckley, Steven J.

    2011-01-01

    The NASA Goddard Space Flight Center (GSFC) and the Department of Defense Operationally Responsive Space (ORS) Office are exercising a multi-year collaborative agreement focused on a redefinition of the way space missions are designed and implemented. A much faster, leaner and effective approach to space flight requires the concerted effort of a multi-agency team tasked with developing the building blocks, both programmatically and technologically, to ultimately achieve flights within 7-days from mission call-up. For NASA, rapid mission implementations represent an opportunity to find creative ways for reducing mission life-cycle times with the resulting savings in cost. This in tum enables a class of missions catering to a broader audience of science participants, from universities to private and national laboratory researchers. To that end, the SMART (Small Rocket/Spacecraft Technology) micro-spacecraft prototype demonstrates an advanced avionics system with integrated GPS capability, high-speed plug-and-playable interfaces, legacy interfaces, inertial navigation, a modular reconfigurable structure, tunable thermal technology, and a number of instruments for environmental and optical sensing. Although SMART was first launched inside a sounding rocket, it is designed as a free-flyer.

  14. Time delay interferometry with moving spacecraft arrays

    International Nuclear Information System (INIS)

    Tinto, Massimo; Estabrook, F.B.; Armstrong, J.W.

    2004-01-01

    Space-borne interferometric gravitational wave detectors, sensitive in the low-frequency (millihertz) band, will fly in the next decade. In these detectors the spacecraft-to-spacecraft light-travel-times will necessarily be unequal, time varying, and (due to aberration) have different time delays on up and down links. The reduction of data from moving interferometric laser arrays in solar orbit will in fact encounter nonsymmetric up- and down-link light time differences that are about 100 times larger than has previously been recognized. The time-delay interferometry (TDI) technique uses knowledge of these delays to cancel the otherwise dominant laser phase noise and yields a variety of data combinations sensitive to gravitational waves. Under the assumption that the (different) up- and down-link time delays are constant, we derive the TDI expressions for those combinations that rely only on four interspacecraft phase measurements. We then turn to the general problem that encompasses time dependence of the light-travel times along the laser links. By introducing a set of noncommuting time-delay operators, we show that there exists a quite general procedure for deriving generalized TDI combinations that account for the effects of time dependence of the arms. By applying our approach we are able to re-derive the 'flex-free' expression for the unequal-arm Michelson combinations X 1 , and obtain the generalized expressions for the TDI combinations called relay, beacon, monitor, and symmetric Sagnac

  15. Relativistic effects of spacecraft with circumnavigating observer

    Science.gov (United States)

    Shanklin, Nathaniel; West, Joseph

    A variation of the recently introduced Trolley Paradox, itself is a variation of the Ehrenfest Paradox is presented. In the Trolley Paradox, a ``stationary'' set of observers tracking a wheel rolling with a constant velocity find that the wheel travels further than its rest length circumference during one revolution of the wheel, despite the fact that the Lorentz contracted circumference is less than its rest value. In the variation presented, a rectangular spacecraft with onboard observers moves with constant velocity and is circumnavigated by several small ``sloops'' forming teams of inertial observers. This whole precession moves relative to a set of ``stationary'' Earth observers. Two cases are presented, one in which the sloops are evenly spaced according to the spacecraft observers, and one in which the sloops are evenly spaced according to the Earth observes. These two cases, combined with the rectangular geometry and an emphasis on what is seen by, and what is measured by, each set of observers is very helpful in sorting out the apparent contradictions. To aid in the visualizations stationary representations in excel along with animation in Visual Python and Unity are presented. The analysis presented is suitable for undergraduate physics majors.

  16. Spacecraft Dynamic Characterization by Strain Energies Method

    Science.gov (United States)

    Bretagne, J.-M.; Fragnito, M.; Massier, S.

    2002-01-01

    In the last years the significant increase in satellite broadcasting demand, with the wide band communication dawn, has given a great impulse to the telecommunication satellite market. The big demand is translated from operators (such as SES/Astra, Eutelsat, Intelsat, Inmarsat, EuroSkyWay etc.) in an increase of orders of telecom satellite to the world industrials. The largest part of these telecom satellite orders consists of Geostationary platforms which grow more and more in mass (over 5 tons) due to an ever longer demanded lifetime (up to 20 years), and become more complex due to the need of implementing an ever larger number of repeaters, antenna reflectors and feeds, etc... In this frame, the mechanical design and verification of these large spacecraft become difficult and ambitious at the same time, driven by the dry mass limitation objective. By the Finite Element Method (FEM), and on the basis of the telecom satellite heritage of a world leader constructor such as Alcatel Space Industries it is nowadays possible to model these spacecraft in a realistic and confident way in order to identify the main global dynamic aspects such as mode shapes, mass participation and/or dynamic responses. But on the other hand, one of the main aims consists in identifying soon in a program the most critical aspects of the system behavior in the launch dynamic environment, such as possible dynamic coupling between the different subsystems and secondary structures of the spacecraft (large deployable reflectors, thrusters, etc.). To this aim a numerical method has been developed in the frame of the Alcatel SPACEBUS family program, using MSC/Nastran capabilities and it is presented in this paper. The method is based on Spacecraft sub-structuring and strain energy calculation. The method mainly consists of two steps : 1) subsystem modal strain energy ratio (with respect to the global strain energy); 2) subsystem strain energy calculation for each mode according to the base driven

  17. The Near Earth Object (NEO) Scout Spacecraft: A Low-cost Approach to In-situ Characterization of the NEO Population

    Science.gov (United States)

    Woeppel, Eric A.; Balsamo, James M.; Fischer, Karl J.; East, Matthew J.; Styborski, Jeremy A.; Roche, Christopher A.; Ott, Mackenzie D.; Scorza, Matthew J.; Doherty, Christopher D.; Trovato, Andrew J.; hide

    2014-01-01

    This paper describes a microsatellite spacecraft with supporting mission profile and architecture, designed to enable preliminary in-situ characterization of a significant number of Near Earth Objects (NEOs) at reasonably low cost. The spacecraft will be referred to as the NEO-Scout. NEO-Scout spacecraft are to be placed in Geosynchronous Equatorial Orbit (GEO), cis-lunar space, or on earth escape trajectories as secondary payloads on launch vehicles headed for GEO or beyond, and will begin their mission after deployment from the launcher. A distinguishing key feature of the NEO-Scout system is to design the spacecraft and mission timeline so as to enable rendezvous with and landing on the target NEO during NEO close approach (the Earth-Moon system using low-thrust/high-impulse propulsion systems. Mission durations are on the order 100 to 400 days. Mission feasibility and preliminary design analysis are presented, along with detailed trajectory calculations.

  18. Safe Handover : Safe Patients - The Electronic Handover System.

    Science.gov (United States)

    Till, Alex; Sall, Hanish; Wilkinson, Jonathan

    2014-01-01

    Failure of effective handover is a major preventable cause of patient harm. We aimed to promote accurate recording of high-quality clinical information using an Electronic Handover System (EHS) that would contribute to a sustainable improvement in effective patient care and safety. Within our hospital the human factors associated with poor communication were compromising patient care and unnecessarily increasing the workload of staff due to the poor quality of handovers. Only half of handovers were understood by the doctors expected to complete them, and more than half of our medical staff felt it posed a risk to patient safety. We created a standardised proforma for handovers that contained specific sub-headings, re-classified patient risk assessments, and aided escalation of care by adding prompts for verbal handover. Sources of miscommunication were removed, accountability for handovers provided, and tasks were re-organised to reduce the workload of staff. Long-term, three-month data showed that each sub-heading achieved at least 80% compliance (an average improvement of approximately 40% for the overall quality of handovers). This translated into 91% of handovers being subjectively clear to junior doctors. 87% of medical staff felt we had reduced a risk to patient safety and 80% felt it increased continuity of care. Without guidance, doctors omit key information required for effective handover. All organisations should consider implementing an electronic handover system as a viable, sustainable and safe solution to handover of care that allows patient safety to remain at the heart of the NHS.

  19. Challenges of pin-point landing for planetary landing: the LION absolute vision-based navigation approach and experimental results

    OpenAIRE

    Voirin, Thomas; Delaune, Jeff; Le Besnerais, Guy; Farges, Jean Loup; Bourdarias, Clément; Krüger, Hans

    2013-01-01

    After ExoMars in 2016 and 2018, future ESA missions to Mars, the Moon, or asteroids will require safe and pinpoint precision landing capabilities, with for example a specified accuracy of typically 100 m at touchdown for a Moon landing. The safe landing requirement can be met thanks to state-of-the-art Terrain-Relative Navigation (TRN) sensors such as Wide-Field-of-View vision-based navigation cameras (VBNC), with appropriate hazard detection and avoidance algorithms. To reach the pinpoint pr...

  20. Touch Temperature Coating for Off-the-Shelf Electrical Equipment Used on Spacecraft

    Science.gov (United States)

    Ungar, Eugene K.; Brady, Timothy K.

    2010-01-01

    Off-the-shelf electrical equipment is frequently used in space-based applications to control costs. However, the reduced heat transfer in the spacecraft microgravity environment causes the equipment to operate at significantly higher temperatures than it would in terrestrial applications. This creates touch temperature issues where items particularly metallic ones become too hot for the crew to handle safely. A touch temperature coating layup has been developed that can be added to spacebased electrically powered hardware. The coating allows the crew to safely handle the hardware, but only slightly impedes the heat transfer from the component during normal operation. In the present work, the coating generic requirements are developed and a layup is described that meets these specifications. Analytical and experimental results are presented that demonstrate the ability of the coating layup to increase the allowable limits of touch temperature while only marginally degrading heat transfer to the environment. This allows the spacecraft crew to handle objects that, if not coated, would be hot enough to cause pain or skin damage.

  1. Resilience Engineering in Critical Long Term Aerospace Software Systems: A New Approach to Spacecraft Software Safety

    Science.gov (United States)

    Dulo, D. A.

    Safety critical software systems permeate spacecraft, and in a long term venture like a starship would be pervasive in every system of the spacecraft. Yet software failure today continues to plague both the systems and the organizations that develop them resulting in the loss of life, time, money, and valuable system platforms. A starship cannot afford this type of software failure in long journeys away from home. A single software failure could have catastrophic results for the spaceship and the crew onboard. This paper will offer a new approach to developing safe reliable software systems through focusing not on the traditional safety/reliability engineering paradigms but rather by focusing on a new paradigm: Resilience and Failure Obviation Engineering. The foremost objective of this approach is the obviation of failure, coupled with the ability of a software system to prevent or adapt to complex changing conditions in real time as a safety valve should failure occur to ensure safe system continuity. Through this approach, safety is ensured through foresight to anticipate failure and to adapt to risk in real time before failure occurs. In a starship, this type of software engineering is vital. Through software developed in a resilient manner, a starship would have reduced or eliminated software failure, and would have the ability to rapidly adapt should a software system become unstable or unsafe. As a result, long term software safety, reliability, and resilience would be present for a successful long term starship mission.

  2. Spacecraft Dynamics Should be Considered in Kalman Filter Attitude Estimation

    Science.gov (United States)

    Yang, Yaguang; Zhou, Zhiqiang

    2016-01-01

    Kalman filter based spacecraft attitude estimation has been used in some high-profile missions and has been widely discussed in literature. While some models in spacecraft attitude estimation include spacecraft dynamics, most do not. To our best knowledge, there is no comparison on which model is a better choice. In this paper, we discuss the reasons why spacecraft dynamics should be considered in the Kalman filter based spacecraft attitude estimation problem. We also propose a reduced quaternion spacecraft dynamics model which admits additive noise. Geometry of the reduced quaternion model and the additive noise are discussed. This treatment is more elegant in mathematics and easier in computation. We use some simulation example to verify our claims.

  3. Electromagnetic Forces on a Relativistic Spacecraft in the Interstellar Medium

    Energy Technology Data Exchange (ETDEWEB)

    Hoang, Thiem [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of); Loeb, Abraham, E-mail: thiemhoang@kasi.re.kr, E-mail: aloeb@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA (United States)

    2017-10-10

    A relativistic spacecraft of the type envisioned by the Breakthrough Starshot initiative will inevitably become charged through collisions with interstellar particles and UV photons. Interstellar magnetic fields would therefore deflect the trajectory of the spacecraft. We calculate the expected deflection for typical interstellar conditions. We also find that the charge distribution of the spacecraft is asymmetric, producing an electric dipole moment. The interaction between the moving electric dipole and the interstellar magnetic field is found to produce a large torque, which can result in fast oscillation of the spacecraft around the axis perpendicular to the direction of motion, with a period of ∼0.5 hr. We then study the spacecraft rotation arising from impulsive torques by dust bombardment. Finally, we discuss the effect of the spacecraft rotation and suggest several methods to mitigate it.

  4. Multi-Terrain Earth Landing Systems Applicable for Manned Space Capsules

    Science.gov (United States)

    Fasanella, Edwin L.

    2008-01-01

    A key element of the President's Vision for Space Exploration is the development of a new space transportation system to replace the Shuttle that will enable manned exploration of the moon, Mars, and beyond. NASA has tasked the Constellation Program with the development of this architecture, which includes the Ares launch vehicle and Orion manned spacecraft. The Orion spacecraft must carry six astronauts and its primary structure should be reusable, if practical. These requirements led the Constellation Program to consider a baseline land landing on return to earth. To assess the landing system options for Orion, a review of current operational parachute landing systems such as those used for the F-111 escape module and the Soyuz is performed. In particular, landing systems with airbags and retrorockets that would enable reusability of the Orion capsule are investigated. In addition, Apollo tests and analyses conducted in the 1960's for both water and land landings are reviewed. Finally, tests and dynamic finite element simulations to understand land landings for the Orion spacecraft are also presented.

  5. 3D Display of Spacecraft Dynamics Using Real Telemetry

    Directory of Open Access Journals (Sweden)

    Sanguk Lee

    2002-12-01

    Full Text Available 3D display of spacecraft motion by using telemetry data received from satellite in real-time is described. Telemetry data are converted to the appropriate form for 3-D display by the real-time preprocessor. Stored playback telemetry data also can be processed for the display. 3D display of spacecraft motion by using real telemetry data provides intuitive comprehension of spacecraft dynamics.

  6. Safe Handover : Safe Patients – The Electronic Handover System

    Science.gov (United States)

    Till, Alex; Sall, Hanish; Wilkinson, Jonathan

    2014-01-01

    Failure of effective handover is a major preventable cause of patient harm. We aimed to promote accurate recording of high-quality clinical information using an Electronic Handover System (EHS) that would contribute to a sustainable improvement in effective patient care and safety. Within our hospital the human factors associated with poor communication were compromising patient care and unnecessarily increasing the workload of staff due to the poor quality of handovers. Only half of handovers were understood by the doctors expected to complete them, and more than half of our medical staff felt it posed a risk to patient safety. We created a standardised proforma for handovers that contained specific sub-headings, re-classified patient risk assessments, and aided escalation of care by adding prompts for verbal handover. Sources of miscommunication were removed, accountability for handovers provided, and tasks were re-organised to reduce the workload of staff. Long-term, three-month data showed that each sub-heading achieved at least 80% compliance (an average improvement of approximately 40% for the overall quality of handovers). This translated into 91% of handovers being subjectively clear to junior doctors. 87% of medical staff felt we had reduced a risk to patient safety and 80% felt it increased continuity of care. Without guidance, doctors omit key information required for effective handover. All organisations should consider implementing an electronic handover system as a viable, sustainable and safe solution to handover of care that allows patient safety to remain at the heart of the NHS. PMID:26734244

  7. Eye safe laser range finders

    International Nuclear Information System (INIS)

    Snir, M.; Margaliot, M.; Amitzi, A.

    2004-01-01

    During the 1970's, Ruby (Q switched) laser based range finders with a wavelength of 694nm were first used. These lasers operated in a pulse mode within the visible light range and produced a risk for the eye retina. The laser beam striking the macula could damage the eye and might cause blindness. Over the years, Nd:YAG (Q switched) lasers were developed (operating at 1064nm) for range finding and designation uses. The wavelength of these lasers, operating in the near Infra-Red range (invisible), is also focused tightly on the retina. The human eye does not respond to the invisible light so there is no natural protection (eye blink reflex) as in the visible light. The operation of these lasers worldwide, especially when the laser beam is exposed, causes occasional eye accidents. Another risk is stemming from the use of observation systems with a high optical gain, in the laser operation areas, which enlarge the range of risk quite significantly. Therefore, research and development efforts were invested in order to introduce eye safe lasers. One of the solutions for this problem is presented in following document

  8. Working safely with radioactive materials

    International Nuclear Information System (INIS)

    Davies, Wynne

    1993-01-01

    In common with exposure to many other laboratory chemicals, exposure to ionising radiations and to radioactive materials carries a small risk of causing harm. Because of this, there are legal limits to the amount of exposure to ionising radiations at work and special rules for working with radioactive materials. Although radiation protection is a complex subject it is possible to simplify to 10 basic things you should do -the Golden Rules. They are: 1) understand the nature of the hazard and get practical training; 2) plan ahead to minimise time spent handling radioactivity; 3) distance yourself appropriately from sources of radiation; 4) use appropriate shielding for the radiation; 5) contain radioactive materials in defined work areas; 6) wear appropriate protective clothing and dosimeters; 7) monitor the work area frequently for contamination control; 8) follow the local rules and safe ways of working; 9) minimise accumulation of waste and dispose of it by appropriate routes, and 10) after completion of work, monitor, wash, and monitor yourself again. These rules are expanded in this article. (author)

  9. Materials for passively safe reactors

    International Nuclear Information System (INIS)

    Simnad, T.

    1993-01-01

    Future nuclear power capacity will be based on reactor designs that include passive safety features if recent progress in advanced nuclear power developments is realized. There is a high potential for nuclear systems that are smaller and easier to operate than the current generation of reactors, especially when passive or intrinsic characteristics are applied to provide inherent stability of the chain reaction and to minimize the burden on equipment and operating personnel. Taylor, has listed the following common generic technical features as the most important goals for the principal reactor development systems: passive stability, simplification, ruggedness, case of operation, and modularity. Economic competitiveness also depends on standardization and assurance of licensing. The performance of passively safe reactors will be greatly influenced by the successful development of advanced fuels and materials that will provide lower fuel-cycle costs. A dozen new designs of advanced power reactors have been described recently, covering a wide spectrum of reactor types, including pressurized water reactors, boiling water reactors, heavy-water reactors, modular high-temperature gas-cooled reactors (MHTGRs), and fast breeder reactors. These new designs address the need for passive safety features as well as the requirement of economic competitiveness

  10. Safe and green nuclear power

    International Nuclear Information System (INIS)

    Kushwaha, H.S.

    2010-01-01

    Energy development plays an important role in the national economic growth. Presently the per capita consumption of energy in our country is about 750 kWh including captive power generation which is low in comparison to that in the developed countries like USA where it is about 12,000 kWh. As of now the total installed capacity of electricity generation is about 152,148 MW(e) which is drawn from Thermal (65%), Hydel (24%), Nuclear (3%) power plants and Renewables (8%). It is expected that by the end of year 2020, the required installed capacity would be more than 3,00,000 MW(e), if we assume per capita consumption of about 800-1000 kWh for Indian population of well over one billion. To meet the projected power requirement in India, suitable options need to be identified and explored for generation of electricity. For choosing better alternatives various factors such as availability of resources, potential to generate commercial power, economic viability, etc. need to be considered. Besides these factors, an important factor which must be taken into consideration is protection of environment around the operating power stations. This paper attempts to demonstrate that the nuclear power generation is an environmentally benign option for meeting the future requirement of electricity in India. It also discusses the need for creating the public awareness about the safe operations of the nuclear power plants and ionising radiation. (author)

  11. SAFE testing nuclear rockets economically

    International Nuclear Information System (INIS)

    Howe, Steven D.; Travis, Bryan; Zerkle, David K.

    2003-01-01

    Several studies over the past few decades have recognized the need for advanced propulsion to explore the solar system. As early as the 1960s, Werner Von Braun and others recognized the need for a nuclear rocket for sending humans to Mars. The great distances, the intense radiation levels, and the physiological response to zero-gravity all supported the concept of using a nuclear rocket to decrease mission time. These same needs have been recognized in later studies, especially in the Space Exploration Initiative in 1989. One of the key questions that has arisen in later studies, however, is the ability to test a nuclear rocket engine in the current societal environment. Unlike the Rover/NERVA programs in the 1960s, the rocket exhaust can no longer be vented to the open atmosphere. As a consequence, previous studies have examined the feasibility of building a large-scale version of the Nuclear Furnace Scrubber that was demonstrated in 1971. We have investigated an alternative that would deposit the rocket exhaust along with any entrained fission products directly into the ground. The Subsurface Active Filtering of Exhaust, or SAFE, concept would allow variable sized engines to be tested for long times at a modest expense. A system overview, results of preliminary calculations, and cost estimates of proof of concept demonstrations are presented. The results indicate that a nuclear rocket could be tested at the Nevada Test Site for under $20 M

  12. Application of advanced electronics to a future spacecraft computer design

    Science.gov (United States)

    Carney, P. C.

    1980-01-01

    Advancements in hardware and software technology are summarized with specific emphasis on spacecraft computer capabilities. Available state of the art technology is reviewed and candidate architectures are defined.

  13. Simulator Facility for Attitude Control and Energy Storage of Spacecraft

    National Research Council Canada - National Science Library

    Tsiotras, Panagiotis

    2002-01-01

    This report concerns a designed and built experimental facility that will allow the conduction of experiments for validating advanced attitude control algorithms for spacecraft in a weightless environment...

  14. Determining Spacecraft Reaction Wheel Friction Parameters

    Science.gov (United States)

    Sarani, Siamak

    2009-01-01

    Software was developed to characterize the drag in each of the Cassini spacecraft's Reaction Wheel Assemblies (RWAs) to determine the RWA friction parameters. This tool measures the drag torque of RWAs for not only the high spin rates (greater than 250 RPM), but also the low spin rates (less than 250 RPM) where there is a lack of an elastohydrodynamic boundary layer in the bearings. RWA rate and drag torque profiles as functions of time are collected via telemetry once every 4 seconds and once every 8 seconds, respectively. Intermediate processing steps single-out the coast-down regions. A nonlinear model for the drag torque as a function of RWA spin rate is incorporated in order to characterize the low spin rate regime. The tool then uses a nonlinear parameter optimization algorithm based on the Nelder-Mead simplex method to determine the viscous coefficient, the Dahl friction, and the two parameters that account for the low spin-rate behavior.

  15. A spacecraft computer repairable via command.

    Science.gov (United States)

    Fimmel, R. O.; Baker, T. E.

    1971-01-01

    The MULTIPAC is a central data system developed for deep-space probes with the distinctive feature that it may be repaired during flight via command and telemetry links by reprogramming around the failed unit. The computer organization uses pools of identical modules which the program organizes into one or more computers called processors. The interaction of these modules is dynamically controlled by the program rather than hardware. In the event of a failure, new programs are entered which reorganize the central data system with a somewhat reduced total processing capability aboard the spacecraft. Emphasis is placed on the evolution of the system architecture and the final overall system design rather than the specific logic design.

  16. Cometary dust size distributions from flyby spacecraft

    International Nuclear Information System (INIS)

    Divine, N.

    1988-01-01

    Pior to the Halley flybys in 1986, the distribution of cometary dust grains with particle size were approximated using models which provided reasonable fits to the dynamics of dust tails, anti-tails, and infrared spectra. These distributions have since been improved using fluence data (i.e., particle fluxes integrated over time along the flyby trajectory) from three spacecraft. The fluence derived distributions are appropriate for comparison with simultaneous infrared photometry (from Earth) because they sample the particles in the same way as the IR data do (along the line of sight) and because they are directly proportional to the concentration distribution in that region of the coma which dominates the IR emission

  17. A corrector for spacecraft calculated electron moments

    Directory of Open Access Journals (Sweden)

    J. Geach

    2005-03-01

    Full Text Available We present the application of a numerical method to correct electron moments calculated on-board spacecraft from the effects of potential broadening and energy range truncation. Assuming a shape for the natural distribution of the ambient plasma and employing the scalar approximation, the on-board moments can be represented as non-linear integral functions of the underlying distribution. We have implemented an algorithm which inverts this system successfully over a wide range of parameters for an assumed underlying drifting Maxwellian distribution. The outputs of the solver are the corrected electron plasma temperature Te, density Ne and velocity vector Ve. We also make an estimation of the temperature anisotropy A of the distribution. We present corrected moment data from Cluster's PEACE experiment for a range of plasma environments and make comparisons with electron and ion data from other Cluster instruments, as well as the equivalent ground-based calculations using full 3-D distribution PEACE telemetry.

  18. Generating Animated Displays of Spacecraft Orbits

    Science.gov (United States)

    Candey, Robert M.; Chimiak, Reine A.; Harris, Bernard T.

    2005-01-01

    Tool for Interactive Plotting, Sonification, and 3D Orbit Display (TIPSOD) is a computer program for generating interactive, animated, four-dimensional (space and time) displays of spacecraft orbits. TIPSOD utilizes the programming interface of the Satellite Situation Center Web (SSCWeb) services to communicate with the SSC logic and database by use of the open protocols of the Internet. TIPSOD is implemented in Java 3D and effects an extension of the preexisting SSCWeb two-dimensional static graphical displays of orbits. Orbits can be displayed in any or all of the following seven reference systems: true-of-date (an inertial system), J2000 (another inertial system), geographic, geomagnetic, geocentric solar ecliptic, geocentric solar magnetospheric, and solar magnetic. In addition to orbits, TIPSOD computes and displays Sibeck's magnetopause and Fairfield's bow-shock surfaces. TIPSOD can be used by the scientific community as a means of projection or interpretation. It also has potential as an educational tool.

  19. Planning Inmarsat's second generation of spacecraft

    Science.gov (United States)

    Williams, W. P.

    1982-09-01

    The next generation of studies of the Inmarsat service are outlined, such as traffic forecasting studies, communications capacity estimates, space segment design, cost estimates, and financial analysis. Traffic forecasting will require future demand estimates, and a computer model has been developed which estimates demand over the Atlantic, Pacific, and Indian ocean regions. Communications estimates are based on traffic estimates, as a model converts traffic demand into a required capacity figure for a given area. The Erlang formula is used, requiring additional data such as peak hour ratios and distribution estimates. Basic space segment technical requirements are outlined (communications payload, transponder arrangements, etc), and further design studies involve such areas as space segment configuration, launcher and spacecraft studies, transmission planning, and earth segment configurations. Cost estimates of proposed design parameters will be performed, but options must be reduced to make construction feasible. Finally, a financial analysis will be carried out in order to calculate financial returns.

  20. Flight mission control for multiple spacecraft

    Science.gov (United States)

    Ryan, Robert E.

    1990-10-01

    A plan developed by the Jet Propulsion Laboratory for mission control of unmanned spacecraft is outlined. A technical matrix organization from which, in the past, project teams were formed to uniquely support a mission is replaced in this new plan. A cost effective approach was needed to make best use of limited resources. Mission control is a focal point operations and a good place to start a multimission concept. Co-location and sharing common functions are the keys to obtaining efficiencies at minimum additional risk. For the projects, the major changes are sharing a common operations area and having indirect control of personnel. The plan identifies the still direct link for the mission control functions. Training is a major element in this plan. Personnel are qualified for a position and certified for a mission. This concept is more easily accepted by new missions than the ongoing missions.

  1. High Gain Antenna Calibration on Three Spacecraft

    Science.gov (United States)

    Hashmall, Joseph A.

    2011-01-01

    This paper describes the alignment calibration of spacecraft High Gain Antennas (HGAs) for three missions. For two of the missions (the Lunar Reconnaissance Orbiter and the Solar Dynamics Observatory) the calibration was performed on orbit. For the third mission (the Global Precipitation Measurement core satellite) ground simulation of the calibration was performed in a calibration feasibility study. These three satellites provide a range of calibration situations-Lunar orbit transmitting to a ground antenna for LRO, geosynchronous orbit transmitting to a ground antenna fer SDO, and low Earth orbit transmitting to TDRS satellites for GPM The calibration results depend strongly on the quality and quantity of calibration data. With insufficient data the calibration Junction may give erroneous solutions. Manual intervention in the calibration allowed reliable parameters to be generated for all three missions.

  2. Human factors issues for interstellar spacecraft

    Science.gov (United States)

    Cohen, Marc M.; Brody, Adam R.

    1991-01-01

    Developments in research on space human factors are reviewed in the context of a self-sustaining interstellar spacecraft based on the notion of traveling space settlements. Assumptions about interstellar travel are set forth addressing costs, mission durations, and the need for multigenerational space colonies. The model of human motivation by Maslow (1970) is examined and directly related to the design of space habitat architecture. Human-factors technology issues encompass the human-machine interface, crew selection and training, and the development of spaceship infrastructure during transtellar flight. A scenario for feasible instellar travel is based on a speed of 0.5c, a timeframe of about 100 yr, and an expandable multigenerational crew of about 100 members. Crew training is identified as a critical human-factors issue requiring the development of perceptual and cognitive aids such as expert systems and virtual reality.

  3. Rechargeable metal hydrides for spacecraft application

    Science.gov (United States)

    Perry, J. L.

    1988-01-01

    Storing hydrogen on board the Space Station presents both safety and logistics problems. Conventional storage using pressurized bottles requires large masses, pressures, and volumes to handle the hydrogen to be used in experiments in the U.S. Laboratory Module and residual hydrogen generated by the ECLSS. Rechargeable metal hydrides may be competitive with conventional storage techniques. The basic theory of hydride behavior is presented and the engineering properties of LaNi5 are discussed to gain a clear understanding of the potential of metal hydrides for handling spacecraft hydrogen resources. Applications to Space Station and the safety of metal hydrides are presented and compared to conventional hydride storage. This comparison indicates that metal hydrides may be safer and require lower pressures, less volume, and less mass to store an equivalent mass of hydrogen.

  4. Space power systems--''Spacecraft 2000''

    International Nuclear Information System (INIS)

    Faymon, K.A.

    1985-01-01

    The National Space programs of the 21st century will require abundant and relatively low cost power and energy produced by high reliability-low mass systems. Advancement of current power system related technologies will enable the U.S. to realize increased scientific payload for government missions or increased revenue producing payload for commercial space endeavors. Autonomous, unattended operation will be a highly desirable characteristic of these advanced power systems. Those space power-energy related technologies, which will comprise the space craft of the late 1990's and the early 2000's, will evolve from today's state-of-the-art systems and those long term technology development programs presently in place. However, to foster accelerated development of the more critical technologies which have the potential for high-payoffs, additional programs will be proposed and put in place between now and the end of the century. Such a program is ''Spacecraft 2000'', which is described in this paper

  5. Land Cover - Minnesota Land Cover Classification System

    Data.gov (United States)

    Minnesota Department of Natural Resources — Land cover data set based on the Minnesota Land Cover Classification System (MLCCS) coding scheme. This data was produced using a combination of aerial photograph...

  6. The SafeCOP ECSEL Project: Safe Cooperating Cyber-Physical Systems Using Wireless Communication

    DEFF Research Database (Denmark)

    Pop, Paul; Scholle, Detlef; Hansson, Hans

    2016-01-01

    This paper presents an overview of the ECSEL project entitled "Safe Cooperating Cyber-Physical Systems using Wireless Communication" (SafeCOP), which runs during the period 2016 -- 2019. SafeCOP targets safety-related Cooperating Cyber-Physical Systems (CO-CPS) characterised by use of wireless...... detection of abnormal behaviour, triggering if needed a safe degraded mode. SafeCOP will also develop methods and tools, which will be used to produce safety assurance evidence needed to certify cooperative functions. SafeCOP will extend current wireless technologies to ensure safe and secure cooperation...

  7. Radiation shielding calculations for the vista spacecraft

    International Nuclear Information System (INIS)

    Sahin, Suemer; Sahin, Haci Mehmet; Acir, Adem

    2005-01-01

    The VISTA spacecraft design concept has been proposed for manned or heavy cargo deep space missions beyond earth orbit with inertial fusion energy propulsion. Rocket propulsion is provided by fusion power deposited in the inertial confined fuel pellet debris and with the help of a magnetic nozzle. The calculations for the radiation shielding have been revised under the fact that the highest jet efficiency of the vehicle could be attained only if the propelling plasma would have a narrow temperature distribution. The shield mass could be reduced from 600 tons in the original design to 62 tons. Natural and enriched lithium were the principle shielding materials. The allowable nuclear heating in the superconducting magnet coils (up to 5 mW/cm 3 ) is taken as the crucial criterion for dimensioning the radiation shielding structure of the spacecraft. The space craft mass is 6000 tons. Total peak nuclear power density in the coils is calculated as ∼5.0 mW/cm 3 for a fusion power output of 17 500 MW. The peak neutron heating density is ∼2.0 mW/cm 3 , and the peak γ-ray heating density is ∼3.0 mW/cm 3 (on different points) using natural lithium in the shielding. However, the volume averaged heat generation in the coils is much lower, namely 0.21, 0.71 and 0.92 mW/cm 3 for the neutron, γ-ray and total nuclear heating, respectively. The coil heating will be slightly lower if highly enriched 6 Li (90%) is used instead of natural lithium. Peak values are then calculated as 2.05, 2.15 and 4.2 mW/cm 3 for the neutron, γ-ray and total nuclear heating, respectively. The corresponding volume averaged heat generation in the coils became 0.19, 0.58 and 0.77 mW/cm 3

  8. Climate change, land use and land surveyors

    NARCIS (Netherlands)

    van der Molen, P.; Mitchell, D.

    2016-01-01

    Research reveals that the land sector is a major emitter of greenhouse gases. But the land sector has also potential to reduce emissions. Different from other emission sectors like energy and transport, the land sector (in particular the rural area including forests) has the potential to also remove

  9. Safe prescribing: a titanic challenge.

    Science.gov (United States)

    Routledge, Philip A

    2012-10-01

    The challenge to achieve safe prescribing merits the adjective 'titanic'. The organisational and human errors leading to poor prescribing (e.g. underprescribing, overprescribing, misprescribing or medication errors) have parallels in the organisational and human errors that led to the loss of the Titanic 100 years ago this year. Prescribing can be adversely affected by communication failures, critical conditions, complacency, corner cutting, callowness and a lack of courage of conviction, all of which were also factors leading to the Titanic tragedy. These issues need to be addressed by a commitment to excellence, the final component of the 'Seven C's'. Optimal prescribing is dependent upon close communication and collaborative working between highly trained health professionals, whose role is to ensure maximum clinical effectiveness, whilst also protecting their patients from avoidable harm. Since humans are prone to error, and the environments in which they work are imperfect, it is not surprising that medication errors are common, occurring more often during the prescribing stage than during dispensing or administration. A commitment to excellence in prescribing includes a continued focus on lifelong learning (including interprofessional learning) in pharmacology and therapeutics. This should be accompanied by improvements in the clinical working environment of prescribers, and the encouragement of a strong safety culture (including reporting of adverse incidents as well as suspected adverse drug reactions whenever appropriate). Finally, members of the clinical team must be prepared to challenge each other, when necessary, to ensure that prescribing combines the highest likelihood of benefit with the lowest potential for harm. © 2012 The Author. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

  10. Safe prescribing: a titanic challenge

    Science.gov (United States)

    Routledge, Philip A

    2012-01-01

    The challenge to achieve safe prescribing merits the adjective ‘titanic’. The organisational and human errors leading to poor prescribing (e.g. underprescribing, overprescribing, misprescribing or medication errors) have parallels in the organisational and human errors that led to the loss of the Titanic 100 years ago this year. Prescribing can be adversely affected by communication failures, critical conditions, complacency, corner cutting, callowness and a lack of courage of conviction, all of which were also factors leading to the Titanic tragedy. These issues need to be addressed by a commitment to excellence, the final component of the ‘Seven C's’. Optimal prescribing is dependent upon close communication and collaborative working between highly trained health professionals, whose role is to ensure maximum clinical effectiveness, whilst also protecting their patients from avoidable harm. Since humans are prone to error, and the environments in which they work are imperfect, it is not surprising that medication errors are common, occurring more often during the prescribing stage than during dispensing or administration. A commitment to excellence in prescribing includes a continued focus on lifelong learning (including interprofessional learning) in pharmacology and therapeutics. This should be accompanied by improvements in the clinical working environment of prescribers, and the encouragement of a strong safety culture (including reporting of adverse incidents as well as suspected adverse drug reactions whenever appropriate). Finally, members of the clinical team must be prepared to challenge each other, when necessary, to ensure that prescribing combines the highest likelihood of benefit with the lowest potential for harm. PMID:22738396

  11. Multiple spacecraft observations of interplanetary shocks: four spacecraft determination of shock normals

    International Nuclear Information System (INIS)

    Russell, C.T.; Mellott, M.M.; Smith, E.J.; King, J.H.

    1983-01-01

    ISEE 1,2,3 IMP8, and Prognoz 7 observations of interplanetary shocks in 1978 and 1979 provide five instances where a single shock is observed by four spacecraft. These observations are used to determine best-fit normals for these five shocks. In addition to providing well-documented shocks for furture techniques. When the angle between upstream and downstream magnetic field is greater than 20, magnetic coplanarity can be an accurate single spacecraft method. However, no technique based solely on the magnetic measurements at one or multiple sites was universally accurate. Thus, we recommend using overdetermined shock normal solutions whenever possible, utilizing plasma measurements, separation vectors, and time delays together with magnetic constraints

  12. Multiple spacecraft observations of interplanetary shocks Four spacecraft determination of shock normals

    Science.gov (United States)

    Russell, C. T.; Mellott, M. M.; Smith, E. J.; King, J. H.

    1983-01-01

    ISEE 1, 2, 3, IMP 8, and Prognoz 7 observations of interplanetary shocks in 1978 and 1979 provide five instances where a single shock is observed by four spacecraft. These observations are used to determine best-fit normals for these five shocks. In addition to providing well-documented shocks for future investigations these data allow the evaluation of the accuracy of several shock normal determination techniques. When the angle between upstream and downstream magnetic field is greater than 20 deg, magnetic coplanarity can be an accurate single spacecraft method. However, no technique based solely on the magnetic measurements at one or multiple sites was universally accurate. Thus, the use of overdetermined shock normal solutions, utilizing plasma measurements, separation vectors, and time delays together with magnetic constraints, is recommended whenever possible.

  13. SAFE/SNAP application to shipboard security

    International Nuclear Information System (INIS)

    Grady, L.M.; Walker, J.L.; Polito, J.

    1981-11-01

    An application of the combined Safeguards Automated Facility Evaluation/Safeguards Network Analysis Procedure (SAFE/SNAP) modeling technique to a physical protection system (PPS) aboard a generic ship is described. This application was performed as an example of how the SAFE and SNAP techniques could be used. Estimates of probability of interruption and neutralization for the example shipboard PPS are provided by SAFE as well as an adversary scenario, which serves as input to SNAP. This adversary scenario is analyzed by SNAP through four cases which incorporate increasingly detailed security force tactics. Comparisons between the results of the SAFE and SNAP analyses are made and conclusions drawn on the validity of each technique. Feedback from SNAP to SAFE is described, and recommendations for upgrading the ship based on the results of the SAFE/SNAP application are also discussed

  14. Precision Landing and Hazard Avoidance Doman

    Science.gov (United States)

    Robertson, Edward A.; Carson, John M., III

    2016-01-01

    The Precision Landing and Hazard Avoidance (PL&HA) domain addresses the development, integration, testing, and spaceflight infusion of sensing, processing, and GN&C functions critical to the success and safety of future human and robotic exploration missions. PL&HA sensors also have applications to other mission events, such as rendezvous and docking. Autonomous PL&HA builds upon the core GN&C capabilities developed to enable soft, controlled landings on the Moon, Mars, and other solar system bodies. Through the addition of a Terrain Relative Navigation (TRN) function, precision landing within tens of meters of a map-based target is possible. The addition of a 3-D terrain mapping lidar sensor improves the probability of a safe landing via autonomous, real-time Hazard Detection and Avoidance (HDA). PL&HA significantly improves the probability of mission success and enhances access to sites of scientific interest located in challenging terrain. PL&HA can also utilize external navigation aids, such as navigation satellites and surface beacons. Advanced Lidar Sensors High precision ranging, velocimetry, and 3-D terrain mapping Terrain Relative Navigation (TRN) TRN compares onboard reconnaissance data with real-time terrain imaging data to update the S/C position estimate Hazard Detection and Avoidance (HDA) Generates a high-resolution, 3-D terrain map in real-time during the approach trajectory to identify safe landing targets Inertial Navigation During Terminal Descent High precision surface relative sensors enable accurate inertial navigation during terminal descent and a tightly controlled touchdown within meters of the selected safe landing target.

  15. Trajectory Control of Rendezvous with Maneuver Target Spacecraft

    Science.gov (United States)

    Zhou, Zhinqiang

    2012-01-01

    In this paper, a nonlinear trajectory control algorithm of rendezvous with maneuvering target spacecraft is presented. The disturbance forces on the chaser and target spacecraft and the thrust forces on the chaser spacecraft are considered in the analysis. The control algorithm developed in this paper uses the relative distance and relative velocity between the target and chaser spacecraft as the inputs. A general formula of reference relative trajectory of the chaser spacecraft to the target spacecraft is developed and applied to four different proximity maneuvers, which are in-track circling, cross-track circling, in-track spiral rendezvous and cross-track spiral rendezvous. The closed-loop differential equations of the proximity relative motion with the control algorithm are derived. It is proven in the paper that the tracking errors between the commanded relative trajectory and the actual relative trajectory are bounded within a constant region determined by the control gains. The prediction of the tracking errors is obtained. Design examples are provided to show the implementation of the control algorithm. The simulation results show that the actual relative trajectory tracks the commanded relative trajectory tightly. The predicted tracking errors match those calculated in the simulation results. The control algorithm developed in this paper can also be applied to interception of maneuver target spacecraft and relative trajectory control of spacecraft formation flying.

  16. Rockets and spacecraft: Sine qua non of space science

    Science.gov (United States)

    1980-01-01

    The evolution of the national launch vehicle stable is presented along with lists of launch vehicles used in NASA programs. A partial list of spacecraft used throughout the world is also given. Scientific spacecraft costs are presented along with an historial overview of project development and funding in NASA.

  17. Design feasibility via ascent optimality for next-generation spacecraft

    Science.gov (United States)

    Miele, A.; Mancuso, S.

    This paper deals with the optimization of the ascent trajectories for single-stage-sub-orbit (SSSO), single-stage-to-orbit (SSTO), and two-stage-to-orbit (TSTO) rocket-powered spacecraft. The maximum payload weight problem is studied for different values of the engine specific impulse and spacecraft structural factor. The main conclusions are that: feasibility of SSSO spacecraft is guaranteed for all the parameter combinations considered; feasibility of SSTO spacecraft depends strongly on the parameter combination chosen; not only feasibility of TSTO spacecraft is guaranteed for all the parameter combinations considered, but the TSTO payload is several times the SSTO payload. Improvements in engine specific impulse and spacecraft structural factor are desirable and crucial for SSTO feasibility; indeed, aerodynamic improvements do not yield significant improvements in payload. For SSSO, SSTO, and TSTO spacecraft, simple engineering approximations are developed connecting the maximum payload weight to the engine specific impulse and spacecraft structural factor. With reference to the specific impulse/structural factor domain, these engineering approximations lead to the construction of zero-payload lines separating the feasibility region (positive payload) from the unfeasibility region (negative payload).

  18. Spacecraft Charging Modeling -- Nascap-2k 2014 Annual Report

    Science.gov (United States)

    2014-09-19

    appears to work similarly in Internet Explorer, FireFox , and Opera, but fails in Safari and Chrome. Note that the SEE Spacecraft Charging Handbook is... Characteristics of Spacecraft Charging in Low Earth Orbit, J Geophys Res. 11 7, doi: 10.1029/20 11JA016875, 2012. 2 M. Cho, K. Saito, T. Hamanaga, Data

  19. Precise Relative Positioning of Formation Flying Spacecraft using GPS

    NARCIS (Netherlands)

    Kroes, R.

    2006-01-01

    Spacecraft formation flying is considered as a key technology for advanced space missions. Compared to large individual spacecraft, the distribution of sensor systems amongst multiple platforms offers improved flexibility, shorter times to mission, and the prospect of being more cost effective.

  20. Spacecraft attitude determination using the earth's magnetic field

    Science.gov (United States)

    Simpson, David G.

    1989-01-01

    A method is presented by which the attitude of a low-Earth orbiting spacecraft may be determined using a vector magnetometer, a digital Sun sensor, and a mathematical model of the Earth's magnetic field. The method is currently being implemented for the Solar Maximum Mission spacecraft (as a backup for the failing star trackers) as a way to determine roll gyro drift.

  1. A Comparison of Learning Technologies for Teaching Spacecraft Software Development

    Science.gov (United States)

    Straub, Jeremy

    2014-01-01

    The development of software for spacecraft represents a particular challenge and is, in many ways, a worst case scenario from a design perspective. Spacecraft software must be "bulletproof" and operate for extended periods of time without user intervention. If the software fails, it cannot be manually serviced. Software failure may…

  2. Low cost spacecraft computers: Oxymoron or future trend?

    Science.gov (United States)

    Manning, Robert M.

    1993-01-01

    Over the last few decades, application of current terrestrial computer technology in embedded spacecraft control systems has been expensive and wrought with many technical challenges. These challenges have centered on overcoming the extreme environmental constraints (protons, neutrons, gamma radiation, cosmic rays, temperature, vibration, etc.) that often preclude direct use of commercial off-the-shelf computer technology. Reliability, fault tolerance and power have also greatly constrained the selection of spacecraft control system computers. More recently, new constraints are being felt, cost and mass in particular, that have again narrowed the degrees of freedom spacecraft designers once enjoyed. This paper discusses these challenges, how they were previously overcome, how future trends in commercial computer technology will simplify (or hinder) selection of computer technology for spacecraft control applications, and what spacecraft electronic system designers can do now to circumvent them.

  3. Historical Mass, Power, Schedule, and Cost Growth for NASA Spacecraft

    Science.gov (United States)

    Hayhurst, Marc R.; Bitten, Robert E.; Shinn, Stephen A.; Judnick, Daniel C.; Hallgrimson, Ingrid E.; Youngs, Megan A.

    2016-01-01

    Although spacecraft developers have been moving towards standardized product lines as the aerospace industry has matured, NASA's continual need to push the cutting edge of science to accomplish unique, challenging missions can still lead to spacecraft resource growth over time. This paper assesses historical mass, power, cost, and schedule growth for multiple NASA spacecraft from the last twenty years and compares to industry reserve guidelines to understand where the guidelines may fall short. Growth is assessed from project start to launch, from the time of the preliminary design review (PDR) to launch and from the time of the critical design review (CDR) to launch. Data is also assessed not just at the spacecraft bus level, but also at the subsystem level wherever possible, to help obtain further insight into possible drivers of growth. Potential recommendations to minimize spacecraft mass, power, cost, and schedule growth for future missions are also discussed.

  4. Iterative Repair Planning for Spacecraft Operations Using the Aspen System

    Science.gov (United States)

    Rabideau, G.; Knight, R.; Chien, S.; Fukunaga, A.; Govindjee, A.

    2000-01-01

    This paper describes the Automated Scheduling and Planning Environment (ASPEN). ASPEN encodes complex spacecraft knowledge of operability constraints, flight rules, spacecraft hardware, science experiments and operations procedures to allow for automated generation of low level spacecraft sequences. Using a technique called iterative repair, ASPEN classifies constraint violations (i.e., conflicts) and attempts to repair each by performing a planning or scheduling operation. It must reason about which conflict to resolve first and what repair method to try for the given conflict. ASPEN is currently being utilized in the development of automated planner/scheduler systems for several spacecraft, including the UFO-1 naval communications satellite and the Citizen Explorer (CX1) satellite, as well as for planetary rover operations and antenna ground systems automation. This paper focuses on the algorithm and search strategies employed by ASPEN to resolve spacecraft operations constraints, as well as the data structures for representing these constraints.

  5. 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.

  6. A Technology Program that Rescues Spacecraft

    Science.gov (United States)

    Deutsch, Leslie J.; Lesh, J. R.

    2004-03-01

    There has never been a long-duration deep space mission that did not have unexpected problems during operations. JPL's Interplanetary Network Directorate (IND) Technology Program was created to develop new and improved methods of communication, navigation, and operations. A side benefit of the program is that it maintains a cadre of human talent and experimental systems that can be brought to bear on unexpected problems that may occur during mission operations. Solutions fall into four categories: applying new technology during operations to enhance science performance, developing new operational strategies, providing domain experts to help find solutions, and providing special facilities to trouble-shoot problems. These are illustrated here using five specific examples of spacecraft anomalies that have been solved using, at least in part, expertise or facilities from the IND Technology Program: Mariner 10, Voyager, Galileo, SOHO, and Cassini/Huygens. In this era of careful cost management, and emphasis on returns-on-investment, it is important to recognize this crucial additional benefit from such technology program investments.

  7. An AFDX Network for Spacecraft Data Handling

    Science.gov (United States)

    Deredempt, Marie-Helene; Kollias, Vangelis; Sun, Zhili; Canamares, Ernest; Ricco, Philippe

    2014-08-01

    In aeronautical domain, ARINC-664 Part 7 specification (AFDX) [4] provides the enabling technology for interfacing equipment in Integrated Modular Avionics (IMA) architectures. The complementary part of AFDX for a complete interoperability - Time and Space Partitioning (ARINC 653) concepts [1]- was already studied as part of space domain ESA roadmap (i.e. IMA4Space project)Standardized IMA based architecture is already considered in aeronautical domain as more flexible, reliable and secure. Integration and validation become simple, using a common set of tools and data base and could be done by part on different means with the same definition (hardware and software test benches, flight control or alarm test benches, simulator and flight test installation).In some area, requirements in terms of data processing are quite similar in space domain and the concept could be applicable to take benefit of the technology itself and of the panel of hardware and software solutions and tools available on the market. The Mission project (Methodology and assessment for the applicability of ARINC-664 (AFDX) in Satellite/Spacecraft on-board communicatION networks), as an FP7 initiative for bringing terrestrial SME research into the space domain started to evaluate the applicability of the standard in space domain.

  8. Spacecraft attitude and velocity control system

    Science.gov (United States)

    Paluszek, Michael A. (Inventor); Piper, Jr., George E. (Inventor)

    1992-01-01

    A spacecraft attitude and/or velocity control system includes a controller which responds to at least attitude errors to produce command signals representing a force vector F and a torque vector T, each having three orthogonal components, which represent the forces and torques which are to be generated by the thrusters. The thrusters may include magnetic torquer or reaction wheels. Six difference equations are generated, three having the form ##EQU1## where a.sub.j is the maximum torque which the j.sup.th thruster can produce, b.sub.j is the maximum force which the j.sup.th thruster can produce, and .alpha..sub.j is a variable representing the throttling factor of the j.sup.th thruster, which may range from zero to unity. The six equations are summed to produce a single scalar equation relating variables .alpha..sub.j to a performance index Z: ##EQU2## Those values of .alpha. which maximize the value of Z are determined by a method for solving linear equations, such as a linear programming method. The Simplex method may be used. The values of .alpha..sub.j are applied to control the corresponding thrusters.

  9. Humidity Testing for Human Rated Spacecraft

    Science.gov (United States)

    Johnson, Gary B.

    2009-01-01

    Determination that equipment can operate in and survive exposure to the humidity environments unique to human rated spacecraft presents widely varying challenges. Equipment may need to operate in habitable volumes where the atmosphere contains perspiration, exhalation, and residual moisture. Equipment located outside the pressurized volumes may be exposed to repetitive diurnal cycles that may result in moisture absorption and/or condensation. Equipment may be thermally affected by conduction to coldplate or structure, by forced or ambient air convection (hot/cold or wet/dry), or by radiation to space through windows or hatches. The equipment s on/off state also contributes to the equipment s susceptibility to humidity. Like-equipment is sometimes used in more than one location and under varying operational modes. Due to these challenges, developing a test scenario that bounds all physical, environmental and operational modes for both pressurized and unpressurized volumes requires an integrated assessment to determine the "worst-case combined conditions." Such an assessment was performed for the Constellation program, considering all of the aforementioned variables; and a test profile was developed based on approximately 300 variable combinations. The test profile has been vetted by several subject matter experts and partially validated by testing. Final testing to determine the efficacy of the test profile on actual space hardware is in the planning stages. When validation is completed, the test profile will be formally incorporated into NASA document CxP 30036, "Constellation Environmental Qualification and Acceptance Testing Requirements (CEQATR)."

  10. Kalman Filter for Spinning Spacecraft Attitude Estimation

    Science.gov (United States)

    Markley, F. Landis; Sedlak, Joseph E.

    2008-01-01

    This paper presents a Kalman filter using a seven-component attitude state vector comprising the angular momentum components in an inertial reference frame, the angular momentum components in the body frame, and a rotation angle. The relatively slow variation of these parameters makes this parameterization advantageous for spinning spacecraft attitude estimation. The filter accounts for the constraint that the magnitude of the angular momentum vector is the same in the inertial and body frames by employing a reduced six-component error state. Four variants of the filter, defined by different choices for the reduced error state, are tested against a quaternion-based filter using simulated data for the THEMIS mission. Three of these variants choose three of the components of the error state to be the infinitesimal attitude error angles, facilitating the computation of measurement sensitivity matrices and causing the usual 3x3 attitude covariance matrix to be a submatrix of the 6x6 covariance of the error state. These variants differ in their choice for the other three components of the error state. The variant employing the infinitesimal attitude error angles and the angular momentum components in an inertial reference frame as the error state shows the best combination of robustness and efficiency in the simulations. Attitude estimation results using THEMIS flight data are also presented.

  11. NASA Medical Response to Human Spacecraft Accidents

    Science.gov (United States)

    Patlach, Robert

    2011-01-01

    This slide presentation reviews NASA's role in the response to spacecraft accidents that involve human fatalities or injuries. Particular attention is given to the work of the Mishap Investigation Team (MIT), the first response to the accidents and the interface to the accident investigation board. The MIT does not investigate the accident, but the objective of the MIT is to gather, guard, preserve and document the evidence. The primary medical objectives of the MIT is to receive, analyze, identify, and transport human remains, provide assistance in the recovery effort, and to provide family Casualty Coordinators with latest recovery information. The MIT while it does not determine the cause of the accident, it acts as the fact gathering arm of the Mishap Investigation Board (MIB), which when it is activated may chose to continue to use the MIT as its field investigation resource. The MIT membership and the specific responsibilities and tasks of the flight surgeon is reviewed. The current law establishing the process is also reviewed.

  12. Medical Significance of Microorganisms in Spacecraft Environment

    Science.gov (United States)

    Pierson, Duane L.; Ott, C. Mark

    2007-01-01

    Microorganisms can spoil food supplies, contaminate drinking water, release noxious volatile compounds, initiate allergic responses, contaminate the environment, and cause infectious diseases. International acceptability limits have been established for bacterial and fungal contaminants in air and on surfaces, and environmental monitoring is conducted to ensure compliance. Allowable levels of microorganism in water and food have also been established. Environmental monitoring of the space shuttle, the Mir, and the ISS have allowed for some general conclusions. Generally, the bacteria found in air and on interior surfaces are largely of human origin such as Staphylococcus spp., Micrococcus spp. Common environmental genera such as Bacillus spp. are the most commonly isolated bacteria from all spacecraft. Yeast species associated with humans such as Candida spp. are commonly found. Aspergillus spp., Penicillium spp., and Cladosporium spp. are the most commonly isolated filamentous fungi. Microbial levels in the environment differ significantly depending upon humidity levels, condensate accumulation, and availability of carbon sources. However, human "normal flora" of bacteria and fungi can result in serious, life-threatening diseases if human immunity is compromised. Disease incidence is expected to increase as mission duration increases.

  13. Programs To Optimize Spacecraft And Aircraft Trajectories

    Science.gov (United States)

    Brauer, G. L.; Petersen, F. M.; Cornick, D.E.; Stevenson, R.; Olson, D. W.

    1994-01-01

    POST/6D POST is set of two computer programs providing ability to target and optimize trajectories of powered or unpowered spacecraft or aircraft operating at or near rotating planet. POST treats point-mass, three-degree-of-freedom case. 6D POST treats more-general rigid-body, six-degree-of-freedom (with point masses) case. Used to solve variety of performance, guidance, and flight-control problems for atmospheric and orbital vehicles. Applications include computation of performance or capability of vehicle in ascent, or orbit, and during entry into atmosphere, simulation and analysis of guidance and flight-control systems, dispersion-type analyses and analyses of loads, general-purpose six-degree-of-freedom simulation of controlled and uncontrolled vehicles, and validation of performance in six degrees of freedom. Written in FORTRAN 77 and C language. Two machine versions available: one for SUN-series computers running SunOS(TM) (LAR-14871) and one for Silicon Graphics IRIS computers running IRIX(TM) operating system (LAR-14869).

  14. Spaceborne intensity interferometry via spacecraft formation flight

    Science.gov (United States)

    Ribak, Erez N.; Gurfil, Pini; Moreno, Coral

    2012-07-01

    Interferometry in space has marked advantages: long integration times and observation in spectral bands where the atmosphere is opaque. When installed on separate spacecraft, it also has extended and flexible baselines for better filling of the uv plane. Intensity interferometry has an additional advantage, being insensitive to telescope and path errors, but is unfortunately much less light-sensitive. In planning towards such a mission, we are experimenting with some fundamental research issues. Towards this end, we constructed a system of three vehicles floating on an air table in formation flight, with an autonomous orbit control. Each such device holds its own light collector, detector, and transmitter, to broadcast its intensity signal towards a central receiving station. At this station we implement parallel radio receivers, analogue to digital converters, and a digital three-way correlator. Current technology limits us to ~1GHz transmission frequency, which corresponds to a comfortable 0.3m accuracy in light-bucket shape and in its relative position. Naïve calculations place our limiting magnitude at ~7 in the blue and ultraviolet, where amplitude interferometers are limited. The correlation signal rides on top of this huge signal with its own Poisson noise, requiring a very large dynamic range, which needs to be transmitted in full. We are looking at open questions such as deployable optical collectors and radio antennae of similar size of a few meters, and how they might influence our data transmission and thus set our flux limit.

  15. Spacecraft with gradual acceleration of solar panels

    Science.gov (United States)

    Merhav, Tamir R. (Inventor); Festa, Michael T. (Inventor); Stetson, Jr., John B. (Inventor)

    1996-01-01

    A spacecraft (8) includes a movable appendage such as solar panels (12) operated by a stepping motor (28) driven by pulses (311). In order to reduce vibration andor attitude error, the drive pulses are generated by a clock down-counter (312) with variable count ratio. Predetermined desired clock ratios are stored in selectable memories (314a-d), and the selected ratio (R) is coupled to a comparator (330) together with the current ratio (C). An up-down counter (340) establishes the current count-down ratio by counting toward the desired ratio under the control of the comparator; thus, a step change of solar panel speed never occurs. When a direction change is commanded, a flag signal generator (350) disables the selectable memories, and enables a further store (360), which generates a count ratio representing a very slow solar panel rotational rate, so that the rotational rate always slows to a low value before direction is changed. The principles of the invention are applicable to any movable appendage.

  16. Meteorological Predictions in Support of the Mars Science Laboratory Entry, Descent and Landing

    Science.gov (United States)

    Rothchild, A.; Rafkin, S. C.; Pielke, R. A., Sr.

    2010-12-01

    The Mars Science Laboratory (MSL) entry, descent, and landing (EDL) system employs a standard parachute strategy followed by a new sky crane concept where the rover is lowered to the ground via a tether from a hovering entry vehicle. As with previous missions, EDL system performance is sensitive to atmospheric conditions. While some observations characterizing the mean, large-scale atmospheric temperature and density data are available, there is effectively no information on the atmospheric conditions and variability at the scale that directly affects the spacecraft. In order to evaluate EDL system performance and to assess landing hazards and risk, it is necessary to simulate the atmosphere with a model that provides data at the appropriate spatial and temporal scales. Models also permit the study of the impact of the highly variable atmospheric dust loading on temperature, density and winds. There are four potential MSL landing sites: Mawrth Valle (22.3 N, 16.5W) , Gale Crater (5.4S, 137.7E), Holden Crater (26.1S, 34W), and Eberswalde Crater (24S, 33W). The final selection of the landing site will balance potential science return against landing and operational risk. Atmospheric modeling studies conducted with the Mars Regional Atmospheric Modeling System (MRAMS) is an integral part of the selection process. At each of the landing sites, a variety of simulations are conducted. The first type of simulations provide baseline predictions under nominal atmospheric dust loading conditions within the landing site window of ~Ls 150-170. The second type of simulation explores situations with moderate and high global atmospheric dust loading. The final type of simulation investigates the impact of local dust disturbances at the landing site. Mean and perturbation fields from each type of simulation at each of the potential landing sites are presented in comparison with the engineering performance limitations for the MSL EDL system. Within the lowest scale height, winds

  17. Landsat: A global land-imaging mission

    Science.gov (United States)

    ,

    2012-01-01

    Across four decades since 1972, Landsat satellites have continuously acquired space-based images of the Earth's land surface, coastal shallows, and coral reefs. The Landsat Program, a joint effort of the U.S. Geological Survey (USGS) and the National Aeronautics and Space Administration (NASA), was established to routinely gather land imagery from space. NASA develops remote-sensing instruments and spacecraft, then launches and validates the performance of the instruments and satellites. The USGS then assumes ownership and operation of the satellites, in addition to managing all ground reception, data archiving, product generation, and distribution. The result of this program is a long-term record of natural and human induced changes on the global landscape.

  18. Vibration and Acoustic Testing for Mars Micromission Spacecraft

    Science.gov (United States)

    Kern, Dennis L.; Scharton, Terry D.

    1999-01-01

    The objective of the Mars Micromission program being managed by the Jet Propulsion Laboratory (JPL) for NASA is to develop a common spacecraft that can carry telecommunications equipment and a variety of science payloads for exploration of Mars. The spacecraft will be capable of carrying robot landers and rovers, cameras, probes, balloons, gliders or aircraft, and telecommunications equipment to Mars at much lower cost than recent NASA Mars missions. The lightweight spacecraft (about 220 Kg mass) will be launched in a cooperative venture with CNES as a TWIN auxiliary payload on the Ariane 5 launch vehicle. Two or more Mars Micromission launches are planned for each Mars launch opportunity, which occur every 26 months. The Mars launch window for the first mission is November 1, 2002 through April 2003, which is planned to be a Mars airplane technology demonstration mission to coincide with the 100 year anniversary of the Kittyhawk flight. Several subsequent launches will create a telecommunications network orbiting Mars, which will provide for continuous communication with lenders and rovers on the Martian surface. Dedicated science payload flights to Mars are slated to start in 2005. This new cheaper and faster approach to Mars exploration calls for innovative approaches to the qualification of the Mars Micromission spacecraft for the Ariane 5 launch vibration and acoustic environments. JPL has in recent years implemented new approaches to spacecraft testing that may be effectively applied to the Mars Micromission. These include 1) force limited vibration testing, 2) combined loads, vibration and modal testing, and 3) direct acoustic testing. JPL has performed nearly 200 force limited vibration tests in the past 9 years; several of the tests were on spacecraft and large instruments, including the Cassini and Deep Space One spacecraft. Force limiting, which measures and limits the spacecraft base reaction force using triaxial force gages sandwiched between the

  19. Understanding land administration systems

    DEFF Research Database (Denmark)

    P. Williamson, Ian; Enemark, Stig; Wallace, Judy

    2008-01-01

    This paper introduces basic land administration theory and highlights four key concepts that are fundamental to understanding modern land administration systems - firstly the land management paradigm and its influence on the land administration framework, secondly the role that the cadastre plays...... in contributing to sustainable development, thirdly the changing nature of ownership and the role of land markets, and lastly a land management vision that promotes land administration in support of sustainable development and spatial enablement of society. We present here the first part of the paper. The second...

  20. Virus Alert: Ten Steps to Safe Computing.

    Science.gov (United States)

    Gunter, Glenda A.

    1997-01-01

    Discusses computer viruses and explains how to detect them; discusses virus protection and the need to update antivirus software; and offers 10 safe computing tips, including scanning floppy disks and commercial software, how to safely download files from the Internet, avoiding pirated software copies, and backing up files. (LRW)

  1. Implementation of an Improved Safe Operating Envelope

    International Nuclear Information System (INIS)

    Prime, Robyn; McIntyre, Mark; Reeves, David

    2008-01-01

    This paper is a continuation of the paper presented at IYNC 2004 on 'The Definition of a Safe Operating Envelope'. The current paper concentrates on the implementation process of the Safe Operating Envelope employed at the Point Lepreau Generating Station. (authors)

  2. Creating Safe Spaces for Music Learning

    Science.gov (United States)

    Hendricks, Karin S.; Smith, Tawnya D.; Stanuch, Jennifer

    2014-01-01

    This article offers a practical model for fostering emotionally safe learning environments that instill in music students a positive sense of self-belief, freedom, and purpose. The authors examine the implications for music educators of creating effective learning environments and present recommendations for creating a safe space for learning,…

  3. Implementation of an Improved Safe Operating Envelope

    Energy Technology Data Exchange (ETDEWEB)

    Prime, Robyn; McIntyre, Mark [NB Power Nuclear, P.O. Box 600, Lepreau, NB (Canada); Reeves, David [Atlantic Nuclear Services Ltd., PO Box 1268 Fredericton, NB (Canada)

    2008-07-01

    This paper is a continuation of the paper presented at IYNC 2004 on 'The Definition of a Safe Operating Envelope'. The current paper concentrates on the implementation process of the Safe Operating Envelope employed at the Point Lepreau Generating Station. (authors)

  4. NASA's Human Mission to a Near-Earth Asteroid: Landing on a Moving Target

    Science.gov (United States)

    Smith, Jeffrey H.; Lincoln, William P.; Weisbin, Charles R.

    2011-01-01

    This paper describes a Bayesian approach for comparing the productivity and cost-risk tradeoffs of sending versus not sending one or more robotic surveyor missions prior to a human mission to land on an asteroid. The expected value of sample information based on productivity combined with parametric variations in the prior probability an asteroid might be found suitable for landing were used to assess the optimal number of spacecraft and asteroids to survey. The analysis supports the value of surveyor missions to asteroids and indicates one launch with two spacecraft going simultaneously to two independent asteroids appears optimal.

  5. The Atsa Suborbital Observatory: An Observatory for a Commercial Suborbital Spacecraft

    Science.gov (United States)

    Vilas, F.; Sollitt, L. S.

    2012-12-01

    The advantages of astronomical observations made above Earth's atmosphere have long been understood: free access to spectral regions inaccessible from Earth (e.g., UV) or affected by the atmosphere's content (e.g., IR). Most robotic, space-based telescopes maintain large angular separation between the Sun and an observational target in order to avoid accidental damage to instruments from the Sun. For most astronomical targets, this possibility is easily avoided by waiting until objects are visible away from the Sun. For the Solar System objects inside Earth's orbit, this is never the case. Suborbital astronomical observations have over 50 years' history using NASA's sounding rockets and experimental space planes. Commercial suborbital spacecraft are largely expected to go to ~100 km altitude above Earth, providing a limited amount of time for astronomical observations. The unique scientific advantage to these observations is the ability to point close to the Sun: if a suborbital spacecraft accidentally turns too close to the Sun and fries an instrument, it is easy to land the spacecraft and repair the hardware for the next flight. Objects uniquely observed during the short observing window include inner-Earth asteroids, Mercury, Venus, and Sun-grazing comets. Both open-FOV and target-specific observations are possible. Despite many space probes to the inner Solar System, scientific questions remain. These include inner-Earth asteroid size and bulk density informing Solar System evolution studies and efforts to develop methods of mitigation against imminent impactors to Earth; chemistry and dynamics of Venus' atmosphere addressing physical phenomena such as greenhouse effect, atmospheric super-rotation and global resurfacing on Venus. With the Atsa Suborbital Observatory, we combine the strengths of both ground-based observatories and space-based observing to create a facility where a telescope is maintained and used interchangeably with both in-house facility

  6. Land Competition and Land-Use Change:

    DEFF Research Database (Denmark)

    Vongvisouk, Thoumthone

    Land competition and land-use changes are taking place in many developing countries as the demand for land increases. These changes are leading to changes in the livelihood conditions of rural people. The Government of Laos (GoL), on the one hand, aims to increase forest protection. On the other...... hand, the government is also working to increase national economic growth by promoting private-sector investment in both agriculture and forest resources – two sectors that compete for the same areas intended for protection. This thesis explores how these contradictory drivers of land-use changes...... software. Quantitative data was compiled in a Microsoft Access database and analyzed in Excel. Land-use and livelihood changes are taking place rapidly in the study sites. Overall, land-use change underwent transformation away from subsistence shifting cultivation to cash crops, intensive agriculture...

  7. Four-spacecraft determination of magnetopause orientation, motion and thickness: comparison with results from single-spacecraft methods

    Directory of Open Access Journals (Sweden)

    S. E. Haaland

    2004-04-01

    Full Text Available In this paper, we use Cluster data from one magnetopause event on 5 July 2001 to compare predictions from various methods for determination of the velocity, orientation, and thickness of the magnetopause current layer. We employ established as well as new multi-spacecraft techniques, in which time differences between the crossings by the four spacecraft, along with the duration of each crossing, are used to calculate magnetopause speed, normal vector, and width. The timing is based on data from either the Cluster Magnetic Field Experiment (FGM or the Electric Field Experiment (EFW instruments. The multi-spacecraft results are compared with those derived from various single-spacecraft techniques, including minimum-variance analysis of the magnetic field and deHoffmann-Teller, as well as Minimum-Faraday-Residue analysis of plasma velocities and magnetic fields measured during the crossings. In order to improve the overall consistency between multi- and single-spacecraft results, we have also explored the use of hybrid techniques, in which timing information from the four spacecraft is combined with certain limited results from single-spacecraft methods, the remaining results being left for consistency checks. The results show good agreement between magnetopause orientations derived from appropriately chosen single-spacecraft techniques and those obtained from multi-spacecraft timing. The agreement between magnetopause speeds derived from single- and multi-spacecraft methods is quantitatively somewhat less good but it is evident that the speed can change substantially from one crossing to the next within an event. The magnetopause thickness varied substantially from one crossing to the next, within an event. It ranged from 5 to 10 ion gyroradii. The density profile was sharper than the magnetic profile: most of the density change occured in the earthward half of the magnetopause.

    Key words. Magnetospheric physics (magnetopause, cusp and

  8. Large-Scale Spacecraft Fire Safety Experiments in ISS Resupply Vehicles

    Science.gov (United States)

    Ruff, Gary A.; Urban, David

    2013-01-01

    Our understanding of the fire safety risk in manned spacecraft has been limited by the small scale of the testing we have been able to conduct in low-gravity. Fire growth and spread cannot be expected to scale linearly with sample size so we cannot make accurate predictions of the behavior of realistic scale fires in spacecraft based on the limited low-g testing to date. As a result, spacecraft fire safety protocols are necessarily very conservative and costly. Future crewed missions are expected to be longer in duration than previous exploration missions outside of low-earth orbit and accordingly, more complex in terms of operations, logistics, and safety. This will increase the challenge of ensuring a fire-safe environment for the crew throughout the mission. Based on our fundamental uncertainty of the behavior of fires in low-gravity, the need for realistic scale testing at reduced gravity has been demonstrated. To address this concern, a spacecraft fire safety research project is underway to reduce the uncertainty and risk in the design of spacecraft fire safety systems by testing at nearly full scale in low-gravity. This project is supported by the NASA Advanced Exploration Systems Program Office in the Human Exploration and Operations Mission Directorate. The activity of this project is supported by an international topical team of fire experts from other space agencies to maximize the utility of the data and to ensure the widest possible scrutiny of the concept. The large-scale space flight experiment will be conducted on three missions; each in an Orbital Sciences Corporation Cygnus vehicle after it has deberthed from the ISS. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew allows the fire products to be released into the cabin. The tests will be fully automated with the data downlinked at the conclusion of the test before the Cygnus vehicle reenters the

  9. Hazard Detection Software for Lunar Landing

    Science.gov (United States)

    Huertas, Andres; Johnson, Andrew E.; Werner, Robert A.; Montgomery, James F.

    2011-01-01

    The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project is developing a system for safe and precise manned lunar landing that involves novel sensors, but also specific algorithms. ALHAT has selected imaging LIDAR (light detection and ranging) as the sensing modality for onboard hazard detection because imaging LIDARs can rapidly generate direct measurements of the lunar surface elevation from high altitude. Then, starting with the LIDAR-based Hazard Detection and Avoidance (HDA) algorithm developed for Mars Landing, JPL has developed a mature set of HDA software for the manned lunar landing problem. Landing hazards exist everywhere on the Moon, and many of the more desirable landing sites are near the most hazardous terrain, so HDA is needed to autonomously and safely land payloads over much of the lunar surface. The HDA requirements used in the ALHAT project are to detect hazards that are 0.3 m tall or higher and slopes that are 5 or greater. Steep slopes, rocks, cliffs, and gullies are all hazards for landing and, by computing the local slope and roughness in an elevation map, all of these hazards can be detected. The algorithm in this innovation is used to measure slope and roughness hazards. In addition to detecting these hazards, the HDA capability also is able to find a safe landing site free of these hazards for a lunar lander with diameter .15 m over most of the lunar surface. This software includes an implementation of the HDA algorithm, software for generating simulated lunar terrain maps for testing, hazard detection performance analysis tools, and associated documentation. The HDA software has been deployed to Langley Research Center and integrated into the POST II Monte Carlo simulation environment. The high-fidelity Monte Carlo simulations determine the required ground spacing between LIDAR samples (ground sample distances) and the noise on the LIDAR range measurement. This simulation has also been used to determine the effect of

  10. Earth land landing alternatives: Lunar transportation system

    Science.gov (United States)

    Meyerson, Robert

    1992-01-01

    The objectives of this study are as follows: (1) develop a landing option such that it is a viable trade option for future NASA missions; (2) provide NASA programs with solid technical support in the landing systems area; (3) develop the technical staff; and (4) advance the state of landing systems technology to apply to future NASA missions. All results are presented in viewgraph format.

  11. Advanced Solar-propelled Cargo Spacecraft for Mars Missions

    Science.gov (United States)

    Auziasdeturenne, Jacqueline; Beall, Mark; Burianek, Joseph; Cinniger, Anna; Dunmire, Barbrina; Haberman, Eric; Iwamoto, James; Johnson, Stephen; Mccracken, Shawn; Miller, Melanie

    1989-01-01

    Three concepts for an unmanned, solar powered, cargo spacecraft for Mars support missions were investigated. These spacecraft are designed to carry a 50,000 kg payload from a low Earth orbit to a low Mars orbit. Each design uses a distinctly different propulsion system: A Solar Radiation Absorption (SRA) system, a Solar-Pumped Laser (SPL) system and a solar powered magnetoplasmadynamic (MPD) arc system. The SRA directly converts solar energy to thermal energy in the propellant through a novel process. In the SPL system, a pair of solar-pumped, multi-megawatt, CO2 lasers in sunsynchronous Earth orbit converts solar energy to laser energy. The MPD system used indium phosphide solar cells to convert sunlight to electricity, which powers the propulsion system. Various orbital transfer options are examined for these concepts. In the SRA system, the mother ship transfers the payload into a very high Earth orbit and a small auxiliary propulsion system boosts the payload into a Hohmann transfer to Mars. The SPL spacecraft and the SPL powered spacecraft return to Earth for subsequent missions. The MPD propelled spacecraft, however, remains at Mars as an orbiting space station. A patched conic approximation was used to determine a heliocentric interplanetary transfer orbit for the MPD propelled spacecraft. All three solar-powered spacecraft use an aerobrake procedure to place the payload into a low Mars parking orbit. The payload delivery times range from 160 days to 873 days (2.39 years).

  12. Time Frequency Analysis of Spacecraft Propellant Tank Spinning Slosh

    Science.gov (United States)

    Green, Steven T.; Burkey, Russell C.; Sudermann, James

    2010-01-01

    Many spacecraft are designed to spin about an axis along the flight path as a means of stabilizing the attitude of the spacecraft via gyroscopic stiffness. Because of the assembly requirements of the spacecraft and the launch vehicle, these spacecraft often spin about an axis corresponding to a minor moment of inertia. In such a case, any perturbation of the spin axis will cause sloshing motions in the liquid propellant tanks that will eventually dissipate enough kinetic energy to cause the spin axis nutation (wobble) to grow further. This spinning slosh and resultant nutation growth is a primary design problem of spinning spacecraft and one that is not easily solved by analysis or simulation only. Testing remains the surest way to address spacecraft nutation growth. This paper describes a test method and data analysis technique that reveal the resonant frequency and damping behavior of liquid motions in a spinning tank. Slosh resonant frequency and damping characteristics are necessary inputs to any accurate numerical dynamic simulation of the spacecraft.

  13. Experiments study on attitude coupling control method for flexible spacecraft

    Science.gov (United States)

    Wang, Jie; Li, Dongxu

    2018-06-01

    High pointing accuracy and stabilization are significant for spacecrafts to carry out Earth observing, laser communication and space exploration missions. However, when a spacecraft undergoes large angle maneuver, the excited elastic oscillation of flexible appendages, for instance, solar wing and onboard antenna, would downgrade the performance of the spacecraft platform. This paper proposes a coupling control method, which synthesizes the adaptive sliding mode controller and the positive position feedback (PPF) controller, to control the attitude and suppress the elastic vibration simultaneously. Because of its prominent performance for attitude tracking and stabilization, the proposed method is capable of slewing the flexible spacecraft with a large angle. Also, the method is robust to parametric uncertainties of the spacecraft model. Numerical simulations are carried out with a hub-plate system which undergoes a single-axis attitude maneuver. An attitude control testbed for the flexible spacecraft is established and experiments are conducted to validate the coupling control method. Both numerical and experimental results demonstrate that the method discussed above can effectively decrease the stabilization time and improve the attitude accuracy of the flexible spacecraft.

  14. Water Rights on Community Lands: LandMark’s Findings from 100 Countries

    Directory of Open Access Journals (Sweden)

    Liz Alden Wily

    2017-11-01

    Full Text Available This paper analyzes whether national laws acknowledge indigenous peoples and other rural communities in 100 countries as owners of waters that arise within their lands. Results derive from information collected by LandMark to score the legal status of community land tenure. Findings are positive; half of all countries recognize communities as lawful possessors of water on their lands. Three quarters permit communities to manage the distribution and use of water on their lands. While 71 percent of countries declare water to be a public resource, this belies the substantial existence of privately owned water. In 29 percent of countries, private water is an identified legal category, and in many other countries obtainable rights to water are sufficiently substantial to imply lawful possession. Communities are beneficiaries mainly where customary rights are accorded status as property rights, or where ownership of public lands and water are devolved to rural collectives. However, opposite trends of nationalization and regulation of water suggest that while legal recognition of community land ownership may rise in the future, this will not necessarily include waters on the land. Irrespective of tenure, rural communities in 72 of 77 countries (93.5 percent are legally assured access to water for domestic purposes. This is consistent with the rising definition of safe drinking water as a human right, although access does not necessarily come free of cost.

  15. Research on intelligent power distribution system for spacecraft

    Science.gov (United States)

    Xia, Xiaodong; Wu, Jianju

    2017-10-01

    The power distribution system (PDS) mainly realizes the power distribution and management of the electrical load of the whole spacecraft, which is directly related to the success or failure of the mission, and hence is an important part of the spacecraft. In order to improve the reliability and intelligent degree of the PDS, and considering the function and composition of spacecraft power distribution system, this paper systematically expounds the design principle and method of the intelligent power distribution system based on SSPC, and provides the analysis and verification of the test data additionally.

  16. Preliminary thermal design of the COLD-SAT spacecraft

    Science.gov (United States)

    Arif, Hugh

    1991-01-01

    The COLD-SAT free-flying spacecraft was to perform experiments with LH2 in the cryogenic fluid management technologies of storage, supply and transfer in reduced gravity. The Phase A preliminary design of the Thermal Control Subsystem (TCS) for the spacecraft exterior and interior surfaces and components of the bus subsystems is described. The TCS was composed of passive elements which were augmented with heaters. Trade studies to minimize the parasitic heat leakage into the cryogen storage tanks are described. Selection procedure for the thermally optimum on-orbit spacecraft attitude was defined. TRASYS-2 and SINDA'85 verification analysis was performed on the design and the results are presented.

  17. Ad hoc laser networks component technology for modular spacecraft

    Science.gov (United States)

    Huang, Xiujun; Shi, Dele; Shen, Jingshi

    2017-10-01

    Distributed reconfigurable satellite is a new kind of spacecraft system, which is based on a flexible platform of modularization and standardization. Based on the module data flow analysis of the spacecraft, this paper proposes a network component of ad hoc Laser networks architecture. Low speed control network with high speed load network of Microwave-Laser communication mode, no mesh network mode, to improve the flexibility of the network. Ad hoc Laser networks component technology was developed, and carried out the related performance testing and experiment. The results showed that ad hoc Laser networks components can meet the demand of future networking between the module of spacecraft.

  18. Fifty-one years of Los Alamos Spacecraft

    Energy Technology Data Exchange (ETDEWEB)

    Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-04

    From 1963 to 2014, the Los Alamos National Laboratory was involved in at least 233 spacecraft. There are probably only one or two institutions in the world that have been involved in so many spacecraft. Los Alamos space exploration started with the Vela satellites for nuclear test detection, but soon expanded to ionospheric research (mostly barium releases), radioisotope thermoelectric generators, solar physics, solar wind, magnetospheres, astrophysics, national security, planetary physics, earth resources, radio propagation in the ionosphere, and cubesats. Here, we present a list of the spacecraft, their purpose, and their launch dates for use during RocketFest

  19. Iodine Plasma (Electric Propulsion) Interaction with Spacecraft Materials

    Science.gov (United States)

    2016-12-28

    Teflon (AGT5, Ag-FEP) Thermal control surface (radiator) Spacecraft Exposure Soda-lime glass (74% SiO2 , 13% Na2O, 8% CaO, 4% MgO, 1% other oxide... Glass Solar panel cover Spacecraft Exposure Buna-N (acrylonitrile butadiene rubber) Seals Iodine Feed System Carbon fiber composite (epoxy resin...Fe Propellant isolator Spacecraft Exposure Lanthanum Hexaboride, LaB6 Cathode emitter Inside Cathode Yes MACOR (46% SiO2 , 17% MgO, 16% Al2O3, 10

  20. Cooper-Harper Experience Report for Spacecraft Handling Qualities Applications

    Science.gov (United States)

    Bailey, Randall E.; Jackson, E. Bruce; Bilimoria, Karl D.; Mueller, Eric R.; Frost, Chad R.; Alderete, Thomas S.

    2009-01-01

    A synopsis of experience from the fixed-wing and rotary-wing aircraft communities in handling qualities development and the use of the Cooper-Harper pilot rating scale is presented as background for spacecraft handling qualities research, development, test, and evaluation (RDT&E). In addition, handling qualities experiences and lessons-learned from previous United States (US) spacecraft developments are reviewed. This report is intended to provide a central location for references, best practices, and lessons-learned to guide current and future spacecraft handling qualities RDT&E.

  1. Spacecraft charging and related effects during Halley encounter

    International Nuclear Information System (INIS)

    Young, D.T.

    1983-01-01

    Hypervelocity (69 km/s) impact of cometary material with surfaces of the GIOTTO spacecraft will induce a number of spurious and possibly harmful phenomena. The most serious of these is likely to be spacecraft charging that results from impact-produced plasma distributions surrounding GIOTTO. The ESA Plasma Environment Working Group, whose studies are the basis for this report, finds that charging may become significant within approx. 10 5 km of the nucleus where potentials of approx. = +20 V are to be expected. In addition to spacecraft charging, impact produced plasma may interfere with in situ plasma measurements, particularly those of ion plasma analyzers and mass spectrometers

  2. Overview of SDCM - The Spacecraft Design and Cost Model

    Science.gov (United States)

    Ferebee, Melvin J.; Farmer, Jeffery T.; Andersen, Gregory C.; Flamm, Jeffery D.; Badi, Deborah M.

    1988-01-01

    The Spacecraft Design and Cost Model (SDCM) is a computer-aided design and analysis tool for synthesizing spacecraft configurations, integrating their subsystems, and generating information concerning on-orbit servicing and costs. SDCM uses a bottom-up method in which the cost and performance parameters for subsystem components are first calculated; the model then sums the contributions from individual components in order to obtain an estimate of sizes and costs for each candidate configuration within a selected spacecraft system. An optimum spacraft configuration can then be selected.

  3. InaSAFE applications in disaster preparedness

    Science.gov (United States)

    Pranantyo, Ignatius Ryan; Fadmastuti, Mahardika; Chandra, Fredy

    2015-04-01

    Disaster preparedness activities aim to reduce the impact of disasters by being better prepared to respond when a disaster occurs. In order to better anticipate requirements during a disaster, contingency planning activities can be undertaken prior to a disaster based on a realistic disaster scenario. InaSAFE is a tool that can inform this process. InaSAFE is a free and open source software that estimates the impact to people and infrastructure from potential hazard scenarios. By using InaSAFE, disaster managers can develop scenarios of disaster impacts (people and infrastructures affected) to inform their contingency plan and emergency response operation plan. While InaSAFE provides the software framework exposure data and hazard data are needed as inputs to run this software. Then InaSAFE can be used to forecast the impact of the hazard scenario to the exposure data. InaSAFE outputs include estimates of the number of people, buildings and roads are affected, list of minimum needs (rice and clean water), and response checklist. InaSAFE is developed by Indonesia's National Disaster Management Agency (BNPB) and the Australian Government, through the Australia-Indonesia Facility for Disaster Reduction (AIFDR), in partnership with the World Bank - Global Facility for Disaster Reduction and Recovery (GFDRR). This software has been used in many parts of Indonesia, including Padang, Maumere, Jakarta, and Slamet Mountain for emergency response and contingency planning.

  4. Large Mass, Entry, Descent and Landing Sensitivity Results for Environmental, Performance, and Design Parameters

    Science.gov (United States)

    Shidner, Jeremy D.; Davis, Jody L.; Cianciolo, Alicia D.; Samareh, Jamshid A.; Powell, RIchard W.

    2010-01-01

    Landing on Mars has been a challenging task. Past NASA missions have shown resilience to increases in spacecraft mass by scaling back requirements such as landing site altitude, landing site location and arrival time. Knowledge of the partials relating requirements to mass is critical for mission designers to understand so that the project can retain margin throughout the process. Looking forward to new missions that will land 1.5 metric tons or greater, the current level of technology is insufficient, and new technologies will need to be developed. Understanding the sensitivity of these new technologies to requirements is the purpose of this paper.

  5. Land management and development

    DEFF Research Database (Denmark)

    Enemark, Stig

    2006-01-01

    Land management is the process by which the resources of land are put into good effect. Land management encompasses all activities associated with the management of land that are required to achieve sustainable development. The concept of land includes properties and natural resources and thereby...... land related data. It is argued that development of such a model is important or even necessary for facilitating a holistic approach to the management of land as the key asset of any nation or jurisdiction.......Land management is the process by which the resources of land are put into good effect. Land management encompasses all activities associated with the management of land that are required to achieve sustainable development. The concept of land includes properties and natural resources and thereby...... encompasses the total natural and built environment. Land Administration Systems (LAS) are institutional frameworks complicated by the tasks they must perform, by national cultural, political and judicial settings, and by technology. This paper facilitates an overall understanding of the land management...

  6. Lunar Soil Erosion Physics for Landing Rockets on the Moon

    Science.gov (United States)

    Clegg, Ryan N.; Metzger, Philip T.; Huff, Stephen; Roberson, Luke B.

    2008-01-01

    To develop a lunar outpost, we must understand the blowing of soil during launch and landing of the new Altair Lander. For example, the Apollo 12 Lunar Module landed approximately 165 meters from the deactivated Surveyor Ill spacecraft, scouring its surfaces and creating numerous tiny pits. Based on simulations and video analysis from the Apollo missions, blowing lunar soil particles have velocities up to 2000 m/s at low ejection angles relative to the horizon, reach an apogee higher than the orbiting Command and Service Module, and travel nearly the circumference of the Moon [1-3]. The low ejection angle and high velocity are concerns for the lunar outpost.

  7. Safe actinide disposition in molten salt reactors

    International Nuclear Information System (INIS)

    Gat, U.

    1997-01-01

    Safe molten salt reactors (MSR) can readily accommodate the burning of all fissile actinides. Only minor compromises associated with plutonium are required. The MSRs can dispose safely of actinides and long lived isotopes to result in safer and simpler waste. Disposing of actinides in MSRs does increase the source term of a safety optimized MSR. It is concluded that the burning and transmutation of actinides in MSRs can be done in a safe manner. Development is needed for the processing to handle and separate the actinides. Calculations are needed to establish the neutron economy and the fuel management. 9 refs

  8. RFP to work on formation flying capabilities for spacecrafts for the GRACE project

    DEFF Research Database (Denmark)

    Riis, Troels; Thuesen, Gøsta; Kilsgaard, Søren

    1999-01-01

    The National Aeronautics and Space Agency of USA, NASA, are working on formation flying capabilities for spacecrafts, GRACE Project. IAU and JPL are developing the inter spacecraft attitude link to be used on the two spacecrafts.......The National Aeronautics and Space Agency of USA, NASA, are working on formation flying capabilities for spacecrafts, GRACE Project. IAU and JPL are developing the inter spacecraft attitude link to be used on the two spacecrafts....

  9. Landing spot selection for UAV emergency landing

    NARCIS (Netherlands)

    Eendebak, P.T.; Eekeren, A.W.M. van; Hollander, R.J.M. den

    2013-01-01

    We present a robust method for landing zone selection using obstacle detection to be used for UAV emergency landings. The method is simple enough to allow real-time implementation on a UAV system. The method is able to detect objects in the presence of camera movement and motion parallax. Using the

  10. Development status of solid polymer electrolyte water electrolysis for manned spacecraft life support systems

    Science.gov (United States)

    Nuttall, L. J.; Titterington, W. A.

    1974-01-01

    Details of the design and system verification test results are presented for a six-man-rated oxygen generation system. The system configuration incorporates components and instrumentation for computer-controlled operation with automatic start-up/shutdown sequencing, fault detection and isolation, and with self-contained sensors and controls for automatic safe emergency shutdown. All fluid and electrical components, sensors, and electronic controls are designed to be easily maintainable under zero-gravity conditions. On-board component spares are utilized in the system concept to sustain long-term operation (six months minimum) in a manned spacecraft application. The system is centered on a 27-cell solid polymer electrolyte water electrolysis module which, combined with the associated system components and controls, forms a total system envelope 40 in. high, 40 in. wide, and 30 in. deep.

  11. LandSat-Based Land Use-Land Cover (Raster)

    Data.gov (United States)

    Minnesota Department of Natural Resources — Raster-based land cover data set derived from 30 meter resolution Thematic Mapper satellite imagery. Classification is divided into 16 classes with source imagery...

  12. LandSat-Based Land Use-Land Cover (Vector)

    Data.gov (United States)

    Minnesota Department of Natural Resources — Vector-based land cover data set derived from classified 30 meter resolution Thematic Mapper satellite imagery. Classification is divided into 16 classes with source...

  13. Project Overview of the Naval Postgraduate School Spacecraft Architecture and Technology Demonstration Experiment

    National Research Council Canada - National Science Library

    Reuer, Charles

    2001-01-01

    The Naval Postgraduate School's current attempt at getting another spacecraft into orbit is focusing on Naval Postgraduate School Spacecraft Architecture and Technology Demonstration Experiment (NPSAT1...

  14. Integrating Standard Operating Procedures with Spacecraft Automation, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Spacecraft automation can be used to greatly reduce the demands on crew member and flight controllers time and attention. Automation can monitor critical resources,...

  15. A small spacecraft for multipoint measurement of ionospheric plasma

    Science.gov (United States)

    Roberts, T. M.; Lynch, K. A.; Clayton, R. E.; Weiss, J.; Hampton, D. L.

    2017-07-01

    Measurement of ionospheric plasma is often performed by a single in situ device or remotely using cameras and radar. This article describes a small, low-resource, deployed spacecraft used as part of a local, multipoint measurement network. A B-field aligned sounding rocket ejects four of these spin-stabilized spacecraft in a cross pattern. In this application, each spacecraft carries two retarding potential analyzers which are used to determine plasma density, flow, and ion temperature. An inertial measurement unit and a light-emitting diode array are used to determine the position and orientation of the devices after deployment. The design of this spacecraft is first described, and then results from a recent test flight are discussed. This flight demonstrated the successful operation of the deployment mechanism and telemetry systems, provided some preliminary plasma measurements in a simple mid-latitude environment, and revealed several design issues.

  16. High-Performance Contaminant Monitor for Spacecraft, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The Vision for Space Exploration demands increasing reliance on real-time trace gas monitors onboard spacecraft. Present grab samples and badges will be inadequate...

  17. LP MOON SPACECRAFT ATTITUDE V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Prospector attitude data set consists of values for the spacecraft spin rate and spin axis orientation (attitude) as a function of time. These values are...

  18. Odor Control in Spacecraft Waste Management, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Spacecraft and lunar bases generate a variety of wastes containing water, including food wastes, feces, and brines. Disposal of these wastes, as well as recovery of...

  19. Internal Mass Motion for Spacecraft Dynamics and Control

    National Research Council Canada - National Science Library

    Hall, Christopher D

    2008-01-01

    We present a detailed description of the application of a noncanonical Hamiltonian formulation to the modeling, analysis, and simulation of the dynamics of gyrostat spacecraft with internal mass motion...

  20. A Sustainable Spacecraft Component Database Solution, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Numerous spacecraft component databases have been developed to support NASA, DoD, and contractor design centers and design tools. Despite the clear utility of...

  1. Passive Devices for Advanced Fluid Management aboard Spacecraft, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Acute challenges are faced by the designers of fluid systems for spacecraft because of the persistently unfamiliar and unforgiving low-g environment. For example,...

  2. Diagnosing Faults in Electrical Power Systems of Spacecraft and Aircraft

    Data.gov (United States)

    National Aeronautics and Space Administration — Electrical power systems play a critical role in spacecraft and aircraft, and they exhibit a rich variety of failure modes. This paper discusses electrical power...

  3. Applicability of ISO 16697 Data to Spacecraft Fire Fighting Strategies

    Science.gov (United States)

    Hirsch, David B.; Beeson, Harold D.

    2012-01-01

    Presentation Agenda: (1) Selected variables affecting oxygen consumption during spacecraft fires, (2) General overview of ISO 16697, (3) Estimated amounts of material consumed during combustion in typical ISS enclosures, (4) Discussion on potential applications.

  4. Trace Contaminant Monitor for Air in Spacecraft, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A need exists for analyzers that can measure trace contaminants in air on board spacecraft. Toxic gas buildup can endanger the crew particularly during long...

  5. Nuclear-powered Hysat spacecraft: comparative design study

    International Nuclear Information System (INIS)

    Raab, B.

    1975-08-01

    The study shows that the all-nuclear spacecraft can have a substantial weight advantage over a hybrid (nuclear/solar) or all-solar spacecraft, owing to a further reduction in power requirement, and to the elimination of such equipment as the sensor gimbal and rotating joint assemblies. Because the need for a sun-oriented section is eliminated, the all-nuclear spacecraft can be designed as a monolithic structure, with the sensor and other payload firmly secured in a fixed position on the structure. This enhances attitude stability while minimizing structural weight and eliminating the need for flexible fluid lines. Sensor motion can be produced, varied, and controlled within the limits specified by the study contractors by moving the entire spacecraft in the prescribed pattern. A simple attitude control system using available hardware suffices to meet all requirements

  6. Conceptual definition of Automated Power Systems Management. [for planetary spacecraft

    Science.gov (United States)

    Imamura, M. S.; Skelly, L.; Weiner, H.

    1977-01-01

    Automated Power Systems Management (APSM) is defined as the capability of a spacecraft power system to automatically perform monitoring, computational, command, and control functions without ground intervention. Power systems for future planetary spacecraft must have this capability because they must perform up to 10 years, and accommodate real-time changes in mission execution autonomously. Specific APSM functions include fault detection, isolation, and correction; system performance and load profile prediction; power system optimization; system checkout; and data storage and transmission control. This paper describes the basic method of implementing these specific functions. The APSM hardware includes a central power system computer and a processor dedicated to each major power system subassembly along with digital interface circuitry. The major payoffs anticipated are in enhancement of spacecraft reliability and life and reduction of overall spacecraft program cost.

  7. Hard-real-time resource management for autonomous spacecraft

    Science.gov (United States)

    Gat, E.

    2000-01-01

    This paper describes tickets, a computational mechanism for hard-real-time autonomous resource management. Autonomous spacecraftcontrol can be considered abstractly as a computational process whose outputs are spacecraft commands.

  8. Spacecraft Water Regeneration by Catalytic Wet Air Oxidation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this project is to develop advanced catalysts for a volatile removal assembly used to purify spacecraft water. The innovation of the proposed...

  9. Modeling Vacuum Arcs On Spacecraft Solar Panel Arrays, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Spacecraft charging and subsequent vacuum arcing poses a significant threat to satellites in LEO and GEO plasma conditions. Localized arc discharges can cause a...

  10. Triple3 Redundant Spacecraft Subsystems (T3RSS), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Redefine Technologies, along with researchers at the University of Colorado, will use three redundancy methods to decrease the susceptibility of a spacecraft, on a...

  11. The Physics and Technology of Solar Sail Spacecraft.

    Science.gov (United States)

    Dwivedi, B. N.; McInnes, C. R.

    1991-01-01

    Various aspects of the solar sail spacecraft such as solar sailing, solar sail design, navigation with solar sails, solar sail mission applications and future prospects for solar sailing are described. Several possible student projects are suggested. (KR)

  12. Micro GC's for Contaminant Monitoring in Spacecraft Air, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this proposal is to create new gas chromatographs (GCs) for contaminant monitoring in spacecraft air that do not require any reagents or special...

  13. High precision relative position sensing system for formation flying spacecraft

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and test an optical sensing system that provides high precision relative position sensing for formation flying spacecraft.  A high precision...

  14. Distributed Control Architectures for Precision Spacecraft Formations, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — LaunchPoint Technologies, Inc. (LaunchPoint) proposes to develop synthesis methods and design architectures for distributed control systems in precision spacecraft...

  15. Passive Wireless Sensors for Spacecraft Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — New classes of sensors are needed on spacecraft that can be interrogated remotely using RF signals and respond with the sensor's identity as well as the...

  16. Stability Analysis of Spacecraft Motion in the Vicinity of Asteroids

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of my proposal is to determine the stability of a spacecraft when in the vicinity of an asteroid. Orbiting an asteroid is a difficult task. The unique...

  17. Charge Dissipating Transparent Conformal Coatings for Spacecraft Electronics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The space environment poses significant challenges to spacecraft electronics in the form of electrostatic discharge (ESD) as a result of exposure to highly charged...

  18. A Fault-tolerant RISC Microprocessor for Spacecraft Applications

    Science.gov (United States)

    Timoc, Constantin; Benz, Harry

    1990-01-01

    Viewgraphs on a fault-tolerant RISC microprocessor for spacecraft applications are presented. Topics covered include: reduced instruction set computer; fault tolerant registers; fault tolerant ALU; and double rail CMOS logic.

  19. Safe-life and damage-tolerant design approaches for helicopter structures

    Science.gov (United States)

    Reddick, H. K., Jr.

    1983-01-01

    The safe-life and damage-tolerant design approaches discussed apply to both metallic and fibrous composite helicopter structures. The application of these design approaches to fibrous composite structures is emphasized. Safe-life and damage-tolerant criteria are applied to all helicopter flight critical components, which are generally categorized as: dynamic components with a main and tail rotor system, which includes blades, hub and rotating controls, and drive train which includes transmission, and main and interconnecting rotor shafts; and the airframe, composed of the fuselage, aerodynamic surfaces, and landing gear.

  20. Revamping Spacecraft Operational Intelligence with Splunk

    Science.gov (United States)

    Hwang, Victor

    2012-01-01

    So what is Splunk? Instead of giving the technical details, which you can find online, I'll tell you what it did for me. Splunk slapped everything into one place, with one uniform format, and gave me the ability to forget about all these annoying details of where it is, how to parse it, and all that. Instead, I only need to interact with Splunk to find the data I need. This sounds simple and obvious, but it's surprising what you can do once you all of your data is indexed in one place. By having your data organized, querying becomes much easier. Let's say that I want to search telemetry for a sensor_name gtemp_1 h and to return all data that is at most five minutes old. And because Splunk can hook into a real ]time stream, this data will always be up-to-date. Extending the previous example, I can now aggregate all types of data into one view based in time. In this picture, I've got transaction logs, telemetry, and downlinked files all in one page, organized by time. Even though the raw data looks completely than this, I've defined interfaces that transform it into this uniform format. This gives me a more complete picture for the question what was the spacecraft doing at this particular time? And because querying data is simple, I can start with a big block of data and whiddle it down to what I need, rather than hunting around for the individual pieces of data that I need. When we have all the data we need, we can begin widdling down the data with Splunk's Unix-like search syntax. These three examples highlights my trial-and-error attempts to find large temperature changes. I begin by showing the first 5 temperatures, only to find that they're sorted chronologically, rather than from highest temperatures to lowest temperatures. The next line shows sorting temperatures by their values, but I find that that fs not really what I want either. I want to know the delta temperatures between readings. Looking through Splunk's user manual, I find the delta function, which

  1. NASA Spacecraft Fault Management Workshop Results

    Science.gov (United States)

    Newhouse, Marilyn; McDougal, John; Barley, Bryan; Fesq, Lorraine; Stephens, Karen

    2010-01-01

    tools that have not kept pace with the increasing complexity of mission requirements and spacecraft systems. This paper summarizes the findings and recommendations from that workshop, as well as opportunities identified for future investment in tools, processes, and products to facilitate the development of space flight fault management capabilities.

  2. Passive Plasma Contact Mechanisms for Small-Scale Spacecraft

    Science.gov (United States)

    McTernan, Jesse K.

    Small-scale spacecraft represent a paradigm shift in how entities such as academia, industry, engineering firms, and the scientific community operate in space. However, although the paradigm shift produces unique opportunities to build satellites in unique ways for novel missions, there are also significant challenges that must be addressed. This research addresses two of the challenges associated with small-scale spacecraft: 1) the miniaturization of spacecraft and associated instrumentation and 2) the need to transport charge across the spacecraft-environment boundary. As spacecraft decrease in size, constraints on the size, weight, and power of on-board instrumentation increase--potentially limiting the instrument's functionality or ability to integrate with the spacecraft. These constraints drive research into mechanisms or techniques that use little or no power and efficiently utilize existing resources. One limited resource on small-scale spacecraft is outer surface area, which is often covered with solar panels to meet tight power budgets. This same surface area could also be needed for passive neutralization of spacecraft charging. This research explores the use of a transparent, conductive layer on the solar cell coverglass that is electrically connected to spacecraft ground potential. This dual-purpose material facilitates the use of outer surfaces for both energy harvesting of solar photons as well as passive ion collection. Mission capabilities such as in-situ plasma measurements that were previously infeasible on small-scale platforms become feasible with the use of indium tin oxide-coated solar panel coverglass. We developed test facilities that simulate the space environment in low Earth orbit to test the dual-purpose material and the various application of this approach. Particularly, this research is in support of two upcoming missions: OSIRIS-3U, by Penn State's Student Space Programs Lab, and MiTEE, by the University of Michigan. The purpose of

  3. Staying Safe on Social Network Sites

    Science.gov (United States)

    ... Tips Security Tip (ST06-003) Staying Safe on Social Networking Sites Original release date: January 26, 2011 | Last revised: ... so you should take certain precautions. What are social networking sites? Social networking sites, sometimes referred to as "friend- ...

  4. Implicit attitudes towards risky and safe driving

    DEFF Research Database (Denmark)

    Martinussen, Laila Marianne; Sømhovd, Mikael Julius; Møller, Mette

    ; further, self-reports of the intention to drive safely (or not) are socially sensitive. Therefore, we examined automatic preferences towards safe and risky driving with a Go/No-go Association Task (GNAT). The results suggest that (1) implicit attitudes towards driving behavior can be measured reliably...... with the GNAT; (2) implicit attitudes towards safe driving versus towards risky driving may be separable constructs. We propose that research on driving behavior may benefit from routinely including measures of implicit cognition. A practical advantage is a lesser susceptibility to social desirability biases......, compared to self-report methods. Pending replication in future research, the apparent dissociation between implicit attitudes towards safe versus risky driving that we observed may contribute to a greater theoretical understanding of the causes of unsafe and risky driving behavior....

  5. High-Protein Diets: Are They Safe?

    Science.gov (United States)

    Healthy Lifestyle Nutrition and healthy eating Are high-protein diets safe for weight loss? Answers from Katherine ... L.D. For most healthy people, a high-protein diet generally isn't harmful, particularly when followed ...

  6. Safe delivery, Service utilization, Metekel Zone

    African Journals Online (AJOL)

    decision making power of subjects were found to have a statistically significant association with preference of safe delivery ... Studies that focused on maternal mortality and proportion of ...... Anna M, Hannekee M, Frank Odhiambo et.al. Use.

  7. The safe transport of radioactive materials

    International Nuclear Information System (INIS)

    Messenger, W. de L.M.

    1979-02-01

    The hazards of radioactive materials in transport are surveyed. The system whereby they are safely transported between nuclear establishments in the United Kingdom and overseas is outlined. Several popular misconceptions are dealt with. (author)

  8. Layered Safe Motion Planning for Autonomous Vehicles.

    Science.gov (United States)

    1995-09-01

    The major problem addressed by this research is how to plan a safe motion for autonomous vehicles in a two dimensional, rectilinear world. With given start and goal configurations, the planner performs motion planning which

  9. AFSC/REFM: Groundfish SAFE Economic Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Groundfish SAFE Economic Report, published annually as a supplement to the Stock Assessment and Fishery Evaluation Reports for Bering Sea and Aleutian Islands...

  10. Think Before You Ink: Are Tattoos Safe?

    Science.gov (United States)

    ... Consumers Consumer Updates Think Before You Ink: Are Tattoos Safe? Share Tweet Linkedin Pin it More sharing ... I be concerned about unsafe practices, or the tattoo ink itself? Both. While you can get serious ...

  11. Safe Eats - Eating Out and Bringing In

    Science.gov (United States)

    ... to stay safe. What's On the Menu? When dining out: Remember that harmful bacteria can be hidden ... above the "danger zone." Remember the 2-Hour Rule : Discard any perishables (foods that can spoil or ...

  12. Safeguards Automated Facility Evaluation (SAFE) methodology

    International Nuclear Information System (INIS)

    Chapman, L.D.; Grady, L.M.; Bennett, H.A.; Sasser, D.W.; Engi, D.

    1978-01-01

    The SAFE procedure is an efficient method of evaluating the physical protection system of a nuclear facility. Since the algorithms used in SAFE for path generation and evaluation are analytical, many paths can be evaluated with a modest investment in computer time. SAFE is easy to use because the information required is well-defined and the interactive nature of this procedure lends itself to straightforward operation. The modular approach that has been taken allows other functionally equivalent modules to be substituted as they become available. The SAFE procedure has broad applications in the nuclear facility safeguards field as well as in the security field in general. Any fixed facility containing valuable materials or components to be protected from theft or sabotage could be analyzed using this same automated evaluation technique

  13. SAFE users manual. Volume 4. Computer programs

    International Nuclear Information System (INIS)

    Grady, L.M.

    1983-06-01

    Documentation for the Safeguards Automated Facility Evaluation (SAFE) computer programs is presented. The documentation is in the form of subprogram trees, program abstracts, flowcharts, and listings. Listings are provided on microfiche

  14. Lunar Landing Trajectory Design for Onboard Hazard Detection and Avoidance

    Science.gov (United States)

    Paschall, Steve; Brady, Tye; Sostaric, Ron

    2009-01-01

    The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project is developing the software and hardware technology needed to support a safe and precise landing for the next generation of lunar missions. ALHAT provides this capability through terrain-relative navigation measurements to enhance global-scale precision, an onboard hazard detection system to select safe landing locations, and an Autonomous Guidance, Navigation, and Control (AGNC) capability to process these measurements and safely direct the vehicle to a landing location. This paper focuses on the key trajectory design issues relevant to providing an onboard Hazard Detection and Avoidance (HDA) capability for the lander. Hazard detection can be accomplished by the crew visually scanning the terrain through a window, a sensor system imaging the terrain, or some combination of both. For ALHAT, this hazard detection activity is provided by a sensor system, which either augments the crew s perception or entirely replaces the crew in the case of a robotic landing. Detecting hazards influences the trajectory design by requiring the proper perspective, range to the landing site, and sufficient time to view the terrain. Following this, the trajectory design must provide additional time to process this information and make a decision about where to safely land. During the final part of the HDA process, the trajectory design must provide sufficient margin to enable a hazard avoidance maneuver. In order to demonstrate the effects of these constraints on the landing trajectory, a tradespace of trajectory designs was created for the initial ALHAT Design Analysis Cycle (ALDAC-1) and each case evaluated with these HDA constraints active. The ALHAT analysis process, described in this paper, narrows down this tradespace and subsequently better defines the trajectory design needed to support onboard HDA. Future ALDACs will enhance this trajectory design by balancing these issues and others in an overall system

  15. Dynamics and control of Lorentz-augmented spacecraft relative motion

    CERN Document Server

    Yan, Ye; Yang, Yueneng

    2017-01-01

    This book develops a dynamical model of the orbital motion of Lorentz spacecraft in both unperturbed and J2-perturbed environments. It explicitly discusses three kinds of typical space missions involving relative orbital control: spacecraft hovering, rendezvous, and formation flying. Subsequently, it puts forward designs for both open-loop and closed-loop control schemes propelled or augmented by the geomagnetic Lorentz force. These control schemes are entirely novel and represent a significantly departure from previous approaches.

  16. Protecting Spacecraft Fragments from Exposure to Small Debris

    OpenAIRE

    V. V. Zelentsov

    2015-01-01

    Since the launch of the first artificial Earth satellite a large amount of space debris has been accumulated in near-earth space. This debris comprises the exhausted spacecrafts, final stages of rocket-carriers and boosters, technological space junk, consisting of the structure elements, which are separated when deploying the solar arrays, antennas etc., as well as when undocking a booster and a spacecraft. All the debris is divided into observable one of over 100 mm in size and unobservable ...

  17. Vibration Antiresonance Design for a Spacecraft Multifunctional Structure

    OpenAIRE

    Li, Dong-Xu; Liu, Wang; Hao, Dong

    2017-01-01

    Spacecraft must withstand rigorous mechanical environment experiences such as acceleration, noise, vibration, and shock during the process of launching, satellite-vehicle separation, and so on. In this paper, a new spacecraft multifunctional structure concept designed by us is introduced. The multifunctional structure has the functions of not only load bearing, but also vibration reduction, energy source, thermal control, and so on, and we adopt a series of viscoelastic parts as connections b...

  18. Darwinian Spacecraft: Soft Computing Strategies Breeding Better, Faster Cheaper

    Science.gov (United States)

    Noever, David A.; Baskaran, Subbiah

    1999-01-01

    Computers can create infinite lists of combinations to try to solve a particular problem, a process called "soft-computing." This process uses statistical comparables, neural networks, genetic algorithms, fuzzy variables in uncertain environments, and flexible machine learning to create a system which will allow spacecraft to increase robustness, and metric evaluation. These concepts will allow for the development of a spacecraft which will allow missions to be performed at lower costs.

  19. Standards for safe operation of research reactors

    International Nuclear Information System (INIS)

    1996-01-01

    The safety of research reactors is based on many factors such as suitable choice of location, design and construction according to the international standards, it also depends on well trained and qualified operational staff. These standards determine the responsibilities of all who are concerned with the research reactors safe operation, and who are responsible of all related activities in all the administrative and technical stages in a way that insures the safe operation of the reactor

  20. Influencing behaviour for safe working environments

    OpenAIRE

    Boer, de, J. (Johannes); Teeuw, W.B. (Wouter)

    2011-01-01

    Safety at work The objective of the project Safety at Work is to increase safety at the workplace by applying and combining state of the art artefacts from personal protective equipment and ambient intelligence technology. In this state of the art document we focus on the developments with respect to how (persuasive) technology can help to influence behaviour in a natural, automatic way in order to make industrial environments safer. We focus on personal safety, safe environments and safe beh...

  1. Licensing issues for inherently safe fast reactors

    International Nuclear Information System (INIS)

    Kastenberg, W.E.; Lee, S.; Okrent, D.

    1986-01-01

    There has been considerable interest recently in a new generation of liquid metal reactor (LMR) concepts in the US. Some significant changes in regulatory philosophy will be required if the anticipated cost advantages of inherently safe designs are to be achieved. The defense in depth philosophy will need to be significantly re-evaluated in the context of inherently safe reactors. It is the purpose of this paper to begin such a re-evaluation of this regulatory philosophy

  2. Mesh Network Architecture for Enabling Inter-Spacecraft Communication

    Science.gov (United States)

    Becker, Christopher; Merrill, Garrick

    2017-01-01

    To enable communication between spacecraft operating in a formation or small constellation, a mesh network architecture was developed and tested using a time division multiple access (TDMA) communication scheme. The network is designed to allow for the exchange of telemetry and other data between spacecraft to enable collaboration between small spacecraft. The system uses a peer-to-peer topology with no central router, so that it does not have a single point of failure. The mesh network is dynamically configurable to allow for addition and subtraction of new spacecraft into the communication network. Flight testing was performed using an unmanned aerial system (UAS) formation acting as a spacecraft analogue and providing a stressing environment to prove mesh network performance. The mesh network was primarily devised to provide low latency, high frequency communication but is flexible and can also be configured to provide higher bandwidth for applications desiring high data throughput. The network includes a relay functionality that extends the maximum range between spacecraft in the network by relaying data from node to node. The mesh network control is implemented completely in software making it hardware agnostic, thereby allowing it to function with a wide variety of existing radios and computing platforms..

  3. Time maintenance system for the BMDO MSX spacecraft

    Science.gov (United States)

    Hermes, Martin J.

    1994-01-01

    The Johns Hopkins University Applied Physics Laboratory (APL) is responsible for designing and implementing a clock maintenance system for the Ballistic Missile Defense Organizations (BMDO) Midcourse Space Experiment (MSX) spacecraft. The MSX spacecraft has an on-board clock that will be used to control execution of time-dependent commands and to time tag all science and housekeeping data received from the spacecraft. MSX mission objectives have dictated that this spacecraft time, UTC(MSX), maintain a required accuracy with respect to UTC(USNO) of +/- 10 ms with a +/- 1 ms desired accuracy. APL's atomic time standards and the downlinked spacecraft time were used to develop a time maintenance system that will estimate the current MSX clock time offset during an APL pass and make estimates of the clock's drift and aging using the offset estimates from many passes. Using this information, the clock's accuracy will be maintained by uplinking periodic clock correction commands. The resulting time maintenance system is a combination of offset measurement, command/telemetry, and mission planning hardware and computing assets. All assets provide necessary inputs for deciding when corrections to the MSX spacecraft clock must be made to maintain its required accuracy without inhibiting other mission objectives. The MSX time maintenance system is described as a whole and the clock offset measurement subsystem, a unique combination of precision time maintenance and measurement hardware controlled by a Macintosh computer, is detailed. Simulations show that the system estimates the MSX clock offset to less than+/- 33 microseconds.

  4. An Orbit Propagation Software for Mars Orbiting Spacecraft

    Directory of Open Access Journals (Sweden)

    Young-Joo Song

    2004-12-01

    Full Text Available An orbit propagation software for the Mars orbiting spacecraft has been developed and verified in preparations for the future Korean Mars missions. Dynamic model for Mars orbiting spacecraft has been studied, and Mars centered coordinate systems are utilized to express spacecraft state vectors. Coordinate corrections to the Mars centered coordinate system have been made to adjust the effects caused by Mars precession and nutation. After spacecraft enters Sphere of Influence (SOI of the Mars, the spacecraft experiences various perturbation effects as it approaches to Mars. Every possible perturbation effect is considered during integrations of spacecraft state vectors. The Mars50c gravity field model and the Mars-GRAM 2001 model are used to compute perturbation effects due to Mars gravity field and Mars atmospheric drag, respectively. To compute exact locations of other planets, JPL's DE405 ephemerides are used. Phobos and Deimos's ephemeris are computed using analytical method because their informations are not released with DE405. Mars Global Surveyor's mapping orbital data are used to verify the developed propagator performances. After one Martian day propagation (12 orbital periods, the results show about maximum ±5 meter errors, in every position state components(radial, cross-track and along-track, when compared to these from the Astrogator propagation in the Satellite Tool Kit. This result shows high reliability of the developed software which can be used to design near Mars missions for Korea, in future.

  5. US State Submerged Lands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Submerged Lands Act (43 U.S.C. Section 1301 et seq.) grants coastal states title to natural resources located within their coastal submerged lands and navigable...

  6. Agriculture: Land Use

    Science.gov (United States)

    Land Use and agriculture. Information about land use restrictions and incentive programs.Agricultural operations sometimes involve activities regulated by laws designed to protect water supplies, threatened or endangered plants and animals, or wetlands.

  7. Land Administration Systems

    DEFF Research Database (Denmark)

    Enemark, Stig

    2014-01-01

    Land administration systems are the operational tool for conceptualizing rights, restrictions and responsibilities (RRRs) in land. Each of the rights, restrictions and responsibilities encompasses a human rights dimension that relates to the overall national land policies and should be unfolded...... as more than just rhetoric. This paper attempts to analyse the aspects of human rights in relation to land administration systems with a special focus on developing countries struggling to build adequate systems for governing the rights, restrictions and responsibilities in land. Human rights....... This relates to national political arrangements and standards for good governance and land administration systems are highly instrumental in this regard. This paper introduces the relation between land administration and human rights. It is argued that human rights and land administration are closely linked...

  8. Focus on land reclamation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-01

    Various aspects of land reclamation, i.e. returning disturbed land to a state where, at minimum, it is at least capable of supporting the same kinds of land uses as before the disturbance, are discussed. Activities which disturb the land such as surface mining of coal, surface mining and extraction of oil sands, drilling for oil and natural gas, waste disposal sites, including sanitary landfills, clearing timber for forestry, excavating for pipelines and transportation are described, along with land reclamation legislation in Alberta, and indications of future developments in land reclamation research, legislation and regulation. Practical guidelines for individuals are provided on how they might contribute to land reclamation through judicious and informed consumerism, and through practicing good land management, inclusive of reduced use of herbicides, composting of household wastes, and planting of native species or ground cover in place of traditional lawns.

  9. The land management perspective

    DEFF Research Database (Denmark)

    Enemark, Stig

    2006-01-01

    paradigm. In many countries, and especially developing countries and countries in transition, the national capacity to manage land rights, restrictions and responsibilities is not well developed in terms of mature institutions and the necessary human resources and skills. In this regard, the capacity......Land management is the process by which the resources of land are put into good effect. Land management encompasses all activities associated with the management of land that are required to achieve sustainable development. The concept of land includes properties and natural resources and thereby...... encompasses the total natural and built environment. Land Administration Systems (LAS) are institutional frameworks complicated by the tasks they must perform, by national cultural, political and judicial settings, and by technology. This paper facilitates an overall understanding of the land management...

  10. Graphite core stability during 'care and maintenance' and 'safe storage'

    International Nuclear Information System (INIS)

    Wickham, A.J.; Marsden, B.J.; Sellers, R.M.; Pilkington, N.J.

    1998-01-01

    The current decommissioning strategy for the graphite-moderated reactors operated by Magnox Electric plc, Nuclear Electric Ltd and Scottish Nuclear Ltd is to delay dismantling and to initiate a monitored period of care and maintenance followed by a period of safe storage totaling up to 135 years. This philosophy has the considerable advantage of permitting the majority of radionuclides to decay, thereby minimising personnel dose during dismantling which itself will require far less complex remote-handling equipment. It also defers the disposal of the graphite and other components so that the provision of a deep land-based repository can be achieved. A comprehensive review of all relevant data on the chemical, physical and mechanical properties of the graphite and its potential reactions, including radioactivity transport, has been undertaken in order to demonstrate that there are no potential mechanisms which might lead to degradation of the core during the storage period. It is concluded that no significant experimental work is necessary to support the safe storage philosophy although, since the ingress of rainwater over long periods of time cannot be assumed incredible, a number of anomalies in chemical leaching rates may be worthy of re-examination. No other potential chemical reactions, such as the radiolytic formation of nitric acid leading to corrosion problems, are considered significant. (author)

  11. Land Prices and Fundamentals

    OpenAIRE

    Koji Nakamura; Yumi Saita

    2007-01-01

    This paper examines the long-term relationship between macro economic fundamentals and the weighted-average land price indicators, which are supposed to be more appropriate than the official land price indicators when analyzing their impacts on the macro economy. In many cases, we find the cointegrating relationships between the weighted-average land price indicators and the discounted present value of land calculated based on the macro economic fundamentals indicators. We also find that the ...

  12. Quantification of encapsulated bioburden in spacecraft polymer materials by cultivation-dependent and molecular methods.

    Directory of Open Access Journals (Sweden)

    Anja Bauermeister

    Full Text Available Bioburden encapsulated in spacecraft polymers (such as adhesives and coatings poses a potential risk to jeopardize scientific exploration of other celestial bodies. This is particularly critical for spacecraft components intended for hard landing. So far, it remained unclear if polymers are indeed a source of microbial contamination. In addition, data with respect to survival of microbes during the embedding/polymerization process are sparse. In this study we developed testing strategies to quantitatively examine encapsulated bioburden in five different polymers used frequently and in large quantities on spaceflight hardware. As quantitative extraction of the bioburden from polymerized (solid materials did not prove feasible, contaminants were extracted from uncured precursors. Cultivation-based analyses revealed <0.1-2.5 colony forming units (cfu per cm3 polymer, whereas quantitative PCR-based detection of contaminants indicated considerably higher values, despite low DNA extraction efficiency. Results obtained from this approach reflect the most conservative proxy for encapsulated bioburden, as they give the maximum bioburden of the polymers irrespective of any additional physical and chemical stress occurring during polymerization. To address the latter issue, we deployed an embedding model to elucidate and monitor the physiological status of embedded Bacillus safensis spores in a cured polymer. Staining approaches using AlexaFluor succinimidyl ester 488 (AF488, propidium monoazide (PMA, CTC (5-cyano-2,3-diotolyl tetrazolium chloride demonstrated that embedded spores retained integrity, germination and cultivation ability even after polymerization of the adhesive Scotch-Weld 2216 B/A. Using the methods presented here, we were able to estimate the worst case contribution of encapsulated bioburden in different polymers to the bioburden of spacecraft. We demonstrated that spores were not affected by polymerization processes. Besides Planetary

  13. 30 years of experience in safe transportation of nuclear materials

    International Nuclear Information System (INIS)

    Kaneko, K.

    2004-01-01

    In April 2003, Nuclear Fuel Transport Co., Ltd. (NFT) marked the 30 th anniversary of its founding. NFT was established in 1973 and in 1978, commenced SF transport to the reprocessing plant in Tokai-mura. And then, after making preparations to transport nuclear materials to the various facilities at the Nuclear Fuel Cycle Center in Rokkasho-mura, NFT successfully started transportation of LLW (low level waste) to Rokksho-mura's LLW disposal center in 1992, domestic land transportation of HLW returned from overseas to the HLW storage center in 1995, domestic land transportation of natural hexafluoride delivered from overseas to the uranium enrichment plant in 1996, and transportation of SF to the reprocessing plant in 2000. NFT has realized an annual SF transportation capacity of 300 MTU and is currently making great company wide efforts to meet the Rokkasho Reprocessing Plant's future SF annual reprocessing capacity of 800MTU. At the end of FY2003, NFT had successfully transported 560 casks (about 1,730 MTU) of SF in more than 200 voyages in total, about 160,000 drums of LLW in around 100 voyages in total. This paper introduces the record of safe transport and its experience over the past 30 years and prospect for future transport business

  14. 30 years of experience in safe transportation of nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, K. [Nuclear Fuel Transport Co., Ltd., Tokyo (Japan)

    2004-07-01

    In April 2003, Nuclear Fuel Transport Co., Ltd. (NFT) marked the 30{sup th} anniversary of its founding. NFT was established in 1973 and in 1978, commenced SF transport to the reprocessing plant in Tokai-mura. And then, after making preparations to transport nuclear materials to the various facilities at the Nuclear Fuel Cycle Center in Rokkasho-mura, NFT successfully started transportation of LLW (low level waste) to Rokksho-mura's LLW disposal center in 1992, domestic land transportation of HLW returned from overseas to the HLW storage center in 1995, domestic land transportation of natural hexafluoride delivered from overseas to the uranium enrichment plant in 1996, and transportation of SF to the reprocessing plant in 2000. NFT has realized an annual SF transportation capacity of 300 MTU and is currently making great company wide efforts to meet the Rokkasho Reprocessing Plant's future SF annual reprocessing capacity of 800MTU. At the end of FY2003, NFT had successfully transported 560 casks (about 1,730 MTU) of SF in more than 200 voyages in total, about 160,000 drums of LLW in around 100 voyages in total. This paper introduces the record of safe transport and its experience over the past 30 years and prospect for future transport business.

  15. Topology Optimization of Spacecraft Transfer Compartment

    Directory of Open Access Journals (Sweden)

    A. A. Borovikov

    2016-01-01

    Full Text Available IntroductionThe subject of this research is topology optimization of the adapter of a spacecraft transfer compartment. The finite element topology optimization [1] is widely used for simple structure elements [6, 7]. It is argued that using this method in conjunction with additive technology (3D - printing it is possible to create construction designs with the best weight characteristics. However, the paper shows that when applying this method to a complex construction design the optimization results are highly sensitive to optimization algorithm parameters. The goal of this research is to study parameters of the topology optimization algorithm and the influence of their variations on results.1.      Problem formulation   A commercial software Altair HyperWorks/OptiStruct (student’s license performed numerical calculations. The paper presents a detailed description of the finite element model.The main features of the proposed model are as follows:-          Simplicity with non-complicated geometry;-          Building a finite element model in terms of computing time minimization;-          Using the lumped mass elements to simulate the impacts of the conjugates on the adapter;-          A limit of material strength, decreased by an order of magnitude, to eliminate stress concentrators;-          The gravitational load applied corresponds to the loads for the Angara-A5 launcher [8]. 2.      Method of solutionA brief description of the SIMP-method realized in the Altair HyperWorks/OptiStruct software is given.3.      ResultsPerformed numerical calculations, and shown the influence of variations of algorithm parameters (DISCRETE, MATINIT, MINDIM, MAXDIM on construction design as well as the parameters SINGLE and SPLIT used to reveal restrictions on manufacturing.Shown that, depending on variations of parameters, an adapter construction strives to «truss» or «shell» type. Described

  16. Studies of the atmosphere of Venus by means of spacecraft: Solved and unsolved problems

    Science.gov (United States)

    Moroz, V. I.

    Many spacecraft were used for exploration of the atmosphere of Venus. Their list consists of 25 items, including fly-by missions, orbiters, descent and landing probes and even balloons. VENERA-4 (1967) was near the beginning of this list, providing the first time in situ experiments on other planet. It started a long sequence of successful Soviet Venera missions. However after the year 1985 there were no missions to Venus in Russia. It probably was a strategic error. Now several groups of scientists in other countries work on proposals for new missions to Venus. The goal of this paper is to present a brief review of already solved and still unsolved problems in the studies of the Venus' atmosphere and to possible future aims in this field.

  17. The Near Earth Object Scout Spacecraft: A Low Cost Approach to in-situ Characterization of the NEO Population

    Science.gov (United States)

    Koontz, Steven L.; Condon, Gerald; Graham, Lee; Bevilacqua, Ricardo

    2014-01-01

    In this paper we describe a micro/nano satellite spacecraft and a supporting mission profile and architecture designed to enable preliminary in-situ characterization of a significant number of Near Earth Objects (NEOs) at reasonable cost. The spacecraft will be referred to as the NEO Scout. NEO Scout spacecraft are to be placed in GTO, GEO, or cis-lunar space as secondary payloads on launch vehicles headed for GTO or beyond and will begin their mission after deployment from the launcher. A distinguishing key feature of the NEO scout system is to design the mission timeline and spacecraft to rendezvous with and land on the target NEOs during close approach to the Earth-Moon system using low-thrust/high- impulse propulsion systems. Mission feasibility and preliminary design analysis are presented along with detailed trajectory calculations. The use of micro/nano satellites in low-cost interplanetary exploration is attracting increasing attention and is the subject of several annual workshops and published design studies (1-4). The NEO population consists of those asteroids and short period comets orbiting the Sun with a perihelion of 1.3 astronomical units or less (5-8). As of July 30, 2013 10065 Near-Earth objects have been discovered. The spin rate, mass, density, surface physical (especially mechanical) properties, composition, and mineralogy of the vast majority of these objects are highly uncertain and the limited available telescopic remote sensing data imply a very diverse population (5-8). In-situ measurements by robotic spacecraft are urgently needed to provide the characterization data needed to support hardware and mission design for more ambitious human and robotic NEO operations. Large numbers of NEOs move into close proximity with the Earth-Moon system every year (9). The JPL Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) (10) has produced detailed mission profile and delta V requirements for various NEO missions ranging from 30

  18. Land Treatment Digital Library

    Science.gov (United States)

    Pilliod, David S.; Welty, Justin L.

    2013-01-01

    The Land Treatment Digital Library (LTDL) was created by the U.S. Geological Survey to catalog legacy land treatment information on Bureau of Land Management lands in the western United States. The LTDL can be used by federal managers and scientists for compiling information for data-calls, producing maps, generating reports, and conducting analyses at varying spatial and temporal scales. The LTDL currently houses thousands of treatments from BLM lands across 10 states. Users can browse a map to find information on individual treatments, perform more complex queries to identify a set of treatments, and view graphs of treatment summary statistics.

  19. Land reclamation in Egypt

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine

    2009-01-01

    on fieldwork in a village in the new lands; it is inhabited by graduates who have received land under the Mubarak Project. The analysis shows that they move there in hope of making a better life especially for their children. Nevertheless, the settlers have difficulties building a sense of belonging to the new....... This paper examines from a micro-perspective, the life of Egyptians resettled in the new lands. The first part of the paper provides an introduction to the discourses of land reclamation, to the policies of reclaimed land distribution, and to the background of the settlers. The second part is based...

  20. Landing gear noise attenuation

    Science.gov (United States)

    Moe, Jeffrey W. (Inventor); Whitmire, Julia (Inventor); Kwan, Hwa-Wan (Inventor); Abeysinghe, Amal (Inventor)

    2011-01-01

    A landing gear noise attenuator mitigates noise generated by airframe deployable landing gear. The noise attenuator can have a first position when the landing gear is in its deployed or down position, and a second position when the landing gear is in its up or stowed position. The noise attenuator may be an inflatable fairing that does not compromise limited space constraints associated with landing gear retraction and stowage. A truck fairing mounted under a truck beam can have a compliant edge to allow for non-destructive impingement of a deflected fire during certain conditions.