Spinning Design
Because of the deleterious effects of long-term microgravity on astronauts, NASA has long looked into rotating space station designs. Even a modest spin would provide a small amount of gravity, which could counteract the weakening of muscles and other effects of extended spaceflight.
This 1969 concept rotates on a central axis and would have been assembled in space from spent Apollo vehicle rocket stages. Most of these concepts were eventually abandoned at NASA in favor the zero-G station designs seen today.