Minimal technology to sustain humans on a hostile world?

[Junghalli]

Something I got to wondering about. What's the minimal level of technology a human society could retain on a non-shirtsleeve world (i.e. one where the outside environment is lethal to an unprotected human) and survive?

For the sake of this scenario, let's say the planet is very much like Earth, except that it happens to be a rogue planet, so it's drifting all by itself through interstellar space. The surface is covered in kilometers-deep frozen water and carbon dioxide with the occassional mountain range poking through, and there is geothermal energy that can be exploited.

So, on a world like this, what would you say is the bare minimum level of technology a human society could have and survive? 1950s level? 1920s? 1900s? Late 1800s? Earlier?

Assume that high tech is available to construct the initial settlement but will eventually break down and not be replaceable. So it's a question of the minimum level an established colony could survive at, not the minimum level needed to build a survivable colony.

[Samuel]

How big is the colony and how high tech? A large enough and well enough constructed biosphere would be extremely low maintainance.

[Junghalli]

How big is the colony

Let's give it a starting population in the hundreds.

[Samuel]

How big is the colony

Let's give it a starting population in the hundreds.

Then it is essentally going to be a space station. The only difference is that you don't need to rotate to have gravity, you use geothermal instead of solar and recycling tech doesn't have to be as perfect because you can use outside ice. The world isn't "no shirt-sleeves"- it is hard vaccum and so what happens depends entirely on how the colony is built.

[Guardsman Bass]

You could probably build the colony underground, either in the ice or in the occasional mountain ranges. You need the technology to get oxygen from the ice, you can use geothermal to potentially heat and power your colony, you'd probably need is some type of lamp so that you could actually grow plant life for consumption (since this is a rogue planet drifting in outer space), and the ability to make suits to go out in the hard vacuum (and possibly not even that, if you're colony is deep enough underground).

Aside from the lamps and agriculture, you could probably do it with 1960s space technology, although with a colony that small you'd never be able to replicate the technology without supplies from the outside world (which would kind of moot that point). Without outside supply, it's basically a matter of keeping your colony sealed and heated, plus growing food and making oxygen.

[Zor]

An apsolute nessesity here is going to be the ability to have electrical machine tools and smelting systems. Coal and gas are unavailable on such a planet and even if they were, oxygen is at a premium. Also, power would be nessisary for expansion, the best way to get Oxygen for new habbitable areas is via electrolysis. Factor in heating and grow lights and you can realise that this colony is going to require a shitload of power. Spacesuits are also going to be nessisary for doing work in the vacuum. I am going to say 1950s tech (to use rough terms, alot of things simply would not be doable)

Zor

[Guardsman Bass]

An apsolute nessesity here is going to be the ability to have electrical machine tools and smelting systems. Coal and gas are unavailable on such a planet and even if they were, oxygen is at a premium. Also, power would be nessisary for expansion, the best way to get Oxygen for new habbitable areas is via electrolysis. Factor in heating and grow lights and you can realise that this colony is going to require a shitload of power. Spacesuits are also going to be nessisary for doing work in the vacuum. I am going to say 1950s tech (to use rough terms, alot of things simply would not be doable)

Zor

I'd question the need for spacesuits, at least once the colony is settled. If you build the colony deep underground, near the boundary between the mountain rock and the ice, then you might be able to simply seal the colony for the most part from the outside elements, as long as you could mine ice for oxygen and get rid of the CO2 (although you'd probably need to re-direct the CO2 to feed your plant life). They certainly wouldn't hurt, but we're talking bare minimum here.

The "Grow Lights" (and lights in general) would be one of the biggest issues, along with creating a habitable breathing atmosphere. You'd need the electrical power for them, along with the materials for the lights themselves and the ability to make them. The colonists would probably need them for themselves as well; even if they lived on the surface, there's no real source of ultraviolet light for Vitamin D purposes.

To be honest, I'm not convinced that an isolated colony in the hundreds would really be viable in the long-term on such a world.

[Lord of the Abyss]

I really have to mention Fritz Leiber's A Pail of Air here.

As far as using geothermal power goes; as I recall, over time geothermal can run out. Such as from the rock & water cooling too much from being used to heat the plant. So they'd need to be able to drill new taps, or they'd need an alternate source like nuclear.

[FOG3]

Well Guardsman Bass already beat me too it, but you need some form of sustainable power to power the system that is maintaining the agricultural base. Given the setup I imagine the hydroponics bay is going to have a atmosphere high in ammonia and CO2 in order to turbocharge plant growth as much as it practical, with less useful algae farms working as the CO2 scrubbers for the dormitories.

Digging a big hole in the ground with sufficient time has been done throughout recorded history, so it's mainly a question of how fast they need to setup shop following their getting dumped on this rock.

You could do that with WW1 technology, but why you'd want to setup shop on such a thing or how could make it truly sustainable I don't see.

[frogcurry]

Independent of the colony population is probably also the size of the initial industrial resource base made available. You can probably get away with a less advanced technology if you have lots of it, allowing sparing of key systems in abundance and re-building anything that needs replacing using onsite machines and tooling. On the other hand a bare minimum industrial base will need to be much more advanced due to the lack of manufacturing resources limiting replacement capacity, as well as needing much more flexibility of each component.