[PaulHoule]

I want to send something to a carbonaceous chondrite asteroid that can extract the volatiles and turn the coal-like substances and stony substances into large plastic (Kapton!) and metal films. These could be used for solar collectors, solar sails, sunshades.

It pays for itself by manufacturing space sunshades to the Earth-Sun L1 point that get their own their own power.

The "something" is probably a factory that builds a factory that builds the factory, at least twice you face a situation like building a ship in a bottle except you are in the bottle. It probably imports microcontrollers by the ton from the Earth. It's an interesting question: do you send people who can interact with the system but need a place to live or do you run it all by remote control and face 60 minute or more round trip delay requiring that the thing make mistakes and recover autonomously.

[ncmncm]

Kapton requires a great deal of hydrogen to make.

L1 sunshades would cement global catastrophe, as unrestricted accumulation of CO2 would further acidify ocean shallows eliminate the base of the ocean food chain.

[PaulHoule]

My guess is that some CC asteroids may have generous amounts of hydrogen. Any reasonable plastic has a lot of hydrogen in it, kapton is harder to make than PE and PET and requires nitrogen which is more of an unknown in terms of a availability.

I think some asteroids might be rather gassy and might require devolatilization before doing anything else and that is awkward because you are going to be at your bottom in terms of equipment inventory, particularly storage tanks.

As for ocean acidification it is a real problem but the severity of what we’re up against means we shouldn’t leave solar geoengineering off the table. The fact that one party could do something very dangerous in fact might break the ‘collective action’ problem.

I presented on this idea at a seminar on geoengineering and I was accused of trying to build a Dyson sphere, I said "no, there is not enough mass in the asteroid belt to cover the Sun but you can build something pretty big, possibly a human habitat much "bigger" than the Earth in land area."

[ncmncm]

By then we will have pB fusion, and have no need of solar arrays. The Kuiper belt will then be more attractive than the asteroids. There is plenty of frozen nitrogen there, and abundant precious cold.

Heat is easy to get, fundamentally hard to shed.

[PaulHoule]

D + D probably wins in conditions out there. The T and He3 that it breeds will be handy.

My guess is that anybody who gets out that far loses interest in dry inner solar system planets completely and isn't going to be interested in exporting products back.

[ncmncm]

By then they might be most interested in getting as far as possible from any nearby magnetars and other existential threats.

Although other people might be the most immediate threat right up until the moment a magnetar sterilizes the vicinity.

I don't know whether we are certain where the nearest one is.