98% of urine and sweat becomes potable water

Last week, the US space agency Nasa communicatedthat she has reached a technological milestone that could one day play a major role in missions to the moon and beyond. She was able to configure the International Space Station’s Environmental Control and Life Support System (ECLSS) to recycle 98 percent of the water that the astronauts “create” on board the station.

Part of the ECLSS uses “advanced dehumidifiers” to capture the moisture that station crew exhale and sweat as they go about their daily tasks.

Another subsystem, the “Urine Processor Assembly”, recovers the water from the astronauts’ urine using vacuum distillation. According to NASA, the distillation process produces water and a urine brine that still contains recoverable H₂O.

This system now results in a 98 percent water recovery rate. So far, an impressive 93 to 94 percent of the water produced by the astronauts on board has been reused.

“This is a very important step in the development of life support systems,” says NASA engineer Christopher Brown, adding: “Let’s say you collect 50 kilograms of water on the station. You lose a pound of that, and the other 98 percent just keep going and going. Keeping that going is quite an accomplishment.”

“The treatment is basically similar to some terrestrial water treatment systems, only in microgravity,” said Jill Williamson, director of ECLSS water subsystems at NASA. “The crew doesn’t drink urine, they drink water that has been reclaimed, filtered and purified so it’s cleaner than what we drink here on Earth.”

Williamson said systems like the ECLSS will be critical as NASA conducts more extra-orbit missions. “The less water and oxygen we have to carry up, the more scientific knowledge can be loaded onto the launch vehicle,” she says. “Reliable, robust regenerative systems mean the crew doesn’t have to worry about it and can focus on the real purpose can focus on their mission.”