NASA today delayed shuttle Atlantis' homecoming by a day due to bad weather expected at the Florida landing site and because it wanted time to examine video of an object seen falling out of the craft.
NASA rescheduled touchdown at the Kennedy Space Center on Thursday. "Based on this weather we're having, we're going to waive off tomorrow," astronaut Terry Virts from Mission Control in Houston told Atlantis commander Brent Jett.
NASA also had concerns about a video taken by a shuttle camera of an unidentified small dark object that appeared to fly out of the craft's payload bay today.
Johnson Space Center spokesman Doug Peterson said the object was a mystery. "At this point, we're not willing to hazard a guess," Peterson said.
Flight controllers told the crew to postpone locking down the shuttle's robot arm and stowing the television antenna in case additional inspections were needed.
Atlantis is returning from a week-long stay at the International Space Station to install the first new upgrade since before the 2003 Columbia shuttle disaster.
It was the first of at least 15 flights planned by NASA to complete the half-finished station. Construction had been on hold since 2003, when shuttle Columbia disintegrated while returning to Earth, killing the seven astronauts on board.
Tests of the Atlantis' flight controls and steering jets showed no problems, following the news that Atlantis' heat shield appears fit for the fiery return through Earth's atmosphere. Columbia's accident was caused by damage to its heat shield.
Atlantis astronauts on Tuesday also took part in a three-way conference call with their counterparts on the station and a Russian Soyuz spacecraft.
"It's a little crowded in the sky this morning," said station astronaut Jeff Williams. Soyuz is en route to the outpost after launching from Kazakhstan yesterday.