Planetes, Oira Uchuu no Tankoufu Recommendations
Anime in general is lacking in science fiction stories that lean towards the "hard" end of the spectrum. Stories focusing more on day to day life in a science fiction world aren't often made. Instead anime sci-fi tends to be about robots, aliens, mutants and feature big battles in space. Anime needs more things like Planetes and Mighty Space Miners. Works that put serious effort into world building and believability. Both are highly recommended to science fiction fans.