Dune-inspired stillsuits could allow astronauts to convert urine into water

If history teaches us anything, it’s that science fiction often gives way to scientific fact. Think of the Star Trek Communicator and the rise of flip phones in the late 1990s and early 2000s, or how 2001: A Space Odyssey predicted orbiting space stations and reusable space planes like the International Space Station (ISS) and Space Shuttle. And who can forget Jules Verne’s classic From the Earth to the Moon and its anticipation of one day walking on the moon? Almost a century later, that dream was realized with the Apollo program.

The latest news comes from Cornell University, where a group of researchers developed a new urine collection and filtration system in a spacesuit, inspired by the suits worn by the Fremen in Frank Herbert's novel Dune. Once integrated into a standard NASA spacesuit, the Extravehicular Mobility Unit (EMU), the system could provide astronauts with additional water and reduce the risk of hygiene-related medical problems. In short, the suit technology could enable longer missions to the surface of the Moon, Mars, and in orbit.

The research team was led by student researchers Sophia Etlin, Luca Belsky, and Julianna Rose, all of whom specialize in space medicine, ornithology, and plant sciences at Cornell University. They were joined by numerous colleagues from the Department of Biology and the Weill Cornell School of Medical Sciences at Cornell University. A paper describing their system appeared July 11 in the journal Frontiers in Space Technologies. As the study notes, the astronauts conduct extravehicular activities (EVAs) aboard the ISS using the same spacesuits as their Apollo predecessors.

These spacesuits include a disposable Maximum Absorbency Garment (MAG) diaper that collects urine and feces during EVAs, which can last up to eight hours. According to the Office of the Chief Health and Medical Officer (OCHMO), astronauts are required to urinate seven times and defecate twice daily, but this frequency varies during spacewalks. Of the 37 spacewalks conducted aboard the ISS between 2021 and 2023, the average spacewalk duration was 6 hours, 26 minutes, with the longest spacewalk lasting 8 hours, 56 minutes.

Prolonged contact with waste leads to hygiene problems that can develop into urinary tract infections (UTIs) and gastrointestinal disorders. In addition, the current EMU comes with a 0.95-liter in-suit hydration bag (IDB). According to NASA recommendations, this volume is approximately 25-35% of what an astronaut needs to consume daily – 3.7 liters for men and 2.7 liters for women. Given that missions to the surface of the Moon and Mars are expected to involve long EVAs, neither of these systems is sufficient for NASA's Moon-to-Mars mission architecture. As Etlin told Universe Today via email, the next-generation suits, known as the Axiom Extravehicular Mobility Unit (AxEMU), were designed to meet recently updated hydration guidelines for extravehicular activity (EVA) — about 240 ml (~8 ounces) per hour, allowing for up to 2 liters (0.5 gallons) of in-suit water capacity. But as Etlin put it, these designs still fall short of hygiene requirements. “The next-generation suits that Axiom Space is currently producing have the same urine purification system as the original suits from the 1970s,” she said.

To address this, the team developed a new in-suit urine collection and filtration system that addresses both issues. Not only does it provide astronauts with a backup supply of water that will be replenished as they perform long EVAs, it also addresses the health and hygiene issue of preventing astronauts from coming into contact with their urine. As Ethlin explains, the inspiration came from the Fremen suits depicted in Frank Herbert’s Dune, which she read as a student in 2022:

“In the novel and film adaptation, the stillsuit is a full-body suit worn by the Fremen, inhabitants of the desert planet Arrakis. It collects all the water their bodies produce — primarily sweat and urine — and filters it into drinking water, helping them survive on a water-scarce planet. As I was getting more into space, I met Dr. Chris Mason through his book The Next 500 Years and decided to send him a letter outlining my stillsuit idea. We met a couple of months later, and his first thought was, 'Why not make this into a spacesuit for astronauts?'

But rather than build a full-fledged spacesuit to house the new system, the team designed a module specifically for collecting and filtering urine that could be built into existing spacesuits. Over time, a multidisciplinary team was assembled that included Mason, Belsky, and Rose, and from there, the spacesuit technology was born. As Etlin explained, the new system consists of two elements: the urine collection device (UCD) and the urine filtration system (UFS):

“The first part of our project would replace the diaper, or MAG, that astronauts currently wear with a garment that sucks urine away from the body when the astronaut begins to urinate. The key function of this garment is to avoid excessive exposure to urine, which causes some of the hygiene issues described in the paper. The urine would then pass through a two-stage filtration system that uses forward osmosis combined with reverse osmosis to produce clean water with minimal energy consumption, another important issue in spacesuits. This clean water would then be pumped into the suit’s drinking bag for consumption.”

The urine collection garment (above) includes a diaper-like section for feces, which Etlin and her colleagues hope to use in the future. The entire apparatus is designed to fit into a bag weighing about 8 kg and measuring 38 x 23 x 23 cm. This bag can be attached to the AxEMU's back, along with the suit's portable life support system (aka backpack), which provides air, heating and cooling, food, and water. The team emphasizes that the slight increase in weight and bulk will be offset by the increased comfort and resource efficiency provided by the system.

This system and its successors could become a standard feature of the spacesuits Artemis astronauts will wear while exploring the lunar surface. The ability to stay healthy, hydrated, and comfortable for long periods of time will enable NASA and its international and commercial partners to build the necessary infrastructure for a “sustainable lunar exploration and development program,” Etlin said.

“Spacewalks will become longer, more frequent, and more physically demanding when we return to the Moon and in the decades to come as we attempt to establish a more permanent presence there. Having reviewed existing spacesuit designs, we believe they may not be adequate to keep astronauts healthy and performing at a high level while performing these increasingly challenging missions. Increasing the amount of water available to astronauts will make them more productive and reduce the risk of health complications during the spacewalk itself, and the urine collection component of our system will help maintain astronaut health and morale in the long term.”