Who Knew a Space Toilet Could Mean So Much?

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Meir said the training is crucial for understanding the old toilets’ plumbing, but the best advice for actually using them comes from her fellow astronauts. When Meir flew to the ISS last year, her best friend, Christina Koch, was already there. Koch showed her how to situate herself and which handrails and foot restraints helped most. “I actually found that I could do it with the existing toilet, even though other females haven’t been able to. So, definitely some anatomical differences, or maybe just some technique differences,” Meir said. “I was so relieved to realize that I could do it, because I was just like, This is going to be really annoying if I can’t do it.”

The newest lavatory was designed specifically with female anatomy in mind. In this way, the Universal Waste Management System is more than a toilet. It is a symbol of a changing American space program that for its first two decades took only men to space. Although men still make up the majority of NASA’s astronaut workforce, there are more women astronauts than ever before, and the agency has recognized that it must adapt its technology to meet their needs. “It’s about time,” Nicole Stott, a retired NASA astronaut who flew two missions to the space station, told me.

NASA consulted women astronauts in the design for the new system, including Stott. While the basic setup is unchanged, engineers have “completely recontoured” the urine funnel to better accommodate the female anatomy, according to Melissa McKinley, the project manager for the effort. They also made changes to the positioning of both the urine funnel and the toilet seat, allowing women to more comfortably use them at the same time. As an added bonus, astronauts don’t have to turn on the toilet before relieving themselves; as soon as they remove the urine funnel from its cradle or lift the toilet lid, the fan kicks on.

It might seem baffling, even a little absurd, that the organization that put men on the moon more than half a century ago did not, until this year, enable them to go number one and number two at the same time. But the problem originates in that very achievement: NASA put men on the moon. The existing toilet on the American side of the space station was developed in the 1990s, using a Soviet model. The gender balance of astronauts in the United States and Russia was even more lopsided at the time than it is today, so male anatomy and needs drove the design. Astronauts used a similar design on the space shuttles, which delivered the hardware to assemble the ISS.

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Stott and Meir likened the clumsy toilet design to NASA’s supply of spacesuits for astronauts working outside the space station. Last year, the agency was forced to reshuffle a spacewalking assignment because there weren’t enough spacesuits on board to fit Koch and Anne McClain, who both wore a size small. A male astronaut replaced McClain on the spacewalk. NASA’s current spacesuit wardrobe, much of it designed in the 1970s, was meant to be customizable, with mix-and-match parts. But production on the smallest sizes was halted in the ’90s because of budget cuts, and because NASA had never planned a two-woman spacewalk before 2019, the ISS simply wasn’t prepared with enough garments for its female crew members.