Space station astronauts conduct 2nd spacewalk to upgrade power systems

Astronauts aboard the International Space Station on Friday conducted their second spacewalk in a week to complete a battery upgrade to the outpost's power system.

American astronaut Shane Kimbrough and Thomas Pesquet of the European Space Agency, a first-time spacewalker, switched their spacesuits to battery power at 6:22 a.m. EST (1122 GMT), signifying the start of Friday's spacewalk planned for about six-and-a-half hours.

The duo are expected to install adapter plates and hook up electrical connections for the remaining three of six new lithium-ion batteries installed on the station's starboard truss.

U.S. space agency NASA said in a statement the three new batteries installed on Jan. 6 during the first spacewalk with Kimbrough and his American counterpart Peggy Whitson are "functioning properly and all electrical loads are being routed normally to systems through that power channel."

Earlier this week, ground controllers have used the Canadian-built robot called Dextre to move the three new lithium-ion batteries for Friday's spacewalk into their ordered slots.

In all, the new lithium-ion batteries will replace 12 nickel-hydrogen batteries currently used on the station to store electrical energy generated by the station' s solar arrays.

Nine of the older batteries will eventually be stowed in a Japanese cargo resupply craft that is expected to depart the station later this month and burn up in the Earth's atmosphere. Three others will remain on the station's truss, disconnected from the power grid.

This is Kimbrough's fourth spacewalk and Pesquet's first. Pesquet tweeted about his excitement on Thursday: "Tomorrow's a big day: better bring our A-game, to be safe & efficient." Enditem