Space station crew cleans house, sends junk into orbit

Two astronauts ventured outside the international space station Monday to rid it of some large pieces of junk.

NASA spacewalker Clayton Anderson, a sportsman who enjoys officiating basketball back on Earth, had the chore of heaving a 635-kilogram, refrigerator-size ammonia tank overboard. He also was to toss out some other outdated pieces of equipment during the morning excursion, with help from Russian crewmate Fyodor Yurchikhin.

"I'll try not to get too attached to this," Anderson told Mission Control as he began the cleanup work. "It's going to go away in a little while."

The ammonia tank was launched in 2001 to provide spare coolant in case of a leak at the orbiting complex. The surplus ammonia was never needed and the tank itself has exceeded its expected lifetime.

NASA normally tries to avoid adding to the orbiting junkyard, but officials felt they had no choice in this case. The equipment has to be moved, and because of a looming 2010 deadline for ending all shuttle flights, NASA does not have room on its remaining missions to return the tank to Earth.

Flight controllers expect the ammonia tank to orbit for 10 or 11 months before re-entering the atmosphere and burning up.

There should be no danger of a collision between the free-floating tank and the station before that happens, officials said. While small chunks are expected to survive next year's fall and make it to Earth, officials hope those chunks will hit the ocean, NASA officials said.

The plan called for Anderson to throw the tank in the opposite direction of the station's travel. The station will be manoeuvred later in the day into a higher orbit to provide additional clearance.

Other junk being discarded includes 90 kilograms of camera-mounting equipment and an attachment mechanism.

Russian cosmonaut Oleg Kotov stayed inside the station to oversee the spacewalk during Anderson's tank toss.

Anderson moved into the space station in June. The two cosmonauts have been on board since April.

"Our spaceship Earth is a beautiful place," Anderson marvelled during the spacewalk, his first.