This story of space toilers clears out many questions I had about spaceflight and... uh, going number 2.
Namely: astronauts try NOT to as much as they can, and when they do go, it's a mess for both them and their crew mates. They suffer through it because being in space is a worthy achievement.
Apparently it's such a mess that NASA estimates this is why astronauts tend to undereat. Apparently Gemini 7's Frank Borman spent 9 days without going number 2 because of this, and planned to hold it in 2 full weeks (the article doesn't clarify whether he managed). Skylab seems to have done some progress, but we're still in the early eras of space toiletry!
On Apollo 13, after the accident, the margins for propellent were so low that the astronauts had to drink very little. Nasa was afraid that venting the pee would set their trajectory off course.
One of the astronauts got an infection from dehydration as a result.
> One piece of feedback from Skylab was that the toilet needed stronger airflow. This meant the Shuttle toilet opening had to be narrow. To practice correctly positioning their body, astronauts on Earth sat on a special training mockup with a camera mounted in the center of the waste tube. A successful docking with the device meant precisely centering one’s nether eye in the crosshairs of a video screen while crewmates looked on and yelled their encouragement.
I knew part of the job for astronauts is being intimate with one's crewmates, but I didn't know it was that intimate.
It depends on the scope of the mission. If you're going to commercialize long term space travel then you're going to want some form of artificial gravity.
If you build a better toilet you need a better pooper to use it. And they need to use it correctly every time or you're going to need a really good waste cleaning and disinfecting strategy for your ship.
I've always wondered about regular toilets and now this. Someone has to test it. I'm sure they have equivalent items to run through them but, eventually, you have to try the real thing so whose job is it to do that and how do they do that?
Welcome to the world of Maximum Peformance (or MAP) testing. 22 municipalities and associations came together across the US and Canada to form a consortium to develop a 'standard' test (and test media) and test toilets to determine who flushes feces the fullest.
And as someone else said....the entire business would be solved if not for our cultural tabboo that requires astronauts to do the whole procedure by themselves. If you could have another crew member actively helping it would be done quicker in a much more hygenic way. But because it's "private" they have to do these crazy acrobatics to do it alone. And like, back on Earth nurses have to do much much worse stuff every day and no one considers that weird - it's just part of the job.
>A successful docking with the device meant precisely centering one’s nether eye in the crosshairs of a video screen while crewmates looked on and yelled their encouragement.
Massive Interstellar vibes, I guess it is "necessary"
If you like space toilets you may be interested in this [0] HN submission where you can track how full the ISS urine tank is from the comfort of your menu bar.
A commonly trotted out argument for continued investment in manned space flight is technological spillover: that all the money we give to NASA generates positive benefits in other sectors of the economy. I'm not so sure space toilets are generating that spillover. This seems like a uniquely expensive humans-in-space engineering problem. I echo the sentiments of Why Not Mars (https://idlewords.com/2023/1/why_not_mars.htm):
> The web of Rube Goldberg devices that recycles floating animal waste on the space station has already cost twice its weight in gold and there is little appetite for it here on Earth, where plants do a better job for free. [...] I would compare keeping primates alive in spacecraft to trying to build a jet engine out of raisins. Both are colossal engineering problems, possibly the hardest ever attempted, but it does not follow that they are problems worth solving. [...] Humanity does not need a billion dollar shit dehydrator that can work for three years in zero gravity, but a Mars mission can’t leave Earth without it.
So liquids are recycled but solids are still bagged and stowed. I hear human excrement is high in methane content... and certain contemporary rockets use methane fuel, right? Poop-powered spacecraft, for the win!
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[ 2.9 ms ] story [ 55.6 ms ] threadNamely: astronauts try NOT to as much as they can, and when they do go, it's a mess for both them and their crew mates. They suffer through it because being in space is a worthy achievement.
Apparently it's such a mess that NASA estimates this is why astronauts tend to undereat. Apparently Gemini 7's Frank Borman spent 9 days without going number 2 because of this, and planned to hold it in 2 full weeks (the article doesn't clarify whether he managed). Skylab seems to have done some progress, but we're still in the early eras of space toiletry!
One of the astronauts got an infection from dehydration as a result.
https://en.wikipedia.org/wiki/Space_toilet
I knew part of the job for astronauts is being intimate with one's crewmates, but I didn't know it was that intimate.
If you build a better toilet you need a better pooper to use it. And they need to use it correctly every time or you're going to need a really good waste cleaning and disinfecting strategy for your ship.
!Spoilers ahead - from Daniel Suarez's dV and Critical Mass novels.
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The second volume (critical mass) talks a lot about exactly that problem.
https://map-testing.com/background/
(And really thorough history! https://map-testing.com/wp-content/uploads/2025/12/Backgroun...)
Apparently, a "MaP Premium" toilet is going to be the golden shitter.
Massive Interstellar vibes, I guess it is "necessary"
right click -> Save Image As
[0] https://news.ycombinator.com/item?id=42505454
> The web of Rube Goldberg devices that recycles floating animal waste on the space station has already cost twice its weight in gold and there is little appetite for it here on Earth, where plants do a better job for free. [...] I would compare keeping primates alive in spacecraft to trying to build a jet engine out of raisins. Both are colossal engineering problems, possibly the hardest ever attempted, but it does not follow that they are problems worth solving. [...] Humanity does not need a billion dollar shit dehydrator that can work for three years in zero gravity, but a Mars mission can’t leave Earth without it.
Why are we doing human spaceflight again?
Edit - I wrote this tongue in cheek but it turns out there really are scientists working on it: https://explore.research.ufl.edu/process-converts-human-wast...