IML-2 STATUS REPORT #11 IML-2 Public Affairs Status Report #11 6:00 p.m. CDT, July 13, 1994 5/6:17 MET Spacelab Mission Operations Control Marshall Space Flight Center IML-2 Payload Specialist Chiaki Mukai and Payload Commander Rick Hieb both got four hours off today, but a full slate of experiment activities continued in orbit and at Spacelab Mission Operations Control in Huntsville. Several IML-2 experiment facilities are being controlled extensively from the ground. This remote commanding capability, called "telescience," multiplies valuable time in orbit because it frees the crew for experiment operations where their hands and eyes are indispensable. "With this amount of science squeezed into a 14-day mission, it is critical to have both the telescience and the remote operations," said Mission Scientist Dr. Bob Snyder, referring to science experiment teams at the Huntsville facility and user support groups at remote sites in Europe and Japan. Critical Point Facility team members in Huntsville examined live video of an experiment that studies how energy is transported within a single-component fluid. Near the critical point - the precise combination of temperature and pressure where liquid and vapor phases coexist - fluids exhibit unusual properties. For instance, energy transport by heat diffusion slows down, while transport driven by changes in pressure speeds up. Dr. Richard Ferrell of the University of Maryland is using two test cells during IML-2 to study the different forces. Today's experiment focuses on pressure changes. Tiny temperature changes are being induced both by external heaters and by heat from a pulse of current passing through a resistance wire inside the cell. An experiment to study heat diffusion is scheduled for Friday. In addition to enhancing fundamental knowledge of fluid physics, Ferrell's experiments should aid the design of other low-gravity, critical point investigations. To plan accurate timelines for their experiments, space researchers need to know how quickly their samples will reach thermal equilibrium after temperature step changes near the critical point. Close cooperation between ground controllers and the crew has become a routine part of operations in the TEMPUS electromagnetic containerless processing facility. Hieb kept a close eye on a zirconium-cobalt alloy as the TEMPUS team sent commands to levitate, then melt, the small metal sphere inside the TEMPUS processing chamber. "The sample looks extremely stable today," the astronaut reported. The TEMPUS team used remote commands to skillfully control their sample, reflecting the experience they have gained over several days of operating the new space facility. They applied short, repetitive bursts of heat to the alloy, causing its temperature to rise and fall. Dr. Hans J. Fecht of the Technical University of Berlin, Germany, will study the length of time it took for the addition or subtraction of heat to be reflected in the sample temperature. He will then factor the results into a new mathematical model to determine the alloy's specific heat capacity. Fecht and Dr. William L. Johnson of California Institute of Technology are using several zirconium alloys during this mission to study the formation of metallic glasses. With their unique mechanical and physical properties, metallic glasses have promising applications in many technological areas. After transferring numerous Biorack sample containers between storage and coolers, Hieb changed out food trays for the fruit flies in Dr. Roberto Marco's experiment. He reported the flies were "buzzing around with excellent vitality." Along with the other Biorack principal investigators, Marco is conducting his experiment at Kennedy Space Center in parallel with operations in space. Project Scientist Dr. Enno Brinckmann, the Biorack team's representative at Spacelab Control in Huntsville, said, "Dr. Marco tells us the flies in space have been more mobile than their counterparts on the ground at Kennedy." Marco's study tests his theory that premature aging of flies in previous space experiments is due to increased activity as they attempt to move in microgravity. Thus far, 10 of the 19 Biorack experiments are complete. Mukai began her work this afternoon with a run of the NIZEMI Slow-Rotating Centrifuge Microscope's cress root experiment. "All of the seeds have germinated," she told Principal Investigator Dr. Dieter Volkmann of the University of Bonn. Scientists have studied the cress plant intensively over the last 20 years to determine in detail how it can perceive and react to gravity. Previous experiments indicate it can respond to gravity changes very quickly. Volkmann hopes to pinpoint the minimum amount of gravity to which it will respond and how long it to takes to respond. Before plants can be considered as possible sources of food or oxygen in space, scientists must thoroughly understand how changes in gravity affect plant growth. When Hieb brought the Free Flow Electrophoresis experiment up for its first operations of the mission this morning, readouts indicated that the inner cooling system line was not functioning correctly. The Japanese life sciences team postponed the electrophoresis experiment Mukai had been scheduled to run this afternoon until the source of the problem can be isolated and corrected. In the meantime, Mukai began operations of Japan's Large Isothermal Furnace, originally scheduled for Saturday afternoon. After powering up the facility, she inserted an experiment by Dr. Randall M. German of Pennsylvania State for several hours of automatic processing. The experiment will study how gravity changes heavy alloys during liquid phase sintering. Sintering is a process for combining dissimilar metals, using heat and pressure to join them without reaching the melting point of one or both metals. The upcoming shift includes the mission's first electrophoresis experiment in the French RAMSES facility and its second Bubble, Drop and Particle Unit investigation. NASA issues four status reports daily on STS-65/IML-2 activities: science operations reports from Spacelab Mission Operations Control in Huntsville at approximately 6 a.m. and 6 p.m., and orbiter operations reports from Mission Control in Houston at approximately 8 a.m. and 5 p.m.