Skip to main content

Space station toilet flushes its way to a new milestone

When you gotta go, you gotta go, and according to the “flush” counter on one of the International Space Station’s three toilets, astronauts have gone more than 40,000 times over the past 20 years.

Current ISS crew member Thomas Pesquet broke the news in a post on Twitter on Wednesday, May 12.

Recommended Videos

Clearly delighted at seeing the toilet’s counter reach a new landmark figure, Pesquet tweeted, “40,000 times this space toilet has been used, a milestone!” He added, “We need to maintain it as clean sanitation and sewage treatment is a human right and a UN Sustainable Development Goal.”

40 000 times this space toilet has been used, a milestone! We need to maintain it as clean sanitation and sewage treatment is a human right and a @UN Sustainable Development Goal. #MissionAlpha #SDG6 pic.twitter.com/ekQYXB3CTc

— Thomas Pesquet (@Thom_astro) May 12, 2021

Image used with permission by copyright holder

The space station currently has three toilets on board, so it should be noted that the habitable satellite has in fact hosted thousands more flushing events over the years.

Of course, the microgravity conditions aboard the ISS mean that going to the bathroom in space is a very different process from here on Earth. Indeed, space toilets are not really flushed in the way most earthlings understand the process. Rather, they use a suction mechanism to capture liquid waste before it has a chance to float away and cause a mess. (Interesting tidbit: Urine on the station is later filtered and processed for use as drinking water.)

Solid waste drops into a plastic bag before being sealed and put in a container located at the toilet’s base, which is emptied after around 30 deposits. And no, number twos are not transformed into food. Instead, it will burn up in the Earth’s atmosphere when ejected as part of the station’s trash, while a small amount will be sent to Earth for scientific analysis.

The most recent commode arrived at the space station last year. Known as the Universal Waste Management System, the compact contraption features a more ergonomic design than the other two toilets and has been built with more durable parts that should reduce the need for maintenance.

NASA astronaut Chris Cassidy last year revealed that the most common question he’s asked is, “How do astronauts go to the bathroom?” In the video below, he kindly offers a run-through of the process using the station’s newest toilet.

How to use the Bathroom in Space

The ISS usually hosts around six astronauts, though last month, during a busy crew rotation process, it briefly had 11 on board, putting a little more pressure on resources and possibly causing the occasional line outside a bathroom or two. Commenting on the unusual situation, former NASA astronaut Nicole Stott said, “It’s a blessing that there are three toilets up there now.”

Trevor Mogg
Contributing Editor
Not so many moons ago, Trevor moved from one tea-loving island nation that drives on the left (Britain) to another (Japan)…
See the polar moon sites where NASA plans to land its astronauts
An artist’s concept of an Artemis astronaut deploying an instrument on the lunar surface.

NASA has updated its list of potential landing sites for the next human visit to the moon, which is planned for 2026. The Artemis III mission will see the first crewed lunar landing since the Apollo era, and the plan is for astronauts to explore the moon's South Pole region where there is thought to be water ice on the lunar surface.

NASA shared a list of 13 candidate landing locations for Artemis III in 2022, but has now updated its list to nine candidates. Some of these were on the list previously, while others have been added such as the Mons Mouton mountain and plateau, which is particularly interesting to scientists because the height of the mountain means that there are permanently shadowed regions nearby. These places, where sunlight never touches, are particularly good candidates when it comes to looking for water ice.

Read more
A SpaceX Crew Dragon spacecraft has set a new record
SpaceX's Crew Dragon spacecraft.

SpaceX’s Crew-8 members are finally on their way home after spending nearly eight months at the International Space Station (ISS).

The crew members were supposed to depart the ISS several weeks ago, but poor weather conditions at the splashdown site off the coast of Florida prompted mission planners to delay the homecoming. Prior to that, delays to departure were caused by measures to deal with Boeing’s troubled Starliner spacecraft, which was docked at the station over the summer.

Read more
Departing ISS astronaut still finds time for stunning night shot
The Nile River, Nile Delta, and Cairo, as seen from the ISS.

NASA astronaut Matthew Dominick is preparing to fly home aboard a SpaceX Crew Dragon capsule at the end of the seven-month Crew-8 mission, but he recently found time to snap an incredible night shot featuring the Nile River, the Nile Delta, Cairo, and beyond.

“Moonlight illuminates Cairo and the Mediterranean on a mostly clear night," Dominick wrote in a message accompanying the photo that was shared on X (formerly Twitter) on Sunday.

Read more