In this historical photo from the U.S. space agency, a 1977 concept drawing for a space station.
Known as the "spider" concept, this station was designed to use Space Shuttle hardware. A solar array was to be unwound from the exhausted main fuel tank.
The structure could then be formed and assembled in one operation. The main engine tank would then be used as a space operations control center, a Shuttle astronaut crew habitat, and a space operations focal point for missions to the Moon and Mars.
Each weekday, SPACE.com looks back at the history of spaceflight through photos (archive).