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This is NASA's press kit for Space Shuttle mission STS-75, dated February 1996 and later edited by Richard W. Orloff. It covers Columbia's planned 13-day flight carrying the Italian Tethered Satellite System reflight (TSS-1R) and the third United States Microgravity Payload. The kit sets out launch and landing plans, abort modes, the timeline, payload weights, crew duties, the tether's science objectives and investigators, and crew biographies. It does not mention any unidentified objects.
Edited by Richard W. Orloff, 01/2001/Page 22 UNITED STATES MICROGRAVITY PAYLOAD-3 (USMP-3) USMP-3 Science Once on orbit, crew members will activate the USMP-3 experiment hardware, while science teams in the Science Operations Area of Marshall's Spacelab Mission Operations Control watch preliminary data, awaiting their turn as primary payload following TSS operations. Science teams will monitor and adjust experiments as necessary, based on data downlinked from Columbia. Cargo Bay Experiments Advanced Automated Directional Solidification Furnace (AADSF) Principal Investigator: Dr. Archibald L. Fripp, NASA Langley Research Center, Langley, VA Objective. The speed and the amount of information that can be stored and sent by computers and high- tech electronics, using sophisticated semiconductor materials, may be increased by better control of how the semiconductor's structure forms. Millions of dollars are invested each year in ground-based research to reach this goal. The Advanced Automated Directional Solidification Furnace (AADSF) will fly again on USMP-3 to expand upon findings from USMP-2 to help researchers develop processes and materials that perform better and cost less to produce. A semiconductor's usefulness is determined by how atoms are ordered within the crystals underlying three- dimensional structure. These materials, when produced under the influence of gravity, often suffer structural damage that limits the crystal's usefulness. A warm fluid is less dense than a cooler sample of the same fluid, and on Earth, gravity causes the cooler, denser material to sink while the warmer fluid rises. Flows caused by this process, known as buoyancy-induced convection, as well as another undesirable phenomenon sedimentation are greatly reduced in the Shuttle's orbiting microgravity laboratory. The effects of gravity on the orbiting spacecraft are roughly a million times less than experienced on the ground. Procedure. During USMP-3, the AADSF will be used to grow a crystal of lead-tin-telluride (PbSnTe), a material used to make infrared radiation detectors and lasers. This will be done by the technique known as directional solidification. This method involves cooling a molten material, causing a solid to form at one end of the sample. The solidification region grows at the point where the solid and liquid meet, known as the solid/liquid interface. This interface is moved from one end of the sample to the other at a controlled rate, resulting in a high degree of crystalline perfection. The facility has multiple temperature zones, ranging from extremely hot above the melting point of the material (about 1600 degrees Fahrenheit/870 Celsius) to cooler zones below the melting point (about 650 degrees Fahrenheit/340 Celsius). Once a region of the crystal is melted, the sample is slowly moved and directional solidification takes place. The solid/liquid interface is where the flows in the molten material influence the final composition and structure of the crystal sample. After the mission, scientists will analyze the solidified sample to determine the density of defects and the distribution of elements in the crystal.
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