From: ISS Science Operations News
Posted: Thursday, September 5, 2002
Research that could lead to electronic materials with improved opto-electronic properties was set to resume today aboard the International Space Station.
Flight Engineer Peggy Whitson was scheduled to install a sample and initiate the sixth test of the Solidification Using a Baffle in Sealed Ampoules (SUBSA) experiment. SUBSA is investigating semiconductor manufacturing processes. Materials scientists want to make better semiconductor crystals to be able to further reduce the size of high-tech devices. Semiconductor crystals are found in computer chips, sensors for medical imaging equipment and detectors of nuclear radiation. Impurities, or dopants, in semiconductors are used to control their properties. Uniform distribution of the dopant is essential to achieve the desired properties. The goal of SUBSA is to identify what causes the motion in melted materials processed in space and to reduce the magnitude of the motion so that it does not interfere with semiconductor production.
SUBSA research was suspended last month after a quartz sample tube cracked during heating. Operations resumed following a safety review by the science team on the ground and cleanup work by Whitson inside the Microgravity Science Glovebox, where the SUBSA experiment is located. Additional SUBSA experiments are tentatively planned for September 10, 11 and 15.
On Friday and Saturday, August 30-31, Whitson replaced the smoke detector in EXPRESS Rack 2. The rack remained powered off this week due to an electrical grounding strap broken during the changeout. There are no active payloads in the rack currently. The payload operations team is looking at replacing the strap. A plan is in place to make a strap onboard out of two system rack straps that could be used until a new strap is launched on a future Shuttle mission.
Also today, selected crewmembers were scheduled to participate in the Crew Interactions experiment, which examines interpersonal factors that can affect the performance of the crew and ground support personnel during long missions. Participating crew fill out the questionnaire on the Human Research Facility laptop computer.
Photography subjects for the Crew Earth Observations project this week included: lakes recently built on the Euphrates River in southwestern Turkey, air quality in the Western Mediterranean, Seattle and Dallas in the United States, Lake Eyre in Australia, the Toshka Lakes of Egypt, fires burning in Angola, air quality in Southeast Africa and the lower Amazon River Basin.
Automated experiments involving biological materials, space construction materials, the station's vibration environment, and plant growth continued to function well aboard the Station, while liver cell, petroleum processing and drug delivery experiments have been completed and are stored for return to scientists on Earth. The crew continued its daily payload status checks to make sure that all experiments and payload facilities continue to operate properly.
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