I gauge the seriousness of all manned space exploration proposals by the attention paid to the toilets. If the toilets are not a solved problem with many nines of reliability, you're just writing science function and are not at all serious about actual manned space exploration. Toilets are the brown M&M clause[0] of manned spaceflight proposals.
Toilets are unglamorous in the extreme but absolutely vital. Humans make hazardous and potentially deadly waste. Every day. It needs to be safely discarded/contained. In a sealed environment in microgravity it's even more dangerous than it is on Earth.
Aerosolized fecal matter can enter the lungs and cause deadly infections. Entering the digestive system can cause debilitating (possibly deadly) illness. Temporary blindness if it gets in the eyes. It can also cause mechanical or electrical problems if it gets in equipment. All of these can lead to a mission failure and in extreme instances a total loss of the crew. Apollo 8 was extremely lucky that Frank Borman's illness didn't cause more problems.
If you're not thinking logistics and infrastructure you're not really serious about an endeavor.
[0] https://www.smithsonianmag.com/arts-culture/why-did-van-hale...
Frankly this is true about Earth too. Not enough effort is spent wisely managing human waste, and many people die as a result.
I see your point. Out of curiosity:
> In a sealed environment in microgravity it's even more dangerous than it is on Earth. / Aerosolized fecal matter can enter the lungs and cause deadly infections.
Would the air filtration / recycling system minimize this risk?
Speaking of this: let’s talk about space settlement.
If you’re going to stay, you are going to be having babies.
Any tech tree proposal for a space settlement (planet, moon, spin stations, whatever) that does not address how to make and reuse or recycle diapers is not serious.
I never see this mentioned in sci-fi or in space nerd discourse around stuff like what you need to settle Mars. It’s up there with potable water, at least if you want humans to reproduce.
>toilets are the Brown M&M clause(0)
I have seen engineering shops where the conversation about fixing some small but simple thing before a deadline gets filed into "better to give the consultants reviewing this some low hanging fruit for the snag list."
(0) Actual backstage contract riders for rock stars : https://www.thesmokinggun.com/backstage