To help its astronauts boldly go, NASA just shipped a newly designed space toilet to the International Space Station. The first new commode designed in decades will eventually be used for deep space missions, but for now the agency wants to test it out a little closer to home.
The toilet, known as the Universal Waste Management System, arrived at the International Space Station on October 5 as part of a cargo resupply shipment. NASA astronaut Chris Cassidy and his Russian colleagues, Ivan Wagner and Anatoly Ivanishin, are in the process of unpacking the cargo ship, and plan to install the toilet very soon.
It took NASA six years and $23 million to come up with the design for the new, high-tech porta potty. That cost actually covers two toilets. Astronauts will install the first one on the space station. If it performs as expected, a second will travel to the moon as part of the agency’s upcoming Artemis 2 mission, which is scheduled to launch in the next few years. The new toilet might also be used on future crewed lunar landers or in spacecraft headed to Mars.
When designing the new toilet, engineers had to take into account the fact that room is limited inside NASA’s future deep-space capsule, called Orion. So any prospective toilet had to be compact and as efficient as the models currently used on the International Space Station. NASA engineers designed a camper-sized toilet that is roughly 65 percent smaller and 40 percent lighter than the ones currently in use. It is also more energy efficient. “Space and power are at a premium on a spacecraft,” Melissa McKinley, project manager for the new toilet at NASA said during a pre-launch press conference. “You can imagine that optimizing those can help out in lots of ways.”
In many ways, the new toilet essentially works the same way as its predecessors. That’s because all space toilets rely on one important thing: suction. In the absence of gravity, everything tends to float. The waste produced by astronauts needs to be pulled into the toilet, otherwise it could end up drifting around the space station. To pee, astronauts use a funnel attached to a hose that uses a fan to pull the urine into a tank. To poop, astronauts sit over a tank that relies on the same fan to pull their business into a collection bag.
The new toilet is a compact cylinder standing about 28 inches tall and features the same type of fan system, as well as a funnel attached to a hose, as previous iterations. It also has a removable waste compactor for the astronauts to deposit their droppings in. Each time an astronaut poops, their business is sucked into a baggie. Once finished, the astronaut will seal the baggie up, and push the packaged poop down into the canister. They then install a new baggie and the process repeats until the canister is full. As the canister fills up, the bathroom stall may not always smell so fresh. The collection bin holds roughly 30 deposits. Once the bin is full, the poop is then discarded with the rest of the trash into outer space.
The new toilet works in much the same fashion as the old, but differs from previous designs in one key way: inclusivity. Historically, space toilets have been designed to accommodate men. NASA says it worked diligently with the agency’s female astronauts to improve both the shape of the funnel and the toilet seat. “The funnel design was completely re-contoured to better accommodate the female anatomy,” McKinley said. “And particularly this is a concern when the crew members are trying to do dual ops—when they’re doing both defecation and urination at the same time.”
Female crew members provided input that helped redesign the shape and length of the funnel, its position next to the toilet, as well as the shape of the seat. “There was a proximity issue, so the seat and urine funnel have both been engineered to improve the experience for female crew,” she said.
The new toilet also has a special built-in system that pre-treats urine before it's passed off to the station’s life-support system to be recycled for water. Urine can occasionally contain solid material that gets stuck inside the toilet, building up over time. To mitigate that, NASA will employ a highly acidic solution to break down any deposits that might be in the urine. Engineers used a special 3-D printing technique to fashion acid-resistant parts for the toilet out of robust metals such as titanium and other durable alloys
“The acid that we use as the pretreat is very strong,” Jim Fuller, the project manager for the new toilet at Collins Aerospace, said during the prelaunch press conference. “It’s so strong that there’s only a handful of metals that NASA is aware of that can hold up to this pretreat over an extended period of time.”
Another upgrade is that the new toilet is automatic. The current toilet requires astronauts to flip a switch to activate it, but the new toilet fan automatically comes on when astronauts either remove the funnel from its cradle or lift the lid. Cassidy will install the new toilet next to the current toilet in the U.S. segment of the space station very soon. However, astronauts began preparing for its arrival last year, installing a new stall for the upgraded commode. During that process, the old toilet sprung a leak, which left the astronauts scrambling to mop up the water. The leak was just the latest in a series of issues the current model has had over the years, which included a faulty urine fan in 2008 and a clog from calcium buildup in the liquid waste processing system in 2010. McKinley hopes this new design will cut down on future malfunctions.
To prepare for its eventual use in space, the toilet has been extensively tested on the ground, with engineers orienting it in many different directions to ensure the suction worked. The new device is expected to get a lot of use over the next several months as there will be five crew members in the U.S. segment of the space station, rather than the normal three.
Using the bathroom in space may not be the most glamorous aspect of space travel, but astronauts today have it a lot easier than some of those who flew in the early days of space travel. When astronaut Alan Shepard had to go, he simply peed in his spacesuit on the launchpad, and during the Apollo 11 mission a few years later in 1969, astronauts urinated into condom-like sleeves that funneled the pee into a collection bladder worn underneath the astronaut’s clothing. The sleeves were replaced daily and spills happened quite frequently. Pooping was even messier; astronauts essentially taped a bag to their butts which collected their business—if they were lucky. It wasn’t an easy setup as Tom Stafford and the crew of Apollo 10 can attest to. During the mission, Stafford had to warn his crewmates that he missed his mark. “Get me a napkin quick. There’s a turd floating through the air,” he is quoted as saying on a NASA transcript of the mission.
The early days of spaceflight were messy and often very smelly during bathroom breaks. Scientists knew little about how the space environment affected the human body, so NASA even requested that its astronauts bring back all of their poop bags for analysis. While on the lunar surface, however, Apollo astronauts couldn’t exactly open up a flap in their suit and break out a poop bag. During moonwalking sessions, the astronauts wore a diaper, but it’s unclear if any of them did more than pee in them.
When NASA launched Skylab in the 1970s, it was the first time an apparatus loosely resembling a toilet was installed on any U.S. spacecraft. The rudimentary unit consisted of a hole in the wall that sucked urine and feces into collection bags. Afterwards, the crew would have to dry their feces in a specal compartment to bring back to Earth. It wasn’t until the shuttle program launched in 1981 that astronauts received any kind of hardware resembling a terrestrial toilet. That commode was essentially a metal bowl with a suction hose and a funnel to use for urine.
As NASA waits for the new toilet’s installation, the agency is busy designing even more toilets and continuously thinking of new ways to improve its waste collection systems. In June, the agency put out a call looking for potential designs for a future lunar toilet. It’s possible the Universal Waste Management System could work, but NASA wants to consider all its options for how its crews will go on the lunar surface.
The agency is also researching the notion of how to extract water from solid waste so it too can be recycled for crewed missions. Water is a precious commodity in space, and studies have shown that feces contain up to 75 percent water by mass. Right now, all of that goes to waste. If water could be successfully extracted from astronaut poop, it could provide more sources of recycled water.
Scientists have also shown that urea could be used for building materials or fertilizer. Urea is the second most common compound in urine after water and a team of researchers from Europe demonstrated earlier this year that urea could be mixed with moon dirt (known as regolith) and used as building materials. The resulting material, known as a geopolymer, is similar to concrete and could be used to build structures like landing pads and habitats on the moon.
All of this research and invention shows that even the messiest parts of human spaceflight have to be taken into consideration when planning missions. “When the astronauts have to go, we want to allow them to boldly go,” Fuller said.