Space shuttle commander says ship safe to return

HOUSTON, Aug 14 (Reuters) The shuttle Endeavour astronauts are confident their spaceship is safe to return to Earth even if NASA decides not to repair a small gouge in its heat shield, the shuttle's commander said TOday.

Laboratory tests and computer simulations were under way at the Johnson Space Centre in Houston to assess whether a small but deep cut in two heat-resistant tiles on the ship's belly would lead to more damage, possibly delaying future flights, when the shuttle flies through the atmosphere before landing.

''I'm not concerned with our safety,'' Scott Kelly, who heads Endeavour's five-man, two-woman crew, said during an inflight interview.

''My understanding is this tile damage is not an issue of the safety of the crew. It's more of an issue of the ability to reuse the orbiter and damaging the orbiter. We still have analysis ongoing. We still might choose to repair it,'' he added.

A decision about whether to patch the hole during a spacewalk before Endeavour leaves the International Space Station was expected by late Wednesday or Thursday. The shuttle arrived at the 100-billion dollars orbital outpost last Friday to deliver new components and supplies.

''We feel pretty confident that whatever needs to be done we can handle it,'' said astronaut Tracy Caldwell, who celebrated her 38th birthday in space.

The crew already has completed two of four spacewalks planned for the flight, which was extended from 11 to 14 days to allow time for the astronauts to prepare the station for new modules later this year.

The shuttle has enough supplies to stay in space as long as 20 days, but NASA reserves at least two days for weather or technical-related landing postponements.

Also today, Caldwell and her crewmate, former teacher Barbara Morgan, used the shuttle's 50-foot (15-metre) robotic arm to pick up a 3.5-tonne spare parts platform from Endeavour's cargo bay and pass it to the station's crane to snap into position on the outside of the complex.

NASA is trying to deliver as much spare equipment as possible to the space station before the shuttle fleet is retired in three years.

At least 11 construction missions are needed to finish the station, which is a project of 16 nations. NASA also would like to fly two resupply missions and a servicing call to the Hubble Space Telescope before the shuttles stop flying.

Morgan, 55, who trained 22 years ago as the backup to teacher-in-space Christa McAuliffe, said she thinks about McAuliffe and the rest of the Challenger crew almost every day.

The Challenger crew died during a launch accident in 1986.

''I hope they know they are here with us in our hearts,'' she said.

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