In this historical photo from the U.S. space agency, a 1929 Hermann Noordung depiction of a space station habitat wheel.
Hermann Potocnik (1892-1929), also known as Herman Noordung, created the first detailed technical drawings of a space station.
Power was generated by collecting sunlight through the concave mirror in the center. This was one of three components of Noordung's space station. The other two were the observatory and the machine room, each connected to the habitat by an umbilical.
Each weekday, SPACE.com looks back at the history of spaceflight through photos (archive).