This is science fiction, so there has to be something about science. All science fiction has to feature some science, or it’s not science fiction. It just depends how much. The subgenre of Hard SF tends to be more realistic and detailed when it comes to science, whereas space opera tends to be looser and mushier in the science department. Freehauler Alcione tries to balance both.
Some important science topics relevant to science fiction, and especially to space opera
FTL (faster than light travel)
Exoplanetology – the science of planets outside our solar system.
Xenobiology – the biology of life on planets other than Earth