The space shuttle Atlantis is returning to Earth, ending a twelve-day mission that re-started construction of the International Space Station (ISS).
Nasa has given Atlantis' six-strong crew the all-clear for a return to Earth at 0621 EDT (1021 GMT).
A planned landing on Wednesday was postponed after astronauts spotted several mysterious objects floating in space outside the orbiter. But inspections found no damage to the spacecraft from the nearby debris. And the US space agency was happy that none of the items posed a risk to the vehicle. At 09:14 GMT Atlantis initiated a three-minute engine burn to commit the spacecraft for the trip back to Earth. The "de-orbit" burn slows the shuttle's velocity by about 329km/h, just enough to slip the craft out of orbit and begin the plunge through Earth's atmosphere. As the shuttle falls towards Earth, temperatures outside will reach nearly 1,650 C. Atlantis will touch down at Nasa's Kennedy Space Centre in Florida.
The space shuttle Atlantis has been cleared to return to Earth by Nasa after inspections found no damage to the spacecraft from several small orbiting objects that were spotted nearby to the orbiter.
The US space agency is confident that the orbiting debris pose no risk to the vehicle. The first landing opportunity will be at the Kennedy Space Centre in Florida at 10:21 GMT (0621 EDT) on Thursday.
The space shuttle Atlantis has undocked from the International Space Station (ISS), after a mission described as one of the most complex in recent years.
During the 11-day mission, astronauts made three spacewalks, installing solar panels on the space station. The panels - which weigh 17 metric tons and span more than 70m - will eventually supply the station with a quarter of its electrical power. The shuttle is expected to return to Earth on Wednesday. The hatch connecting Atlantis to the ISS was closed and sealed at 10:28 GMT after the shuttle astronauts said goodbye to their colleagues.