NASA has cancelled what would have been the first all-female space walk in history over ill-fitting spacesuits, the agency announced Monday.
The extra-vehicular activity (EVA) is still planned for Friday, but will now be conducted by NASA astronauts Christina Koch and Nick Hague. It was originally supposed to be performed by Koch and NASA astronaut Anne McClain.
NASA has been receiving backlash and accusations of sexism about the cancellation on social media. While the gender gap in spaceflight is a very real problem, the lack of appropriate spacesuits in this instance has more to do with McClain’s adjustment to the microgravity environment than gender bias from NASA.
McClain conducted her first space walk with Hague on March 22 and wore a large hard upper torso component that worked well for her in ground exercises. During the space walk, McClain found that the component didn’t fit as well as expected, and decided she would be better equipped with a medium.
“Anne did train in both a large and a medium hard upper torso on the ground,” Brandi Dean, a spokesperson for NASA, confirmed in an email to Motherboard. “We do our best to anticipate the spacesuit sizes that each astronaut will need, based on the spacesuit size they wore in training on the ground, and in some cases astronauts train in multiple sizes.”
That said, microgravity changes the human body in unpredictable ways. “No one training environment can fully simulate performing a spacewalk in microgravity, and an individual may find that their sizing preferences change in space,” Dean said.
Though there are two medium components on the International Space Station (ISS), only one is EVA-ready. It would take about 12 hours of crew time to get the second medium suit ready for the space walk. Time on the ISS is valuable, so NASA opted to switch the roster instead.
NASA officials have also stated that the first all-female EVA was not intentionally planned to be a historic event—it was just how the selection process happened to shake out.
“It just wasn’t something that jumped out at us because it all starts here with competence and abilities, regardless of being male or female,” Kenny Todd, ISS Mission Operations Integration Manager, said in a media briefing about the space walk on March 19. “It’s a great opportunity and a great way to highlight some of the things that are going on here, but these two space walkers are just solid astronauts.”
In the same briefing, Mary Lawrence, NASA’s flight director for this series of EVAs, noted that the roster could change. “Anne and Christina will have the opportunity to be the first all-female EVA which I think will be a proud moment for NASA—if the assignments stay as we planned,” she said.
Lawrence also emphasized that microgravity can throw a wrench into EVA planning. “When [astronauts] launch on board, we know pretty well what suit size they are but, of course, your body changes slightly in space due to fluid shifts or spine elongation,” she said.
The series of three space walks is focused on installing new lithium-ion batteries connected to the ISS’s solar panels. At this time, there is no planned future EVA involving only female space walkers.
Koch will wear the medium suit on Friday with Hague. McClain will wear the suit on a third space walk with Canadian Space Agency astronaut David Saint-Jacques that is tentatively scheduled for April 8.
Ultimately, the call to change assignments was made for the safety of the astronauts. While it is disappointing that McClain and Koch will not get to work together for this series of EVAs, the proportion of female astronauts is steadily growing. Half of NASA’s 2016 class of astronauts were women, including McClain, and about a third of NASA’s active astronaut candidates are women. The odds are good that two women will be paired together in the coming years.
McClain and Koch will still get to join the elite club of space walkers within the already elite club of astronauts.
“It is a rare experience within a rare experience to get to do a space walk,” said former NASA astronaut Kathryn Sullivan, who became the first American woman to perform an EVA in 1984, in a phone call with Motherboard. “It’s a very memorable thing and all you want to do is do more.”
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This article originally appeared on VICE US.