Beginning with matters as elementary as the distinction between stars and other bodies (moon and planets) that might ""shine,"" Bergaust goes on to discuss the ""fantastic amounts"" of different kinds of energy that emanate from the sun, and how Satellite Solar Power Stations might harness some of that energy for use on earth. From such 50-person stations it's a big jump to manmade habitats for 10,000-100,000 people, but the prospect of such colonies transmitting solar power to earth and engaging in zero-gravity manufacturing (with materials) mined from the moon) is attractive enough to have inspired much speculation on just how they might be constructed--perhaps a rotating wheel with communities on the rim will be the pattern. The environments will be attractive, pollution-free, scientifically planned. . . . Bergaust's humorless prospective does acknowledge that ""there will be some reverse flow of people who find they cannot accept colony life. This has always been normal during the colonization of areas here on Earth."" This is clear and neatly packaged like Bergaust's Colonizing the Planets (1975), but equipped with no new wrinkles that might nose out Knight's Colonies In Orbit or Golden's Colonies in Space (both reviewed in the May 15, 1977, KR).