Shuttle Atlantis Closes In on Space Station
The International Space Station as seen by the last shuttle mission to visit it, the STS-131 flight of the shuttle Discovery in April 17, 2010.
Credit: NASA

The space shuttle Atlantis is closing in on the International Space Station with six astronauts and a new Russian room for the orbiting lab onboard.

Atlantis launched Friday on her final planned journey to space ? the 12-day STS-132 mission. The shuttle is slated to dock at the orbiting laboratory Sunday at 10:27 EDT (1427 GMT).

"The orbiter has been performing exceptionally well," STS-132 Mission Management Team co-chair LeRoy Cain said Saturday. "We're looking forward to being back at the space station tomorrow."

Atlantis' crew, led by commander Ken Ham, woke up at 3:20 a.m. EDT (0720 GMT). They are playing orbital catch-up with the station, which is circling Earth at about 220 miles (354 km) up.

Shuttle acrobatics

Before the two spacecraft link up, Ham will steer Atlantis on a back flip ? called the rendezvous pitch maneuver ? at 9:26 a.m. EDT (1326 GMT). The move will allow astronauts on the station to snap detailed photographs of the shuttle's underbelly, where a sensitive heat shield covers the surface to protect it during re-entry to Earth. These photos will be analyzed to make sure the insulating tiles weren't damaged by foam dislodged from the shuttle's external tank during Atlantis' launch.

"It's a manually flown rendezvous with the shuttle to the space station," pilot Tony Antonelli said in a preflight interview. "[Ham will] get us up underneath the space station and do a back flip so they can take pictures of our tile. That?ll complete the part of the inspection that we don?t get done on Flight Day 2."

Shuttle astronauts made a detailed scan of the heat shield on the shuttle's wings and nose on Saturday. The inspection was slowed down by a camera glitch, but the crew was able to use a backup camera to complete most of the scan. Mission managers say preliminary data suggest Atlantis is looking good.

"The external tank performance looked very, very good," Cain said. "But we did see a few debris items and then we saw a little bit of places where we lost some foam in the external tank video imagery."

He said further review of the launch videos and inspection data will be needed before NASA can determine for sure if Atlantis is safe to fly back home.

Space debris

Docking will be a bit less complicated than it might have been since mission managers determined that it wouldn't be necessary to move the station to a higher orbit to avoid a rogue piece of space junk.

NASA contemplated the maneuver when tracking showed a bit of space junk on a course that may have posed a risk of collision with the station. After analysis, though, engineers decided the debris would fly outside the risk zone, so the station was allowed to stay in its current orbit. Even if the move had been necessary, it would have impacted the docking plans very little, mission managers said.

After Atlantis links with the orbiting laboratory astronauts must spend time checking the seal between the two craft for leaks. They plan to open the hatches between the shuttle and station at 12:30 p.m. EDT (1630 GMT).

All six astronauts on the STS-132 mission are veteran spaceflyers. Many are looking forward to returning to the space station for a repeat visit.

"At some point in there you actually look out the window when you?re close and you see this monstrosity that is out there orbiting the planet," Ham recalled of seeing the station on approach. "There?s that moment of 'Holy cow! What has humanity built up here?' It is amazing and I?m looking forward to that because the station?s even bigger than it was last time I was there."

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.