Late Thursday evening, a Northrop Grumman rocket will take off from the Virginia coast, carrying an advanced space toilet for astronauts to the International Space Station. Advertised as smaller and lighter than current toilets on the ISS, the new dresser is also expected to be more accommodating for female astronauts who need to use space facilities.
Called the Universal Waste Management System, the bathroom is one of two upgraded toilets NASA is making to the tune of $ 23 million. While the one to be launched tonight is destined for the ISS, a second identical toilet will also be added to NASA̵
Since this toilet will travel in deep space, NASA needed something compact but just as efficient as the toilets of the past. Heavier and more bulky items are more expensive and more difficult to throw. So NASA did its best to optimize the size of the bathroom, making it 65% smaller and 40% lighter than current ISS toilets. The agency also says engineers have made the bathroom more energy efficient. “You can imagine that optimizing these can help in many ways because space and power are at a premium on a spacecraft,” said Melissa McKinley, project manager for UWMS at NASA, at a news conference last week .
Despite these updates, the new UWMS toilet works in much the same way as toilets already in space. All microgravity toilets rely on one important thing: suction. The suction ensures that the waste produced by the astronauts is actually dragged into the toilet and does not inadvertently float around the crew cabin. To pee in the current toilets aboard the ISS, astronauts use a funnel attached to a tube, with a fan inside, which pulls urine into a tub. For number two, the astronauts “sit” on a tank that uses the same fan that drags their business into a baggy.
The UWMS also relies on a ventilation system and a funnel connected to a pipe. But NASA says it worked diligently with the agency’s female astronauts to better design both the shape of the funnel and the toilet “seat” to fit them. “The funnel design has been completely redesigned to better fit the female anatomy,” said McKinley. “And especially this is a concern when crew members are trying to do two operations – when they are doing both defecation and urination at the same time.” According to McKinley, women’s contributions helped define the shape, length and location of the funnel near the toilet. The seat has also been shaped to make it easier for female astronauts to go to number two while using the tube.
Another important feature of this toilet is that NASA engineers used a special 3D printing technique to make various parts of the system with exotic metals such as Inconel, Elgiloy and titanium. These are sturdy metals, which are necessary for the toilet to withstand a very acidic solution used within the system to treat urine. Urine can sometimes contain solid deposits that get stuck in the toilet and build up over time, so NASA pre-treats the urine with an acid solution to break down those deposits before sending it to an onboard recycling system.
“The acid we use as a pretreatment is very strong,” Jim Fuller, project manager for UWMS at Collins Aerospace, who helped develop the toilet, said at the press conference. “It is so strong that there is only a handful of metals that NASA is aware of that can withstand this pretreatment for an extended period of time.” Those metals tend to be heavy, so NASA devised a special 3D printing technique to create the parts it needed, allowing them to be made lighter than usual. Perhaps the largest 3D printed piece in the system is the titanium toilet fan, which is responsible for extracting all the waste.
One last big update to this system is that it’s all automatic. At this time, the astronauts must turn on a switch to use the other toilets on the ISS, but the UWMS fan turns on automatically when the astronauts remove the funnel from its crib or lift the seat for the “dresser”.
NASA did some tests with the toilet on the ground, orienting it in different positions to see how well the suction worked. Now, the toilet is scheduled to take off Thursday at 9:38 PM ET on Thursday, atop Northrop Grumman’s Antares rocket from NASA’s Wallops Flight Facility in Virginia. Driving inside Northrop’s Cygnus cargo capsule, the toilet will be retrieved by the astronauts once the capsule is attached to the ISS. The astronauts will install the UWMS next to one of the current toilets already on board and test it in the first three months. Eventually, the toilet will become just another bathroom option for astronauts aboard the ISS.
Meanwhile, NASA has even more space toilets to design. In June, the space agency began looking for toilet designs that astronauts could use when working on the moon. When it comes to all kinds of human spaceflight, the messy parts of sending people into space must be considered in order to achieve a smooth mission. “When astronauts have to go, we want to allow them to go boldly,” Fuller said.