Discovery Launch Pushed To February

The long-postponed final mission for the space shuttle Discovery has been postponed again.

This time it was until February of next year.

The delay will give engineers an opporunity determine the root cause of perplexing cracks in the shuttle’s 15-story external tank.

The Japanese cargo carrier will have to be moved from an initial docking port to another on the U.S. side of the station to clear the way for Discovery and its crew. The move opens up the possibility of launching during the early February window. The next opportunity after that would be a window that opens on Feb. 27.

Endeavour had been slated to launch Feb. 27. But its mission to deliver a large particle physics experiment to the station now will be pushed back to April 1.

Congress has approved one additional shuttle flight to the station, but money for that mission has not yet been appropriated. That mission still is being targeted for launch June 28.

NASA had been targeting launch for a short window that opens Dec. 17 and closes Dec. 20. Managers determined that tests and analyses intended to determine the cause of the cracks would not be complete in time to launch during that last 2010 opportunity.

Discovery’s flight had been slated for launch Nov. 1 but faced a series of technical problems. A Nov. 5 launch attempt was scrubbed as a result of a gaseous hydrogen leak during external tank propellant-loading operations. Cracks in foam insulation on the tank were subsequently found, and then engineers discovered cracks in metal braces beneath the foam.

Engineers still have not determined the cause of the cracks. The concern is that the crack could cause foam insulation to break loose during launch and damage the shuttle’s heat-shield components.