In 1977, George Lucas changed the future in a single movie when he introduced audiences to the "used future." If all Lucas had done was make a 70s SciFi move, almost perfectly lacking in geodesic domes, that would be worth celebrating, but for the first time in the history of cinema Lucas introduced a future with a past. Before Star Wars all spaceships we conceived as totalities. The model was the Modernist Architect Corbusier's great admiration for oceanliners: "“The steamship is the first stage in the realization of a world organized according to the new spirit.” wrote Corbusier. For the Modernists, the ideal to be reached was "visual unity": as if a single hand had designed the entire world at a single sitting. Before Star Wars, all spaceships were Modernist; after Star Wars nothing was Modernist.
Without making any extravagant claims about the destruction of the Death Star marking the end of Modernism (but it was); it is not extravagant to point out that "visual unity" has been all but entirely replaced with an ethic that is very much like the "used future" we were first shown in Star Wars. Which begs the question: what exactly a "used future" is. Lucas told his set designer, John Barry, that he wanted the Millenium Falcon to look like a ship from Stanley Kubrick's 2001, "that had aged two hundred years."
2001: A Space Odyssey (1968); Star Wars: The Empire Strikes Back (1980)
Ben Burt, the sound designer for all the Star Wars films, explains the "used future" further:
[Lucas] wanted the sounds to have a worldly quality. That they would sound like real objects, real motors, actual places. The doors would be rusty on the space ships or the places where people lived. The engines would sound like that they were maybe mis-tuned or would backfire once in a while. He wanted a used universe in a sense.For those who will complain that Douglas Trumbull's Silent Running pioneered this sort of used-worldly quality, there is another, overlooked component to the "used future" that makes what we saw in Star Wars for the first time a break with all film scifi that preceded it. Ralph McQuarrie gives a clue, in an interview about his thoughts for what Coruscant might have looked like, had it appeared in the original trilogy:
I imagined it to be dark and spooky with enormous buildings and a metal surface and, down below, huge avenues like on Wall Street in Manhattan. George stated that he wanted a planet that was a city with endless built-up areas. In my mind it was built a thousand years ago, layer after layer."
The flying hamburger was my favorite design. I thought that the other design was too close to Space 1999 and too conventional looking. I wanted something really off the wall, since it was the key ship in the movie; I wanted something with a lot more personality. I thought of the design on the airplane, flying back from London: a hamburger.”