2019-08-29 07:02

Image from NASA Ames Research Center.

All writing, imagery, etc. produced by the federal government is automatically in the public domain, available for anyone to use, share, remix, etc. For example, here’s a NASA page with some 1970s concept images of space colonies: https://settlement.arc.nasa.gov/70sArtHiRes/70sArt/art.html (via @AlanRalph).