The Space Station's current commander and NASA astronauts Anne McClain, Nick Hague and Christina Koch will also be aboard. Hague is designated extravehicular crew member 2 (EV 2), wearing the suit with no stripes, and with helmet camera #17.
Ms McClain and Mr Hague will replace nickel-hydrogen batteries that power a section of solar arrays.
As the inhabitants of Earth busied themselves with their daily lives far below, two NASA astronauts donned their spacesuits at the International Space Station this morning to begin a planned six-and-a-half hour space walk. McClain and Hague left the ISS around 8AM ET this morning, and NASA will be showing live views of their spacewalk throughout the day. This will mark the first all-female spacewalk, a historic event.
The station's eight electrical power channels originally were supported by 48 nickel-hydrogen - NiH2 - batteries, six per channel. The agency isn't sure yet when the next battery-swap spacewalks will take place, as the ISS still needs to get a new shipment of lithium-ion units.
These new batteries provide an improved power capacity for operations with a lighter mass and a smaller volume than the nickel-hydrogen batteries. The work is delicate and demanding, and they have to do it all in zero gravity, making for a very special kind of entertainment.
Another set of batteries for a different power channel is due to be replaced a week from today. "But the space station, it's been up here for 20 years, and it's time to do some upgrades on the outside, and we are ready". Since 2017, NASA has been replacing them with newer lithium-ion batteries, which hold twice as much charge as the old batteries even at their best.