Published: May 24, 2010 12:25 PM EDT
Updated: May 24, 2010 12:24 PM EDT

CAPE CANAVERAL, Fla. (AP) - 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


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.