HOUSTON - Astronauts on space shuttle Atlantis conducted a final inspection of their spacecraft's heat shield Monday in preparation for their return to Earth. As currently planned by NASA, Atlantis will be landing for the final time this week after flying 32 missions since 1985.
The inspection is part of work to ready Atlantis for its safe re-entry into the atmosphere and landing at the Kennedy Space Center in Florida after a week-long visit to the International Space Station. The first landing opportunity is targeted for 8:48 a.m. EDT (1248 GMT) on Wednesday, weather permitting.
"I fully expect things will look good and we'll be ready for landing on Wednesday," said NASA mission operations representative Brian Lunney on Sunday.
Atlantis and its crew are returning home from the International Space Station (ISS) after seven days docked to the orbiting laboratory, where they installed a new Russian research module and changed out six solar array batteries over the course of three spacewalks. The shuttle launched on May 14 and undocked from the orbiting lab on Sunday.
To prepare for their return, Atlantis' commander Ken Ham, pilot Dominic "Tony" Antonelli and mission specialists Piers Sellers, Garrett Reisman, Stephen Bowen and Michael Good spent Monday morning using the shuttle's robotic arm and its 50-foot extension boom to conduct a routine "late inspection" of the orbiter's thermal protection system tiles and reinforced carbon-carbon surfaces, including the wing leading edges and nose cap.
The inspection is to ensure Atlantis was not damaged by micrometeroids while docked to the station, but it will also provide analysts on the ground with the chance to add to the abbreviated survey data that was collected earlier in the mission after a cable snag prevented the use of the extension's primary camera system.
Reisman and Bowen cleared the snag during the mission's second spacewalk, so the boom and its associated sensor package was fully operational for today's survey. Other imagery and engineering data was used to fill in gaps in the post-launch inspection.
"We've convinced ourselves, as a team, through all of the launch imagery that we've recovered via the solid rocket boosters recently, as well as the standard launch imagery, the wing leading-edge sensors, the [modified] flight day two inspection that we got via the digital camera on the orbiter boom sensor system, the rendezvous pitch maneuver images and then images obtained during the first spacewalk that Atlantis and its tile are ready to go and we just need to do the standard orbital debris inspection," explained lead shuttle flight director Mike Sarafin.
Space shuttle inspections have been standard parts of every mission since heat shield damage led to the tragic loss of shuttle Columbia and its crew in 2003. Atlantis' heat shield has already received a clean bill of health after two earlier surveys during this mission. Today's inspection is the final look at the heat shield to make sure nothing has changed while Atlantis has been in space.
While the inspections are going on, Good and Bowen were also scheduled to stow the spacesuits using during the mission's spacewalks for landing. All the astronauts will also take part in exercise sessions to help prepare their bodies for the return to gravity.
On Tuesday, Ham and Antonelli are scheduled to test the wing control surfaces and thrusters that will enable Atlantis' entry glide through the atmosphere while their crewmates will begin packing the cabin for landing and stow the high bandwidth communications antenna that enables video to be sent to the ground.
NASA currently plans to retire Atlantis after this flight, but will ready the spacecraft to serve as a rescue ship as a safety precaution for the agency's final space shuttle mission slated to fly in late November. NASA and some lawmakers have been lobbying to take that rescue mission and turn it into a full-fledged extra shuttle flight for Atlantis, but the space agency has not yet received approval to add the flight.
After this mission, only two more shuttle flights remain, on shuttles Discovery and Endeavour, before the orbiter fleet is retired to make room for new technology development and vehicles aimed at sending astronauts to an asteroid or Mars.
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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.