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?

Frankly this is true about Earth too. Not enough effort is spent wisely managing human waste, and many people die as a result.

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

The second law of thermodynamics dictates that everything poops.

Anything alive that is using energy and doing work and transforming matter must poop in some form or another.

We don’t know what form life out there might take, but we know it poops.

Even post biological machine life would poop in the form of industrial waste, waste heat, etc.

Even near perfect recycling can only be near perfect, not perfect, due to the second law, which means a super efficient organism or closed cycle ecosystem or industry will still poop. Just not much. It will also emit a ton of waste heat, which I guess is kind of poop since mass and energy are ultimately equivalent.

If there’s weird life out there made of plasma or something, it poops. Probably charged particles or something.

The monolith in 2001? It poops. Somehow.

... and we seem to be unable to make something that works without "turning it off and turning it on again" :-)

It needed more than a flush.

/ducks

I hope they remember to cut the mics during the fluid disposal event

https://www.youtube.com/watch?v=ruCsYGL3QlY

How do you simulate zero gravity on earth?

Warning: gross

Of course, but the fundamental problem is that difficulties compound. It starts with: pooping is much harder when gravity isn't there to persistently tug on the turd. Something that is slightly obnoxious on Earth (using a bag, using a suit flap) turns into an absolute trainwreck when you have a bag, a suit flap, and turd separation failure. Now you have to do precise mechanical manipulation of an object you don't want to touch behind your back through a bag and a suit flap, every failure multiplies the work, and now the turds can float away to multiply the work outside your immediate vicinity. Ditto for kneading the antibacterial into the poo: if you fail to do this thoroughly on Earth, bacterial offgassing causes the bag to vent, but in all likelihood that's the end of it because you can arrange for gravity to keep the poo away from the vent. In fact, you would probably do this without even thinking or imagining how it could go wrong. In zero gravity, you can't simply arrange "vent on top, poo on bottom", so the event is likely to launch aerosolized poo into your living environment where you have to put up with it for the next few days.

It's difficult to fully appreciate gravity until it's gone.

Astronauts are heroes for the risks they take, but they are also heroes for dealing with this.

Apollo was largely driven with the purpose of achieving the goal rather than obsessing on the details on the way to that goal. In fact during Apollo they even completely scrapped mathematical risk modeling because the results it always gave were basically 'you die.'

So for instance a relevant and famous anecdote is that the original tests for Apollo launches didn't have any sort of urine/fecal disposal systems at all. In one delayed launch during testing Alan Shepard was in the capsule for hours and ended up needing to go pee. He asked for permission to depart the capsule, but that was declined to keep it all on track. So he ended up having to just pee all over himself in the suit.

Another piss poor anecdote is Buzz Aldrin on the Moon! When he departed the lunar lander capsule, the impact ended up breaking the urine collection device inside his suit. So his journey on the Moon involved having a healthy dose of urine sloshing around in his boot where it settled.

Of course there's a balance in all things. It's not like they just YOLO'd their way to the Moon. But things where the worst case outcome would be astronaut discomfort were seen as extremely low priority. In the original design, the capsule didn't even have a window or manual controls. So the astronauts were basically just being treated like human Laikas. They had to fight just to get those 'features.'

---

I think a big part of the reason for this is because there are basically infinite things that can go wrong. And so if you obsess on getting every single thing right, you'll end up never doing anything at all. In 1962 Kennedy gave his famous 'to the Moon' speech. At that time, we'd only just barely put the first man in orbit but had never done anything beyond that, at all. Just 7 years later a man would walk on the Moon. In modern times we've been basically trying to recreate what we did in the 60s, and spent decades doing so. And this obsession on the details is certainly a big part of the reason why.

GP is saying that was previously required, not that it was invented. The new one can handle the mixture; not necessarily (presumably not?) by separating it.

Livestock farmers have been doing this for decades. However they have very different constraints. It doesn't matter if a little of one gets mixed with the other - in fact they need enough water in the solids for proper decomposition. Both are normally pumped as well, so the solids are generally expected to be more a viscous liquid than actual solids. They don't want too much water in some stages, but they have plenty of room for a large setteling tank (read gravity works for them). They are also dealing with far more waste than a space mission, so they need something that is efficient/cheap at quantity.

More like turn them both into a liquid.

High stakes situation:)

Are you sure? I wouldn't have thought the skills would be transferable. I don't mean to judge, but I think if your toilet needs heat shield engineers, maybe you should see your doctor.

The dust while writing doesn't matter. You can still write with a rounded tip. The problem is sharpening the pencil.