Colin Cantwell, a concept artist, animator and computer engineer who helped bring the Star Wars universe to life, designing and building prototypes for a fleet of epic spacecraft – from the menacing TIE fighter to the elegant, dart-shaped X-wing – and giving the Death Star its alien look and fatal flaw (a trench), died Saturday at his home in Colorado Springs. He was 90.

The cause was dementia, said Sierra Dall, his partner of 24 years and only immediate survivor.

A veteran of NASA’s Jet Propulsion Laboratory, where he created educational programs to teach the public about early space launches, Cantwell went on to work with directors including Stanley Kubrick, George Lucas and Steven Spielberg, developing miniatures, computer graphics and other visual effects for movies including “2001: A Space Odyssey” (1968) and “Buck Rogers in the 25th Century” (1979).

He was best known for his work on “Star Wars” (1977), when he created the first designs for many of the movie’s most memorable ships, helping to define the look of the blockbuster franchise even though he worked on only its first installment. “He was a fairly quiet, very nice and extremely talented man,” said Craig Miller, a former director of fan relations for Lucasfilm.

When Lucas hired Cantwell in late 1974, the director was still negotiating financing with Twentieth Century Fox, working out concepts like the Force and overhauling a screenplay that was tentatively titled “Adventures of the Starkiller, Ep. 1: The Star Wars.” The script mentioned a number of spacecraft, but offered only vague descriptions of what they looked like and how they moved.

Cantwell was tasked with filling in the details, instructed by Lucas to make the ships look realistic but with “a comic book nobility,” according to Brian Jay Jones’s book “George Lucas: A Life.” He exchanged drawings with the director before landing on final sketches that he used to make his models, assembling plastic miniatures from thousands of pieces – including pill containers, lamp pieces, and parts of commercial model kits for planes, cars and boats – that he stored in a set of eight-foot-tall drawers.

Whether the spacecraft were shown individually or en masse, zipping across the screen in formation or chasing one another in a dogfight, Cantwell wanted them to be immediately recognizable, and to generate a sense of nervousness or excitement depending on their place in Lucas’s science fiction saga. “My premise was you had to instantly know the bad guys from the good guys . . . by how [a ship] looks and feels,” he said in a 2014 interview for the website Original Prop Blog.

His design for the X-wing, the Rebel Alliance’s signature starfighter, was inspired by seeing a dart thrown at an English pub and was meant to suggest the image of a cowboy drawing his guns outside a saloon. His sleek initial model for the Millennium Falcon, on the other hand, was meant to evoke a lizard that was poised to strike – and was used instead as the basis for the rebel blockade runner that appears in the film’s opening scene. (Other artists, including Joe Johnston and Ralph McQuarrie, ultimately contributed to the Millennium Falcon’s worn-down, hamburger-shaped look.)

Cantwell also created prototypes for the imperial star destroyer, the wedge-shaped ship that fills the screen in the film’s opening moments (to determine its size, he asked Lucas whether the ship was supposed to be “bigger than Burbank”; the answer was yes), and created the Death Star, the laser-equipped space station capable of destroying entire planets.

The film’s climax featured an attack run across the Death Star’s equator, in which Luke Skywalker (Mark Hamill) flies through a canyonlike trench to fire torpedoes at the space station’s one weak point. As Cantwell told it, the scene originated by chance, after he had almost finished making the Death Star model from a plastic sphere measuring about 14 inches across.

The sphere came in two halves, which he transformed into the Death Star by scratching features into its surface, but the halves shrunk at the middle where they were supposed to meet. “It would have taken a week of work just to fill and sand and refill this depression,” he said in an interview with the Montecito Journal of California. “So, to save me the labor, I went to George and suggested a trench, with armaments projecting from the sides of the trench resulting in battles with starships flying in and out of the trench. Lucas agreed, and it became a key point in the film.”

Colin James Cantwell was born in San Francisco on April 3, 1932. His father was a commercial artist, and his mother worked as a riveter during World War II to support the military effort. One of his uncles was Robert Cantwell, a journalist for Time and Sports Illustrated who wrote a pair of well-received novels.

As a boy, Cantwell was bedridden with tuberculosis and a partially detached retina. “The cure was to confine me to a dark room with a heavy vest across my chest to prevent coughing fits,” he recalled in a 2016 “Ask Me Anything” interview on Reddit. “I spent nearly TWO YEARS of my childhood immobilized in this dark room. Suffice to say, nothing else could slow me down after that!”

Cantwell studied at the University of California at Los Angeles, where he made student films and received a bachelor’s degree in applied arts in 1957.

During the 1969 moon landing, he served as the conduit between CBS broadcaster Walter Cronkite and NASA, listening to the communications line between Apollo 11 astronauts and Mission Control so that he could update Cronkite on the space capsule’s progress.

By then, he had started making scientific and commercial films and was using his technical expertise for big-budget pictures. Traveling to London, he helped Kubrick shoot space scenes for “2001” and befriended the director; years later, he recalled visiting Kubrick’s home one night and, while dining on turkey sandwiches, suggesting the film’s dramatic opening scene, a celestial image of the sun, moon and Earth scored to Richard Strauss’s “Also sprach Zarathustra,” which became the movie’s main theme.

Cantwell later wrote and directed “Voyage to the Outer Planets,” a large-screen trip through the solar system that ran at what is now the Fleet Science Center in San Diego, and contributed technical dialogue for “Close Encounters of the Third Kind” (1977).

He also worked as a computer graphics consultant for Hewlett-Packard, helping to develop one of the first color display systems for a desktop computer. Cantwell used the system to create graphics for the Cold War techno-thriller “WarGames” (1983), in which a dozen giant computer screens flash with the positions of Soviet nuclear missiles.

Cantwell later conducted quantum physics research, according to his partner, Dall, in addition to writing a two-volume science-fiction epic called “CoreFires.” He rarely spoke about his “Star Wars” work until he was in his mid-80s, when he began appearing at fan conventions and selling prints of his concept art, after decades when far more fans seemed to know the work of collaborators such as McQuarrie.

Interviewed by the Denver Post, he said he felt that Lucas had underplayed his role in the creation of “Star Wars” because Cantwell had declined an offer to run the director’s special-effects shop, Industrial Light & Magic. He was far less interested in continuing his effects work, he said, than in pursuing new avenues of invention.

“Colin told me one time that this is the way he went through life, that he liked to create things that people couldn’t unthink,” Dall told the Denver Post. “That’s how he got into a lot of things: He would come up with such original, creative and intelligent ideas that people would look at it, and then they couldn’t go back.”