How Do You Go to the Toilet in Space?

by JoHarrington

Zero gravity presents its own challenges, not only for answering a call of nature but other things too. Ingenuity is needed when everything wants to just float away.

Those working in the International Space Station exist for months on end without feeling the effects of gravity. With no sense of up or down, those astronauts can simply float down corridors enjoying their weightlessness.

The experiments and research conducted in space add so much to the sum of human knowledge. It's humbling to know that our kind has evolved to the point where we can leave our planet, and survive.

But how do astronauts wash their hair, when water simply drifts away? And what happens if someone gets ill?

Haynes International Space Station: 1998-2011 Owners' Workshop Manual

What is Zero Gravity?

More correctly called Zero Net Gravity, it is when there is no gravitational force exerting itself upon any part of an object or body.

Image: Astronauts on the ISS eating a meal.If you can physically touch it, then gravity is working upon it. It's that force, invisible to the naked eye, which holds all matter together.  But we can see its effect. 

Drop a stone from your hand and it will plummet to the ground. Jump into the air and you'll soon be returned to your feet.

This is because our planet is using gravity to keep us close.  The bigger the matter, the greater its gravitational pull. Planet Earth is the biggest ball of matter in our vicinity. Eat all the hamburgers you want, you'll never be larger.

Even the moon up there can't counteract the gravitational force of the Earth. It's too small. But it tries. Oceans swish back and forth, like our seabeds are little more than gigantic bowls, as the water tries to reach the moon. It won't fly off into space. Even here the Earth keeps it close. It rises up and down shorelines instead, high tide and low tide corresponding to wherever the moon is orbiting in the sky.

But get far enough way from the Earth and that gravity field weakens. It's still there, because the gravity field is infinite. Those on the International Space Station (ISS) are far enough away from our planet to encounter what happens next. They are effectively in free-fall towards the Earth. Their bodies, and all of the tools and apparatuses that they use, appear and act weightless. This is Zero Gravity.

So how then, amidst all this wonder, do they clip their toe nails?

Astronaut Chris Hadfield: Nail Clipping in Space

What Happens to Matter in Zero Gravity?

Unlike on Earth, things dropped (or otherwise let loose) won't just plummet to the floor. The Space Station itself is falling at the same rate as everything in it.

Accordingly items have the propensity to simply hang in the air, or float away, following its own momentum.

A similar effect can be seen on Earth, when we blow bubbles from a wand. There both the soapy membrane and the air inside are very light. Our bubble is able to drift on top of carbon dioxide in the air, thus appearing to defy gravity.

In space, the weightlessness is real and so is the aimless drifting. That stone dropped could hover around until it collides with another solid object. Like someone's head.

Small objects, such as nail clippings, could so easily be breathed in by an astronaut. Hence the need to keep them contained.

Gravity by Brian Clegg

What Happens if you Vomit in Space?

Unsavory Things Floating About in Zero Gravity

With such an enclosed system, as on the ISS, there is no way for matter to escape. It's imperative that nothing is allowed to drift through the air, which could endanger the astronauts on board.

Nail clippings can choke. Scissors can put eyes out. Larger objects might cause a nasty crack on the head.  But other things could be downright toxic.

Human waste is expelled from the body for a reason. Allowing vomit, excrement or urine to drift away at will could easily lead to astronauts becoming quite sick. It could enter the eyes, causing infection. It could be breathed in leading to a stomach upset at least. At worst, we're looking at typhoid or cholera.

It's not just the 'ewwww' factor, which makes people want to control those bodily fluids in space. It's plain health and safety.

Chris Hadfield Demonstrates Wringing a Wet Washcloth in Space

How Liquids Behave in Space

In addition to objects floating around, Zero Net Gravity will cause other things to behave differently to how they do on Earth.

Liquids form as droplets in the air, or else they are bound by their surface tension to the nearest larger object.

Both phenomena were demonstrated in the YouTube video above, when Canadian astronaut Chris Hadfield attempted to wring out a water drenched towel on the ISS. While some droplets did drift away, he was able to retain much of the water on his hands and wash-towel. He was just careful not to break the surface tension.

This is precisely how astronauts wash their hair, as shown in the footage below.  In the first, Mike Fossum talks us through the process. It's fascinating and quite wonderful, but immediately begs the question - how do you wash LONG hair in space?

Fortunately astronaut Anousheh Ansari also allowed her ablutions to be filmed aboard the ISS. The answer is - patiently!

Space Hygiene: Hair Washing in Space

Washing Hair in Zero Gravity

The International Space Station Children's Books

How Do You Go to the Toilet in Zero Gravity?

Having looked at the problems and the dangers, it's time to finally answer the question.

Image: ISS space toiletThe first issue for any astronaut answering a call of nature is their own weightlessness. They can't just sit down on the toilet and emit a sigh of relief. They'd float off again.

It all requires training back on Earth, plenty of practice, then a bit of preparation while on board the ISS. More than anything, it demands a perfect aim.

Our desperate astronaut slips his or her feet into the foot slots. It provides the anchorage to brace themselves in place. Two foam covered handles can be maneuvered across their thighs to help pin themselves onto the toilet bowl. Some astronauts simply reach up and hold onto the ceiling as well.

A clear plastic bag is inserted into the silvery receptacle to their side. It's ready to receive any tissues. Such things cannot be dropped into the bowl beneath them.

Then it's decision time. Number one or number two? They can't happen together, because each is collected and disposed of in different ways. In order to urinate, the male astronauts take a tube attached to the unit. It's placed over their anatomy and they are good to go.

A light flow of air persuades the urine droplets to continue down the tube, instead of floating away. The suction cannot be too great, as that would cause the poor gentleman an injury.

For female astronauts, the method is nearly the same, except they have further choices before they begin. Three different funnels may be attached, each shaped slightly differently in order to gain the closest match. For the ladies, the key here is to position the funnel snug against them. They haven't anything to insert into the tube, unlike the men!

Even more problematic are bowel movements. With the astronaut's rear end pressed as tightly to the toilet seat as possible, they are able to expel their waste. However, they are aiming at a hole just four inches in diameter. This takes a lot of practice to get right!

ISS Commander Suni Williams and the Space Loo

International Space Station Kits and Books

Updated: 02/07/2014, JoHarrington
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JoHarrington on 06/09/2013

I'd love to go into space. If only to 'fly' through the ISS.

It used to creep me out, particularly when I thought about Michael Collins - the bloke who kept flying the spaceship around the dark side of the moon, while Armstrong and Aldrin were exploring on the moon. I tried to imagine what it would be like for him, unable to see the Earth, so far away, on his own. *shudder*

But now I know he would have been chatting with Houston all along, and it would probably have been mindbogglingly amazing.

Digby_Adams on 06/09/2013

I have to admit that I've always wondered about this. Just one more reason, I'll never go into space. I really found this interesting.

JoHarrington on 06/08/2013

Well you have now! And such things are hard to stop thinking about. :)

AngelaJohnson on 06/08/2013

Things I haven't thought about!

JoHarrington on 06/07/2013

Ragtimelil - Maybe there's a vocation in there for you. Bathroom finder supreme! Need a bathroom? Any place, anywhere, Ragtimelil Restroom Spotters will find one just for you!

Slogan written. Now we just have to print the posters.

JoHarrington on 06/07/2013

Dustytoes - Ever since I researched and wrote this article, that keeps coming to mind. How often do you go to the toilet for one thing, and it turns into another? They have to ensure that it doesn't!

Sorry, bad mental images...

Ragtimelil on 06/07/2013

I always spot the nearest bathroom as soon as I go anywhere. It runs in my family....

dustytoes on 06/07/2013

I couldn't be an astronaut. I don't think I'd go to the bathroom ever. Then I would explode and be all over the ship. Really, these are special people.

JoHarrington on 05/30/2013

Ragtimelil - I'm taking that as a huge compliment! :D Thanks! I hadn't wondered at all, because it hadn't crossed my mind. But as soon as it did, it took over. I had to find out then!

JoHarrington on 05/30/2013

Spirit of RS - I'm glad to have rekindled some of that childhood wonder! Your model shuttle sounds tremendous.

I haven't seen 'Spacecamp', nor even heard of it before. I've made a note of it now though, so I can check it out. Thanks for the heads up.

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