A Soyuz spacecraft that launched three new crew members to the International Space Station docks on March 15. (Agence France-Presse/Getty Images)

Mary Robinette Kowal is the author of the space exploration novel “The Fated Sky.”

Space sounds like the future. It’s rocket ships and astronauts, Buck Rogers and Captain James T. Kirk. But our concepts of the future are built on 1950s sexism — and not just our ideas, but the actual infrastructure of space travel. How can we boldly go where no one has gone before when two women apparently can’t spacewalk at the same time?

This week, a seemingly perfect PR opportunity for NASA turned into a disaster when the first all-women spacewalk scheduled in the agency’s 50-year history was scrapped due to logistics.

The spacewalk was a coincidence in the first place. Last year, a Soyuz spacecraft malfunctioned during launch, which shifted the staffing schedule on the International Space Station, causing astronauts Anne McClain and Christina Koch to be stationed there at the same time.

It’s already telling enough that having two women in space at this particular moment is an accident. But the scenario worsened after McClain’s first spacewalk last week, when she realized that she needed to use the medium size of the Extravehicular Mobility Unit, which astronauts use for spacewalks. So does Koch.

The EMUs were designed more than 40 years ago, when all the astronauts were men. Eleven of the original 18 are still in use, but only four are rated for spaceflight and all of those are on the space station.

There are two medium hard upper torsos for the EMUs on the station, but because the only people taking spacewalks in the past year have been men using the large and extra-large suits, the other medium hard upper torso isn’t prepared for use. That procedure takes hours of effort with no margin for corner-cutting. There are only six people on the station, and their time is tightly scheduled.

The size of the suits is not a matter of aesthetics. Cady Coleman, a shuttle-era astronaut, had to improvise padding to wear inside an EMU when she was in the Neutral Buoyancy Lab, the training facility where astronauts practice spacewalks. This put her at a disadvantage since NASA decides who gets the opportunity to spacewalk based on their performance in the NBL.

If astronauts are too small for the hard upper torso parts of their EMUs, they face multiple problems such as loss of mobility or trouble reaching the dials that control suit temperature in the vacuum of space. Story Musgrave experienced frostbite on his fingers during an equipment test in 1993. Gemini astronauts had problems with overheating. Improper fit isn’t just a matter of comfort, but of safety.

When NASA does design logistics or equipment specifically for women, the results can be off-kilter — or revealing.

The first American woman in space, Sally Ride, had to explain that women didn’t need 100 tampons for a one-week mission. The agency also designed a makeup kit for the female astronauts, which Ride laughed at. But her colleague, Rhea Seddon, requested it because she knew how the media represented women who appeared without makeup.

NASA has been aware of the problem with the EMUs for decades but lacks the funding to create new ones. All they can do is try to keep 40-year-old suits going, carrying a decades-long imprint of sexism into the present. Why are we asked to adapt our own spacesuits just to participate in space exploration? What kind of expectations are we carrying into the future when we have to figure out how to conform to decidedly earthbound expectations of beauty?

I was talking to my friend Kari Love, a retired spacesuit designer, who said that “while we can look back and understand why women were an afterthought in aerospace to this point, we are at serious risk for that to be reproduced as we move into the commercial spaceflight era.”

The decision to restaff the spacewalk by having astronaut Nick Hague join Koch was absolutely correct. The astronauts need to be safe. Having an all-female spacewalk was an accident. It wasn’t a priority. We have never been the priority. In the future of NASA and commercial spaceflight, it’s time to shift our priorities to include everyone.