in short, Solaris fails.
it happens right at the end, when the station is going down. the film is basically an exploration of love that tries to become a love story, and force a happy ending down upon the viewer. given the fact that george clooney's wife is dead, and he's being sucked into a planet, the idea is misplaced. but it is with the end of the film that most of it falls apart. there is, primarily, not enough story meat to hang onto the narrative, not enough of anything left at the end of the film to provide a strong end, and this is why everything fails. in addition to this, small twists are simple to pick, and so is clooney's final decision.
however, the film isn't bad for the most part. it succeeds totally in bringing a science fiction film that is exploring love, and the ethics and morals behind it, without resulting in pointless gadgets. space and the planet solaris form a sort of visual metaphor for the film that, while i think doesn't completely work, give it a sense of place.
but still, it fails in the end. which is a shame, i think.