NASA will try again Wednesday to launch the space shuttle Endeavour to the International Space Station, avoiding an end-of-mission conflict with an upcoming Russian resupply mission by undocking early to get out of the way.
Space station planners believe they can still accomplish all mission objectives by moving some cleanup and crew time off until after the orbiter undocks from the station. But if a Wednesday launch doesn't work out they may remove some mission objectives to permit a launch as late as Thursday.
Senior agency managers asked their Russian counterparts to delay the Progress docking after its scheduled July 24 launch to allow a later shuttle launch, according to Mission Management Team chairman Mike Moses. But the Russians were already limited in the amount of time they could loiter before docking, and said no to preserve a single contingency day beyond the four days already being used.
"They were willing to play ball, Moses said.
Crews at Kennedy Space Center will use Tuesday to reattach a temporary thruster cover that had come loose, which will require closing the rotating service structure at Pad 39A back around the orbiter. Launch on Wednesday is set for 6:03 p.m. EDT.
A launch attempt Monday was scrubbed, marking the third time since Saturday the STS-127 mission was delayed by summer thunderstorm at the Florida launch site.