ISS Science Operations Status Report for week ending Sept. 4, 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.
