Washington - Two astronauts Tuesday completed the third spacewalk of the latest shuttle mission to the International Space Station, putting the finishing touches on a Canadian-built, double-armed robot. Rick Linnehan and Robert Behnken worked for nearly seven hours to equip the robot with tools and spare parts before Dextre, as the robot is called, begins to help astronauts with their spacewalks and takes over some maintenance and service work on the expanding space station.
On an earlier spacewalk, Linnehan and Mike Foreman attached Dextre's two arms, each 3.35 metres long, to the station.
Dextre, which cost more than 200 million dollars, is the final component of the station's mobile servicing system.
Before the shuttle returns to Earth March 26, the Endeavour astronauts are to perform two more spacewalks outside the station on Thursday and Saturday.
Over the past year and a half, shuttles have transported huge elements to the space station construction site, including large solar collectors and truss structures.
The goal is to finish construction by 2010 with double the space for orbiting astronauts and an expanded capacity for experiments so the US space agency could retire the 26-year-old shuttles.
After the shuttle programme retires, Russia's Soyuz craft would continue to lift astronauts to the station, but because of their small size, they are unable to carry the huge construction pieces and experimental modules now being transported by shuttles.
