Shuttle heads toward space station rendezvous

HOUSTON, June 10 (Reuters) The space shuttle Atlantis winged toward a rendezvous with the International Space Station today, lugging the heaviest payload ever for the orbital outpost and troubled only by a small tear in a heat-protecting thermal blanket.

Atlantis was scheduled to link up with the station at 0208 hrs IST for a week-long stay in which the shuttle crew will install electricity-generating solar panels on the half-finished station.

Last night, Atlantis astronauts tested tools for the planned rendezvous more than 320 km above the earth and fired the ship's engines to speed it on its way after it launched from Florida on Friday.

The shuttle is carrying a 14-metre long, 16,183 kg aluminum structure that will become part of the station's structural backbone and includes the solar panels. Its crew members are scheduled to perform three spacewalks to install the new parts and retract an old solar array.

Among the seven Atlantis astronauts is Clayton Anderson, of Ashland, Nebraska, who will join Russian cosmonauts Fyodor Yurchikhin and Oleg Kotov on the station, replacing Sunita Williams.

Williams, after six months on the 100 billion dollars outpost that is a joint project of 16 nations, will catch a ride home on Atlantis.

NASA plans to fly 12 more missions to complete the station.

It also wants to make two flights to store spare parts and service the Hubble Space Telescope a final time before its three-shuttle fleet is retired in 2010.

DELAYED BY HAIL This shuttle journey, the first since December, was slated for March but a hail storm while it was being prepared on the launch pad damaged insulating foam on the shuttle fuel tank, which forced NASA to delay the mission for repairs.

Fuel tank foam has been a big worry for NASA since loose foam damaged Columbia's heat shield at launch in 2003, triggering a breakup during its fiery re-entry to the earth's atmosphere 16 days later. The seven astronauts on board were killed.

An ensuing investigation severely criticized NASA and led to safety procedures that now dominate the first days of all shuttle missions.

Atlantis astronauts spent most of yesterday maneuvering a sensor-laden robot arm to inspect their ship's heat shield for damage. The only known problem so far was a small gouge in a heat-protecting thermal blanket at the ship's rear that deputy shuttle program manager John Shannon said was being studied.

Shannon said the damage was in an area that does not get the greatest heat during re-entry, but that a spacewalking astronaut can repair it if necessary.

''If we decide this is a problem, we have a lot of capabilities to go address it,'' he told reporters at Johnson Space Center.

The back of the shuttle experiences temperatures of 371 to 538 degrees Celsius during re-entry, compared to 1,611 C for the leading edge of the shuttle wings, Shannon said.

As part of the inspection process, station crewmembers will take high-resolution photos of Atlantis' belly as it approaches for docking.

REUTERS SG VV1112