Astronauts to Inspect Shuttle Heat Shield
The space shuttle Discovery's heat shield can be seen in this view from its external tank as the 15-story fuel reservoir fell away from the shuttle as planned after a successful March 15, 2009 launch.
Credit: NASA TV

Astronauts aboard the space shuttle Discovery will inspect their spacecraft?s vital heat shield for damage today as they head toward the International Space Station.

One day after their spectacular evening launch, shuttle commander Lee Archambault and his seven-astronaut crew plan to use a sensor-laden inspection pole to scan Discovery?s wing edges and nose for signs of new dings or divots.

?We didn?t see anything at all in the first quick look,? NASA?s space operations chief Bill Gerstenmaier said of Discovery?s heat shield after the shuttle launched into space Sunday night. ?It looked pretty clean.?

The heat shield inspection is scheduled to begin at about 2:28 p.m. EDT (1828 GMT) and is the first of several in-flight surveys to search for damage to Discovery?s fragile heat-resistant tiles and panels from launch debris. It has been a standard practice since the 2003 loss of the shuttle Columbia during re-entry due to heat shield damage.

?This is about 5 1/2 to six hours of inspection work using our space shuttle robotic arm,? Archambault said before flight.

Discovery is headed to the International Space Station to deliver the outpost?s final set of U.S.-built solar arrays and a nearly 16-ton girder to complete its power grid and backbone-like main truss. The shuttle is also ferrying Japanese astronaut Koichi Wakata to the space station, where he will replace NASA astronaut Sandra Magnus as a member of the orbiting laboratory?s crew.

Three spacewalks are planned for the 13-day mission, which was delayed more than a month, first by fuel valve concerns and later by a hydrogen gas leak last week.

Shuttle health check

A team of engineers is poring over video of Discovery?s launch, but today?s inspection is the first up-close view they will have to check shuttle?s heat shield health.

?The inspection has become somewhat standard now,? said Discovery pilot Dominic ?Tony? Antonelli before flight. ?We?ll grab this boom out of the shuttle?s payload bay. It?s got sensors on the end and we?ll use those sensors to scan the leading edge and the nose are of the space shuttle to make sure we didn?t sustain any damage from ascent.?

Antonelli, a first-time spaceflyer, is Discovery?s lead robotic arm operator. He will attach the 50-foot (15-meter) inspection boom to the end of the shuttle?s already 50-foot (15-meter) robotic arm and use the tip-mounted cameras and laser sensors to scan Discovery?s nose and wing edges - areas that see the highest temperatures during the scorching heat of re-entry.

?It?s very tedious work and you?re operating the inspection boom within very close proximity of the orbiter for an extended period of time,? Archambault said, adding that he and other crewmates will share the job with Antonelli to ease the workload. ?The idea here is not to let anyone get complacent and keep everyone focused on the job at hand.?

NASA has kept a close watch on shuttle heat shield integrity since the 2003 loss of the shuttle Columbia and its seven-astronaut crew during landing. A piece of foam insulation from Columbia?s fuel tank broke off during launch and punched a hole in the shuttle?s heat shield on its left wing edge, leading to the shuttle?s destruction during re-entry 16 days later.

Shuttle analysts will study the images from today?s inspection and combine them with data from two more in-flight surveys of Discovery?s heat shield scheduled during the 13-day mission. Astronauts aboard the International Space Station will snap high-resolution photos of Discovery?s tile-covered underbelly just before the shuttle docks on Tuesday in another survey. The last scan, performed after undocking, will search for new dings etched by micrometeorites or other space debris.

NASA flight controllers told Discovery?s crew late Sunday that, so far, the spacecraft appears to be in fine shape after its evening liftoff.

"There are no observations indicating any concern for the vehicle or success of the mission," astronaut George Zamka radioed up to the shuttle from Mission Control at NASA?s Johnson Space Center in Houston.

Discovery is due to dock at the space station on Tuesday at 5:13 p.m. EDT (2113 GMT).

SPACE.com is providing continuous coverage of STS-119 with reporter Clara Moskowitz in Cape Canaveral and senior editor Tariq Malik in New York. Click here for mission updates and SPACE.com's live NASA TV video feed.