Nasa called off today's launch attempt for space shuttle Endeavour because of another hydrogen gas leak.
The space station construction mission is now postponed until July.
It's the same type of leak that cropped up on Saturday during fuelling, in the hydrogen gas vent line that connects to the external tank.
Managers ordered repairs similar to those carried out in March, when a similar leak halted a shuttle flight. The repairs did not work this time.
Nasa was already running three hours behind because of thunderstorms that delayed fuelling last night. The leak did not appear until early today.
Nasa had postponed an unmanned moon launch to give Endeavour one last chance of launching before a thermal blackout period kicks in.Reuse content