In a video posted on NASA’s YouTube channel this week, International Space Station (ISS) astronaut Chris Cassidy said that by far the most popular question the crew receives from Earthlings is: “How do astronauts go to the bathroom?”
Happy to offer some insight into the procedure — without offering too much detail — Cassidy explained the various steps required to relieve yourself when living aboard the orbiting outpost 250 miles above Earth.
The American astronaut described the process using the space station’s newly delivered toilet, which, despite its updated design, operates in a similar way to the previous version.
As you can see from the video (below), the new toilet — officially known as the Universal Waste Management System (UWMS) — sports a compact design, and hardly resembles the kind of contraption we’re used to using here on terra firma.
Doing “number ones” in microgravity conditions would ordinarily be a messy affair, which is why the ISS’s toilet deploys a suction mechanism to “catch” urine before it floats off, ending up who-knows-where. Once removed, the urine is filtered and processed so it can be used as drinking water.
Solid waste, on the other hand, is deposited in a plastic bag that’s then sealed up and pushed into a container in the toilet’s base, which can hold around 30 deposits before it needs emptying. You’ll be pleased to know that this particular waste is not transformed into food. Instead, some of it is returned to Earth for analysis, while the rest is loaded into a cargo ship that burns up on re-entry through Earth’s atmosphere.
The new space station toilet includes a more ergonomic design that requires less clean-up time, and has been constructed using more durable parts that should cut down on maintenance. It’s also lighter and a little smaller than its predecessor.
At the 6:10 mark in the video, look out for Cassidy’s handwritten message under the toilet seat, informing future astronauts that the UWMS was installed this week “by your friendly ISS plumber.”
Cassidy ends the video by saying that he hopes people find it educational, while at the same time admitting that it’s unlikely to have any effect on the number of times he’s asked about how astronauts use a bathroom in space.