[ExI] Asteroidal mining was Nukes was less expensive > energy

[Tom Nowell]

I remember reading "Man and the planets" by Duncan Lunan, from 1980, which summarised some thinking about exploiting the solar system that had been going around in the late 70s.

One method mentioned was constructing a large plastic film in a sphere around your asteroid, metallising half of it to form a reflector which then heats up the asteroid. The most volatile parts vaporise and form a shell on the inside of the film. You cut this apart, then repeat the process for higher and higher temperatures, each time getting a different set of temperature-controlled vapor, until you are left with highly refractory stuff in the centre. Not having a copy of the book to hand, I can't quote the original source that Lunan would have quoted from. It's an interesting idea, and certainly seems less mass-intensive than some solutions.

Tom