Personal Hygiene in Space: How it Works

NASA Space Toilet - How To Use The Bathroom in Space
NASA Space Toilet - NASA Potty Training. NASA

There are many things we take for granted here on Earth that take on a whole new aspect when you're orbiting in microgravity. One of the most-asked questions that NASA receives involves bathroom rituals. All human missions have to deal with these issues as humans do more living and working in space.  In particular, for long-duration missions, these ordinary daily habits take on added importance since they require sanitary conditions to operate in the weightlessness of space.

Let's see what it's like to do personal hygiene in space.

Taking a Shower

There used to be no way to take a shower on an orbital craft, so astronauts had to make do with sponge baths until they returned home. They washed with wet washcloths and utilized soaps that do not need to be rinsed off. Keeping clean in space is as important as it is at home, and even doubly so since astronauts do, at times, spend long hours in space suits wearing diapers so they can stay outside and get their work done. 

Things have changed and nowadays, there ARE shower units on the International Space Station. They jump into a round, curtained chamber, do their thing, and then suction up all the water droplets when they're done. To provide a little privacy, they extend the curtain of the WCS (Waste Collection System), the toilet or bathroom. These same systems may well be used on the Moon or an asteroid or Mars, when humans get around to visiting those places in the near future.


Brushing those Teeth!

Just because you're in space doesn't mean you can't brush your teeth. In fact, dental hygiene is incredibly important, since the nearest dentist is a few hundred miles away if you get a cavity. But, toothbrushing presented a unique problem for astronauts because toothbrushing is a messy operation and you can't really just spit in space and expect your environment to stay tidy.

So, a dental consultant with NASA's Johnson Space Center in Houston developed a toothpaste that can be swallowed. It is now marketed commercially as NASAdent. It has been a great breakthrough for the elderly, hospital patients, and others who have trouble brushing their teeth. It is foamless and ingestible.

Astronauts who can not bring themselves to swallow the toothpaste, or who have brought their own favorite brands sometimes spit into a washcloth.

Toilet Habits in Space

Since there is no gravity to either hold a toilet bowl full of water in place or pull human wastes down, designing a toilet for zero-gravity was not an easy task. NASA had to develop a way to use air flow to make the urine or feces go where they wanted.

The toilets on the International Space Station are designed to be as much as possible like those on Earth. However, there are some unique differences. Astronauts use straps to hold their feet against the floor. Pivoting bars swing across the thighs, ensuring the user remains seated. Since the system operates on a vacuum, a tight seal is essential.

Besides the main toilet bowl, there is a hose, which is utilized as a urinal by men and women. It can be used in a standing position or can be attached to the commode by a pivoting mounting bracket for use in a sitting position.

A separate receptacle allows for disposal of wipes. All units use flowing air instead of water to move waste through the system.

The human waste is separated and solid wastes are compressed, exposed to vacuum, and stored for later removal. Waste water is vented to space, although future systems may recycle it. The air is filtered to remove odor and bacteria and then returned to the station.

Future waste-removal systems on long-term missions may involve recycling for onboard hydroponics and gardens systems, or other recycling requirements. Space bathrooms have come a long way from the early days, when astronauts had pretty crude methods to handle the situation.


Edited and updated by Carolyn Collins Petersen.