Live In Orbit: Spacewalks End Station Excursion

Spacewalking astronauts Steve Swanson and Ricky Arnold are back inside the International Space Station after mounting the final segment of an 11-part central truss that serves as the outpost's metallic backbone.

The two shuttle mission specialists made their way back into the Quest airlock and switch their spacewalks off internal battery power after a six-hour, seven-minute excursion. The installation and activation of the S6 truss element completes the U.S. electrical power system and caps a decade-long effort to assemble the station's central truss.

"You guys just did a fantastic job today," Discovery mission specialist Joe Acaba told his crewmates. "It was really good work."

"Hey we just echoed that. That was just outstanding," spacecraft communicator Lucia McCullough said from NASA's Mission Control Center at Johnson Space Center in Houston. "For you and the rest of the combined crew, we're delighted to accept delivery and installation of the S6 truss."

Station skipper Mike Fincke chimed in, too.

"I just wanted to say welcome back aboard the space station. It's a lot bigger than when you left it. Great job out there. You guys were outstanding. Thanks for your hard work."

The spacewalk was the 121st performed in the assembly and maintenance of the station since the first two building blocks of the outpost were linked in low earth orbit in late 1998.

Astronauts and cosmonauts have spent 762 hours and three minutes of spacewalking work during the assembly effort.

Ninety-three of the spacewalks have been staged from station airlocks; 28 have been staged from shuttle airlocks.

It was the third spacewalk for veteran astronaut Swanson. He now has tallied 19 hours and 44 minutes of spacewalking work.

It was the first spacewalk for Arnold.

The spacewalk set the stage for the deployment of the fourth and final set of American solar wings, which are integrated into the S6 truss segment. That work now is being moved up a day to Friday.