Astronauts go on 2nd spacewalk at space station

As soon as they floated outside, Steven Swanson and Joseph Acaba made their way all the way to the end of the space station's power-grid framework. They loosened bolts holding down batteries that will be replaced on the next shuttle visit in June, and deployed an equipment storage platform.

A space station alarm went off as the spacewalkers wrapped up that job. The gyroscopes that were maintaining the position of the station-shuttle complex became overloaded from the astronauts' work on the end of the truss. Discovery quickly assumed control with its thrusters.

"Nothing to worry about," Mission Control assured the astronauts.

Other work that was being tackled by the spacewalkers: installing a GPS antenna and using an infrared camera to photograph a pair of radiators, one of which has a peeling cover.

It was the second spacewalk in three days for the crew of shuttle Discovery. On Thursday, Swanson and another astronaut installed the final pair of solar wings at the orbiting outpost. The panels were unfurled Friday.

Saturday's excursion, though just as busy, was not expected to have the drama associated with the multimillion dollar, high-priority solar wings. NASA was still basking in that success, telling the astronauts in a wake-up message that the space station "now looks like the artist renderings that we've been seeing for years. A day to celebrate!"

Swanson and Acaba, a former Florida schoolteacher making his first spacewalk, were tackling some chores that were added just this past week. The antenna work, for instance, was supposed to occur on a later spacewalk that ended up being canceled because of shuttle Discovery's repeated launch delays.

The GPS antenna, the second to be installed on the Japanese laboratory, will be needed when Japan launches a new space station cargo carrier this fall.

Swanson and Acaba's battery work took them to the far left end of the space station framework that holds the space station wings, the opposite side from where Thursday's job took place. NASA said there could be some induced electrical voltage way out there, but the risk of shock was considered small and well within acceptable limits. Indeed, nothing wayward happened.

Nonetheless, as a precaution, the metal wrist rings on the men's spacesuits were covered with insulating tape. They also kept checking their cuffs to make sure they were down and fastened.

One more spacewalk is planned Monday during Discovery's mission.

The shuttle will depart the space station Wednesday, eight days after arriving, and return to Earth next Saturday.

---

On the Net:

NASA: http://spaceflight.nasa.gov

©2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.