Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Soyuz Project”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Low-gravity homogenization and solidification of aluminum antimonide

The III-V semiconducting compound AlSb shows promise as a highly efficient solar cell material, but it has not been commercially exploited because of difficulties in compound synthesis. Liquid state homogenization and solidification of AlSb were carried out in the Apollo-Soyuz Test Project Experiment MA-044 in the hope that compositional homogeneity would be improved by negating the large density difference between the two constituents. Post-flight analysis and comparative characterization of the space-processed and ground-processed samples indicate that there are major homogeneity improvements in the low-gravity solidified material.

Ang, C.-Y.↗
NASA NTRS1976

Recovery of atmospheric parameters from the Apollo/Soyuz-ATS-F radio occultation data

As part of the Apollo-Soyuz Test Project, Apollo was tracked in the satellite-to-satellite tracking mode by ATS-F. The tracking data obtained at occultation of Apollo by the earth has been used in this study to compute atmospheric parameters like pressure and temperature. The results of the numerical inversion have been compared with data from a radiosonde station near the occultation site. Near the surface of the earth, the refractivity computed from occultation data agreed with the radiosonde-derived values to within 3%. A pressure profile deduced from the refractivity profile by using a simplified model of the atmosphere showed good agreement with radiosonde measurements.

Rangaswamy, S.↗
NASA NTRS1976

Electrophoretic characterization of aldehyde-fixed red blood cells, kidney cells, lynphocytes and chamber coatings

Ground-based electrokinetic data on the electrophoresis flight experiment to be flown on the Apollo-Soyuz Test Project experiment MA-011 are stipulated. Aldehyde-fixed red blood cells, embryonic kidney cells and lymphocytes were evaluated by analytical particle electrophoresis. The results which aided in the interpretation of the final analysis of the MA-011 experiment are documented. The electrophoresis chamber surface modifications, the buffer, and the material used in the column system are also discussed.

Source record↗
NASA NTRS1976

ASTP chemical and microbiological analysis of potable water

The Apollo-Soyuz Test Project procedures for potable water system servicing and the results of preflight and postflight chemical and microbiological analyses of the water are discussed. Tables show results of the analyses. The effectiveness of the water system is evaluated.

Sauer, R. L.↗
NASA NTRS1976

Quantitative determination of zero-gravity effects on crystal growth from the melt (experiment MA-060)

The purpose of experiment MA-060 was to investigate quantitatively the effects of near-zero gravity conditions on crystal growth and dopant segregation during directional solidification from the melt. Gallium-doped germanium single crystals were successfully grown from the melt with simultaneous interface demarcation during the Apollo Soyuz Test Project mission. The analysis of the experimental data indicates striking differences of dopant segregation and growth behavior in the presence and absence of gravity. The results obtained are believed to have far-reaching implications on materials processing under zero-gravity conditions and on the theory of crystal growth and segregation in general.

Gatos, H. C.↗
NASA NTRS1976

Crystal growth from the vapour phase (ASTP experiment MA-085)

The positive effects of microgravity on crystal quality and fundamental properties of the vapor transport reaction were established by analyzing the results of three transport experiments on multi-component systems performed during the Apollo Soyuz Test Project (ASTP) mission. The systems employed were GeSe(0.99)Te(0.01) - GeI4 (A), GeS(0.98)Se(0.02) - GeCl4 (B), and GeS - GeCl4-Ar (C). The crystallographic analysis is based on a direct comparison of space and ground-based (prototype) crystals, employing X-ray diffraction, microprobe, microscopic, and chemical etching techniques. The results demonstrate a considerable improvement of the space-grown crystals in terms of chemical and crystalline homogeneity, surface morphology, and bulk perfection relative to ground specimens. The confirmation of greater mass transport rates than predicted for micro-gravity by present vapor transport models is of basic scientific and practical importance for the improvement of transport models and techniques on earth and for the development of a transport model for space conditions. The internal consistency and agreement between ASTP and Skylab results obtained for different compounds, transport agents, and temperature gradients strongly support the validity of these observations. The combined findings of improved crystal quality and high mass transport rates are of technological significance for space-processing applications.

Wiedemeier, H.↗
NASA NTRS1977

Space processing on Skylab and ASTP

The Skylab and Apollo Soyuz Test Project (ASTP) missions provided the opportunity the influence of micro-gravity on the processing of various materials. The results of physical and engineering experiments in metallurgy, fluids handling and crystal growth on two space missions are discussed. The majority of the experiments concern the solidification of alloys, semiconductors, and composite materials or basic liquid-liquid and solid-liquid interactions necessary to understand complex processing. Potential advantages of space processing to several materials disciplines are identified.

Snyder, R. S.↗
NASA NTRS1977

Electrophoresis experiment. Experiment MA-014

A continuous free-flow electrophoresis study was conducted during the Apollo-Soyuz Test Project Mission to investigate and evaluate the increase in sample flow rate and sample resolution achievable in space. The electrophoresis equipment was designed for the separation of four mixtures of biological cells with variable sample flow rates, buffer flow rates, and electric field gradients. Separation quality was assessed by measuring the light from a quartz lamp through the electrophoresis channel and onto a photodiode system. The data evaluation indicates that all monitored systems operated correctly during the experiment. The optical system produced a light that was too bright to discern true cell distributions, but final analysis of scientific data by computer processing shows the expected distribution of separated cells.

Hannig, K. H.↗
NASA NTRS1977

Monotectic and syntectic alloys. Experiment MA-044

The flight test furnace run of the monotectic and syntectic alloys experiment was successfully performed during the Apollo-Soyuz Test Project mission in July 1975. Examination of the returned sample cartridges and the formal comparative characterization of the low-g and one-g processed samples of lead-zinc and aluminum antimonide were completed. The results for aluminum antimonide show that polycrystalline and multiphased material can be homogenize in space under low-g conditions. Microstructural study on the lead-zinc flight samples shows that complete interdiffusion of lead and zinc had not been achieved, even though the flight data indicated a soak temperature in the miscible region that was 40 K above the published consolute temperature.

Lacy, L. L.↗
NASA NTRS1977

Quantitative determination of zero-gravity effects on electronic materials processing germanium crystal growth with simultaneous interface demarcation. Experiment MA-060

Experiment MA-060 was designed to establish the crystal growth and segregation characteristics of a melt in a directional solidification configuration under near zero-g conditions. The interface demarcation technique was incorporated into the experiment since it constitutes a unique tool for recording the morphology of the growth rate throughout solidification, and for establishing an absolute time reference framework for all stages of the solidification process. An extensive study was performed of the germanium crystals grown during the Apollo-Soyuz Test Project mission. It was found that single crystal growth was achieved and that the interface demarcation functioned successfully. There was no indication that convection driven by thermal or surface tension gradients was present in the melt. The gallium segregation, in the absence of gravity, was found to be fundamentally different in its initial and its subsequent stages from that of the ground-based tests. None of the existing theoretical models for growth and segregation can account for the observed segregation behavior in the absence of gravity.

Gatos, H. C.↗
NASA NTRS1977

Crystal growth from the vapor phase. Experiment MA-085

The positive effects of microgravity on crystal quality and the fundamental properties of the vapor transport reaction were established by analyzing the results of three transport experiments on multicomponent systems performed during the Apollo-Soyuz Test Project mission. The systems employed were GeSe0.99Te0.01-GeI4(A), GeS0.98Se0.02-GeCl4(B), and GeS-GeCl4-Ar (C). The crystallographic analysis is based on a direct comparison of space and ground-based (prototype) crystals employing X-ray diffraction, microprobe, microscopic, and chemical etching techniques. The results demonstrate a considerable improvement of the space-grown crystals in terms of chemical and crystalline homogeneity, surface morphology, and bulk perfection relative to ground specimens.

Wiedemeier, H.↗
NASA NTRS1977

Germanium-silicon solid solutions

An experiment on melting and directional crystallization of an antimony (Sb) doped germanium silicon (GeSi) solid solution was designed for the Apollo-Soyuz Test Project (ASTP) to study the possibility of using zero-g conditions for obtaining solid-solution monocrystals with uniformly distributed components. Crystallization in the zero-g environment did not occur under ideal stationary growth and segregation conditions. Crystallization under zero-g conditions revealed the heterogeneous nature of Si and Sb distribution in the cross sections of crystals. The presence of the radial thermal gradient in the multipurpose furnace could be one of the reasons for such Si and Sb distribution. The structure of space-grown crystals correlates with the nature of heterogeneities of Si and Sb distribution in crystals. The type of surface morphology and the contour observed in space-grown crystals were never observed in ground-based crystals and indicate the absence of wetting of the graphitized walls of the ampoule by the melt during melting and crystallization.

Zemskov, V. S.↗
NASA NTRS1977

JSC thunderstorm experiment results

To gain more insight into the various effects of lightning and thunderstorms on future shuttle vehicle launch and landing operations, an experiment was conducted to obtain data on the nature of electric fields in the vicinity of thunderstorms and particularly in the region of cumulonimbus cloud anvils during their various stages of build-up, maturity, and dissipation. These data supplement the airborne electric field data collected during the summer of 1975 in support of the Apollo Soyuz Test Project and the Viking launches. A Learjet aircraft was outfitted with four special electric field meters for collecting data. The onboard aircraft radar was also used to investigate cells embedded in large thunderstorm systems such as those found in frontal and squall line activities. Data were collected from 33 storm cells and used to establish a launch criteria to preclude triggering lightning during shuttle vehicle operations in close proximity to thunderstorms.

Source record↗
NASA NTRS1976

Joint inflight biomedical experiments performed during the ASTP spaceflight

Two joint inflight biomedical experiments were conducted during the unique Apollo-Soyuz Test Project (ASTP) spaceflight. One experiment evaluated rhythmicity of spore production of Streptomyces levoris. The other evaluated components of the infectious disease process by measuring alteration in: (1) the composition of the microbial population inhabiting USA and USSR crewmembers and spacecraft; (2) the ability of each crewmember's defense mechanism to resist infection; and (3) the ability of certain microorganisms to originate infections. These two experiments are described and the major results discussed.

Taylor, G. R.↗
NASA NTRS1977

Extreme ultraviolet photometer for observations of helium in interplanetary space

A four-channel photometer sensitive to two solar EUV lines which are resonantly scattered by helium gas was developed for flight on the Apollo-Soyuz Test Project. Two channels observed the 58.4-nm line of He I and used helium gas resonant absorption cells to determine the intensities of the center and wings of that line. The other two channels observed the 30.4-nm line of He II. The instrument surveyed much of the celestial sphere during a series of slow rolling maneuvers by the Apollo spacecraft. The experiment operated properly, and usable data were obtained. Study of the distributions of flux seen, and of the ratio 58.4-nm fluxes seen with gas cells full and empty, will refine current understanding of several poorly known properties of the local interstellar medium. Study of the 30.4-nm flux distribution will refine present knowledge of the structure of the earth's plasmasphere.

Bowyer, S.↗
NASA NTRS1977

Static free-fluid electrophoresis in space

The weightless environment onboard spacecraft in drifting flight has provided a unique opportunity to do experiments that cannot be done on the ground. High resolution free-fluid electrophoresis of particles proposed in the late 1960s to take advantage of reduced gravity began with brief experiments done during two Apollo flights. The recent Apollo Soyuz Test Project mission had two major experiments that accomplished the separation of viable biological cells. Experiments now are being planned for the Space Shuttle which will attempt to achieve high resolution of the separated species by using zone electrophoresis. These experiments will return a quantity sufficient for laboratory testing and establish the potential of fractionation and purification of biological materials in space.

Snyder, R. S.↗
NASA NTRS1977

The local interstellar helium density

During the Apollo-Soyuz Test Project, an extreme-ultraviolet telescope observed the region of the sky from which the interstellar medium approaches the sun. The instrument had a tin filter whose bandpass included the 584-A line of neutral helium. The observations set an upper bound for the number density of neutral helium in the local interstellar medium of 0.004 + or - 0.0022 per cu cm, which is significantly lower than previously reported. The stated error is dominated by the present uncertainty in the solar 584-A flux, which is taken to be approximately 200 million photons/sq cm per sec at earth's orbit. The result is not consistent with previous resonant-scattering Ly-alpha observations of interstellar hydrogen passing through the solar system, which generally yield a hydrogen number density of about 0.1 per cu cm, unless interstellar helium is locally depleted below its cosmic abundance. The result is consistent with cosmic abundances if the much lower average hydrogen densities inferred from recent column-density measurements to nearby hot stars are in fact representative of the immediate solar neighborhood.

Freeman, J.↗
NASA NTRS1977

Analysis of results of ASTP experiment in electrophoresis

The Apollo-Soyuz Test Project (ASTP) included an electrophoretic separation experiment of biological cells. The nature separation results of aldehyde-fixed rabbit, human and horse red blood cells, which were taken in the form of photographs taken at three-minute intervals, are the subject of this report. The electrophoretic separation was successful in that fractionation according to mobility did occur and was found in the sliced samples. Photographic evidence indicates that the low electroosmotic methylcellulose coating was successful in reducing the electroosmosis to a near zero value. Also, the flight film shows that the bands migrated down the column as theory would predict, producing two bands of high cell concentration separated and surrounded by regions of lower cell concentration. However, most likely some clumping of cells occurred to cause the trailing band to be larger than expected from theory. Overall, the experiment was a success in demonstrating a static electrophoresis separation under microgravity conditions with a resolution not possible on earth.

Vanderhoff, J. W.↗