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]
* An artist's impression of Pluto Fast Flyby. * Credit: NASA * Source: http://planetary.s3.amazonaws.com/assets/images/spacecraft/2015/20150626_pluto-ff.jpg {{PD-NASA}}
Captions
An artist's impression of Pluto Fast Flyby.
Een impressie van de ruimte-sonde "Pluto Kuiper Express" die langs Pluto scheert.