In 1968 the movie industry realized that okay science fiction movies could become great with the right soundtrack. Case in point, 2001: A space Odyssey. The story is convoluted. It is based on a short story I read before most people reading this were born. How they managed to stretch it out to a full length movie eludes me. I do not remember any of the characters in the film, they were inconsequential. I do vaguely remember HAL the computer. He was the best actor in the film. But the film is best remembered for its score, which ironically was composed by Richard Strauss, born in 1864 and died in 1949, almost 20 years before the movie was made. It is a great composition, and well used to provide some sort of narrative to a weak story.
Of course, sometimes you can get both a good story and a good soundtrack. Case in point: Star Wars. I remember the characters, Spielberg certainly gets credit for creating memorable characters not only in Star Wars but in most of his films (even the bombs). Spielberg hit a homerun with picking John Williams to compose the music. His music has moved film after film from mediocre to great.
Unfortunately, some pretty good science fiction films have been ruined with poor musical scores. The Space between Us was a great story, but often losing the narrative and acting to a score that seemed totally mismatched to the film. Compared to the weak story and overuse of special effects (consider the seemingly endless panning around the Enterprise) The Space between us is a heart stopping and interesting science fiction tale. Sadly it did not have Jerry Goldsmith (Star Trek) nor John Williams to score the film.