Discovery docks with space station for tricky mission (AFP)

12.12.2006 08:26 Space - Source: Yahoo space

HOUSTON, United States (AFP) - The Space Shuttle Discovery successfully docked with the orbiting

International Space Station, as its astronauts prepare for one of the most complex space construction missions ever attempted.

"Welcome aboard," said the ISS commander, US astronaut Mike Lopez-Alegria, shortly after the shuttle linked up with the orbiting laboratory at 2212 GMT.

The delicate maneuver took place about 220 miles (350 kilometers) above southeast Asia, NASA said, after the Discovery shot into orbit in a rare night launch late Saturday.

When the Discovery was about two kilometers (1.2 miles) from the ISS easing slowly into position, the crew of the space station turned on all its lights in a sign of welcome. About an hour and a half after the rendezvous, astronauts opened hatches and the crews of the two vehicles met to shake hands.

During the eight days Discovery remains docked to the ISS, two teams of two astronauts each will perform three space walks for what the National Aeronautics and Space Administration says will be the trickiest tasks ever carried out in space.

On Tuesday, Stockholm physicist Christer Fuglesang -- the first Swede in space -- and mission specialist Robert Curbeam will attach a two-ton aluminum truss segment expanding the ISS.

During the two other space walks, astronauts will rewire the US-made portion of the ISS during which power to half of the space station will have to be switched off.

The work will also include activating solar arrays, installed during a September shuttle mission, that will double the current electrical output of the ISS.

Less than three hours after docking, the crew's work schedule was interrupted to conduct an inspection the Discovery's left wing after a sensor indicated an object may have struck the vehicle at "low-intensity", NASA said.

Two astronauts were using a robotic arm to examine the wing leading edge, but so far there was no cause for concern, NASA said, adding that they will decide whether further inspection is needed on Tuesday.

Except for Fuglesang, all the astronauts are from the United States, including US Navy commander Sunita Williams, 41, whose father is from India and who will stay behind in the space station after Discovery leaves.

Before Discovery linked up with the orbiting laboratory, shuttle Commander Mark Polansky maneuvered the shuttle into a backflip under the ISS to allow the station crew to film its underbelly.

The images will be examined to detect any potential damage to Discovery's heat shield in what has become a routine part of shuttle flights since the 2002 Columbia tragedy.

Columbia's heat shield was pierced by foam insulation that peeled off its fuel tank during liftoff, causing the shuttle to disintegrate during its return to Earth in February 2003.

While shuttle missions in July 2005 and July 2006 focused on improving safety following the Columbia accident, the September 2006 Atlantis mission marked the resumption of ISS construction.

Discovery blasted off late Saturday from Cape Canaveral in the first night launch in four years.

NASA's confidence has been boosted by two nearly flawless missions this year, as the US space agency races to finish the ISS by 2010, when the shuttle fleet, down to three orbiters, is to be retired.

The Discovery mission, which ends with a December 21 landing, is part of 14 shuttle flights NASA has planned over the next four years.

The Discovery crew comprises two women and five men.