NASA astronaut Serena Auñón-Chancellor does plumbing in the waste and hygiene compartment of the ISS. Photo: NASA / Wikimedia Commons
Whether you use a hole in the floor or a fancy gold-plated toilet on earth, gravity pulls your trash down and away from you. It is a little more complicated for astronauts to “do their duty”. Without gravity, loose drops or drips could float out of the toilet. This is not good for the health of the astronauts or for the sensitive equipment in the space station.
I study volcanoes on other planets and am interested in how people can work in extreme environments like space.
How do you go to the bathroom in space or on the International Space Station (ISS)? Carefully – and vacuumed.
A bathroom vacuum cleaner
In 1961, Alan Shepard became the first American in space. His trip was supposed to be short, so there was no plan for peeing. However, the launch was delayed by more than three hours after Shepard climbed into the missile. Finally he asked if he could get off the missile to pee. Instead of wasting more time, Mission Control concluded that Shepard was safe to pee in his spacesuit. The first American in space rose in damp underwear.
Fortunately, there is a toilet on the space station these days. The original toilet was designed for men in 2000 and was difficult to use for women: you had to pee standing up. To poop, astronauts used thigh straps to sit on the small toilet and to ensure a tight seal between their floor and the toilet seat. It didn’t work very well and was difficult to keep clean.
In 2018, NASA spent $ 23 million on a new and improved toilet for astronauts on the ISS. To avoid the problems of weightless bathroom breaks, the new toilet is a specially developed vacuum toilet. There are two parts: a hose with a funnel on the end for peeing and a small raised toilet seat for pooping.
The bathroom is full of handles and kicks to keep astronauts from drifting in the middle of their business. To pee, they can sit or stand and then hold the funnel and tube tightly against their skin so that nothing comes out. To poop, astronauts lift the toilet lid and sit on the seat – just like here on earth. But this toilet begins to vacuum as soon as the lid is lifted to prevent it from drifting away – and to control the stench. To ensure there is a tight fit between the toilet seat and the astronauts’ back, the toilet seat is smaller than the one in your house.
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After the deed is done
Pee is more than 90% water. Since water is heavy and takes up a lot of space, it is better to recycle pee than to get clean water from the earth. All astronauts pee is collected and converted back into clean, potable water. Astronauts say: “Today’s coffee is tomorrow’s coffee!”
Astronaut poop is sometimes brought back to Earth for investigation, but most of the time bathroom trash – including poop – is incinerated. Poop is sucked into garbage bags that are placed in airtight containers. Astronauts also put toilet paper, towels, and gloves – gloves help keep everything clean – in the bins too. The containers are then loaded onto a cargo ship that brought supplies to the space station, and that ship is fired to earth and burned in the upper atmosphere.
If you’ve ever seen a falling star, it could be a meteorite burning in the Earth’s atmosphere – or burning astronaut feces. And next time you need to pee or poop, be grateful that you are doing it with the help of gravity.
Tracy KP Gregg is an Associate Professor of Geology at Buffalo University. This article was first published on The Conversation as part of the Curious Kids series. Read the original article.