Discovery Finds No Launch Luck

A faulty liquid hydrogen valve forces NASA to delay its second launch attempt of the space shuttle Discovery. NASA is now shooting for an Aug. 28 launch to deliver to International Space Station more than seven tons of supplies, science racks and equipment, as well as additional environmental hardware to sustain six crew members on the orbital outpost.

NASA scrubbed the second launch attempt of the space shuttle Discovery Aug. 26 when a liquid hydrogen valve developed problems during tanking operations. An Aug. 25 launch was scratched when thunderstorms struck the Cape Canaveral area.

The space agency tentatively rescheduled the launch for Aug. 28 at 12:22 a.m. with a second launch window at 11:59 p.m. NASA has set Aug. 30 as the latest launch date for Discovery before standing down due to a conflict with other scheduled missions by Russia and Japan. Mission managers said if Discovery is forced to stand down in August, the next opportunity for a shot at the ISS (International Space Station) will be in October.

The Aug. 26 launch delay occurred when NASA commanded the liquid hydrogen valve to close and did not receive a closed indication. NASA is concerned that the valve is either open or partially open, but the situation needs to be evaluated for confirmation.

"Prudence does dictate that we take a look at it," said Pete Nickolenko, NASA's launch director. Detailed test data about the valve will be examined before Discovery's fuel tank is loaded with propellant ahead of Friday morning's launch attempt.

Unlike previous missions, which have focused on the ongoing construction of the ISS, 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 orbital outpost.

Commanded by veteran astronaut Rick "C.J." Sturckow, the Discovery crew will deliver refrigerator-sized racks full of scientific equipment. When the good 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.