Comment by giantrobot | Hacker News Reader

Comment by giantrobot | Hacker News Reader

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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...

>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

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?

The air filtration will actually help spread aerosols because air currents will carry them through the cabin before they're captured by a filter.

A high power "eliminate aerosols" mode would be one of those infrastructure things that need to be designed (and tested). Even then a single compartment spacecraft like the Orion or Dragon wouldn't have anywhere for the crew to bivouac while some aerosol evacuation mode was active. So you'd want a whole procedure designed around it.

Part of the need for the Apollo Constant Wear Garments was to make up for the lack of faculties in the command module and LEM. Such a thing would be impractical for a long duration mission so toilets (and waste disposal in general) need to be a reliably solved problem.

I could imagine the belters in The Expanse just throwing on suits and venting. Of course that only works if you have a bunch of canned air or something that makes it by cracking minerals on board.

Good points. A few hot takes:

> The air filtration will actually help spread aerosols because air currents will carry them through the cabin before they're captured by a filter.

The toilet facilities could have input / suction into the air filtration system. Maybe wise anyway.

> A high power "eliminate aerosols" mode would be one of those infrastructure things that need to be designed (and tested).

I expect the technology is mature in industrial settings, though of course that is much different than microgravity and the constrained resources of the spacecraft. Maybe it exists on the space station? That context still seems significantly different.

> a single compartment spacecraft like the Orion or Dragon wouldn't have anywhere for the crew to bivouac

In their spacesuits, though their exteriors may need decontamination. Maybe they just go outside, though probably not a great idea to have the entire crew outside the spacecraft simultaneously! Maybe in an emergency.

The Space Shuttle and ISS (and Orion) had/have microgravity toilets. They have some active suction and spinning tines that push the material against the walls of the containment vessel. The ISS toilet has changeable waste containers that are dumped in the unmanned supply capsules.

The Space Shuttle's toilet was just cleaned during servicing after a mission. The Shuttle had a max flight duration of about two weeks so there wasn't a need to have changeable waste containers.

In the case a toilet catastrophically malfunctions in microgravity imagine a snow globe. Whatever way you want to filter out the "snow"...it's going to land on everything inside.

In the most literal sense shit is serious in space.

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

Municipal plumbing is one of the wonders of the modern world and I appreciate it every time I use it.

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.

> If you’re going to stay, you are going to be having babies

This is a hurdle for settlement. Not exploration. Toilets are a hurdle for exploration, as is trauma medicine.

I’m not dismissing the need to do experiments with pregnant rats on the Moon. But until we’re dealing with multi-year missions on Mars, gestation isn’t on the Gantt chart.

> I never see this mentioned in sci-fi

The Expanse and A City on Mars speak to this precisely and extensively.

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