Astronaut explains extremely 'complicated and expensive' way they have to poop in space

We’ve all wondered it - what happens to an astronaut’s poop in space?

People can spend months at a time floating above the Earth’s atmosphere in the International Space Station.

They live, sleep and eat on board the spacecraft, so it begs the question, what happens to their poop?

One astronaut has lifted the lid to explain the extremely “complicated and expensive” way they have to poop in space.

In an interview with WIRED, astronaut Mike Massimino was tasked with answering questions from social media about what it’s like to go to space, replying to burning questions about wearing belts in space, fixing equipment without gravity and how they fill the time while traveling up to space.

Massimino was happy to shed light on the internet’s queries, reading out one user’s comment which asked: “Question for astronauts, where your poo poo go?”

Astronaut Mike Massimino explained what happens when you poop in space (Dia Dipasupil/Getty Images)

Massimino explained: “On the space shuttles, we did have a commode. It was not a flush toilet. It had a seat on it. It was fairly complicated.

“You had to turn it on and create a vacuum and make sure everything was where it's supposed to. And then, every couple of days, the poop would be kind of compressed.”

The astronaut detailed how the “ingenious” method would use different screens, “and so poop would be in there, then one screen would go and compact it and then more poop, and then another screen... But we just collected that poop over the course of a couple of weeks.”

The astronaut revealed that pooping in space is extremely "complicated" (SCIEPRO/Getty Images)

But if you’re worrying that the poop gets ejected from the shuttle, left to fly back down to Earth, fear not!

Massimino explained how the fecal matter gets brought back home with the astronauts.

He said: “Everybody's poop went into the same thing. We brought all that poop back with us for no reason other than we didn't know what else to do with it.

“I don't think there was any science behind it, but that poop came back to Earth and it was serviced on the ground, never to be seen again, as far as I know.”

Astronaut Mike Massimino answered the internet's burning questions (Brad Barket/Getty Images)

However, he revealed that the toilet facilities at the International Space Station work a little bit differently.

Massimino continued: “The toilet is a can with a seat on top of it and a plastic bag as a liner.

“So you poop into that can, you close up the bag, and then you get it to the bottom of the can and you put a new liner in for the next person.

One viewer asked the astronaut what happens when people poop in space (quantic69/Getty Images)

“Once that can fills up, you take the seat off, you cap it, and you put it in a cargo ship that is now a dumpster.

“There are certain cargo ships that come up and then they don't return to Earth with anything.

“They're used as a dumpster, so all your waste, garbage, things you don't need, go in there.

“It re-enters [the atmosphere] and everything burns up during re-entry.”

Now you know!