NASA astronauts Meir and Koch on the International Space Station (ISS). NASA astronauts Jessica Meir (left, born 1977) and Christina Koch (right, born 1979) inside the Quest airlock preparing the US spacesuits and tools they used on their first spacewalk together (on 18 October 2019). They were the first women to participate in an all-female spacewalk. The Expedition 61 flight engineers are holding the pistol grip tools they used to swap out a failed power controller (battery charge-discharge unit) that regulates the charge to batteries that collect and distribute power to the International Space Station. Photographed on 15 October 2019.