Cape Canaveral-AP -- If it turns out today's space shuttle tragedy was caused by damage during the launch, NASA says there's nothing that could have prevented it.
During Columbia's launch last month, a chunk of insulating foam peeled away from a fuel tank and smacked into the ship's left wing. An engineering analysis concluded that any damage to Columbia's thermal tiles would be minor. The tiles protect the shuttle from the extreme heat of re-entry into the atmosphere.
It was also the left wing that exhibited sensor failures and other problems before the shuttle disintegrated over Texas. Shuttle manager Ron Dittemore says it's too soon to know if there's a connection.
Dittemore says if the tiles do turn out to have been the problem, there's nothing the astronauts could have done to repair them, and nothing flight controllers could have done to bring home a severely scarred shuttle.