There was a bunch of work on space development (as opposed to planets) in the 70s and 80s, starting with Gerard O'Neill. My favorite popular book was http://www

There was a bunch of work on space development (as opposed to planets) in the 70s and 80s, starting with Gerard O'Neill. My favorite popular book was http://www.nss.org:8080/settlement/ColoniesInSpace/index.html http://www.nss.org:8080/settlement/ColoniesInSpace/index.htm... O'Neill was overoptimistic about launch prices coming down in the near term and about the economic case for solar power satellites and for people in space to mine the materials and build and maintain the powersats, etc. But as I remember it this community made a good case that you don't need planets to live on; with their gravity wells and atmospheres and night/day cycles they're mostly a big nuisance compared to free-space habitats built with lunar and asteroid materials.