Space shuttle Discovery touched down safely at 3:14 P.M. (Eastern Daylight Time) at Kennedy Space Center in Florida, completing its 13-day mission to the International Space Station (ISS). The landing time was pushed back from 1:39 P.M. due to uncertain weather at the landing site earlier in the day.

Discovery delivered a 45-foot (14-meter) truss segment to the ISS, completing the station's 335-foot (102-meter) "backbone," as well as the final set of solar arrays needed to power the station once its crew swells from three to six in the coming months. The ISS now boasts 38,400 square feet (3,570 square meters) of U.S. solar panels, nearly a full acre, generating about 120 kilowatts of electricity. (Unlike solar-powered buildings here on Earth, the space station doesn't need to worry about cloud cover.)

The shuttle also brought up a replacement unit to resurrect a faulty water-purification system on the ISS that filters urine to make potable water. Discovery is carrying samples from a test run of the urine processor for analysis on the ground before the residents of the station get the go-ahead to start drinking its output.

The shuttle mission, officially designated STS-119, was not without its quirks and glitches. Even its launch, which one NASA official characterized as "picture-perfect," appears to have cost one wayward bat its life. The creature was spotted pre-liftoff clinging to the shuttle's external fuel tank and was still hanging on as the engines lit and the shuttle cleared the tower.

Then there were the threats of space debris—one piece had NASA briefly considering an evasive maneuver for the ISS as the shuttle approached for docking, and another actually necessitated such a move while the shuttle and ISS were attached. Meanwhile, spacewalk activities were partly stymied by a stuck cargo platform intended to hold spare parts on future missions. After numerous attempts to swing the cargo carrier into position, the astronauts ultimately lashed it down, tabling the issue for a later date.

Landing aboard the shuttle were mission commander Lee Archambault, pilot Tony Antonelli, and mission specialists Joseph Acaba, John Phillips, Steve Swanson, Richard Arnold and Sandra Magnus. Magnus flew to the station on space shuttle Endeavour in November and has been replaced on the ISS by Japanese astronaut Koichi Wakata, who flew up with the Discovery crew.