The shuttle, which delivered the Columbus laboratory to the International Space Station (ISS), undocked from the ISS on February 18 and followed a flight path over the South Pacific, El Salvador, and Cuba. It touched down at 9:07 a.m. EST (2:07 p.m. GMT).
The STS-122 crew performed three spacewalks to install the $2 billion laboratory, which had taken some 10 years to construct and is Europe's main contribution to the ISS.
The completion of the 121st shuttle mission opens the way for Washington to safely shoot down a rogue U.S. spy satellite with hazardous toxic fuel on board. The satellite may now be shot down on Wednesday, possibly from a Navy ship in the Pacific.
Atlantis' flight back to Earth was safe, despite a previously discovered tear in the shuttle's thermal shielding. The damage was said to be insignificant, however and on February 14, a NASA spokesperson said the shuttle was ready for re-entry without repairs having been carried out.
NASA began paying particular attention to thermal shield damages after the space shuttle Columbia exploded on re-entry into Earth's atmosphere in 2003, killing the crew of seven. A piece of isolating foam, which had peeled off from an external fuel tank and punctured one of the wings on liftoff, was later established as the cause of the tragedy.
Last June, U.S. astronaut John Olivas repaired damage to Atlantis' thermal blanket during a spacewalk, enabling the shuttle to return to Earth safely.
