Atlantis Shuttle Crew Prepares to Leave Space Station

Space shuttle Atlantis will undock from the International Space Station (ISS) on Sunday, beginning its return to Earth for what NASA expects to be its final landing.

Atlantis pilot Dominic ?Tony? Antonelli, assisted by commander Ken Ham and their four STS-132 crewmates, are scheduled to undock the space shuttle from the International Space Station (ISS) at 11:22 a.m. EDT (1522 GMT), a couple of hours after closing the hatches between the two vehicles. 

The astronauts completed the last of their major mission objectives on Saturday with the return of a cargo pallet to Atlantis? payload bay. Earlier, they delivered a new Russian research module and replaced six batteries for one of the station?s four solar array wings during the seven days they were docked with the ISS.

?We?ve got the integrated cargo carrier back in the payload bay, we got three very successful spacewalks under our belt, and the Rassvet module installed on the International Space Station and so now the mission shifts to returning Atlantis home, hopefully mid-next week,? said lead shuttle flight director Mike Sarafin on Saturday.

Weather permitting, the crew will land Atlantis at the Kennedy Space Center in Florida on Wednesday.

Early on Sunday morning, the astronauts planned to complete the final transfer of equipment and experiment results from the station to the shuttle in preparation for their departure.

?They?ll transfer the suits that they used to perform their spacewalks back into Atlantis and we?ll perform a final verification to make sure all the science and transfer items are back across the hatch and ready for return,? said Sarafin.

The six shuttle crew members and their six station counterparts also took part in a news conference with U.S. and Japanese media before bidding each other farewell, closing the hatches and then undocking their spacecraft. Once separated by a distance of about 400 to 600 feet, Atlantis will perform a 360-degree flyaround of the ISS while the crew photographs the orbiting laboratory.

?We should get some outstanding views of the International Space Station for engineering data as well as a good view of the Rassvet module that was most recently installed,? Sarafin explained.

Before landing, the STS-132 astronauts will take a few days to prepare the shuttle for reentry. They will perform a routine inspection of their heat shield to ensure no damage was sustained by micrometeroid impacts while docked to the station and then test the control surfaces and thrusters that will guide the orbiter back into and through the atmosphere. 

The astronauts, including Ham, Antonelli and mission specialists Garrett Reisman, Piers Sellers, Stephen Bowen and Michael Good, will then set-up for Atlantis? final planned landing on the Shuttle Landing Facility at Kennedy Space Center, presently targeted for 8:48 a.m. EDT (1248 GMT) on Wednesday. 

NASA plans to retire its space shuttle fleet after just two more missions to be flown by Discovery and Endeavour in September and November, respectively.

Atlantis will be prepared to fly as an emergency rescue vehicle for the final space shuttle mission but otherwise is slated to be the first orbiter to retire after 32 missions. Atlantis launched on it current mission on May 14.

?I very much look forward to seeing Atlantis come home,? said Sarafin. ?I had a talk with [Atlantis?] flow director Angie Brewer prior to the launch of Atlantis and I promised I?d give her back in the same condition that we got her and we?ve come very close to that. I look forward to greeting her and her team out at the Kennedy Space Center and fulfilling that promise.?

• POLL: Should NASA Retire the Space Shuttles?
• Gallery - Photos From the Last Launch of Atlantis
• Wow! Shuttle, Space Station Photographed Crossing the Sun

SPACE.com is providing complete coverage of Atlantis' STS-132 mission to the International Space Station with Senior Writer Clara Moskowitz and Managing Editor Tariq Malik based in New York. Click here for shuttle mission updates and a link to NASA TV.