We don't want to conquer space at all. We want to expand Earth endlessly. We don't want other worlds; we want a mirror. We seek contact and will never achieve it. We are in the foolish position of a man striving for a goal he fears and doesn't want. Man needs man!
Why it is hard sci-fi
Tarkovskys 1972 adaptation of Lems novel about a research station orbiting a planet whose ocean appears to be a single sentient organism. The film is slow on purpose. The crew are studying a phenomenon they cannot map onto human cognition, and the ocean responds by manifesting their suppressed memories as living people. The scientific puzzle is held strictly to a research-station frame.
Science inside it
A planet-scale neural substrate as a model of non-human intelligence, the limits of contact when the other does not share human concepts, and the use of neural projection as a way for one mind to study another. Lems original argument was that we keep failing at first contact because we look for our own image. The film honours that.