Endeavour Launch Likely Off Until May 8

NASA officials say an electrical switching box hooked up to Endeavour's hydraulic power system will have to be replaced, and that likely will push a second launch attempt back to at least May 8.

The Load Control Assembly is in a difficult-to-access part of the shuttle's rear engine compartment, and once it is replaced, it will take at least two days to complete testing on a spare unit.

It's highly unlikely the swap-out and the testing can be completed prior to the planned May 6 launch of an Atlas V rocket with a new-generation missile warning satellite. NASA has until May 4 to launch the shuttle. The next day, the Eastern Range must prepare its tracking and range safety systems for the Atlas launch.