NASA shuttle prepares to dock with ISS

CAPE CANAVERAL (AFP) - The US shuttle Endeavour prepared to dock with the International Space Station on Friday after sustaining minor damage to its external fuel tank during lift-off, NASA said.

The Endeavour, which blasted off on its 11-day mission on Wednesday, was set to rendezvous and dock with the ISS at 1753 GMT after the shuttle crew inspected the spacecraft's thermal insulation on Thursday.

A NASA official said it may have been hit by three small pieces of insulation material from its external fuel tank on blast-off.

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, adding he was "very confident" there was no serious damage.

Shortly before docking on Friday, Endeavour will flip over so the ISS astronauts can photograph its thermal tiles to inspect them.

Damage to heat tiles is a major concern since a broken one caused the shuttle Columbia to disintegrate on re-entry on February 1, 2003, killing all seven aboard and putting the shuttle program on hold for two and a half years.

The Endeavour crew, due to continue construction work on the orbiting space station, is carrying the first teacher in space in 21 years, after the 1986 Challenger explosion killed Christa McAuliffe and her six fellow crew members.

Barbara Morgan, 55, had trained as a back-up to fellow teacher McAuliffe for the Challenger mission.

After the shuttle docks with the ISS on Friday, Morgan will operate robotic arms on the ISS and the shuttle to unload and install new equipment and supplies on the space station.

During three spacewalks, astronauts will also replace a defective gyroscope on the ISS and install an external stowage platform.

As the probe headed towards the orbiting laboratory hundreds of miles above the Earth, NASA official Michael Griffin moved to tackle troubling reports of drunken astronauts that tainted the agency in the run-up to the mission.

After the Endeavour and its crew of seven made a flawless lift-off late Wednesday from Kennedy Space Center, Griffin told reporters he could find no evidence to support the allegations Aviation Week & Space Technology journal made last month.

"Right now, we've gone back 10 years and we can't even find where it would be a possibility there was crew under the influence on either a Soyuz (Russian space craft) or a shuttle," he said.

Before the shuttle departed on its mission, Endeavour Commander Scott Kelly also spoke out to defend his crew and fellow astronauts amid reports some NASA crew members had shown up for duty drunk.

"To imply that my crew or I would ever consider launching on our mission in anything but the best possible condition is utterly ridiculous," Kelly said in a letter to US media distributed by NASA.

It was not the final word on the matter, however, since USA Today newspaper said NASA security chief Bryan O'Connor was looking through the agency's records from 16 years earlier.

Griffin's comment, quoted in the specialist journal, that he found "zero evidence" of astronauts drunk on the job was his first public response to the magazine article, which was based on a NASA-commissioned report on the psychological health of its astronauts.

In that report, US Air Force physician Richard Bachman said he was given two accounts of astronauts being so drunk that doctors had raised safety concerns about the missions they were about to embark on, including a Russian Soyuz mission to the ISS.

Other astronauts at Cape Canaveral were shocked at the allegations.

"I have never heard anything like that. I stayed 30 days in quarantine ... and I never see anything like that," Catherine Coleman, a US Air Force captain with two shuttle missions under her belt, told AFP.

The drunkenness allegations compounded damage to NASA's reputation after a scandal earlier this year with astronaut Lisa Nowak, who was arrested and charged with attempting to kidnap a woman dating another married astronaut.