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.
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.
Source: http://i.space.com/images/i/000/031/397/i300/space-colonies-elysium-130802c-02.jpg?1375479744
