Geek.com reports that today NASA's Ames Research Center released a kickass set of space colony concept designs. Basically, during the 1970s NASA commissioned a collection of incredibly cool concept designs for if, and when, we start colonizing space. These massive rotating colonies are straight out of the Jetsons. I love them.
The concept fall into 3 categories: Cylindrical and toroidal (donut-shaped) colonies, and Bernal Spheres. Most of them include a form of gravity, whether from spinning a torus around its center axis (like a wheel on a spoke) or spinning a cylinder like a rolling pin. Some resemble the concepts from Larry Niven's Ringworld — though given that that book was published in the '70s itself, it might be just as accurate to suspect that the Ringworld looks like these drawings.
Bernal Spheres are one particularly cool concept, which propose that people live on the interior of an enormous hollow sphere. Its segments could rotate independently, allowing gravity to pull people outward for everywhere but the poles (as defined by the axis rotation). The poles would house so-called "crystal palace" greenhouses soaking up raw sunlight to keep the air refreshed and the larders stocked. A Bernal Sphere just 500 meters across (tiny by the standards of many proposed space colonies) could comfortably house 10,000 people.
Images via the Ames Research Center.