Endeavour Launch Off Until At Least Next Sunday

NASA is pushing back the last launch of Endeavour to at least next Sunday and perhaps May 10 so a faulty electronic switch box that routes power to critical systems can be replaced.

The launch time Sunday would be 12:09 p.m., and a May 10 liftoff would occur at 11:21 a.m. A launch attempt on May 9 is not a possibility because Endeavour and a Russian Soyuz with an Earthbound crew both would have to depart the outpost on May 23.

NASA and its international partners don't schedule same-day departures of different vehicles because the onboard station crew would have to work during what normally would be a sleep shift.

NASA had hoped to launch Endeavour on Monday. But it became clear that the switch box would have to be replaced, and the work could not have been completed in time to launch prior to a planned Atlas rocket flight on Friday.

The United Launch Alliance Atlas V rocket is scheduled to blast off from Launch Complex 41 at Cape Canaveral Air Force Station at 2:14 p.m. Friday. Sunday May 8 represents the first opportunity after the Atlas launch to fly the shuttle.

An initial launch attempt was scrapped Friday after heaters on one of the shuttle's Auxiliary Power Units failed. The problem was traced to the switch box, which will be replaced early this week. The testing of a spare switch box is expected to take an additional two days.