O'Neill Cylinder

Summarized from wikipedia published under the Attribution Share-Alike 4.0 Creative Commons license.

An O'Neill cylinder (also called an O'Neill colony) is a space settlement concept proposed by American physicist Gerard K. O'Neill in his 1976 book The High Frontier: Human Colonies in Space. O'Neill proposed the colonization of space for the 21st century, using materials extracted from the Moon and later from asteroids.

Physical Design

O'Neill cylinders consist of two counter-rotating cylinders. The cylinders rotate in opposite directions, canceling any gyroscopic effects that would otherwise make it difficult to keep them aimed toward the Sun.

Dimensions

Each is 5 miles (8.0 km) in diameter and 20 miles (32 km) long, connected at each end by a rod via a bearing system. Their rotation would provide artificial gravity.

O'Neill cylinders are 256 square km, 350 times as much habitable 1G surface area compared to a small Stanford Torus space settlement, as a 10,000 resident Stanford Torus is only .731 square km or so.