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Serious question: How do you get the energy (and other resources) back to earth in a way that is cost competitive with extracting them here? If it costs more mo
by ljw1001 9y ago
Serious question: How do you get the energy (and other resources) back to earth in a way that is cost competitive with extracting them here? If it costs more money, people will use up what's here before they import the resources from Mars.
- abecedarius 9y agoBringing a thing from space down to earth should, if we're smart about it, be a free source of energy. If it's very expensive instead, that's from some combination of insufficient capital base and poverty of ideas. For instance, a skyhook -- a spinning tether in orbit -- could lower one payload into the atmosphere and boost another into space, at no net energy cost. A pretty good, if very old, popular intro to this kind of thinking was Heppenheimer's Colonies in Space (free on the web now). Mars seems unpromising because it's at the bottom of a gravity well, has an inconvenient atmosphere, should be preserved for scientific research while there's still a chance of traces of life, etc. Asteroids seem way more useful, and the Moon is nearer.