spacetoday.net: Shuttle launch postponed

Posted: Sat, Feb 21, 2009, 10:30 AM ET (1530 GMT)

NASA announced late Friday night that it has postponed once again the launch of the shuttle Discovery in order to resolve outstanding issues with a key valve. The agency had hoped to clear Discovery on Friday for a launch February 27 on the STS-119 mission to the ISS. However, by Friday evening shuttle managers concluded that they did not have all the information the needed to resolve concerns about a flow control valve that channels gaseous hydrogen in the shuttle's main engines. A similar valve was damaged on Endeavour on the STS-126 mission last year, and engineers are concerned that any debris that breaks off the valve could damage other engine components. NASA did not set a new target launch date Friday, instead instructing shuttle officials to develop a plan by next Wednesday to resolve the concerns and move ahead. Officials said they hope to be able to launch the shuttle by mid-March, after which time they would have to wait until a Soyuz taxi mission to the ISS finishes in early April.