The Empire Strikes Back by Ralph McQuarrie

These tremendous aerostatic control vanes regulate the flow of air inside the reactor shaft. Technologically this enables the citizens to change their city's position in space, moving it along any plane. The lights in the background belong to huge loading ports. All cargo flights in the shaft must be coordinated, for the uncontrolled winds can hurl the best of crafts to their doom.

(Last updated at: 980414)