A new sci-fi-inspired spacesuit that recycles urine into drinking water may soon enable astronauts to perform lengthy spacewalks on upcoming lunar expeditions.

The prototype, modeled after the “stillsuits” from the sci-fi classic Dune, collects urine, purifies it, and returns it to the astronaut through a drinking tube within five minutes. This innovative suit could potentially be used before the end of the decade in NASA’s Artemis program, which aims to learn how to live and work for extended periods on another world.

“The design includes a vacuum-based external catheter leading to a combined forward-reverse osmosis unit, providing a continuous supply of potable water with multiple safety mechanisms to ensure astronaut wellbeing,” said Sofia Etlin, a researcher at Weill Cornell Medicine and Cornell University and co-designer of the suit.

NASA is preparing for the Artemis III mission in 2026, which aims to land a crew on the lunar south pole, with the ambition of launching crewed missions to Mars by the 2030s. While urine and sweat are already routinely recycled on the International Space Station (ISS), Etlin notes that an equivalent system is needed for when astronauts are on expeditions.

“Astronauts currently have only one liter of water available in their in-suit drink bags,” said Etlin. “This is insufficient for the planned longer-lasting lunar spacewalks, which can last 10 hours, and even up to 24 hours in an emergency.”

Longstanding complaints persist about the current waste management solution, known as the maximum absorbency garment (MAG), essentially an adult diaper. These garments are reported to be leak-prone, uncomfortable, and unhygienic, leading some astronauts to limit their food and drink intake before spacewalks and causing others to experience urinary tract infections (UTIs).

“If you’re giving NASA billions of dollars, you’d think they wouldn’t keep the diaper,” said Sofia Etlin, who surveyed astronauts while researching the new design. “It’s commonplace for the MAG to leak,” she added. “The astronauts talk about how, at a certain point, they can’t tell whether it’s urine or sweat anymore. They’re like, ‘Yes, I’m an astronaut, and this is a burden I have to bear.’”

Etlin suggested that future commercial astronauts might be less likely to tolerate such issues. Prof. Christopher Mason of Weill Cornell Medicine, the study’s senior author, said: “Even in the absence of a large desert planet, like in Dune, this is something that could be better for astronauts.”

The proposed stillsuit system includes a molded silicone collection cup that fits around the genitalia, available in different shapes and sizes for men and women. This cup is contained within an undergarment made of multiple layers of flexible fabric.

The silicone cup connects to a moisture-activated vacuum pump that automatically activates when the astronaut begins to urinate. Once collected, the urine is diverted to the filtration system, where it is recycled into water with an efficiency of 87%. The system uses osmosis to remove water from urine and a pump to separate water from salt. Collecting and purifying 500ml of urine takes only five minutes. In practice, the purified water could be enriched with electrolytes and returned to the astronaut as an energy drink.

The system measures 38cm by 23cm by 23cm and weighs approximately 8kg, making it sufficiently compact and light to be carried on the back of a spacesuit. The team plans to recruit 100 volunteers in New York this autumn to test the system for comfort and functionality.

“Our system can be tested in simulated microgravity conditions, as microgravity is the primary space factor we must account for,” said Mason. “These tests will ensure the system’s functionality and safety before it is deployed in actual space missions.”