An excellent and nostalgic collection of eary science-fiction art, the sort that is somewhat pulpesque and redolent of early comic books. The dreams we all dreamed, before NASA and the USSR made manned spaceflight a reality and we discovered what spacesuits and starships really look like...
You might want this collection just to revel in it, but should it prove appropriate to something you are writing, the licence terms are generous (although - a pet hate of mine - you only see them after you have purchased and downloaded the product!). Note that the resolution is suitable for electronic use - webpages or perhaps PDF - only, it is not good enough for full-blown print use.
It's a real feast visually, with all the classic images - space helmets that look like goldfish bowls, scantily-dressed ladies (although at least one such lady is busy rescuing a man!), rayguns and hideous tentacled aliens... oh, and there's a jet pack or two, and man-eating plants!
As well as a fine array of action scenes, there's a bunch of 'head shots' which might be used, for example, to decorate your character sheet in an appropriately-themed game.