File:Casing for the first Soviet atomic bomb, RDS-1.jpg

Photograph of a casing for the first Soviet atomic bomb, RDS-1, detonated in August 1949. The cartoonish "eyes" on the bomb are radar fuses.

This particular photograph is taken from this page, where it is indicated that it is copyright the Minatom Archive. Most likely this means it is considered to be under active copyright protection, especially in Russia. Its use on Wikipedia is under the fair use claim of U.S. copyright law, which it should satisfy especially because:
 * 1) It is not an essentially "creative" photograph, and it is one for which a free alternative would be especially hard to find (the museum is off-limits to the public)
 * 2) It is being used in an encyclopedic and analytical context on Wikipedia, as it in particular can be easily juxtaposed to the Fat Man weapon
 * 3) Its usage on Wikipedia will not deny any revenue to the Minatom Archive, if there is any revenue they would normally derive from such things.