IML-2 Status Report #21 IML-2 Public Affairs Status Report #21 6:00 p.m. CDT, July 18, 1994 10/6:17 MET Spacelab Mission Operations Control Marshall Space Flight Center International teams of scientists in space and on the ground worked together to make the most of research opportunities as the IML-2 Spacelab mission entered its eleventh day in orbit. Payload Specialist Chiaki Mukai and Payload Commander Rick Hieb finished their fourth Lower Body Negative Pressure test today. As part of their natural adaptation to microgravity, space travelers experience a shift of fluid into their upper body. This experiment reduces pressure around a crew member's lower body to force fluids back to the legs. Echocardiograph and blood pressure tests made during various steps of lowered pressure show scientists how the crew member's cardiovascular system has adapted to microgravity. The experiment is part of the Johnson Space Center's Extended Duration Orbiter Medical Program, designed to protect the health and safety of the crew during 12- to 17-day missions aboard the Space Shuttle. Dr. Dieter Volkmann of Bonn, Germany, continued using the NIZEMI Slow Rotating Centrifuge Microscope to compare cress roots grown in microgravity with those grown in the Biorack centrifuge. The samples are being exposed to one-tenth of Earth's gravity on the NIZEMI centrifuge. "Thus far, we have observed a difference in gravity sensitivity between the microgravity samples and the one-gravity samples. That's a first," said Volkmann. "The microgravity roots responded in six minutes, while samples grown in the one- gravity centrifuge took 10 minutes." Volkmann will study the preserved roots after landing to pinpoint the structures within them that perceive low-level gravity. IML-2 controllers adjusted today's planned schedule to allow Mukai to perform the mission's second experiment in the Free Flow Electrophoresis Unit. The Japanese space agency experiment team says the facility has been "doing great" since Payload Commander Rick Hieb completed a successful maintenance procedure yesterday afternoon. The FFEU experiment, developed by Principal Investigator Dr. Wes Hymer, of Pennsylvania State University, examines rat pituitary cells. "Previous space flights have shown that the 'factory' which leads to the production of growth hormone is modified in space," said Hymer. "We are trying to find out whether the change occurs on the surface of the cell itself or on the surface of an individual growth-hormone-containing particle within the cell." When Mukai removed the cell culture kit from the incubator, she reported that a majority of the cells had come loose from the bottom of the container and were clumping together. She went ahead with the planned procedure for separating the sample into individual cells, but they remained clumped. Since unattached cells are required for electrophoresis, she returned the culture kits to storage. "The same procedures were done on identical cell cultures at Kennedy Space Center, and this did not happen," said Hymer. "It will take some time to determine whether flight factors caused the unexpected clumping." The second part of Hymer's experiment, which studies cells broken down into their individual sub-cellular components, will be conducted if a time slot becomes available on the next shift. Dr. Shankar Subramanian of Clarkson University in Potsdam, New York, expanded his study of the interactions and migration of liquid drops in the Bubble, Drop and Particle Unit. For this experiment run, multiple drops are being injected into a container of silicone oil. Subramanian and his team are studying the drops' size, shape and speed of motion. The team will compare the observations with their calculations predicting the motion of drops in microgravity. This afternoon's Large Isothermal Furnace experiment evaluates a technique for improving the quality of alloys used in high-tech aircraft and spacecraft. Hieb placed a cartridge containing four titanium-aluminum alloys into the furnace to be melted and solidified. Two of the samples have ceramic particles added. The particles should increase the high-temperature strength of the material, improving its microstructure and thus its mechanical properties. On Earth, differences in density between the ceramic particles and the metal alloy keep the particles from distributing uniformly, but in space they should remain spread evenly within the samples. Dr. Masao Takeyama of Japan's Research Institute of Metals will compare the processed alloys to determine whether addition of ceramic particles is an effective method for controlling alloy structure. Hieb provided additional video of the fruit flies in Dr. Roberto Marco's Biorack experiment. Marco, who is conducting parallel experiments at Kennedy Space Center, reports the IML-2 flies appear to be adapting to microgravity. After greatly accelerated activity near the beginning of the mission, their current behavior is about the same as flies in Biorack's simulated gravity centrifuge in space and in his control experiment on the ground. This confirms a similar observation aboard the Russian BION-10 satellite in 1993. Mukai reported that the Animal Aquatic Experiment Unit seems to be working well, and the Medaka fish all appear to be healthy. A procedure has been designed to remove the newt which died last night from one of the four aquarium cassettes, so decomposition products will not get into the system's water loops. It will be carried out tonight, and the newt will be frozen to preserve it for analysis after landing. Newt eggs which were launched inside the cassette will remain to continue development. The eight principal investigators for the TEMPUS electromagnetic containerless processing facility shared brief observations of a one-quarter- inch sphere of pure nickel. They commanded operations from the ground, in order to give the crew more time for other experiment activities. The thermal equilibration experiment in the Critical Point Facility, which began Saturday, will continue throughout the night. The crew will work with Biorack, RAMSES electrophoresis separation facility, and Bubble, Drop and Particle Unit experiments. 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.