US-Space/ ISS astronauts load broken part on Atlantis during spacewalk

Jul 12, 2011, 20:48 GMT

Washington - Two members of the International Space Station crew retrieved a broken part of the orbiting laboratory during a spacewalk Tuesday and loaded it into the shuttle Atlantis.

It was the final spacewalk to be conducted at the station while a space shuttle is docked there.

US astronauts Michael Fossum and Ron Garan exited the ISS at 1322 GMT to remove the failed external cooling pump, to be returned to Earth aboard the shuttle Atlantis. During the six-hour, 31-minute spacewalk, the duo also conducted other maintenance tasks and installed science experiments outside the station.

Atlantis is making the final space shuttle flight to the ISS as NASA retires the 30-year-old fleet of orbiters, which are the only spacecraft large enough to transport bulky cargo, such as the pump. Without its heavy-lift capacity, the orbiting laboratory could never have been constructed.

The pump broke last year, disabling half the station's cooling system and prompting a series of emergency spacewalks.

ISS crew members, rather than members of the Atlantis crew, conducted the spacewalk because the shuttle has a smaller than usual four-person crew that was already constrained by a tight training schedule.

The final spacewalk by shuttle astronauts was part of the previous shuttle mission of the Endeavour in May.

NASA has added an extra day to the mission, due to the amount of material that must be transferred from Atlantis to the space station, with the shuttle's expected return to Earth on July 21 for the last-ever shuttle landing.