NASA prepared to launch space shuttle Endeavour to the International Space Station on Saturday to deliver a Japanese porch and spare parts needed to keep the outpost going after the shuttle fleet's retirement next year. The space agency planned to begin fueling the ship just after 10 a.m. (1400 GMT) for liftoff from the Kennedy Space Center in Florida at 7:39 p.m. (2339 GMT), Reuters reported. NASA tried twice last month to launch Endeavour, but was stymied by potentially dangerous hydrogen fuel leaks. Engineers discovered a misalignment in a line that vents hydrogen from the fuel tank as it is being filled. Technicians made repairs and tested the work last week. "I have extremely high confidence" in the repair, said Mike Moses, who oversees the shuttle program at the Kennedy Space Center. The only issue may be the weather. Meteorologists on Friday predicted a 60 percent chance that thunderstorms and rain would be too close to the launch site for Endeavour to fly. "I don't worry about things I can't control and I certainly can't control the weather," Moses said.