The ISS Is Getting A New WC

Every home needs renovations after a few decades, and the International Space Station is no different. This fall, they’ll be getting a new Universal Waste Management System (UWMS), aka a new toilet.

Though the news coincides with increased traffic to the ISS, this move stems from a more serious issue with bacterial contamination during longer-term space travel. Today’s ISS toilets already recycle urine back into potable water and scrub the air reclaimed from solid waste as it gets compacted and stored. The new UWMS will act more like a food dehydrator, reducing the water content as much as possible to save on space, and petrifying the poo to inactivate the bacteria.

The current commode on the American side of the ISS was designed in the 1990s and is based on the Space Shuttle’s facilities. It has a funnel with a hose for urine and a bag-lined canister with a seat for solid waste, both of which are heavily vacuum-assisted.

Though the current toilet still does everything it’s supposed to do, there is room for improvement. For instance, women find it difficult to engage both parts of the system at the same time, and almost everyone prefers the toe bars on the Russian toilet to the more encumbering thigh bars on the American throne. Also, the current commode’s interface is more complicated than it needs to be, which takes up valuable crew time.

Check out that cheek cleaver! Via NASA (PDF)

The most intimate change is probably the seat design. In a weightless environment, it’s more like a hovering zone than a throne. According to the white paper (PDF), the UWMS seat has homing ridges and “includes a tailbone section to encourage crew cheek separation”. Maybe the vacuum works against separation? We’re not sure.

Although the new latrine wasn’t designed specifically for the ISS, the crew members will make excellent guinea pigs to test the new features. And they don’t have to send it back or anything — it will stay up there until it breaks, or until the ISS is retired, whichever comes first. A second unit is being built for those longer-term missions and will be installed on the Orion capsule, which is slated to return to the Moon in 2024.

32 thoughts on “The ISS Is Getting A New WC

        1. If you’re talking about the one that looks like a crap bucket and urine funnel with a vacuum hose, there is way too much room for error there.

          At least the seat can form some type of cheek seal…don’t need any rouge deuces floating around the interior of the ISS.

          1. You don’t want it to seal against the buttocks. You need an airflow into the collector from all sides or else your business won’t move towards it and will just cling on and smear.

      1. I think, it was the other way round: “Rocket science is mostly highly sophisticated plumbing.” And when I look at the enormous pipes of (liquid fuel) engine, I can understand this. :-)

    1. Eventually, yes, but it would stay in orbit for a long time. And you don’t really want junk floating around the space station when trying to dock a space craft.

      If you wanted to deorbit it quickly, you would have to launch it. Scott Manley did a video on this.

      1. “And you don’t really want junk floating around the space station when trying to dock a space craft.”

        Nah, that’s no problem… *looking up aerospace windshield wiper manufacturers and buying shares*

        1. im sure with a little lox you could get a semi decent isp out of it. be sort of a hybrid engine. they used to burn dried crap (aka buffalo chips) on the american frontier, and probably a few other times/places. so it is flammable and likely even more so after be vacuum dedicated and compressed.

          1. Yeah but you might need to form them into tubes to approximate the breadstick + oxygen (if I remember right) cutter that someone baked up ages ago. Nobody wants that job.

    2. Depends on which has the better ballistic coefficient.

      The station has huge solar panels which drag it down faster compared to an aerodynamic and dense frozen turd, so there’s a real danger that the turd will actually come back a few orbits later. Sort-of like how some fighter pilots managed to shoot themselves by firing the guns and then diving below the hail of bullets faster than the bullets would fly.

  1. Since gravity isn’t a problem the squatting position should be used as the way to interface to it, and make it more equal for both sexes and truly international.

    1. That is hard to do weightless. It will need squatting straps and a pooping harness I wager. Maybe a Johnson Strap. Automatic enema deployment for those tough situations. This could be quite a machine, and very entertaining to watch :-)

    2. Why should that be “truly international”? I am perfectly fine with a western style toilette and find it very difficult if I have to use a squatting position – luckily I very rarely have to do “it” at a tree.
      I think the urge to propagate a squatting position is just the urge from some people – mostly ‘alternative’ or ‘green’ – to educate people to something uncomfortable just for the sake of education or change.
      If something has to be made equal that is different by nature, normally the only way is to make it harder for the one who has it a little more comfortable, because the other way round is not possible, otherwise it would not be harder for the other part.

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