Shuttle spacewalkers to install space station piece

HOUSTON, Dec 12 (Reuters) Astronauts aboard the shuttle Discovery today planned a spacewalk to install the sixth of 11 segments in the International Space Station's girder-like backbone.

The outing is the first of three scheduled for the 12-day space-station construction mission. On this trip, astronauts will also rewire the station to allow the addition of more solar power arrays.

''Now the real work starts,'' said John Shannon, deputy shuttle program manager, late yesterday.

Discovery docked with the space station yesterday afternoon 220 miles above Earth after being launched Saturday night from Kennedy Space Center in Florida.

''Tally-ho on the new home. It's beautiful,'' astronaut Sunita Williams said as Discovery approached. She is scheduled to spend six months on the station.

The seven astronauts on Discovery, five making their first spaceflight, joined station commander Michael Lopez-Alegria and crew Mikhail Tyurin of Russia and Thomas Reiter of Germany.

After handshakes and hugs, the crews began preparing for one of the most complex of 14 more missions planned to finish the station in 2010.

The flight was proceeding ''flawlessly,'' lead flight director Tony Ceccacci said. But ''we have seven challenging docked days ahead of us.'' Inspections of the shuttle's heat shield showed very little damage during launch. Shannon said teams would continue studying photographs and data but Discovery looked healthy.

Intensive checks of tiles that protect the shuttle from the heat generated during the return to Earth are among safety measures imposed after shuttle Columbia broke up as it headed for landing in 2003.

Seven astronauts aboard Columbia died because the agency failed to detect damage to the left wing caused by insulation falling from a fuel tank.

SPACEWALK SCHEDULED The 11-million dollar, two-ton truss will add 11 feet to the space station's metal backbone, taking it to 180 feet in length. It will be more than 250 feet long when finished.

Space-suited astronauts Robert Curbeam and Christer Fuglesang were to leave the station's air lock at 2:42 pm CST (3:42 p.m. EST/2042 GMT) to begin installation of the truss.

Curbeam, a veteran US astronaut with three previous spacewalks, and Fuglesang, a European Space Agency rookie, were to finish six hours and 10 minutes later.

The truss segment spent the night attached to the space station's robot arm after being lifted out of the shuttle cargo bay late yesterday.

Astronauts Williams and Joanie Higginbotham were to help Curbeam and Fuglesang by operating the station's robot arm from inside the station.

They planned to use the arm to maneuver the aluminum segment into place on the station's port or left side.

Curbeam and Fuglesang then were to tighten bolts, securing the new piece in place. Then they planned to attach wiring.

Two more spacewalks are planned to rewire the station so it can use a new set of solar power arrays delivered in September and two more sets awaiting launch.

The increased power is needed for laboratory modules built by Europe and Japan expected to be attached to the station beginning next year.

Williams replaces Reiter on the space station and will stay until June. Reiter, after six months on the station, returns to Kennedy Space Center with the shuttle on December 21.

REUTERS SHB VV1446