NASA has long had a gender problem. The space agency that launched its first man into space in 1961 did not fly the first woman — astronaut Sally Ride — until 1983. Since then, more than 40 other American women have followed. It’s a figure that still compares poorly with the 300-some men who have earned their space wings, but the astronaut corps is at least sufficiently co-ed that the term “manned spaceflight” has finally been replaced with the gender-neutral “crewed.”

One gender barrier that hasn’t been broken, however, is the all-female spacewalk, or “extravehicular activity” (EVA). While women have gone on spacewalks many times before, there’s never been a multiple-astronaut EVA involving solely women. That was finally supposed to change this Friday, when astronauts Christina Koch and Anne McClain were set to venture outside the International Space Station (ISS) to upgrade batteries on the station’s solar panels. On Monday, however, NASA announced that the plan had changed. An EVA will go ahead as scheduled, but male astronaut Nick Hague, who just conducted a spacewalk with McClain on March 22, will accompany Koch instead of McClain. The reason: There were not enough spacesuits aboard the station in the proper size for both women.

...