Space-station astronauts begin spacewalk

CAPE CANAVERAL, Fla., Jan 31 (Reuters) The commander of the International Space Station and one of his flight engineers floated outside the orbital complex today to begin the first of three spacewalks to hook up a new cooling system.

The work is the most ambitious NASA has attempted on the half-built station without a space-shuttle crew present.

''See you in a couple of hours,'' NASA astronaut Sunita Williams told Russian cosmonaut Mikhail Tyurin, who was staying aboard the station during the spacewalk.

''Good luck,'' Tyurin replied, shutting the door to seal off the outermost segment of the station's Quest air lock.

Once the chamber depressurized, commander Michael Lopez-Alegria slipped open the hatch to venture into space.

The spacewalk began at 2044 IST.

Williams, who was making her second spacewalk, and Lopez-Alegria, on his seventh, will resume work started in December during NASA's last shuttle mission to the station.

That flight left the half-built, 100-billion dollar complex with a new electrical grid and the plumbing to replace the station's temporary cooling loops with an integrated system.

The upgrades are needed to prepare the station for additional modules built by the European Space Agency and Japan.

The station is a multinational project, headed by the United States and Russia. Partners include Canada, Japan, Brazil and 11 member nations of the European Space Agency.

Today's spacewalk, which was expected to last about 6 1/2 hours, is the first of a three-part series scheduled over nine days. The next spacewalk is scheduled for Sunday and the final one on February 8.

The work kicks off a year of what is scheduled to be the busiest in space station assembly, with five Russian resupply missions, two Russian crew transfer flights, six shuttle construction missions and the first flight of Europe's new cargo hauler slated through early 2008, said deputy station program manager Kirk Shireman.

Shuttle and station crew members have 23 spacewalks planned during that time as well.

Reuters SP DB2150