Photo credit: Space.com
If you've seen the movie Elysium, then this rotating space colony concept probably is still fresh in your mind, but did you know that this concept was first brought up in the 1970s, by NASA? The Stanford torus is a proposed design for a space habitat capable of housing 10,000 to 140,000 permanent residents. The Stanford torus was proposed during the 1975 NASA Summer Study, conducted at Stanford University, with the purpose of speculating on designs for future space colonies. Continue reading for videos and more information.
Sunlight is provided to the interior of the torus by a system of mirrors. The ring is connected to a hub via a number of "spokes", which serve as conduits for people and materials travelling to and from the hub. Since the hub is at the rotational axis of the station, it experiences the least artificial gravity and is the easiest location for spacecraft to dock. Zero-gravity industry is performed in a non-rotating module attached to the hub's axis.
The interior space of the torus itself is used as living space, and is large enough that a "natural" environment can be simulated; the torus appears similar to a long, narrow, straight glacial valley whose ends curve upward and eventually meet overhead to form a complete circle. The population density is similar to a dense suburb, with part of the ring dedicated to agriculture and part to housing.