Discovery Overcomes Launch Woes, Blasts Off for ISS
The space shuttle Discovery finally got under way late Aug. 28 for a
resupply mission to the International Space Station. After two postponements-one
for weather and another due to a faulty liquid hydrogen valve-Discovery's midnight launch went smoothly, and the
spacecraft is expected to arrive Aug. 30 at the ISS.
Unlike recent ISS missions, which have focused on the ongoing construction of the orbital outpost, the Discovery mission is primarily focused on delivering more than seven tons of supplies, science racks and equipment, as well as additional environmental hardware to sustain six crew members on the ISS.
Commanded by veteran astronaut Rick "C.J." Sturckow, the Discovery crew will deliver refrigerator-size racks full of scientific equipment. When the goods are delivered, NASA says it will be a "quantum leap" in the scientific capability of the orbital laboratory.
The Discovery's payload includes the Materials Science Research Rack (MSRR-1), the Minus Eighty Degree Laboratory Freezer for ISS (MELFI) and the Fluids Integration Rack (FIR).
MSRR-1 will be used for basic materials research related to metals, alloys, polymers, semiconductors, ceramics, crystals and glasses in the microgravity environment. MELFI will be used for long-term storage of experiment samples that are to be returned to Earth for detailed analysis. The FIR is a fluid physics research facility designed to host investigations in areas such as colloids, gels, bubbles, wetting and capillary action, and phase changes, including boiling and cooling.
Discovery's cargo bay also includes the COLBERT (Combined Operational Load Bearing External Resistance Treadmill) treadmill, an exercise device named after comedian Stephen Colbert. Equipment and science racks for the orbiting laboratory are riding inside the Leonardo cargo module, which is secured tightly inside Discovery's payload bay. The module will be lifted out of Discovery and locked onto the station so the crew can transfer the gear efficiently.
Three spacewalks are scheduled for the 13-day mission.
After thunderstorms in the Cape Canaveral launch area scratched the original Aug. 25 launch date, NASA tried again Aug. 27, but that blastoff also was called off when NASA engineers commanded the liquid hydrogen valve to close and did not receive a closed indication, indicating either a faulty valve or sensor device. Engineers cycled the valve five times Aug. 26 after the launch scratch to collect data on the valve and its associated actuator and position indicator.
After a day of studying the issue, NASA decided the hydrogen value was operating properly and the problem was a faulty sensor.
After reaching the ISS, U.S. astronaut Nicole Stott will trade places with station resident Tim Kopra, who went into space last month aboard Endeavour.