A long time ago in a galaxy far, far away...
Why it is hard sci-fi
Soft. The original 1977 film established the visual grammar of hyperspace, blasters, and used-future starships, none of which have working physics. The Death Star superlaser is famously over-budget for any real energy source and the film does not pretend otherwise.
Science inside it
Targeting computers, droid AI, and a final attack run that uses an unguided proton torpedo through a thermal exhaust port. The thermal exhaust port at least nods to a real engineering problem. Heat dissipation on a station that size would be a real constraint.