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Wednesday, July 2, 1997, 6 p.m. CDT
STS-94 Mission Science Report # 3s

After just 36 hours in orbit, the crew of the Microgravity Science Laboratory mission, along with science teams on the ground, have successfully activated Spacelab’s experiment facilities and are getting down to the primary business of the mission -- to conduct fundamental scientific research in space.

“Everything is where it should be and we’re excited about bringing experiments to a definitive conclusion on this mission,” said Mission Scientist Dr. Mike Robinson with Marshall Space Flight Center in Huntsville, Ala.

This morning, Mission Specialist Dr. Donald Thomas initiated the first of two runs of a diffusion of liquid metals study being conducted in the Large Isothermal Furnace. Diffusion is the process by which liquid metals mix without stirring -- similar to how the smell of baking bread, for instance, spreads from the oven throughout the house. This process cannot be adequately studied on Earth because of fluid movement caused by gravity.

The investigation is a study of the diffusion of impurities in molten salts. The experiment is aimed at determining the diffusion coefficient -- a fundamental quantity which describes the diffusion process -- of the sample. As the first sample began processing, researchers on the ground detected unexpected readings from the sample’s temperature sensor and decided to replace it with a backup sample of the same make-up. Processing of the backup sample has been under way since late this afternoon.

This study, headed by Dr. Tsutomu Yamamura of Tohoku University in Sendai, Japan, is designed to reveal ideal conditions for electrolysis of molten salts. Electrolysis is the use of an electrical current to break down a dissolved substance into its constituent components. Findings may also benefit basic science and engineering processes on Earth.

The blue shift -- Payload Commander Dr. Janice Voss and Payload Specialist Dr. Roger Crouch -- began their 12-hour shift at noon today.

Voss ignited the first flame of the mission’s combustion science experiments this afternoon to begin a study of the properties of soot. This investigation is collecting information on flame shape, the type and amount of soot produced under various conditions and the temperature of soot components.

Researchers say the first flight of the Microgravity Science Laboratory in April gave them a first look at how these soot particles form and allowed them to enhance the experiment for this flight. They are excited about the scientific possibilities this mission will bring.

“Soot is responsible for 4,000 deaths in unwanted fires and 15,000 to 60,000 deaths each year as a pollutant,” said principal investigator Dr. Gerard Faeth, of the University of Michigan in Ann Arbor.

Information gathered from this study may lead to a better understanding of how to contain unwanted fires and limit the number of fatalities from carbon monoxide emissions.

Crouch readied the TEMPUS facility this afternoon for operations. This electromagnetic containerless processing facility will be used to conduct studies of the undercooling and rapid solidification of metals and alloys. Undercooling occurs when a solid is melted into a liquid then cooled below its normal freezing point without solidifying. Gravity’s requirement for a container and its influence on fluid flows make it nearly impossible to conduct these studies on Earth. Findings from this research may improve ground-based techniques processing materials and in turn improve materials and produce.

Crouch then checked out the Middeck Glovebox facility in preparation for a fluid physics study set to begin later this evening. The experiment will examine non-contact and remote manipulation techniques for controlling the position and motion of liquids in low-gravity. Results of the study may find application in improving many important processes used by chemical manufacturing industries on Earth, including the petroleum technology, cosmetics and food sciences industries.

Also ahead, Voss will set up the Droplet Combustion Apparatus for a study of burning fuel droplets. The study is gathering information on burning rates of flames, flame structures and conditions under which flames are extinguished. Results of the investigation will provide researchers with a better understanding of the combustion process and may lead to cleaner, safer ways to burn fossil fuels as well as more efficient methods of generating heat and power on Earth.

The next scheduled Public Affairs status report will be issued at approximately 6 a.m., July 3.


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