NASA is recycling 98 percent of astronaut pee and sweat on the ISS into drinkable water

It’s a big deal for future missions beyond Earth.


NASA has achieved a technological milestone that could one day play an important role in missions to the Moon and beyond. This week, the space agency revealed (via that the International Space Station’s Environmental Control and Life Support System (ECLSS) is recycling 98 percent of all water astronauts bring onboard the station. Functionally, you can imagine the system operating in a way similar to the Stillsuits described in Frank Herbert’s Dune. One part of the ECLSS uses “advanced dehumidifiers” to capture moisture the station’s crew breaths and sweat out as they go about their daily tasks.

Another subsystem, the imaginatively named “Urine Processor Assembly,” recovers what astronauts pee with the help of vacuum distillation. According to NASA, the distillation process produces water and a urine brine that still contains reclaimable H20. The agency recently began testing a new device that can extract what water remains in the brine, and it’s thanks to that system that NASA observed a 98 percent water recovery rate on the ISS, where previously the station was recycling about 93 to 94 percent of the water astronauts were bringing aboard.

“This is a very important step forward in the evolution of life support systems,” said NASA’s Christopher Brown, who is part of the team that manages the International Space Station’s life support systems. “Let’s say you collect 100 pounds of water on the station. You lose two pounds of that and the other 98 percent just keeps going around and around. Keeping that running is a pretty awesome achievement.”

If the thought of someone else drinking their urine is causing you to gag, fret not. “The processing is fundamentally similar to some terrestrial water distribution systems, just done in microgravity,” said Jill Williamson, NASA’s ECLSS water subsystems manager. “The crew is not drinking urine; they are drinking water that has been reclaimed, filtered, and cleaned such that it is cleaner than what we drink here on Earth.”

According to Williamson, systems like the ECLSS will be critical as NASA conducts more missions beyond Earth's orbit. “The less water and oxygen we have to ship up, the more science that can be added to the launch vehicle,” Williamson said. “Reliable, robust regenerative systems mean the crew doesn’t have to worry about it and can focus on the true intent of their mission.”