Engineers working on the problematic hydrogen flow control valves on space shuttle Discovery have made enough progress that NASA has tentatively set a March 12 launch date for the mission to bring the last set of solar arrays to the International Space Station. NASA said an exact target launch date will be determined as work progresses with the three valves on the shuttle. Launching Discovery in March would allow plans to proceed for the Hubble repair mission, planned for liftoff on May 12 launch with Atlantis, as well as shuttle mission STS-127, also in May. If Discovery is delayed to April, the Hubble flight would slip to around June 2.
At NASA’s Kennedy Space Center in Florida, technicians have started removing Discovery’s three valves, two of which will undergo detailed inspection, looking to identify what caused damage to the valves during Endeavour’s flight in November 2008. Approximately 4,000 images of each valve will be reviewed for evidence of cracks. Valves that have flown fewer times will be installed in Discovery. Engineering teams also will complete analysis and testing to understand the consequences if a valve piece were to break off and strike pressurization lines between the shuttle and external fuel tank. Hardware modifications may be made to the pressurization lines to add extra protection in the unlikely event debris is released.
NASA managers will hold a review on the progress on March 4 and decide if the shuttle will be ready to go for the March 12 date.