Space alien toilets

Am I the only writer that wonders how the toilets might work on a space station full of aliens? Sure, our loos work with water and gravity but what about diverse biologies in say, Mos Eisley? Man, I’d hate to be the plumber that has to keep that place running.

Warning: This post contains toilet humour (duh)!

Research problems


alien toilet roomsWhen I want to write about something weird, like what sort of toilets space aliens might use, I tend to start by Googling it. For no reason that I can think of (apart from the obvious), not many people seem to have been talking about space loos. So when it came to imagining what it might be like to drop a captains log on various starships, I had to get imaginative.

While I cannot tell you who cleaned the toilets on the Death Star, when Captain Picard visits the little room, or who deals with the blocked toilets after a wookie goes for a dump, I do have a few thoughts about toilets in space settings. Not least of which, that our assumption of neat species binary divisions is a little short-sighted.

Biologies with dense poo

We’ve all had that moment where we’ve been to the bathroom and sat on the throne only to leave a log that will not flush even on the third try. Don’t deny it, I know this has happened to you.

Think how much worse it would be if the alien’s poo out dense materials like lead, gold, or mercury. The water pressure you’d need would be mental.


As this video shows, if your alien laves enough mercury-based poo in an earth toilet, that toilet is perma-blocked.


A note of caution for the science realist writers – mercury does not lend itself well to organic processes.

Choosing the right loo

Space Shuttle toilet on display at the Johnson Space Center in Houston
By SvobodatOwn work, CC BY-SA 3.0, Link

When travelling to unfamiliar locations, the only problem with loo visits tends to be finding them. That and maybe the local manners and taboos which can lead to some, well, embarrassing encounters.

That got me thinking, though. How much harder would going to the bathroom get in a multi-cultural, post-alien contact, world? Not only would toilets be divided into male and female rooms (or some non-binary separation) but might also be further divided based on environmental requirements.

But assuming you enter an air-breathing room of an appropriate gravity setting, you might encounter more than the usual water seat and urinal drain away. Just consider the competing biologies, cultural demands, and chemical compositions of waste. That’s quite a range of needs.

Creatures with large tails would, on the whole, require a water tank that is placed higher up or further back. Four-legged creatures could have further rear end orientation issues.

And don’t even get me started on height differences. Due to my ongoing back issues, I actually have an adaption to my own loo that makes the seat much higher. Some guests struggle to use my bathroom as a result. One regular guest – you know who you are K.A. – disassembles the whole thing and leaves it in the bath.

You might also find something equivalent to a space litter box. Perhaps some cultures feel a requirement to buy what they leave behind.

All in all, choosing the right loo could be quite taxing on an inexperienced human traveller.

Space toilets in the real world

The toilets on space stations are, due to lack of gravity, something that you may not even recognise as a loo in the first place.

While the one show to the right looks sort of like a toilet, the loo photographed by Svobodat looks like you might need advanced training just to use it. It looks space aged because, well, it is.

The loo above is the Space Shuttle toilet on display at the Johnson Space Center in Houston. The loo tot he right is from the International Space Station’s toilet in the Zvezda Module.

If you think all those nobs and tubes and suction parts are complicated for just one species, imagine what a space station toilet room might look like when many different cultures and biologies need to use the loo.

I pity the power Star Wars designer that ever gets tasked with showing us the toilets on a spaceship.

I think, on reflection, the reason why the loos are never shown on science fiction shows is a combination of embarrassment and cost that comes with complexity. In other words, no one wants to design them because they would be too fiddly. Imagine having “designed and built the toilets for the new space show” on your CV. Kiss goodbye to your dreams of working on the bridge any time soon.

Look how complicated human space toilets are…

Space toilet

Toilets in space-based stories

I cannot help but feel that toilets are a missing part of so many authors world-building efforts. Given how complicated multi-species bathroom needs are, I am sure entire seasons worth of plot has been missed out on entirely.

I wonder, for example, why Doctor Who writers have yet to have a new Tardis passenger encounter a strange and incomprehensible room only for the Doctor to tell them it is a toilet. It would be a good way to establish the companions lack of experience with other space-faring species and be good for a few memes too.

The BBC’s lack of Tardis toilets aside, imagine the plot twists that a twisty poo or a significantly acidic pee might bring to a story. Think about it and tell me you don’t have ten new ideas right now.

One comment

  1. Pingback: World building for very small characters • Matthew D Brown

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