Under the wing

If there was ever any doubt that one-time teacher Barbara Morgan has had a career change, it ended on Sunday. For three painstaking, tedious hours, she flew the shuttle’s robotic arm over damage sites on her space shuttle’s heat shield so engineers could assess if any repairs will be needed before the ship is cleared to return to Earth next week.

“I know it was long and harrowing,” astronaut Chris Ferguson from Mission Control in Houston told the shuttle Endeavour crew when the task was finally complete. “Thanks for all your hard work.”

Helping Barbara with the arm operations were crewmates Tracy Caldwell and commander Scott Kelly. NASA managers told the Endeavour astronauts to make a second inspection of their ship’s heat shield after photographs taken by the space station crew prior to Endeavour’s docking on Friday showed a potentially deep gash in a tile located beneath the right wing.

The ceramic tiles protect the orbiter’s aluminum skin from melting during the fiery plunge back through Earth’s atmosphere prior to landing.

The laser data and images taken during Barbara’s scans will be analyzed to determine if spacewalking astronauts will need to patch the tile’s hole to make sure the shuttle won’t overheat during re-entry. A major heat shield breach is what doomed the Columbia crew in 2003.

Even if it turns out Endeavour is OK to land as is, NASA now faces a thorny question: Should it risk flying three more missions until a new tank that fixes the problem seen during Endeavour’s flight is ready?

With the shuttles retiring in three years and at least 11 more shuttle flights needed to finish building the space station, NASA will have a lot to wrestle with before it decides whether to fly its next shuttle mission in October.