CAPE CANAVERAL, Fla. — Space shuttle Atlantis' astronauts surveyed their ship using a newly repaired instrument that scanned for damage Monday, two days ahead of their return to Earth.
The laborious inspection — the last one for the mission — was saved until Atlantis was flying free of the International Space Station.
Atlantis undocked from the space station Sunday, leaving behind a new 20-foot compartment loaded with supplies and six fresh batteries. It's scheduled to land Wednesday.
The six-man crew used a 100-foot inspection boom Monday morning to check Atlantis' heat shield for any micrometeorite damage that might have occurred during the past 1½ weeks. A snagged cord prevented the astronauts from conducting a thorough survey earlier in the flight. The cable was untangled during a spacewalk last week, and it appeared to work properly Monday.
Engineers expect the survey to provide a full 3-D scan of the left wing. Some sections of the wing were missed in the initial check because of the boom problem, but extra photos taken while Atlantis was at the space station made up for the loss.
The wings and nose are especially vulnerable during re-entry, enduring the most heat. NASA implemented the inspections following the 2003 Columbia accident.
"Great job," Mission Control radioed after Atlantis' nose cap was checked. "You guys are very efficient."
Unless the White House grants a reprieve, this is the final mission for Atlantis. Only two shuttle flights remain, by Discovery and Endeavour. Both space station trips are scheduled for fall.
NASA is under presidential direction to get out of the business of launching astronauts into orbit around the Earth and, instead, focus on sending them to asteroids and Mars. The Obama Administration would like private business to pick up the slack. Until that happens, NASA astronauts will continue catching rides to and from the space station on Russian rockets.
An American will be returning from the space station on a Russian Soyuz spacecraft at the beginning of June, following a mission of more than five months. Two other U.S. astronauts will fly up on a Soyuz in mid-June.
The plan is to keep the space station going until 2020.