Scientists unveil prototype spacesuit system that recycles urine as drinking water

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more.

A marvel of the “Dune” sci-fi film franchise is the survival outfit worn by the desert-dwelling Fremen — “stillsuits” that recycle all bodily fluids into potable water. Now, such technology appears to be on the horizon, with scientists unveiling a prototype spacesuit system that turns urine into drinking water.

Astronauts can spend a considerable amount of time outside their space habitat doing extra-vehicular activities, or EVAs. There were 37 spacewalks conducted between 2021 and 2023 for either scientific experiments or to carry out repairs on the International Space Station, and they lasted an average of 6 hours and 26 minutes, according to a study by scientists at Cornell University published Friday in the journal Frontiers in Space Technology. Spacewalks can last up to more than 8 hours.

When spending these long periods on spacewalks, astronauts currently wear the familiar white puffy EVA suits, which contain a maximum absorbency garment. These disposable garments are essentially diapers that collect and contain urine and feces. They are required to be able to contain up to one liter (1.8 pints) of urine and 75 grams (2.6 ounces) of fecal matter a day for each crew member.

However, these EVA suits were designed more than 40 years ago, and NASA currently does not have concrete plans to renew or replace them. The space agency announced in June that it was canceling contracts worth more than $100 billion with Collins Aerospace to create next-generation spacesuits, though at least two other US companies are currently working on spacewalk suits and NASA can solicit additional contractors, the space agency confirmed to CNN.

“You’d think in the 21st century, astronauts would not be using diapers,” lead study author Sofia Etlin, an astrobiologist and research staff member at Weill Cornell Medical College’s Mason Lab in New York, told CNN on Friday.

While the diapers can effectively absorb waste, they have been found to harm astronauts’ health and cause discomfort. Astronauts have reported diapers leaking, making them unable to distinguish between their urine and sweat, and complained of skin rashes and odor issues. Crew members face medical risks such as cross contamination with fecal matter, urinary tract infections and gastrointestinal distress, which are made worse by the reduced access astronauts have to medical care.

Some have even reduced their meals several days before an EVA to avoid having to wear one, which could impact their performance on strenuous spacewalks, according to the researchers.

Simply being in space causes dehydration, and physically demanding spacewalks cause further dehydration, which impairs astronauts’ performance. Yet, the in-suit drink bag, which currently provides astronauts with 32 ounces of water and a small dose of glucose, also has “significant issues,” including being time-consuming to prepare, contributing to reduced work efficiency, according to the researchers. Astronauts have said the current amount of water it provides is not enough.

‘Dune’ system

To “promote astronaut wellbeing,” the researchers have designed a novel in-suit urine collection and filtration system, or “Dune” system,” Etlin said.

The system would recycle urine using forward and reverse osmosis, a model used by the current wastewater management treatment system aboard the space station, to remove contaminants from the urine and filter it to drinking water.

One aspect of the system is a urine collection device, which would feature a silicon cup, shaped differently for men and women. The device would have several layers of fabric, including an antimicrobial fabric, to allow urine to be drawn away from the body quickly to the outer surface of the cup, where it can be pumped away, reducing the health risk posed by extended exposure to the urine.

The liquid would then enter the filtration system, a two-step apparatus that removes water from urine into a salt solution, with a pump then separating pure water from salt.

The study authors proposed that a volume of 500 milliliters (0.9 pints) of urine could be processed in less than five minutes, with the effective recycling of more than 86.8% of it into drinking water.

The water would then be pumped into the in-suit drink bag, where it would be replenished with electrolytes, and potentially carbohydrates, for nutrition and energy needs.

The whole apparatus would sit in a pouch that could be mounted on the back of an EVA suit, adding 8 kilograms (17.6 pounds) to its overall weight.

While the suit’s “weight is certainly a concern for upcoming lunar missions, we believe that the increased comfort and resource efficiency provided by the system will more than make up for the slightly increased bulk,” the study authors said.

Spacesuits reimagined

Etlin said this is a “prime time” to be developing this technology since “spacesuits as we know it are being reimagined.”

While NASA canceled its contract with Collins Aerospace for space suits to be worn on the ISS, it still has a contract worth up to nearly $230 million to develop lunar spacesuits with Houston-based company Axiom Space.

Designed to have better flexibility and motion, provide more visibility and insulation, and have a portable life support system, the suits could serve a crucial role in NASA’s Artemis III mission, which seeks to return astronauts to the moon later this decade, to venture further than ever before.

However, even these novel suits designs currently still have the old-style diaper, according to Etlin. (Axiom did not immediately respond to a request for comment about its spacesuit design.)

“In the Artemis missions, astronauts might be out there for hours and hours on end, or there might be sort of emergency scenarios where they need to return to the base, but their rover broke down. You have all sorts of contingency scenarios where you need water and you need a waste system that isn’t limited to what a diaper can hold,” she said.

In addition to the Artemis program, which seeks to land a woman and person of color on the moon for the first time, the race is on for for Mars, where drinking water would be a luxury.

For more CNN news and newsletters create an account at CNN.com