Two astronauts made history last October when they participated in the first ever all-female spacewalk. During a spacewalk, astronauts leave their spacecraft, usually to fix or replace something on the vessel’s exterior. In this case, the astronauts were aboard the International Space Station (ISS), a laboratory larger than a football field floating about 250 miles above Earth.
Christina Koch and Jessica Meir spent almost 7 hours outside the ISS replacing a broken battery. Koch will come home to Earth in February, and Meir will return in March. Koch will have spent a total of 335 days in space, just shy of the NASA record for a single space mission. Scientists will study her to understand how extended stints in space affect a woman’s body.