HOUSTON (Reuters) - Two visiting space shuttle astronauts floated outside the International Space Station on Thursday to hook up a final set of solar panel wings to bring the orbital outpost to full power.
Spacewalkers Steven Swanson and Richard Arnold left the space station’s Quest airlock at around 1:20 p.m. EDT to begin a scheduled 6 1/2-hour outing.
“Have a good run and do good work out there,” Discovery pilot Tony Antonelli told his crewmates as they slipped outside the airlock.
The goal of the spacewalk, the first of three planned during Discovery’s eight-day stay, is to install the last metal girder onto the station’s exterior spine.
The 31,000-pound (14,060-kg) segment, built by Boeing for NASA, contains a pair of delicate panels studded with solar cells to collect light from the sun. With the new wings, the station will be able to generate 124 kilowatts of usable electricity, enough to power about 42 average U.S. homes.
NASA and its partners in the $100 billion project plan to use the extra power to support an expanded, six-person crew — double the current size — and more science experiments.
The station, a project of 16 nations under construction for more than 10 years, is scheduled to be finished in 2010.
From their vantage point outside the station, Swanson and Arnold helped robot arm operators John Phillips and Koichi Wakata ease the truss, which is 45 feet long and 16 feet wide, into position on the right side of the station.
“Basically, it’s like backing your car in the garage,” Swanson said in a preflight interview. “We’ll be telling John, ‘a little bit closer, a little bit to the left, little bit to the right,’ and they will fly it into position where we can then drive the bolts.”
Swanson, a veteran of two previous spacewalks, and Arnold, a rookie astronaut, were working against the clock to get the truss off battery power and wired into the station’s electrical system.
The men had to make four electrical connections — two power and two data — to attach the new beam to one already anchored along the station’s right side. It was tough going for a while, with the astronauts struggling with clamps and other equipment.
Just before 4 p.m. (2000 GMT), the crew radioed to Mission Control that they were finished with the job.
“It wasn’t quite as smooth as we had hoped, but those guys did a great job and I’m very happy to say you have a go for (truss) activation,” Discovery astronaut Joseph Acaba told ground control teams.
The spacewalkers then turned their attention to opening boxes holding the station’s solar panels so they can be deployed later in the mission. They also were scheduled to unfurl radiator panels on the truss.
The first order of business, however, was acclimating to open space. “You see the moon straight above?” Swanson asked his spacewalking partner as he took in sights from 220 miles above Earth. “It’s a nice view.”
Editing by Jane Sutton and Eric Walsh