Published: Nov 05, 2010 7:23 PM EDT
Updated: Nov 05, 2010 4:21 PM EDT

CAPE CANAVERAL, Fla. (AP) - Space shuttle Discovery's final voyage was postponed Friday until the end of the month so NASA can fix a fuel leak.

It's the fourth delay in a week for Discovery's mission to the International Space Station with six veteran astronauts and the first humanoid robot bound for orbit.

NASA tried to launch Discovery on Friday, but a potentially dangerous hydrogen gas leak cropped up midway through the fueling process and the countdown was halted.

The launch was initially put off until at least Monday. But by early afternoon, it was clear that more time was needed to fix the problem on the fuel tank.

NASA is now targeting Nov. 30 for Discovery's final liftoff. The space agency has to wait until then because of unacceptable solar angles for most of November. Those sun angles would cause the shuttle to overheat while docked to the station.