The doors to Discovery's payload bay were shut, the first step in a landing attempt. The astronauts planned to don their orange spacesuits as they aimed for a 9:14 a.m. EDT landing at the Kennedy Space Center. A second opportunity was possible at 10:50 a.m. EDT.

When Mission Control woke up the astronauts just after 1 a.m. EDT, Discovery commander Steve Lindsey made it clear that his crew, weary after a 13-day mission that he said was the busiest of his four fights, wanted to come.

"Hopefully, with good weather we will be on the ground" later Monday, Lindsey told Mission Control as he woke up.

The weather forecast improved Monday morning at the Kennedy Space Center in Florida, the only landing site NASA has called up for the day. Rain clouds to the north had been forecast to dip south, but astronauts doing reconnaissance weather flights reported few problems.

The landing rules say rain has to be 30 miles away because rain could damage the shuttle's tiles.

NASA's spaceflight meteorology group had predicted scattered Monday morning showers and storms, with worse weather Tuesday.

Landing officials have to make a "go-no-go" decision for the first landing try at 7:47 a.m. EDT.

On that first landing attempt, Discovery would fly to Florida from the south, coming over the Yucatan Peninsula, pass by the western tip of Cuba and into Kennedy. This would be the first landing at Kennedy in nearly four years. Last year's flight of Discovery, after weather delays, came down at Edwards Air Force Base in California, the backup site.

If Discovery can't land at Kennedy on Monday, NASA will call up Edwards and try to land at either location Tuesday, weather permitting, landing director Steve Stich said. The shuttle has to land no later than Wednesday because after that it will run out of oxygen for its fuel cells, he said.

Landing at Edwards costs NASA about $1.7 million more because it has to get the shuttle back to Florida.

As he went to bed Sunday evening, Lindsey said he hoped that Monday he'd wake up and be able to walk on the ground later that day.

The shuttle itself was cleared Sunday for landing. After seven different inspection efforts, engineers and astronauts couldn't find any damage to the shuttle's heat shield. A small leak with one of three power units that control braking and maneuvering for landing did not appear to be a big deal, NASA mission managers decided Sunday.

Discovery successfully completed all its assigned tasks, including making sure repairs to the shuttle external tank were successful, fixing a rail car on the international space station, and bringing the station a new crew member.

Mission control woke the crew with the song "The Astronaut" by Something Corporate.

Besides Lindsey, Discovery's crew includes pilot Mark Kelly and mission specialists Mike Fossum, Lisa Nowak, Stephanie Wilson and Piers Sellers. Astronaut Thomas Reiter, who rode up in Discovery, remained at the international space station for a six-month stay.

CNN