One of the astronauts on the spacewalk, Bob Behnken, recently made headlines when he took off in the SpaceX Crew Dragon

By Rachel DeSantis
June 26, 2020 01:09 PM

A pair of astronauts have ventured outside the International Space Station some 254 miles above Earth for a spacewalk that is being streamed live by NASA.

Chris Cassidy and Bob Behnken started their spacewalk around 7:35 a.m. on Friday to begin replacing aging nickel-hydrogen batteries for one of the orbiting laboratory’s two power channels, NASA said.

The new lithium-ion batteries the men are replacing the old batteries with arrived at the International Space Station last month on a Japanese cargo ship.

Their spacewalk is expected to last up to seven hours, and they’ll go for round two — which will also be broadcast live — on Wednesday.

In the stream, which is being broadcast on both Twitter and YouTube, Cassidy is wearing the spacesuit with red stripes, while Behnken’s suit has no stripes.

Friday’s mission is the seventh spacewalk for both Cassidy and Behnken, who were selected by NASA in 2004 and 2000, respectively.

The International Space Station said on Twitter around 12 p.m. ET that the mission was about two hours ahead of schedule, and that the astronauts were removing the fourth battery, something they weren’t expected to do until Wednesday. About an hour later, they were on to the sixth battery.

Cassidy is the commander of Expedition 63, while Behnken recently joined the crew after arriving aboard SpaceX’s Crew Dragon on the Demo-2 test flight.

The two spacewalks will be the 228th and 229th in support of space station assembly, maintenance and upgrades, NASA said. The missions come after NASA astronauts Christina Koch and Jessica Meir made history when they performed the first-ever all-women spacewalk in October.