The second spacewalk in history to be conducted entirely by female astronauts started at the International Space Station on Wednesday.
It is the second time in history when two women performed a spacewalk without any men. NASA astronauts Jessica Meir and Christina Koch are scheduled to swap the batteries outside of the International Space Station.
The space station relied on nickel-hydrogen batteries to store energy generated by the vehicle’s solar panels for decades. But since 2017, NASA has been periodically replacing these old batteries with newer lithium-ion batteries.
The new batteries are lighter, hold more of a charge, and are supposed to last much longer than the originals.
These both are the same astronauts who completed the first all-female spacewalk in October. These will be the second and third spacewalks for Meir and the fifth and sixth for Koch.