During several summers in the 1970s, a small team of experts — professors of engineering, physical science, social science, and architecture, as well as volunteers and students — set out to design a system for large-scale space colonization. Cylindrical colonies: double cylinder colony, exterior. | (NASA Ames Research Center) Working at the NASA Ames Research Center in California, these field experts explored every feasible aspect of building self-sufficient, Earth-orbiting cities.