Dec 24 1985
From The Space Library
Marshall Space Flight Center (MSFC) announced preliminary scientific results from Spacelab 3 flown on the Space Shuttle Challenger on mission 51-B launched April 29, 1985. Researchers and participants in the seven-day flight gathered in December at the Center to present their initial findings.
“The mission has made some major contributions in the physical and life sciences,” said Dr. George Fichtl of MSFC's Systems Dynamics Laboratory.
“We have gained a lot of insight for future Spacelab and space station re- search. And I think we can now say that space research is becoming routine.” Initial results from the three Spacelab 3 crystal growth experiments were very promising, Ficthl noted. The two triglycine sulfate crystals and the single mercuric iodide crystal grown in the space laboratory were at least as good as the best crystals grown to date on earth. And they might actually be better, although additional testing was necessary to confirm this, Fichtl said. “This is of major significance, because normally we must grow between one and two thousand crystals on earth to get just one crystal that is equal to the quality of those grown on Spacelab 3. Mercuric iodide crystals have application in X-ray detectors, and triglycine sulfate crystals are used in infrared detectors,” he said.
In addition, the flight proved the reliability of the methods used to grow the crystals. Triglycine sulfate crystals were grown from a solution as part of an experiment provided by Alabama A&M University. The mercuric iodide crystal grew using a vapor transport process in an experiment provided by EG&G Energy Measurements Inc.
The third crystal growth experiment, provided by France and which also used mercuric iodide, performed as expected and added to researchers knowledge about the process of crystal nucleation, a process difficult to study on earth because of gravity-induced convection.
The Drop Dynamics Module, a fluid physics experiment developed by the Jet Propulsion Laboratory, enabled researchers to do some experiments not possible on earth. Results confirmed some of the theories on how drops behaved when rotated, the first opportunity to test theories posed centuries ago including those by Isaac Newton. The experiment also proved that using sound waves was a viable technique for manipulating liquids in a microgravity environment, which had direct application to containerless materials processing in space. The technique allowed processing of materials without incurring the contaminating effects of the container. The experiment showed that the “acoustic bottle” or “crucible of sound” containing the droplet had much better characteristics than originally theorized.
Drop dynamics experiments confirmed theories on how drops behaved when rotated slowly; however, experiment data showed violation of some basic theories relating to the behavior of drops rotated at higher rates. It was found, for example, that drops tended to transition (change) to a new shape at rotation rates lower than predicted. “All this tends to indicate that some of our theories may need to be modified,” Fichtl said.
Researchers for the Geophysical Fluid Flow Cell Experiment reported that all 102 hours of data looked good, confirming existing theories of convection, and were expected to lead to a better understanding of the dynamics of stellar interiors and planetary atmosphere. However, the research team noted that at higher heating rates-such as those that might be found on the sun-the data showed some significant departures from that anticipated. After the mission, researchers developed computer models of some of this new information.
The Atmospheric Trace Molecules Spectroscopy (ATMOS) experiment, sponsored by the Jet Propulsion Laboratory, for the first time simultaneously measured the concentrations of chemical compounds associated with carbon, nitrogen, oxygen, and other chemical cycles in the atmosphere. This would provide better insight into the chemical processes that governed the distribution of minor and trace gases in the atmosphere between 10 and 100 kilometers. The instrument recorded concentrations of gases as low as parts per 100 billion, the first time such sensitive measurements were made, and detected and measured traces of nitrogen pentoxide, a compound previously undetected in the atmosphere.
Results from the Research Animal Holding Facility showed that the apparent case of space adaptation syndrome in one of the monkeys supported the contention that this species would be a good model for future studies of vestibular adaptation in microgravity. Results from studies of the largest group of rats flown aboard a single spacecraft showed their hind muscles became 11 to 36% smaller and the bones were less strong after their flight. (MSFC Release 85-73)
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