The latest Star Wars Insider special is here, the Star Wars: The Empire Strikes Back 40th Anniversary Special and StarWars.com look at the section pertaining to Hoth and how the ice planet came into the story.
As he did for A New Hope, George Lucas made a list of planets in his notes when he started imagining the sequel. Among them, he named: the Wookiee planet—on which production illustrator Ralph McQuarrie started working since he signed his contract in October 1977, but that would not appear in the film; a gas planet called Hoth—which would later become Bespin where Lando’s Cloud City floats; and a generic “Ice Planet”. It was only in the second draft of the script in 1978 that the name was assigned to the actual ice planet where the rebels would set up their new outpost. From the Ice Kingdom of Mongo featured in Alex Raymond’s Flash Gordon comics series (March 12, 1939 to April 7, 1940) to Howard Hawks’s The Thing from Another World (1951), several influences shaped Hoth’s concept and development. This is how Lucas himself described the planet in 1977: “We could start on the Ice Planet, which would be striking. We’ve never been there before, an underground installation in a giant snow bank. Very hostile, with wind blowing around and the cold.”
In parallel to the world of the Wookiees, covered in huge trees, McQuarrie was already painting ice and snow: based on Lucas’ instructions, since no finished script was available at that time, the artist was developing Darth Vader’s home. Initially set in a cold environment, the metal castle of the Sith Lord was later placed amid boiling lava, but it didn’t make it in the film anyway—its first appearance would only be in 2005 in Revenge of the Sith, though it was not actually called Vader’s castle in the final prequel film. Some of the concept paintings were later converted to first illustrate the rebel base in the context of Hoth. In the following months the metal structure disappeared and the base was moved inside the ice caves, which were considered natural to the planet. Trying to figure out the design of the interiors, Ralph McQuarrie and visual effects art director Joe Johnston imagined how the rebels carved the ice out to make room for the hangar and the equipment: “It was my feeling that lasers would be used to accomplish the cutting in long, straight lines. That helped give me a key to part of the solution.”
Star Wars: The Empire Strikes Back: 40th Anniversary Special (Hardcover) @ ForbiddenPlanet.com