Towards a rational strategy for the human settlement of space

This paper revisits the core issues of space policy from the viewpoint of optimal decision theory. First it argues for a metric: maximizing the probability that humans and their technology in space someday reach what Rostow called the “economic takeoff” point where autonomous growth becomes possible, not bound by the rate of growth on earth. Next it discusses three concrete requirements to reach that point: benefits to earth which exceed costs to earth, large and diverse enough “exports” from space to earth, and advancements in technology and infrastructure. Energy from space (ES) is now one of the most promising export possibilities, based on what was learned in the last open US government effort on that topic, “JIETSSP,” led jointly by NSF and NASA. I review several options for ES, and propose a new one which, while slightly riskier, offers real hope of electricity at a price that could compete with coal and fission-plus-enrichment.