Astronauts go on 2nd spacewalk at space station

Cape Canaveral: Astronauts took another spacewalk at the international space station on Saturday, this time to lighten the workload for future crews.

Steven Swanson and Joseph Acaba floated outside early in the afternoon, as the station-shuttle complex soared 220 miles (354 kilometers) above the South Pacific.

They promptly made their way to the end of the space station's framework, and loosened bolts holding down batteries that will be replaced on the next shuttle visit in June.

Also on their to-do list are jobs such as deploying equipment storage platforms, 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 on 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!"

In this image provided by NASA Astronaut Richard Arnold participates in the mission's first scheduled spacewalk to connect the S6 truss segment to the International Space Station Thursday March 19, 2009. The blackness of space and Earth's horizon provide the backdrop for the scene. On Saturday afternoon, astronauts Steven Swanson and Joseph Acaba are scheduled to float out of the linked space station and shuttle to do some chores that will ease the burden for future spacewalkers.

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.

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.