August 27, 2009

John Yembrick
Headquarters, Washington
202-358-1100


Allard Beutel
Kennedy Space Center, Fla.
321-867-2468


RELEASE: 09-200

NASA DELAYS SPACE SHUTTLE DISCOVERY LAUNCH

CAPE CANAVERAL, Fla. -- NASA managers postponed Friday's 12:22 a.m.
EDT launch of space shuttle Discovery to allow engineers more time to
develop plans for resolving an issue with a valve in the shuttle's
main propulsion system. Launch now is targeted for no earlier than
11:59 p.m. Friday, Aug. 28, from NASA's Kennedy Space Center in
Florida.

During loading of the shuttle's external fuel tank for Wednesday's
launch attempt, a liquid hydrogen fill and drain valve located in
Discovery's aft compartment failed to provide the proper indication
when it was commanded to close. Engineers cycled the valve five times
Wednesday evening to collect data on the valve and its associated
actuator and position indicator.

NASA managers decided Thursday that more time is needed to analyze the
test data and develop alternative procedures for confirming that the
valve is closed if the valve fails to provide the proper closed
indication during Discovery's next launch attempt.

Discovery's 13-day STS-128 flight to the International Space Station
will deliver storage racks; materials and fluids science racks; a
freezer to store research samples; a new sleeping compartment; an air
purification system; and a treadmill named after comedian Stephen
Colbert.

For information about the space station, visit:

http://www.nasa.gov/station

For the latest information about the STS-128 mission and its crew,
visit:

http://www.nasa.gov/shuttle

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