Thunderstorms are threatening to delay NASA's planned launch Saturday of space shuttle Endeavour.

Endeavour is back from a series of hydrogen gas leaks for a third launch attempt. But forecasters say there is a 60-percent chance that storms could force a postponement.

Launch manager Mike Moses said Friday that he's not worrying about the weather since there's nothing he can do about it, even if his name is Moses.

Endeavour is a full month late in blasting off to the international space station. The shuttle and its crew will deliver and install the third and final piece of Japan's huge space station lab.

Seven shuttle astronauts plus six station residents will make for the biggest crowd ever in orbit.