McKendree cylinder

A McKendree cylinder is a scaled-up version of the O'Neill cylinder. It is a space habitat originally proposed by NASA engineer Tom McKendree. As with other space habitat designs, the cylinder would spin to produce artificial gravity by way of centrifugal force. It would use carbon nanotubes instead of steel, allowing the habitat to be built much larger. In the original proposal, the habitat would consist of a cylinder approximately 460 km (290 mi) in radius and 4600 km (2900 mi) in length, containing 13 million square kilometers (5.1 million square miles) of living space, nearly as much land area as that of Russia.