[Animats]

> Every terrestrial concentration process relies on things an asteroid lacks: gravity-driven sedimentation, water-based flotation, density separation in fluids, atmospheric combustion.

That's a good point. Most bulk industrial processes won't work in zero G. This limits asteroid mining. Breaking off pieces of rock and accelerating them to somewhere, maybe. Building a big wheel and spinning it up to get some gravity, maybe. Materials processing in open space, not so much.

The "seed" to start up an industrial economy might be the size of the industrial base of, say, Israel or North Korea, both of which try to be self-sufficient. We get to find out when someone tries to do something self-sustaining on Luna or Mars.

[giantrobot]

Both North Korea and Israel are notable (compared to space) for their dense oxygen rich atmospheres, accessible large reservoirs of water, access to solvents/lubricants, and a generally "shirt sleeves" environment for workers. Asteroids, the Moon, and deep space don't really have these things. So you're not just bootstrapping an industrial facility at those locations but all the basic infrastructure that industry requires to exist.

With space manufacturing the first widget out of a factory costs trillions of dollars. There's also few if any raw materials that are far more abundant in space than here on Earth (at orders of magnitude smaller cost).

[neaden]

"Israel or North Korea, both of which try to be self-sufficient" - Neither of them do any such thing though. From a quick search Israel imports about 80% of their calories though they also export some food they are heavily reliant on imported grains and meat. North Korea is obviously harder to get information on but it imports large amounts of food from China.

[SideburnsOfDoom]

North Korea has an official ideology of "Juche", and "The goal of Juche is to establish a self-reliant state" (1)

It may not be like that in practice. But nevertheless, self-reliance is in their stated goals, and North Korea is one of the least "open" states in the world.

I think you can make the case that they "try to be self-sufficient". They do try.

As for Israel, eh, it depends. They certainly don't rely on neighbouring countries.

1) https://en.wikipedia.org/wiki/Juche#Core_principles

[neaden]

Sure North Korea tries, but they don't succeed so it's not really helpful as an example of a self sufficient society to base a space colony off of. As for Israel yeah, they mostly don't import food from their neighbors (most of whom also import the majority of their food calories) but I don't see what that has to do with anything, as I said they import 80% of their calories which is certainly not tenable for a space colony to do.