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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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NASA NTRS1986

Radar investigation of asteroids

The number of radar detected asteroids has climbed from 6 to 40 (27 mainbelt plus 13 near-Earth). The dual-circular-polarization radar sample now comprises more than 1% of the numbered asteroids. Radar results for mainbelt asteroids furnish the first available information on the nature of these objects at macroscopic scales. At least one object (2 Pallas) and probably many others are extraordinarily smooth at centimeter-to-meter scales but are extremely rough at some scale between several meters and many kilometers. Pallas has essentially no small-scale structure within the uppermost several meters of the regolith, but the rms slope of this regolith exceeds 20 deg., much larger than typical lunar values (approx. 7 deg.). The origin of these slopes could be the hypervelocity impact cratering process, whose manifestations are likely to be different on low-gravity, low-radius-of-curvature objects from those on the terrestrial planets. The range of mainbelt asteroid radar albedoes is very broad and implies big variations in regolith porosity or metal concentration, or both. The highest albedo estimate, for 16 Psyche, is consistent with a surface having porosities typical of lunar soil and a composition nearly completely metallic. Therefore, Psyche might be the collisionally stripped core of a differentiated small plant, and might resemble mineralogically the parent bodies of iron meteorites.

Ostro, S. J.↗
NASA NTRS1985

Theoretical and experimental studies in support of the geophysical fluid flow experiment

Meteorologists and astrophysicists interested in large scale planetary and solar circulations have come to recognize the importance of rotation and stratification in determining the character of these flows. In particular, the effect of latitude-dependent Coriolis force on nonlinear convection is thought to play a crucial role in such phenomena as differential rotation on the Sun, cloud band orientation on Jupiter, and the generation of magnetic fields in thermally driven dynamos. The continuous low-gravity environment of the orbiting space shuttle offers a unique opportunity to make laboratory studies of such large-scale thermally driven flows under the constraint imposed by rotation and sphericity. This is possible because polarization forces in a dielectric liquid, which are linearly dependent on fluid temperature, give rise to an effectively radial buoyancy force when a radial electrostatic field is imposed. The Geophysical Fluid Flow Cell (GFFC) is an implementation of this ideal in which fluid is contained between two rotating hemispheres that are differentially heated and stressed with a large a-c voltage. The experiment, to be flown on Spacelab III (currently set for launch April 29, 1985), will explore non-linear mode selection and high Rayleigh number turbulence in a rotating convecting spherical shell of liquid. Experiments will be carried out in a low driving parameter range where some limited numerical experimentation is currently feasible, as well as in a parameter range significantly beyond numerical computation for many years.

Hart, J.↗
NASA NTRS1987

Reference Mission Operational Analysis Document (RMOAD) for the Life Sciences Research Facilities

The space station will be constructed during the next decade as an orbiting, low-gravity, permanent facility. The facility will provide a multitude of research opportunities for many different users. The pressurized research laboratory will allow life scientists to study the effects of long-term exposure to microgravity on humans, animals, and plants. The results of these studies will increase our understanding of this foreign environment on basic life processes and ensure the safety of man's long-term presence in space. This document establishes initial operational requirements for the use of the Life Sciences Research Facility (LSRF) during its construction.

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NASA NTRS1987

Microgravity science and applications bibliography, 1986 revision

This edition of the Microgravity Science and Applications (MSA) Bibliography is a compilation of Government reports, contractor reports, conference proceedings, and journal articles dealing with flight experiments utilizing a low-gravity environment to elucidate and control various processes or ground-based activities providing supporting research. It encompasses literature published in FY-86 and part of FY-87 but not cited in the 1985 Revision, pending publications, and those submitted for publication during this time period. Subdivisions of the bibliography include six major categories: Electronic Materials, Metals, Alloys, and Combustion Science. Other categories include Experimental Technology and General Studies. Included are publications from the European and Soviet programs. In addition, there is a list of patents and a cross reference index.

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NASA NTRS1987

Combustion of velcro in low gravity

An experimental program was conducted to investigate the low gravity burning characteristics on nylon and Nomex Velcro fastening tapes in an atmosphere of 30-percent oxygen, 70-percent nitrogen at a 70-kPa pressure. The tests were conducted using the NASA Lewis Research Center Zero Gravity Facility. The test results, as documented by high-speed cameras, indicate that both nylon and Nomex burn in low gravity for the full 5.18 sec test time but that Nomex burns less vigorously than nylon. Nylon melts as it burns, whereas Nomex forms a solid char. Nylon also sputters burning droplets as it burns. Thus, from these limited tests, it appears that Nomex Velcro is less hazardous than nylon Velcro for spacecraft applications. The results also show that residual gas velocities, and by analogy spacecraft air circulation, can enhance the low-gravity combustion.

Olson, Sandra L.↗
NASA NTRS1987

Overview: Fluid acquisition and transfer

This brief overview introduced the symposium session on microgravity fluid acquisition and transfer. It states the objective of NASA efforts in this technology and the approach being taken in the technology program. The problems are outlined and various methods for low-gravity fluid acquisition and transfer are summarized. Applications for the technology are described and an assessment of the current state of the art is presented. NASA and DOD on-going and planned programs are listed.

Meserole, Jere S.↗
NASA NTRS1987

Shuttle middeck fluid transfer experiment: Lessons learned

This presentation is based on the experience gained from having integrated and flown a shuttle middeck experiment. The experiment, which demonstrated filling, expulsion, and fluid behavior of a liquid storage system under low-gravity conditions, is briefly described. The advantages and disadvantages of middeck payloads compared to other shuttle payload provisions are discussed. A general approach to the integration process is described. The requirements for the shuttle interfaces--such as structures, pressurized systems, materials, instrumentation, and electrical power--are defined and the approach that was used to satisfy these requirements is presented. Currently the middeck experiment is being used as a test bed for the development of various space fluid system components.

Tegart, James↗
NASA NTRS1987

Spacelab 3 Mission Science Review

Papers and abstracts of the presentations made at the symposium are given as the scientific report for the Spacelab 3 mission. Spacelab 3, the second flight of the National Aeronautics and Space Administration's (NASA) orbital laboratory, signified a new era of research in space. The primary objective of the mission was to conduct applications, science, and technology experiments requiring the low-gravity environment of Earth orbit and stable vehicle attitude over an extended period (e.g., 6 days) with emphasis on materials processing. The mission was launched on April 29, 1985, aboard the Space Shuttle Challenger which landed a week later on May 6. The multidisciplinary payload included 15 investigations in five scientific fields: material science, fluid dynamics, life sciences, astrophysics, and atmospheric science.

Fichtl, George H.↗
NASA NTRS1986

Effects of transient propellant dynamics on deployment of large liquid stages in zero-gravity with application to Shuttle/Centaur

This paper describes the application of a recently developed CFD program, HYDR-3D, to the analysis of separation of the Centaur G-Prime vehicle from the Shuttle Orbiter. The typical application presented illustrates a particularly difficult design task - deployment of a large, liquid-filled, densely packaged vehicle from a manned vehicle. Since it represents a potential catastrophic hazard, a vast number of conditions and parameters must be analyzed to ensure tolerance of at least two credible failures. Validation of the HYDR-3D program against zero- and low-gravity experimental data is also presented. Using the fluid dynamics program, this approach can be used confidently to analyze and determine design requirements for a variety of OTV/space-station deployment and docking problems.

Martin, R. E.↗
NASA NTRS1987

Processing materials in space - The history and the future

The development of materials processing in space, and some of the Soyuz, Apollo, Skylab, and Shuttle orbital materials experiments are reviewed. Consideration is given to protein crystal growth, electrophoresis, low-gravity isoelectric focusing, phase partitioning, a monodisperse latex reactor, semiconductor crystal growth, solution crystal growth, the triglycine sulfate experiment, vapor crystal growth experiments, the mercuric iodide experiment, electronic and electrooptical materials, organic thin films and crystalline solids, deep undercooling of metals and alloys, magnetic materials, immiscible materials, metal solidification research, reluctant glass-forming materials, and containerless glass formation. The space processing apparatuses and ground facilities, for materials processing are described. Future facilities for commercial research, development, and manufacturing in space are proposed.

Chassay, Roger↗
NASA NTRS1986

Microstructural variations induced by gravity level during directional solidification of near-eutectic iron-carbon type alloys

The effects of gravity on the microstructure of directionally solidified near-eutectic cast irons are studied, using a Bridgman-type automatic directional solidification furnace aboard a NASA KC-135 aircraft which flies parabolic arcs and generates alternating periods of low-g (0.01 to 0.001 g, 30 seconds long) and high-g (1.8 g, 1.5 minutes long). Results show a refinement of the interlamellar spacing of the eutectic during low-g processing of metastable Fe-C eutectic alloys. Low-g processing of stable Fe-C-Si eutectic alloys (lamellar or spheroidal graphic) results in a coarsening of the eutectic grain structure. Secondary dendrite arm spacing of austenite increases in low-g and decreases in high-g. The effectiveness of low-gravity in the removal of buoyancy-driven graphite phase segregation is demonstrated.

Stefanescu, Doru M.↗
NASA NTRS1986

Current program to investigate phenomena in a microgravity environment

Current NASA Microgravity Science and Applications Division Shuttle and terrestrial experiments to acquire basic data for space-based materials processing activities are summarized. The research is carried out to increase the understanding and to improve ground-based and space-based processing, to enhance the understanding of basic physical phenomena, and to characterize the forces which effect low-gravity processing. The main areas of research are crystal growth, metallic alloy solidification, bioseparation processes, blood rheology, containerless processing, and studies of combustion processes, chemical and transport phenomena, cloud microphysics and fluid behavior and surface phenomena in microgravity. Specific experiments, which exemplify the research goals and were performed on KC-135 flights along Keplerian trajectories and on Shuttle missions, are described.

Oran, William A.↗
NASA NTRS1987

Research and technology, 1987

Three broad goals were presented by NASA as a guide to meet the challenges of the future: to advance scientific knowledge of the planet Earth, the solar system, and the universe; to expand human presence beyond the Earth into the solar system; and to strengthen aeronautics research and technology. Near-term and new-generation space transportation and propulsion systems are being analyzed that will assure the nation access to and presence in space. Other key advanced studies include large astronomical observatories, space platforms, scientific and commercial payloads, and systems to enhance operations in Earth orbit. Longer-range studies include systems that would allow humans to explore the Moon and Mars during the next century. Research programs, both to support the many space missions studied or managed by the Center and to advance scientific knowledge in selected areas, involve work in the areas of atmospheric science, earth science, space science (including astrophysics and solar, magnetospheric, and atomic physics), and low-gravity science. Programs and experiment design for flights on the Space Station, free-flying satellites, and the Space Shuttle are being planned. To maintain a leadership position in technology, continued advances in liquid and solid propellant engines, materials and processes; electronic, structural, and thermal investigations; and environmental control are required. Progress during the fiscal year 1987 is discussed.

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NASA NTRS1988

Spacecraft Fire-Safety Experiments for Space Station: Technology Development Mission

Definitions, overall descriptions, and preliminary apparatus and instrumentation requirements are presented for three spacecraft fire-safety experiments appropriate for inclusion in a growth-version of the Space Station. The experiments are as follows: 1. Combustion and Flame Spread of Typical Spacecraft Materials in a Low­ Velocity Convective Flow in Low Gravity 2. Fire and Fire-Extinguishant Interactions with Various Fire Scenarios in Low Gravity 3. Smoldering and Deep-Seated Combustion in Low Gravity. The experiments were selected from an assessment of recommendations for advanced technologies for prevention, detection, and control of fires in spacecraft. The experiments and their facilities are intended to constitute a portion of a Spacecraft Fire Safety Technology Development Mission (TDM). Basic requirements for the mission study are that the Space Station is essential for the accomplishment of the experimental objectives and that the technology being developed is appropriate for the growth version of the Space Station. The advantages of these three experiments are that, not only do they explore problems relevant to the Space Station operation and utilization, but also they constitute tests adaptable to two multiuse facilities installed in the Space Station laboratory module, the Combustion Tunnel Facility and the Combustion Facility. Three additional spacecraft fire-safety experiments, essential precursors to the TD M for near-term performance, are also described as follows: 1. Near-Term Testing of Materials for Combustion and Flame Spread 2. Near-Term Extinguishment of Fires in a Low-Gravity Test Bed 3. Post-Fire Recovery of Sensitive Electrical and Electronic Equipment. For all the experiments, the study defines accommodations in terms of first-order space, mass, power, consumables, and crew-time estimates. The study also reviews the key problems to be addressed, namely experiment safety hazards, non-intrusive diagnostics development and waste-products disposal. A preliminary task and time schedule for design, development, and experiment fabrication is proposed.

Youngblood, Wallace W.↗
NASA NTRS1987

Polymer crystal growth facility concept for Space Station laboratory module

Interest in materials processing in space began to evolve in the late 1950's through low gravity simulation and some experiments on Apollo flights. Encouraged by the early results and considerations of the likely behavior of liquids and solidification process in low-gravity gave the recognition that this environment might be useful for a variety of unique processes. This generated a number of experimental ideas and gave rise to the design and development of facilities that will perform the experiments in space vehicles. These include the evolution of apparatus leading to the development of facilities for processing of materials on Skylab and now for the Space Transportation System (STS). The U.S. module on Space Station (SS) is going to expand this unique laboratory environment with practically no constraint on materials processing activity. This will need technology advancement for the hardware that will be required in this era. This presentation discusses the current concept for the experimental facility which will be housed in the U.S. Laboratory module on the Space Station and will allow the growth of single crystals of polymeric and organic materials using the state-of-the-art growth techniques.

Mookherji, Tripty↗
NASA NTRS1987

Electrodeposition and codeposition under low gravity/nonconvecting conditions

An experimental electrodeposition system was developed for modeling the behavior of inert particles codepositing in an electroplating matrix under low-gravity conditions. The device consists of a Co-electrodeposition cell operating in a convectionless mode (cathode over anode) and containing polystyrene particles with density approximating that of the electroplating solution. Data were obtained in shielded cells at 1 g, and the experiment was duplicated at 0.01 g on a KC-135 flight. No difference was found between convection-free bench experiments and the 0.01 g KC-135 experiments with 0.0900 M CuSO4. Codeposition experiments using 11.8-micron matched-density polystyrene spheres in 1 M CoSO4 have revealed that a noticeable particle gradient is created as the solution density mismatches in the vicinity of the cathode; gentle stirring was required to maintain a homogeneous particle suspension. Cr3C2 dust, which readily disperses at 1 g, tended to coagulate into spherical globules at 0.01 g, when stirred.

Riley, Clyde↗
NASA NTRS1987

Results from a compound semiconductor crystal growth experiment in a low gravity environment

A directional solidification experiment in the compound semiconductor lead tin telluride has been carried out in a low-gravity environment on board the Space Shuttle during a flight in October, 1985. Optical etching techniques and concentration profiles from wavelength dispersive electron microscopy indicate that there was a significant amount of convection during the solidifcation of the sample. A preliminary hypothesis of this result, that even at gravity levels on the order of 0.0001 g, the convective forces can be significant compared to mass transport due to diffusion, is being tested.

Crouch, Roger K.↗
NASA NTRS1987

Phase partitioning in space and on earth

The influence of gravity on the efficiency and quality of the impressive separations achievable by bioparticle partitioning is investigated by demixing polymer phase systems in microgravity. The study involves the neutral polymers dextran and polyethylene glycol, which form a two-phase system in aqueous solution at low concentrations. It is found that demixing in low-gravity occurs primarily by coalescence, whereas on earth the demixing occurs because of density differences between the phases.

Van Alstine, James M.↗