Space shuttle Discovery astronauts prepared for a Florida landing yesterday at the end of a mission NASA hopes will show the fleet is fit to fly safely, three years after the fatal Columbia accident.

The crew awakened just after midnight to get ready for a scheduled 9:14 a.m. EDT (13:14 GMT) touchdown at Kennedy Space Center, from which they launched on July 4. “Looking forward to a good day here and hopefully with good weather we will be on the ground here in about eight, 10 hours,” flight commander Steve Lindsey radioed to Mission Control at Johnson Space Center in Houston.

To get ready for landing, astronauts closed Discovery’s payload bay doors before sunrise at Cape Canaveral. About an hour before landing, the shuttle crew will fire its twin rockets in a braking maneuver to start its descent from about 200 miles (320 km) above Earth’s surface.

The 13-day flight has been almost flawless, giving the troubled US space agency hope it is finally back on track after the 2003 Columbia disaster.

Discovery suffered no damage during launch, which was NASA’s key goal, and crew members Piers Sellers and Michael Fossum, who made three spacewalks, performed a repair to the International Space Station critical to future construction of the half-finished $100 billion outpost. The shuttle also dropped off German astronaut Thomas Reiter at the station, giving it a full three-person crew for the first time in three years.

Discovery launched amid controversy, with NASA’s top safety officer saying it was not ready because of doubts that the problem that doomed Columbia had been fixed.

Columbia’s wing heat shield was cracked at launch by a chunk of insulating foam falling from the fuel tank, but no one knew it because there was no way to inspect the shuttle during flight. The spacecraft disintegrated over Texas 16 days later when fiery atmospheric gases penetrated the broken shield during its return to Earth. The seven astronauts on board were killed. The flyaway foam problem showed up again on a subsequent shuttle flight last summer.