An Inside Look at the Water/Urine Recycling System on the Space Station

NASA's Water Recovery System. Credit: NASA

International Space Station Commander Chris Hadfield “lifts the lid” on the Water Recovery System, the first liquid recycling system to be flown in space that cleans almost all the “water” (greywater, urine, sweat) produced by crew members so that it can be used again. As previous space station resident Don Pettit has said, “Yesterday’s coffee becomes today’s coffee.”

Previously, Russia’s space station Mir recycled cosmonaut’s sweat, but this system on the ISS can recycle about 93 percent of the liquids it receives. The ISS’s water recycler uses a distiller that looks like a keg. On Earth, distilling is a simple process of boiling water and cooling the steam back into pure water. But without gravity, the contaminants in water never separate from the steam no matter how much heat is used. So, the keg-sized distiller spins to produce an artificial gravity field while boiling the water. The contaminants in the urine or greywater press against the sides of the drum while the steam gathers in the middle and is pumped to a filter.

Nancy Atkinson

Nancy has been with Universe Today since 2004, and has published over 6,000 articles on space exploration, astronomy, science and technology. She is the author of two books: "Eight Years to the Moon: the History of the Apollo Missions," (2019) which shares the stories of 60 engineers and scientists who worked behind the scenes to make landing on the Moon possible; and "Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos" (2016) tells the stories of those who work on NASA's robotic missions to explore the Solar System and beyond. Follow Nancy on Twitter at https://twitter.com/Nancy_A and and Instagram at and https://www.instagram.com/nancyatkinson_ut/