Stanford torus

The Stanford torus is a proposed NASA design[1] for a space settlement capable of housing 10,000 to 140,000 permanent residents.

"Stanford torus" refers only to this particular version of the design, as the concept of a ring-shaped rotating space station was previously proposed by Konstantin Tsiolkovsky ("Bublik-City", 1903),[5] Herman Potočnik (1923)[6] or Wernher von Braun (1952),[7] among others.

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.

[9] 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.

A mass catcher at L2 would collect the materials, transporting them to L5 where they could be processed in an industrial facility to construct the torus.

Exterior view of a Stanford torus. Bottom center is the non-rotating primary solar mirror, which reflects sunlight onto the angled ring of secondary mirrors around the hub. Painting by Donald E. Davis.
Interior of a Stanford torus, painted by Donald E. Davis
Collage of figures and tables of Stanford Torus space habitat, from Space Settlements: A Design Study book. Charles Holbrow and Richard D. Johnson, NASA, 1977.