Discovery touched down at 2232 GMT on the landing strip at the Kennedy Space Center, near Cape Canaveral, where it had lifted off in a night time launch on December 9.
The Discovery astronauts spent eight days at the International Space Station (ISS), continuing the construction of the orbiting laboratory by attaching a two-tonne truss to its girder-like structure in the first of four space walks. During the next two space walks, they rewired the station?s power system and put it on a permanent basis. A fourth space walk was added Monday to shake loose a solar array panel that had gotten stuck as it was being folded.
Poor weather conditions in Florida had scotched an earlier scheduled landing Friday and NASA officials had considered bringing the shuttle down at alternative sites. A decision to land at Kennedy was made only at the last minute and ?it turned out to be a great one,? Michael Griffin, a NASA administrator, said.
Discovery carried astronaut Sunita Williams to the ISS, where she will remain for six months. Williams replaced Thomas Reiter, a German ESA astronaut who had been on the station since July.