If history has taught us one thing, it is that science fiction often gives way to science fact. Consider 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 the Space Shuttle. And who can forget Jules Verne’s classic, From the Earth to the Moon, and how it anticipated that humans would one day walk on the Moon? Almost a century later, this dream would be realized with the Apollo Program.
The latest comes from Cornell University, where a team of researchers has developed a novel in-suit urine collection and filtration system inspired by the suits the Fremen wore in Frank Herbert’s Dune. Once integrated into NASA’s standard spacesuit—the Extravehicular Mobility Unit (EMU)—this system has the potential to provide astronauts with additional water while reducing the risk of hygiene-related medical events. In short, the stillsuit technology has the potential to enable longer-duration missions on the surface of the Moon, Mars, and orbit.
The research team was led by student researchers Sofia Etlin, Luca Bielski, and Julianna Rose, specialists in space medicine, ornithology, and plant science at Cornell University. They were joined by multiple colleagues from the Department of Biology and the Weill Cornell Graduate School of Medical Sciences at Cornell University. Their paper that described their system appeared on July 11th in Frontiers in Space Technologies. As they indicate in their study, astronauts have been conducting extravehicular activities (EVAs) aboard the ISS using the same spacesuits as their Apollo predecessors.
The Extravehicular Mobility Unit (EMU). Credit: NASA
These suits include a disposable diaper, the Maximum Absorbency Garment (MAG), which collects urine and feces during EVAs lasting up to 8 hours. According to a report by the Office of the Chief Health and Medical Officer (OCHMO), astronauts are expected to have seven urination and two defecation events daily, but the frequency varies during spacewalks. Based on the 37 EVAs conducted aboard the ISS between 2021 and 2023, NASA recorded an average spacewalk duration of 6 hours and 26 minutes, while the longest lasted 8 hours and 56 minutes.
Exposure to waste for extended periods leads to hygiene problems that could develop into urinary tract infections (UTIs) and gastrointestinal distress. In addition, the current EMU comes with a 0.95 liter (0.25 gallon) In-suit Drink Bag (IDB). According to NASA guidelines, this volume is roughly 25% to 35% of what an astronaut needs to consume daily – 3.7 liters (1 gallon) for men and 2.7 liters (0.71 gallons) for women. Given that missions on the lunar surface and Mars are expected to entail long-duration 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 spacesuits, known as the Axiom Extravehicular Mobility Unit (AxEMU), were designed to reflect the recently updated Extravehicular Activity (EVA) hydration guideline of approximately 240 mL (~8 oz) per hour – effectively increasing the suit’s water supply to 2 liters (0.5 gallons). But as Etlin told Universe Today via email, these designs still fall short in the hygiene department. “In the new generation of spacesuits, which are currently being produced by the company Axiom Space, the system that deals with urine is being left as it was in the original suits from the 70s,” she said.
To address this, the team developed a novel in-suit urine collection and filtration system that addresses both concerns. Not only will it ensure that astronauts have a reserve supply of water that is replenished as they conduct long-duration EVAs. It also addresses the issue of health and hygiene by preventing the astronauts from remaining in contact with their urine. As Etlin explained, the inspiration came from the Fremen stillsuits featured in Frank Herbert’s Dune, which she read as an undergrad in 2022:
“In the novel and film adaptations, the stillsuit is a full-body suit worn by the Fremen, the people of the desert planet Arrakis. It collects all water produced by their body—primarily sweat and urine—and filters it into drinking water, helping them survive on their water-scarce planet. As I dove more into space, I came across Dr. Chris Mason through his book, The Next 500 Years, and decided to cold-email him, presenting my stillsuit idea. We had the chance to meet a couple of months later, and his first thought was: ‘Why not build this into a spacesuit for astronauts?'”
The prototype “stillsuit” that could be integrated into future spacesuits. Credit: Etlin, S. et al. (2024)However, instead of building a full-body suit to accommodate this new system, the team designed a module focused specifically on urine collection and filtration that can fit into existing spacesuits. In time, a multidisciplinary team that included Mason, Bielski, and Rose was assembled, and from this, their stillsuit technology was born! As Elfin explained, the new system consists of two elements: the Urine Collection Device (UCD) and the Urine Filtration System (UFS):
“The first part of our design would replace the diaper, or MAG, that the astronauts currently wear with a garment that sucks urine away from the body when the astronaut starts to urinate. The key function of this is to avoid excessive exposure to urine, which causes some of the hygiene issues we outline in the paper. Next, the urine goes through a two-stage filtration system that uses forward osmosis coupled with reverse osmosis to produce pure water while minimizing energy use, which is another big concern in spacesuits. This clean water is then brough to the in-suit drink bag to be consumed.”
The urine collection garment (see above) maintains a diaper-like portion for feces, which Elfin and her colleagues hope to address in the future. The whole apparatus is intended to be placed in a pouch weighing about 8 kg (17.6 lbs) and measuring 38 x 23 x 23 cm (15 x 9 x 9 inches). This pouch could be mounted on the back of the AxEMU along with the suit’s portable life support system (aka the 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 regular feature in spacesuits worn by Artemis astronauts as they explore the lunar surface. The ability to remain healthy, hydrated, and comfortable for longer periods will ensure that NASA and its international and commercial partners can build the necessary infrastructure to allow for a “sustained program of lunar exploration and development.” Said Elfin:
Artist’s illustration of the new spacesuit NASA and Axiom are designing for Artemis astronauts. It’s called the xEMU, or Exploration Extravehicular Mobility Unit. Credit: NASA
“Spacewalks are going to become longer, more frequent, and more physically demanding when we go back to the Moon and in the decades following as we attempt to establish a more permanent presence there. After looking at the current spacesuit designs, we think they may be insufficient to keep the astronauts healthy and performing at a high level through these increasing challenges. The increased water available to astronauts would make them more productive and decrease the risks of any health complications during the spacewalk itself, while the urine collection component of our system would better preserve their health and morale in the long term.”
Further Reading: Frontiers in Space Technology
