Rare all-woman spacewalk this month won't be the last, NASA says

Two women will make a sortie together into space later this month in a rare moment in spacewalk history.

The International Space Station (ISS) spacewalk with NASA astronauts Jasmin Moghbeli and Loral O'Hara will be only the fourth extravehicular activity (EVA) with an all-woman crew (the other three were all done by the same two people). It's currently set for Oct. 30, after a delay due to a leak on the orbiting complex.

"U.S. spacewalk 90 will be the 4th spacewalk to be conducted by two women astronauts, and it will not be the last as we continue to live and work in space," NASA officials wrote in a statement to Space.com Friday (Oct. 13).

Moghbeli and O'Hara's excursion was delayed 10 days, from Oct. 20, after a leak of ammonia coolant was detected in a backup radiator for the Russian Nauka science module on the ISS. NASA managers decided on Wednesday (Oct. 11) to postpone two upcoming U.S. spacewalks as a precaution; the flakes are toxic, and any nearby spacewalks require decontamination procedures. Russia will conduct its own EVA on Oct. 25 to learn more about what happened.

Related: International Space Station leaks coolant into space, but astronauts are not in danger

EVAs using current NASA spacesuits, called the extravehicular mobility unit or EMU, are rare with smaller bodies that may include women's. That's because the hardware was designed in the 1970s, when American astronauts were all men, and men typically have larger bodies. (New spacesuits being made for future NASA programs, including moon exploration, will be far more friendly for different sizes.)

It was a different time for hires more generally in the 1970s; back then, NASA sourced most of its astronauts from the military, whose own corps was majority white male. The first NASA astronaut class with women and people of color was in 1978, as NASA was pivoting its spaceflyer corps deeper into science and technical hires.

Female NASA astronauts so far have overcome the sizing issues with exactly one set of astronauts: a threesome of excursions that Christina Koch and Jessica Meir performed in 2019 and 2020. After their historic first venture on Oct. 18, 2019, the women wrote a Washington Post op-ed expressing their aims in removing "faulty stereotypes built up by decades of limited-size spacesuits," emphasizing that with the work of technicians and trainers they were safely able to execute their tasks.

A previous effort to walk in space with two women was canceled before Koch's and Meir's trio of EVAs, however. Koch had expected to join NASA astronaut Anne McClain on a spacewalk in March 2019, but McClain pulled out after finding she was uncomfortable in the medium-sized parts for her spacesuit assigned for that task. NASA considered swapping out those parts in orbit but elected not to, due to scheduling concerns.

The new spacewalk with Moghbeli and O'Hara will focus on maintenance tasks, including removing a faulty electronics box from a communications antenna and replacing a bearing assembly (one of 12) on the solar alpha rotary joint supporting the station's port truss solar panel. The bearings are needed to track the sun as the station goes around Earth.

Assuming another spacewalk, with O'Hara and European Space Agency astronaut Andreas Mogensen, goes forward on Oct. 19, the all-woman spacewalk will be O'Hara's second and Moghbeli's first.