NSSDCA ID: 1973-027A-57
Mission Name: SkylabThe Skylab multipurpose electric furnace system provided a means to perform experiments on solidification, crystal growth and other processes involving phase changes in materials. The furnace system was used to perform experiments involving phase changes at elevated temperatures in systems comprising selected combinations of solid, liquid, and vapor phases. Because of the near zero gravity aboard Skylab, the liquid and vapor phases were essentially quiescent and phases of different density had little or no tendancy to separate. The system consisted of three main parts -- the furnace, designed to interface with the M512 (73-027A-39) materials processing facility, a programmable electronic temperature controller which controlled the temperature levels in the furnace, and experiment cartridges which contained the sample materials. The furnace had three specimen cavities so that three material samples could be processed in a single run. The furnace was constructed to provide three different temperature zones along the length of each sample cavity, as follows -- a constant temperture hot zone at the end of the sample cavity where temperature up to 1,000 deg c (1,832 deg f) could be reached, a gradient zone next to the hot zone where temperature gradients ranging from 20 deg c (63 deg f) to 200 deg c (392 deg f) per centimeter could be established in the samples, and a cool zone in which heat conducted along the samples were rejected by radiation to a conducting path that carried the heat out of the system. Each sample of material was enclosed in a cartridge in which the actual temperature distribution applied to the sample was controlled by the thermal design of the cartridge. The control package provided active control of the furnace temperature. It was set to any specified temperature within the furnace's capability by the astronaut operating the system. Two timing circuits in the controller enabled the astronaut to program the soak time spent at the set temperature and the cooling rate of the furnace at the end of the soak period. Active temperature control continued during programmed cooling. Once the specimens were installed in the furnace and the system activated by the astronauts, the system operated automatically except for complete system shutdown. The material cartridges were returned to earth for examination. The experiment equipment was comprised of the furnace, control package, and 33 cartridges (11 experiment sets), cables to inter-connect the system and to connect the system to power and data outlets, two cartridge containers, a tube of thermal grease, and a cartridge extraction tool. The 11 experiments which used the multipurpose electric furnace and the objectives where -- (1) vapor growth of II-VI compounds (M556) - to determine the degree of improvement that can be obtained in the perfection and chemical hemogeneity of crystals grown by chemical vapor transport under weightless conditions in space, (2) immiscible alloy compositions (M557) - to determine the effects of near-zero gravity on the processing of materials compositions which normally segregate on earth, (3) radioactive tracer diffusion (M558) - to measure self-diffusion and impurity diffusion effects in liquid metals in space flight and characterize the disturbing effects, if any, due to spacecraft acceleration, (4) microsegregation in germanium (M559) - to determine the degrees of microsegregation of doping impurities in germanium caused by convectionless directional solification under conditions of weightlessness, (5) growth of spherical crystals (M560) - to grow doped germanium crystals of high chemical homogeneity structural perfection and study their resulting physical properties in comparison with theoretical values for ideal crystals, (6) whisker-reinforced composites (M561) - to produce void-free samples of silver reinforced with oriented silicon carbide whiskers, (7) indium antimonide crystals (M562) - to produce doped semiconductor crystals of high chemical homogeneity and structural perfection and to evaluate the influence of weightlessness in attaining these properties, (8) mixed III-V crystal growth (M563) - to determine how weightlessness affects directional solidification of binary semiconductor alloys and, if single crystals were obtained, to determine how their semi-conducting properties depend on alloy composition, (9) metal and halide eutectics (M564) - to produce highly continuous controlled structures in samples of the fiber-like sodium flouride-sodium chloride and plate-like bismuth-cadmium and lead-tim eutectics, and to measure their physical properties, (1) silver grids melted in space (M565) - to determine the effects of weightlessness on the formation of lamellar structure in eutectic alloys when diectionally solidifed.
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Name | Role | Original Affiliation | |
---|---|---|---|
Mr. Earl A. Hasemeyer | Other Investigator | NASA Marshall Space Flight Center | |
Dr. H. Walter | Other Investigator | University of Alabama | |
Dr. T. Kawada | Other Investigator | National Research Institute | |
Dr. Anthony Onu Ukanwa | Other Investigator | NASA Marshall Space Flight Center | |
Dr. F. A. Padavani | Other Investigator | Texas Instruments Corporation | |
Mr. J. L. Reger | Other Investigator | TRW Systems Group | |
Dr. William R. Wilcox | Other Investigator | University of Southern California | wilcox@clarkson.edu |
Dr. August F. Witt | Other Investigator | Massachusetts Institute of Technology | |
Dr. Harry C. Gatos | Other Investigator | Massachusetts Institute of Technology | |
Dr. Alfred S. Yue | Other Investigator | University of California, Los Angeles | |
Dr. A. Deruytherre | Other Investigator | Catholic University of Belgium | |
Dr. Heribert Wiedemeier | Principal Investigator | Rensselaer Polytechnic Institute | wiedeh@rpi.edu |