Shuttle Astronauts Survey Heat Shield

Discovery's astronauts are inspecting the shuttle's vulnerable wing panels and nose cap in a bid to detect any damage that might endanger the ship and its crew during an atmospheric reentry planned for Wednesday.

Wielding a sensor-laden boom, the astronauts are scanning the shuttle's right wing for any damage that might have been done by micrometeorites or orbital debris while Discovery was docked at the International Space Station. The survey is identical to one done the day after Discovery's Feb. 24 launch. That one was aimed at detecting damage from any debris hits during the shuttle's nine-minute climb into orbit.

The inspections have been standard operating procedure since the shuttle fleet returned to flight after the 2003 Columbia accident. Wing panel damage that went undetected during a 16-day science flight led to the loss of Columbia and its seven-member crew.

The astronauts also will survey the shuttle's composite carbon nose cap as well as its left wing before berthing the inspection boom in Discovery's cargo bay for the trip back to Earth.

The shuttle and its crew are due back at Kennedy Space Center at 11:58 a.m. Wednesday.