The early ‘70s was a time of change at the big movie studios.

Many of the great directors of the previous era were being brushed aside as new audiences demanded different styles of storytelling, and the success of the 1969 counterculture film Easy Rider appeared to show the way. Universal Studios came up with the concept of commissioning a series of low-budget experimental projects instead of paying for a single larger production, and so Douglas Trumbull was given his directorial debut with his science fiction story Silent Running.

Trumbull wasn’t exactly a beginner, though. His father, Don, had worked on movies decades earlier, while Douglas himself had worked on the main effects sequences for Stanley Kubrick’s 2001: A Space Odyssey. That movie was the starting point for Silent Running because the visual effect Trumbull wanted to achieve for the classic movie's stargate sequence proved to be technologically impossible at the time. What people saw in Silent Running's Saturn sequence was what they should have seen in 2001, if Trumbull was able to make it work four years earlier.

Silent Running is set on an American Airlines cargo vessel, one of several in a fleet near Saturn. Each ship carries several domes in which the final gardens of Earth are stored. Human actions have rendered the planet a barren place, but very few people seem to care since they all have work and entertainment. One person who does care is botanist Freeman Lowell, aboard the ship the Valley Forge. When the cargo contract is terminated, the crew of each vessel is told to destroy the gardens and come home. Unable to bring himself to comply, Lowell kills his crewmates, flies the Valley Forge through the rings of Saturn to make it look like it’s been destroyed and reprograms two drone robots to help him keep the gardens alive. In the end, he’s discovered and, believing there’s only one way out, sets the last garden loose with a drone to look after it and then destroys himself and the ship.

The cold, battered technical world is contrasted with the beautiful natural environment of the gardens and its wildlife, while Joan Baez provides appropriate politically aware music.

Watch the Original 'Silent Running' Trailer

Trumbull – who died in February 2022 at 79 – offered several thoughts on his eco-aware storyline over the years. “It was the ‘60s, it was during the Vietnam War wind down and everybody was very environmentally conscious at the time, and it seemed like an appropriate way to tell this story that I wanted to tell,” he said in 2014, although at other times he suggested the hippie angle was foisted upon him.

Indeed, his first version of the script was a first-contact story, with Lowell stealing the ship simply because he doesn’t want to go back to Earth and then receiving a message from an alien ship. He tries to reach it while being chased by his bosses, and ends up being killed by boarders just after ejecting a dome with a drone, which is then met by the aliens in the closing scene.

Lowell is played by Bruce Dern, who delivers a convincing performance as a social outsider regarded as mad while being certain it’s everyone else who’s mad. The moment he tries to persuade his colleagues not to destroy the gardens is a prime piece of method acting, as he shows them a photograph of a young girl, using a real-life experience of losing an 18-month daughter a decade earlier. At another point, he pleads with them to listen to their own words: “Every time we have the argument, you say the same thing to me, you give me the same three answers all the time. … ‘Well, everybody has a job.’ That’s always the last one. But you know what else there is no more of, my friend? There is no more beauty, and there is no more imagination, and there are no frontiers left to conquer, and you know why? Only one reason why … the same attitude that you three guys are giving me right here in this room today. And that is: Nobody cares.”

Watch Lowell Speak Up for Nature in 'Silent Running'

"I looked at a lot of actors, and I was just drawn to him," Trumbull recalled. "I thought he was really miscast in most of his movies, because he’s really a warm, loving kind of person, and he was always being cast as a monster. So when we talked to him about doing this movie, he was really thrilled and eager to do it, because he was finally getting a chance to do something outside that realm. It worked really well for him.”

Despite the overarching impression of doom and human failure, there is a thread of hope running through Silent Running. Dern enjoyed his 32 days on the set of a redressed Navy vessel in February and March 1971. “Given that we were playing astronauts aboard a huge space freighter, you really couldn’t have hoped for a better location,” he said. “We all felt pretty small aboard that ship, which is how I imagine Douglas wanted us to feel.”

The three drones – nicknamed Huey, Dewey and Louie after Lowell programs them with personalities – were played by actors who had amputations. Trumbull recalled seeing one such actor in the movie Freaks and being struck by “this remarkable, beautiful guy, with this amazing agility, leaping and running on his hands through the room, jumping on chairs. … And not once did you feel horrified. You’re amazed and respectful at his adjustment. That impression stayed with me when it came time to cast the drones. I knew what I wanted.”

Mark Persons, Steve Brown, Cheryl Sparks and Larry Whisenhunt were given the demanding task of rendering the metal boxes feel like personalities, which they achieve. The scene in which Lowell tells the drones they’ve made a mess of planting a tree is a prime example. (The drones were so impressive that George Lucas received permission from Trumbull to base his Star Wars droid R2-D2 on the Silent Running characters.)

Watch the 'Silent Running' Saturn Sequence

With Trumbull’s abilities as an inventor, effects designer and now director, the movie was visually at a level that belied its budget of around $1 million. (Trumbull got some help from his dad, who came out of retirement and developed the Valley Forge’s buggy cruisers.)

Although the movie found a cult following later, it flopped at the box office after its release on March 10, 1972. "It was just a great experience for me as a filmmaker," Trumbull said later. "But I didn't know that I was part of an experiment by Universal Studios … to see if it was possible to have a movie survive on word of mouth alone without an advertising campaign."

Still, the movie has been influential. British sci-fi sitcom Red Dwarf notably based its titular spacecraft on the Valley Forge. The aerobraking scene in 2010: The Year We Make Contact feels similar to Silent Running’s Saturn scene. Director Duncan Jones' 2009 sci-fi movie Moon features a droid that recalls Trumbull’s pool-playing robot. "We’ve allowed ourselves to be convinced that SF should be frivolous, for teenage boys," said Jones (David Bowie's son). "We’re told that the old films, the Outlands and Silent Runnings, were too plaintive, too whiney. I think that’s ridiculous."

Trumbull would go on to work on movies including Close Encounters of the Third Kind, Star Trek: The Motion Picture and Blade Runner, and provided advice and custom-built movie-making devices until his death. He directed only one other movie, 1983’s Brainstorm. But even if his original intention for Silent Running was nothing like the environmentalist warning it became, it’s helped secure the film’s five-decade lifespan. Perhaps now more than ever, watching Lowell’s desperate attempt to persuade his peers to “look up” and see what they’re doing, we see an even more urgent red alert.

After Lowell reflects on the corporation’s breaking of the (real-world) Outdoor Life Conservation Pledge, he decides that the extreme actions he’s been thinking about need to be taken, including murder and theft. As he lies to his superior about the Valley Forge being in trouble, the boss tells him: “You’re a hell of an American.” “Thank you, sir,” Lowell replies, then cuts the comms link. “I think I am.”

Watch Lowell Say Goodbye in 'Silent Running'

Top 100 '70s Rock Albums

From AC/DC to ZZ Top, from 'Bridge Over Troubled Water' to 'London Calling,' they're all here.