Shuttle shifts storage platform to space station

DALLAS, Aug 14 (Reuters) NASA astronauts used robot arms to move a storage platform from the visiting space shuttle Endeavour to the International Space Station today as engineers on the ground investigated what problems may be posed by a worrying pit in the spacecraft's heat shield.

The gouge was caused by a piece of insulating foam that broke off the shuttle's fuel tank during launch last Wednesday.

The fatal 2003 Columbia accident was traced to a more serious impact from falling tank insulation, although NASA has not been alarmist about the problem, stressing that the pit is not a crew safety issue. But it wants to minimize any related damage to future flights.

''We are doing a lot of analysis now including computer modeling as well as putting tiles that are in that same configuration into test chambers and exposing them to high heat ... That will allow us to decide if any repair is needed,'' said NASA spokesperson Ed Campion.

''In the meantime we have a team here on the ground working on the assumption that a repair is needed and they are practicing the techniques that would be needed so we are ready,'' he said.

The patching job would require spacewalking astronauts to get into position on a boom on the end of the shuttle's robotic arm and then to apply thermal paint and a caulk-like filling.

NASA officials have said that should they decide to make repairs, the work would take place no earlier than Friday, during the mission's fourth spacewalk.

NASA also is considering extending Endeavour's stay at the station beyond 10 days and adding a fifth spacewalk.

Meanwhile, today's shifting of the 3,175-kg external storage platform -- which contains spare parts for the space station -- was a delicate task involving both the shuttle and the outpost's mechanical arms.

The shuttle's robot arm was lifting the storage platform out of the spacecraft's payload bay to pass to the station's arm, which would then attach it to an external structure on the outpost.

It is the first time that such a task has been attempted.

''(This is) a new moment for us. It is a challenge ... there is the choreography of handing the piece of equipment from one arm to the next,'' flight director Heather Rarick said earlier in the day.

Astronauts Barbara Morgan and Tracy Caldwell -- who turned 38 today -- were scheduled later in the day to do interviews with US television news networks.

Morgan is a former teacher who trained two decades ago as a backup for the teacher-astronaut on the ill-fated space shuttle Challenger, which blew up shortly after launch in 1986. She was also to take questions from school children today.

REUTERS RSA KP2328