Sunday, February 22, 2009
NASA announced during a press conference on Friday night that the agency has decided to delay the launch of Space Shuttle Discovery, which was scheduled for takeoff on February 27. NASA cited the need for additional time to evaluate the shuttle’s hydrogen fuel flow control valves. A new launch date has yet to be scheduled, though NASA is considering mid-March as an option. Another review of Discovery’s flight readiness is scheduled for February 25.
Discovery had originally been scheduled for liftoff on February 12, but NASA wanted to perform additional tests on the valves which control the amount of hydrogen fuel pumped into the external tank when the shuttle is taking off. When Space Shuttle Endeavour went into space in November 2008, one of the valves broke. NASA fears that if one breaks off on this mission, then it could damage the outside of the shuttle.
“We need to complete more work to have a better understanding before flying,” said Bill Gerstenmaier, associate administrator for Space Operations at NASA Headquarters in Washington, D.C. who chaired Friday’s Flight Readiness Review. “We were not driven by schedule pressure and did the right thing. When we fly, we want to do so with full confidence.”
The current scheduled mission, STS-119, is set to fly the Integrated Truss Structure segment (“S” for starboard, the right side of the station, and “6” for its place at the very end of the starboard truss) and install the final set of power-generating solar arrays to the International Space Station. The arrays consist of two 115-foot-long arrays, for a total wing span of 240 feet, including the equipment that connects the two halves and allows them to twist as they track the sun. Altogether, the four sets of arrays can generate 84 to 120 kilowatts of electricity – enough to provide power for more than 40 average homes.
Commander Lee Archambault will lead Discovery’s crew of seven, along with Pilot Tony Antonelli, and Mission Specialists Joseph Acaba, John Phillips, Steve Swanson, Richard Arnold, and Japan Aerospace Exploration Agency astronaut Koichi Wakata.