Without Pavel Klushantsev, Kubrick might never have made 2001.

In 1954, Klushantsev, pioneering Soviet sci-fi film director, began working on a short film, part-documentary, part-visionary projection, about the Soviet conquest of space. The film follows a young man as he learns the basic principles of space flight, before the final parts of the film depict the launch of the first Soviet man in space, life on an orbiting space station, the first man to set foot on the moon, and concludes with the possibilities of colonising Mars.

You can watch the film online here.

In 1957 Sergei Korolev, the 'father' of the Soviet space program, proclaimed "the road to the stars is open" following the historic flight of Sputnik 1. Klushantsev quickly shot footage to represent this momentous occasion, and the film was released a month later.

Road to the Stars is a delirious film, stunning in its prescience about many aspects of space exploration that would unfold over the next 40 years.The similarities between Road to the Stars and Kubrick's 2001 are obvious, and Kubrick was known to have been inspired by Klushantsev's film. Indeed, parts of 2001 can be considered a homage, or as this article states, a shot-for-shot copy.

[Slightly related, here's an article I wrote called Road to the Stars for Kino Fist about Baikonour and a space station called Kosmograd from the short story Red Star, Winter Orbit, by William Gibson and Bruce Sterling.]