USML-2 Public Affairs Status Report #12 6:00 a.m. CDT, Oct. 27, 1995 6/21:07 MET Spacelab Mission Operations Control Marshall Space Flight Center "We feel like we're back home at Marshall in the Payload Crew Training Complex," said Mission Specialist Cady Coleman last night, referring to the Marshall Space Flight Center Spacelab mockup where she and her crewmates spent many hours preparing for the second United States Microgravity Laboratory mission. Overnight, Coleman and Payload Specialist Fred Leslie performed now-familiar duties with protein crystal growth and fluid flow experiments, and also tested a new vibration- isolation facility. Coleman completed the mission's first technical demonstration with the Suppression of Transient Acceleration by Levitation Evaluation, or STABLE. Developed cooperatively by the Marshall Space Flight Center and McDonnell Douglas, STABLE is the first facility to use electromagnetic levitation to isolate sensitive experiments from disturbances in the Shuttle. Coleman activated a simple experiment within the levitation device by heating a fluid-filled cell, then observed it with a laser light. To the delight of the science team in Huntsville, the experiment's small optical system recorded the resulting heat diffusion. This experiment, known as "CHUCK," was designed in Marshall's Space Sciences Lab as a small, simple system to study materials processes in microgravity that are applicable to crystal growth mechanics. For the first run, the STABLE platform floated free through the action of electromagnets. The platform was locked in place for a repeat run. Comparisons should help determine the effectiveness of STABLE for reducing background vibrations. Both STABLE and CHUCK were produced in less than five months, from the time designers got the go-ahead for construction this past January until they delivered the equipment to Kennedy Space Center in June. Engineers on these projects were working under a new NASA committment to streamline the development of lower cost space hardware. Later in the shift, Coleman examined growing protein crystals under the Glovebox microscope. Commercial Protein Crystal Growth team members watched downlink video of the magnified crystals from their home lab at the University of Alabama in Birmingham. Coleman reported that the crystals were bigger and seemed to be growing in isolation rather than in clumps. One crystal in particular was so well-formed that the fist look at it elicited applause from the Birmingham team. Coleman then activated more samples of the same proteins based on observations of growth progress thus far. She jokingly told the experiment team that she has given up caffeinated coffee just for them, "since you have to be so careful with these things," referring to the delicate handling required for protein crystals. The Glovebox protein crystal growth evaluation is one of several USML-2 experiments aimed at determining the best methods for growing protein crystals. In the middeck, the European Space Agency's Advanced Protein Crystallization Facility is growing protein crystals by three different methods. An internal camera is recording video images of the growing crystals. After the mission, researchers will study development of the crystals in microgravity to determine why and how proteins nucleate and begin to form crystals. A decade of Shuttle protein crystal growth experiments has led to improved methods for ground-based experiments, as well as producing well-ordered crystals which have allowed the structures of several proteins to be determined. Understanding the structures of proteins, such as those related to diseases, is important for developing custom- tailored molecules, such as drugs, to interact with them. As has been true for the majority of the mission, Leslie spent most of his shift working with the Surface Tension Driven Convection Experiment. The Lewis Research Center investigation is gathering extyensive new data on subtle fluid flows created by surface temperature variations. In a typical operation, Leslie drew down the volume of silicone oil within a 1-1/4 inch (3 centimeter) cylinder until it formed a deeply concave surface -- a surface shape possible only in microgravity with a container this large . Leslie heated the fluid, first very steadily, and again in several pronounced steps. The Case Western Reserve University science team reported seeing distinct differences in the heating power levels at which fluid flows became unsteady, or began to oscillate, with the two heating scenarios. A thorough understanding of fluid physics forms a valuable base for improvements in sophisticated materials processing. Also last night, Coleman reset a Drop Physics Module circuit breaker which tripped yesterday when some film jammed, and the facility is ready for experiment operations later today. More Surface Tension Driven Convection Experiment runs are also scheduled. Growth of a gallium arsenide semiconductor within the Crystal Growth Furnace will continue until early tomorrow morning. Status reports are issued from Johnson Space Center's Mission Control at 8 a.m. and 5 p.m.; and from Marshall Space Flight Center's Spacelab Mission Operations Control at 6 a.m. and 6 p.m. weekdays, 6 a.m. on weekends. For additional information, see the Internet USML-2 payload homepage, http://liftoff.msfc.nasa.gov/spacelab/usml2/welcome.html and the STS-73 Shuttle homepage, http://shuttle.nasa.gov