NASA astronauts, working in pairs, have carried out more than 200 spacewalks in the past two decades. At a press conference at the agency’s headquarters in Washington, D.C., before the historic spacewalk, a reporter asked officials why it had taken this long to conduct one featuring two women.

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“There are some physical reasons that make it harder sometimes for women to do spacewalks,” said Ken Bowersox, the acting associate administrator for NASA’s division of human exploration and operations. “It’s a little bit like playing in the NBA. I’m too short to play in the NBA, and sometimes physical characteristics make a difference in certain activities, and spacewalks are one of those areas where just how your body is built in shape, it makes a difference in how well you can work the suit.”

Bowersox, a former astronaut who flew on the Space Shuttle five times and spent more than five months on the ISS, pointed to the fact that women are statistically smaller in stature than men. “There have been a lot of spacewalks where very tall men were the ones that were able to do the jobs because they were able to reach in and do things a little bit more easily, get into crevices and things like that,” he said.

Bowersox went on to say that women astronauts have worked around these constraints. “But we’ve also brought women into the crews because of their brains,” he said. “They come in, they bring different skills, they think of things differently. And by using their brains, they can overcome a lot of those physical challenges.”

The remarks were startling. They bore the echoes of early discussions about women’s fitness for spaceflight—for any work once considered the sole domain of men, really—that focused on women’s physical and biological attributes, and, often, the reasons those attributes disqualified them from the job. Bowersox’s comments glossed over factors that might better explain why it’s taken 20 years for two women to spacewalk at the same time—none of which has to do with women’s bodies.

Today’s astronauts wear spacesuits that were made in the 1970s. The earliest designs called for suits to come in a variety of sizes, from extra small to extra large, but budget cuts eventually trimmed down the options. Most astronauts fit into the mediums and larges, but not all, and the sizing constraints actually influenced who got to live on the ISS and who didn’t. Every crew member must be able to spacewalk, and that depends on fitting in a suit. “As a woman, doing spacewalks is more challenging mostly because the suits are sized bigger than the average female,” Peggy Whitson, a retired NASA astronaut who helped build the ISS and conducted 10 spacewalks, once said.

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But this is a limitation of the design of spacesuits, not women’s bodies. “Absolute ugh,” Ellen Stofan, a former NASA chief scientist and the current director of the Smithsonian’s National Air and Space Museum, tweeted when she saw Bowersox’s remarks on social media. “No physical reasons. Not small enough spacesuits. Equipment problems held women back—and the men who made decisions about that equipment.” This argument came up in the spring, when Koch and Anne McClain both needed medium-size spacesuits. The ISS had two on board but only one was properly configured for spacewalking, and the other would take half a day to prepare. As far as the public was aware, NASA had never had a problem dressing two men for spacewalks. McClain ended up sitting out the spacewalk, and Nick Hague, a male colleague, took her spot.