NATIONAL BRIEFING / FLORIDA

NASA cleared space shuttle Discovery for liftoff Tuesday, and the weather looks promising as long as thunderstorms stay away from Cape Canaveral during fueling.

Managers decided that Discovery is in good shape to fly to the International Space Station. A power controller issue -- one had to be replaced a week ago in the shuttle -- did not stand in the way of the launch. Forecasters said there was an 80% chance the weather would cooperate for Discovery’s 1:36 a.m. liftoff. That’s better than previous forecasts.

But there is a 40% chance that thunderstorms could interfere with this afternoon’s fueling. A fueling delay of more than three hours would bump the flight into the next day.

Discovery and seven astronauts will deliver about 17,000 pounds of space station supplies and equipment. Three spacewalks are planned during the 13-day flight.