In the summer of 1975, NASA brought together a team of physicists, engineers, and space scientists―along with architects, urban planners, and artists―to design large-scale space habitats for millions of people. This Summer Study was led by Princeton physicist Gerard O’Neill, whose work on this topic had previously been funded by countercultural icon Stewart Brand’s Point Foundation. Two painters, the artist and architect Rick Guidice and the planetary science illustrator Don Davis, created renderings for the project that would be widely circulated over the next years and decades and even included in testimony before a Congressional subcommittee. A product of its time, this work is nevertheless relevant to contemporary modes of thinking about architecture. Space Settlements examines these plans for life in space as serious architectural and spatial proposals.