How to go to the toilet…in space!
On Earth, we heavily rely on gravity when we use the loo. It pulls everything into the toilet bowl so we can flush it all away.
In space, you don’t get that luxury. Going to the bathroom in zero gravity can get messy because not only will urine and faeces float around the space ship but you’re also likely to float straight off the toilet seat!
Luckily, scientists have invented a solution to protect astronauts’ health and sanity.
Hank Green, a Montana-based scientist, explained in his Youtube video how astronauts use space toilets and how some of that waste is reused on the International Space Station (ISS).
First up, he describes how the toilets for ‘number twos’ work. We’re used to toilet seats with a diameter of up to 28 inches but astronauts have to contend with openings of just four inches wide.
To ensure that no waste escapes, the astronauts are strapped to the toilet seat with restraints similar to car seat belts. They’re given training for this, and NASA has a toilet with a camera inside so the astronauts can practice positioning themselves correctly.
Functionality-wise, the toilet operates like a vacuum cleaner, using differential air pressure to suck the faeces into a separate storage container. The waste is then exposed to the vacuum of space, effectively freeze-drying it, to kill bacteria and eliminate the smell. It is later disposed of on a capsule when returning to Earth.
‘Number ones’ require different apparatus: personal urinal funnels, which are connected to a hose adapter.
Women can place the funnel directly against their bodies but it’s a little more risky for men, who must hold the funnel close enough to catch all of the urine whilst keeping it at a safe distance to prevent an injury.
When astronauts use the funnels, fans suck the urine out into a wastewater tank. The urine is then purified and recycled for the astronauts to drink and bathe in!
None of this comes cheap; the toilet itself costs upwards of £11 million whilst the entire set-up weighs in at a hefty £150 million.
Eventually, NASA hopes to generate electricity from astronauts’ urine using a process known as forward osmosis. ‘If only we could find some equally useful thing to do with our space poop!’ Green concludes.