Endeavour hit by flaking insulation on blastoff

Altogether, nine pieces of insulation flaked off during the initial minutes of ascent, but only three may have struck the shuttle itself, Mission Management Team chairman John Shannon told reporters.

None of the particles appear to have been big enough to cause serious damage, he said, adding that he was "very confident."

"Whether it caused damage or not, we will find out in great detail during Friday's rendezvous with the ISS," he said, referring to the orbiting International Space Station the Endeavour is scheduled to dock with.

Shortly before docking, shuttle Commander Scott Kelly will flip the Endeavour over so the ISS astronauts can photograph the shuttle's thermal tiles to inspect them for any damage from the falling insulation.

It is a routine inspection that NASA has ordered for all shuttles reaching the ISS, since a broken thermal tile led to the February 1, 2003 disintegration of shuttle Columbia on re-entry, killing all seven aboard and putting the shuttle program on hold for two-and-a-half years.

The Columbia's thermal shield was compromised by a 700 gram piece of insulation that broke off the shuttle's fuel tank at launch.

Shannon said it was impossible to estimate the size of the insulation fragments that broke off on the Endeavour's launch because engineers do not know exactly what part of the fuel tank they came from.

Images taken of the fuel tank when it separated from the shuttle, eight minutes after launch, showed no major gaps in its insulation layer, prompting NASA's hope that only minimal damage has been caused, he said.

The NASA official also said nothing abnormal had turned up during a routine, six-hour inspection of the thermal shield on the Endeavour's nose and leading edges of its wings, carried out by a high-definition camera atop the shuttle's robotic arm.

"It looks very very clean," he said.

Endeavour and its crew of seven, including two women and a Canadian astronaut, will continue construction work on the ISS during its 11-day mission, that will include three spacewalks.

NASA could prolong the mission by three days to include a fourth space walk, to prepare for installation of a boom on the ISS that will allow crews to inspect for potential damage to the shuttle's heat shield. © 2007 Australian Broadcasting Corporation