The weather looked favorable for space shuttle Discovery to return to Earth Saturday after a two-week mission in which it delivered a new Japanese lab to the international space station.

"Mission's coming to an end but it's gonna be good to get home today," said shuttle commander Mark Kelly.

Discovery has two opportunities to land at the Kennedy Space Center in Florida.

"The weather is looking very good. We have a decent shot," said flight director Richard Jones.

The first landing opportunity will be best one on Saturday as the weather begins to deteriorate somewhat during the second with a chance of clouds and showers forming.

Since Discovery has enough supplies to allow it to stay in orbit until Tuesday, NASA will only aim on Saturday to bring home the shuttle in Florida, the primary landing site.

Florida would remain the only choice on Sunday as well, if Saturday's opportunities don't pan out, Jones said.

The backup site of Edwards Air Force Base in the California desert would not be considered until Monday.

NASA engineers said a metal clip that broke off Discovery's rudder on Friday poses no threat to the shuttle's landing.

The clip broke loose during a routine checkout of the flight systems needed for Saturday's descent.

Space shuttles have returned to Earth in the past with clips missing from the rudder, which opens like a book to serve as a speed brake. The V-shaped spring tabs, just 2 1/2 inches by 1 inch, protect that area from the intense heat of liftoff by providing a seamless barrier down the back edge of the rudder, or tail, panels.

Engineers suspect this clip, or tab, came loose during the vibrations of launch on May 31, and it wasn't until the speed brake panels were opened for checkout Friday, that it floated away.

Ever since the Columbia tragedy five years ago, any shuttle part seen floating away in orbit is quickly and intensely studied by NASA.

A protrusion in the same area at the tail, reported by the astronauts around the same time, also was found to be harmless.

Discovery's crew of seven is returning after delivering and installing the new lab named Kibo, Japanese for hope, to the space station.

Besides delivering the lab, the shuttle also dropped off Gregory Chamitoff, the station's newest crew member. He traded places with Garrett Reisman, who lived on the station for three months. Chamitoff will stay for six months.

The 37-foot lab, about the size of a bus, is the biggest room at the space station. Kibo also has a storage closet and a 33-foot robotic arm. A final section _ a "porch" for exterior experiments _ and a second, smaller robotic arm will be delivered next year.

Discovery also brought a pump that fixed the space station's malfunctioning toilet.

___

On the Net:

NASA: http://spaceflight.nasa.gov