Quick Scoop: Astronauts poop in space using a specially designed vacuum toilet that holds them in place with footrests or straps and uses suction instead of gravity to move waste away. On the International Space Station, the toilet lid triggers suction right away to keep things from floating off and to control odors.

How it works

  • Pooping: Astronauts sit on a small toilet seat, and the toilet starts sucking air as soon as the lid is lifted.
  • Staying put: Because there’s no gravity, the bathroom has handholds and footholds, and astronauts may strap in so they don’t drift away mid-use.
  • What happens to waste: Waste is collected in sealed containers; on many missions it is later burned up when a cargo ship reenters Earth’s atmosphere.

Why it’s tricky

In space, loose droplets or solids can float around, which is bad for astronauts and for equipment, so toilets rely on suction and careful sealing instead of gravity. The system is also designed to reduce smells and keep the cabin clean.

Fun fact

Astronaut toilets are a serious engineering problem, not a joke: NASA even spent millions developing improved space toilets for the ISS.

If you want, I can also explain how astronauts pee in space or what happens on long missions like Mars.