NASA said Sunday they have cleared space shuttle Discovery for liftoff Tuesday, adding that the weather looks promising.

After a meeting on Sunday, managers said the power controller issue — one had to be replaced a week ago in the shuttle — did not stand in the way of the launch.

According to Associated Press, the chairman of the mission management team, Mike Moses, said there is no way of knowing with certainty whether the new power controller in Discovery might break like the old one did.

To minimize the risk of a power failure, some equipment will be left on longer than usual - rather than shutting it down and then turning it back on, he added.

Discovery's six-man, one-woman crew is poised to fly a 13-day resupply mission to the space station.

The astronauts will take up to about 15,200 pounds of new science gear, supplies and spare parts to the orbiting laboratory. Three spacewalks are planned for the mission.