The NASA website hosts a large number of images from the Soviet/Russian space agency, and other non-American space agencies. These are not necessarily in the public domain.
The SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use. [2]
Saint Croix Island, United States Virgin Islands - January 1993; rotated with North at the top. image description [http://eol.jsc.nasa.gov/sseop/EFS/photoinfo.pl?PHOTO=STS054-74-49 here] {{PD-USGov-NASA}}