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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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The development of the Delta second stage nitrogen tetroxide fueling system is briefly summarized. The nitrogen tetroxide fueling system and the equipment used to protect the spacecraft environment from the toxic nitrogen tetroxide fumes are described. Topics covered include: the nitrogen tetroxide transfer system; loading operations; safety precautions; and chemical treatment of all toxic vapors.
Test data of the RFS Program in the Production phase and computer automation are presented, as an essential element in the evaluation of the RFS performance in a simulated spacecraft environment. Typical production test data will be discussed for stabilities from 1 to 100,000 seconds averaging time and simulated time error accumulation test. Also, design considerations in developing the RFS test systems for the acceptance test in production are discussed.
The mating of rats was studied to determine the effects of: simulated reentry stresses at known stages of pregnancy, and full flight simulation, consisting of sequential launch stresses, group housing, mating opportunity, diet, simulated reentry, and postreentry isolation of male and female rats. Uterine contents, adrenal mass and abdominal fat as a proportion of body mass, duration of pregnancy, and number and sex of offspring were studied. It is found that: (1) parturition following full flight simulation was delayed relative to that of controls; (2) litter size was reduced and resorptions increased compared with previous matings in the same group of animals; and (3) abdominal fat was highly elevated in animals that were fed the Soviet paste diet. It is suggested that the combined effects of diet, stress, spacecraft environment, and weightlessness decreased the probability of mating or of viable pregnancies in the Cosmos 1129 flight and control animals.
The performance of a hollow corner cube retroreflector made up of three mutually perpendicular optically flat mirrors when undergoing the thermal-mechanical strains induced by a spacecraft environment was studied. Of particular interest was a device of 200 square centimeter optical aperture used on a satellite in a synchronous orbit. It was assumed that the reflector always faces the earth. The effects of direct solar irradiance, earthshine, and albedo were considered. The results included the maximum mirror surface temperature during the orbit as well as the worst-case loss of optical performance due to thermally-induced mirror distortions. It was concluded that a device made of three suitably coated flat ULE mirrors, optically contacted to each other and supported mechanically in a nonrigid mount, would be expected to concentrate over 80 percent of the theoretical maximum energy in the central of the far field diffraction pattern. Continued development of the device through a detailed design, fabrication, and test phase was recommended.
The aeromedical research reported considers the safety of the human component in manned space flight. The effects of spacecraft environment, radiation and weightlessness on human biological and psychological processes are covered.
The various elements of the Information Adaptive System (IAS) program are discussed along with the design features, approaches, and algorithms employed within the system. This program was initiated by NASA in order to develop an adaptable data processing system which will accommodate high speed multispectral image data in the real-time spacecraft environment. The development of this system is examined, including the test and support equipment required to evaluate and demonstrate the operational performance of the system in terms of the applicability of the design to high speed onboard processing. In addition to a high throughput rate capability, this system will be flexible, programmable, and capable of adapting its operation to external commands and characteristics of the data stream.
The design of gas adsorption refrigerators used for cryogenic cooling in the temperature range of 4K to 120K was examined. The functional relationships among the power requirement for the refrigerator, the system mass, the cycle time and the operating conditions were derived. It was found that the precool temperature, the temperature dependent heat capacities and thermal conductivities, and pressure and temperature variations in the compressors have important impacts on the cooling performance. Optimal designs based on a minimum power criterion were performed for four different gas adsorption refrigerators and a multistage system. It is concluded that the estimates of the power required and the system mass are within manageable limits in various spacecraft environments.
A bibliography containing 476 documents introduced into the NASA scientific and technical information system in May 1984 is presented. The primary subject categories included are: life sciences, aerospace medicine, behavioral sciences, man/system technology, life support, and planetary biology. Topics extensively represented were space flight stress, man machine systems, weightlessness, human performance, mental performance, and spacecraft environments. Abstracts for each citation are given.
Computational models for the flight experiment demonstration system (FEDS) code 580 were developed. The FEDS is a modification of the automated orbit determination system which was developed during 1981 and 1982. The purpose of FEDS is to demonstrate, in a simulated spacecraft environment, the feasibility of using microprocessors to perform onboard orbit determination with limited ground support.
Candidate high-power supply systems for future space missions are discussed. Solar cells, particularly made from GaAs materials, are projected to be amenable large arrays that will have a 10 yr lifetime with a 15 percent efficiency at the end. Concentrator arrays using GaAs cells could furnish over 200 W/sq m with 100 suns irradiance. Different battery systems, other than the present low-power NiCd storage systems, will be required, and could be either fuel cell systems or NiH2 batteries. The flywheel also offers promise, especially if integrated within the attitude control system. Solar thermal systems are also possible, featuring SiGe thermocouples, or boron alloys or rare earth calcogenides in thermoelectric generators or thermionic converters equipped with alkali metal elements. Mechanical systems, notably the Brayton cycle engine, offer multihundredwatt performance and higher, with at least 3.5 yr lifetimes. Experimentation is still needed to characterize the power supply interaction with the spacecraft environment and to design efficient and long-lasting radiators if heat engines are implemented.
The contributions of airborne astronomy to the knowledge of our solar system are reviewed, beginning in 1967 when planetary observations became a vigorous part of NASA's airborne astronomy initiatives using aircraft outfitted with 30 cm diameter telescopes for infrared observations at altitudes between 12 and 15 km. These early facilities and their successor, the Kuiper airborne observatory (KAO), profoundly influenced many areas of planetary science by providing optimized platforms for the conduct of certain types of remote sensing experiments that were incompatible with both ground-based and spacecraft environments. Specific topics reviewed include energy balance in the outer planets, the composition and structure of planetary atmospheres, and planetary ring systems.
Atmospheric monitoring needs and requirements associated with the use of the Mass Spectrometer Electro-Optical Ion Detector for space stations contamination studies are discussed. Instrument performance requirements and design specifications are examined. A general overview is presented of the types of chemical contaminants found in spacecraft environments.
Components passed stringent qualification tests tabulated and described. Destructive and nondestructive qualification testing confirmed parts capable of withstanding spacecraft environments without excessive degradation and have stable characteristics during operating lives. Testing assessed effects of electrical, environmental, and mechanical stresses in various levels and time durations.
The performance and productivity of astronauts in space are studied. The effects of the space and spacecraft environments, man/machine interaction, work-rest cycles, and psychological factors on man's performance in space are examined. The objectives of the Gemini, Apollo, and Skylab programs and the performance data collected on these missions are analyzed.
The purpose of the Flight Experiment Demonstration System (FEDS) was to show, in a simulated spacecraft environment, the feasibility of using a microprocessor to automate the onboard orbit determination functions. The software and hardware configuration used to support FEDS during the demonstration and the results of the demonstration are discussed.
Growing concern over trace gaseous contaminant accumulations in the enclosed atmospheres of long duration spacecraft missions has prompted the development of a trace contaminant data base on the basis of gas, lithium hydroxide, and charcoal samples collected on Space Shuttle missions. A model trace contaminant gas mixture containing 14 compounds was chosen with the aid of a FORTRAN program, on the strength of contaminant chemical and toxicological categories, frequency of occurrence, and worst-case concentration. The model gas mixture can be used to test trace contaminant control hardware for a manned spacecraft environment.
A workshop was held with the specific objective of reviewing the state-of-knowledge regarding Space Station contamination, the extent to which the various categories of contamination can be predicted, and the extent to which the predicted levels would interfere with onboard scientific investigations or space station functions. The papers presented at the workshop are compiled and address the following topics: natural environment, plasma electromagnetic environment, optical environment, particulate environment, spacecraft contamination, surface physics processes, laboratory experiments and vented chemicals/contaminants.
Advanced microgravity plant biology research and life support system development for the spacecraft environment are critically hampered by the lack of a technology base. This inadequacy stems primarily from the fact that microgravity results in a lack of convective currents and phase separation as compared to the one gravity environment. A program plan is being initiated to develop this technology base. This program will provide an iterative flight development effort that will be closely integrated with both basic science investigations and advanced life support system development efforts incorporating biological processes. The critical considerations include optimum illumination methods, root aeration, root and shoot support, and heat rejection and gas exchange in the plant canopy.