Thisstory was updated at 9:20 a.m. EDT.
CAPECANAVERAL, Fla. ? The space shuttle Atlantis sailed back to Earth Wednesday tomake a flawless landing in Florida, ending what is expected to be its finaltrip to space after 25 years of flight.
Withtwo resounding sonic booms, Atlantisannounced its arrival just minutes before landing at NASA's Kennedy SpaceCenter with commander Kenneth Ham at the controls. Touchdown occurred at 8:48 a.m.EDT (1248 GMT) to cap the last scheduled mission for Atlantis.
"Thatwas pretty sweet," Mission Control radioed Ham. "For you and yourcrew, that was a suiting end to an incredible mission."
Rainshowers that threatened to postpone the landing did not materialize, andAtlantis was able to land during its first planned opportunity. Returning toEarth with Ham were pilot Dominic "Tony" Antonelli and missionspecialists Garrett Reisman, Michael Good, Stephen Bowen and Piers Sellers.
Theastronauts completed a 12-day flight to the International Space Station todeliver a new Russian research room and a host of spare supplies, including newbatteries and a communications antenna. The shuttlelaunched May 14.
"Fromour point of view it's been a very successful mission," Good toldreporters Tuesday. "We took up a new space-to-ground antenna, a newsix-pack of batteries? we brought up a new Russian module, so we added to thespace inside of the International Space Station."
Atlantisand her sister shuttles Endeavour and Discovery are due tobe retired this year after two more missions, planned for September andNovember.
"Thisis the 32nd mission for Atlantis," mission specialist Stephen Bowen saidTuesday from space. "It's served our country really well. It's part of alegacy of exploration that we hope will continue."
Overall,Atlantis has travelled more than 120 million miles during its spaceflightcareer and visited quite a few destinations, including the former Russian Mirspace station, the Hubble Space Telescope, and of course, the InternationalSpace Station.
"Ihope that when she lands successfully? she'll go somewhere and get the respectshe deserves as a ship of exploration," mission specialist Piers Sellerssaid in a video the Atlantis crew made from space to commemorate the shuttle'slast mission.
Onthis trip the astronauts carried with them an American flag flownon Atlantis' first flight, the STS-51J mission in October 1985.
Theorbiter is named after the RV Atlantis, a two-masted sailing ship that servedas a research vessel for the Woods Hole Oceanographic Institute in Woods Hole,Mass.
"Shehas definitely lived up to her name over the past 20 years or so," Bowensaid.
Afterretirement, all three space shuttles will be sent to museums around thecountry, while NASA focuses on the next step in human spaceflight.
U.S.President Barack Obama has proposed encouraging private companies to developthe next spaceships to carry astronauts to low-Earth orbit and the spacestation. Meanwhile, NASA would work on designing a heavy-lift vehicle thatcould propel humans farther out in the solar system to visitan asteroid or Mars.
Thoughthis mission is the final planned flight for Atlantis, there is a chance theshuttle could fly again. The orbiter is slated to be the backup shuttle for thelast planned mission, the STS-134 flight of Endeavour in late November. Ifthere is an emergency with that shuttle, Atlantis could lift off to rescue theastronauts.
Tobe safe, NASA will process Atlantis one last time on the ground so it is readyfor launch if necessary.
Somewithin NASA and Congress hope to secure funding to turn that rescue missioninto one more final shuttle flight to deliver even more supplies to the spacestation. If approved by the White House, that mission would likely fly in June2011.
Hamand his crew departed the space station on Sunday, capping off a hecticmission that included three spacewalks to install the new parts on the orbitinglab.
Thenew hardware will help outfit the station for the era after the space shuttlesretire, taking with them their large cargo-carrying capacity. Russian Soyuzspacecraft and unmanned Russian and commercial cargo vehicles will continue totravel to the orbiting lab, but none can fit payloads as large as the shuttlescan.
Thisflight of Atlantis was the third of five shuttle missions planned for 2010.
"She'sbeen an amazing ship and it's an honor to have served upon her," Reismansaid.
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SPACE.comis providing complete coverage of Atlantis' STS-132 mission to the InternationalSpace Station with Senior Writer Clara Moskowitz in Cape Canaveral, Fla., andManaging Editor Tariq Malik based in New York. Click here for shuttlemission updates and a link to NASA TV.