Astronauts could drink their own urine with water-recycling spacesuit

Astronauts on spacewalks may soon be able to drink their own urine, thanks to a water filtration and recycling system that could be ready in time for NASA’s upcoming crewed missions to the moon.

Waste water from urine and sweat is already recycled on the International Space Station, but the bulky equipment required for this doesn’t fit in a spacesuit. NASA’s current solution is the Maximum Absorbency Garment, which, despite the technical name, is essentially just an adult diaper for collecting urine and faeces. At the end of a spacewalk, these diapers go into the ISS’s waste system, eventually being burnt up in Earth’s atmosphere – an unsatisfactory waste of resources.

Chris Mason at Cornell University in New York says the current solution is fine for spacewalks that tend to last only a few hours, but increasing activity in space means a better solution will be needed. He and his colleagues have now developed an 8-kilogram device around the size of a shoe box that can recycle urine – collected by unisex external catheters – with 87 per cent efficiency through a two-step osmosis filter.

The purified water is then ready to drink and can be piped into an in-suit bag. This has the additional benefit of ensuring a steady supply of drinking water: the current NASA spacesuits provide just under a single litre of drinking water, which is often insufficient for a long spacewalk. The remaining 13 per cent of the water content cannot be extracted and remains in the filter.

“I thought this would have been done already, but it’s not,” says Mason. “People that are pushing the limits of humanity will often trade discomfort for the opportunity to explore an entirely new area of science or medicine.”

The filtration technique is the same one as already used on the ISS. But the team says it is easier to extract water from pure urine as it doesn’t include soaps and chemicals, unlike the ISS waste water. Extracting water from stool isn’t “totally solved” yet, but this is less of a limitation because astronauts often claim to simply hold bowel movements in during spacewalks, says Mason.

Many of NASA’s current spacesuits have worked until now, he says, but astronauts in the future are likely to be a more diverse range of shapes and sizes than previous recruits, meaning that change is needed. “The democratisation of space opens new opportunities, but also new challenges that we have to address.”

Currently, the device is a prototype tested only in the laboratory, but human trials that include collecting urine, recycling it and drinking the resulting water will begin by November.

The researchers say the device could be built into new versions of spacesuits that are planned for NASA’s upcoming Artemis missions to the moon. NASA has contracted a private company, Axiom Space, to build its new suits, but the company declined to answer New Scientist‘s questions about how it would be dealing with human waste. NASA didn’t respond to a request for comment.