NASA astronauts Chris Cassidy and Robert Behnken have begun the first of two scheduled spacewalks to replace batteries on one of two power channels on the far starboard truss (S6 Truss) of the International Space Station.
The spacewalkers switched their spacesuits to battery power at 7:32 a.m. EDT to begin the spacewalk, which may last as long as seven hours.
Watch the spacewalk on NASA TV and on the agency’s website.
Cassidy and Behnken will be removing existing nickel-hydrogen batteries and replacing them with new lithium-ion batteries that arrived on a Japanese cargo ship last month. The batteries store electricity for one pair of the station’s solar arrays, and the swap will upgrade the station’s power supply capability. The batteries store power generated by the station’s solar arrays to provide power to the microgravity laboratory when the station is not in sunlight as it circles Earth during orbital night.
This is the 228th spacewalk in support of space station assembly and maintenance. Cassidy is extravehicular crew member 1 (EV 1), wearing the spacesuit with red stripes, and using helmet camera #18. Behnken is extravehicular crew member 2 (EV 2), wearing the spacesuit with no stripes and helmet camera #20. It is the seventh spacewalk for both astronauts.
Behnken arrived at the space station in May in SpaceX’s Crew Dragon with NASA astronaut Doug Hurley as part of the Commercial Crew Program’s Demo-2 mission, which returned astronaut launches into orbit from U.S. soil for the first time since the space shuttle’s retirement in 2011.