Space.com today has an article and the infographic shown below about the in-space colony concepts developed by Princeton Prof. Gerard K. O’Neill and his collaborators during the 1970s and 80s. (They got some NASA grants but it’s a huge exaggeration to say NASA had a “plan to put thousands of people in Space Colonies”.)
See the Space Studies Institute for more details and the HobbySpace Art section for links to more space colony artwork.
- Incredible Technology: How to Build a Space Station Colony -Space.com
- NASA’s Giant Space Colony Concepts Explained (Infographic) – Space.com
Source SPACE.com: All about our solar system, outer space and exploration.