A small science fiction film debuted in America's theaters in 1972. It was a passion project for its director, Douglas Trumbull, former special effects photographer on Stanley Kubrick's film 2001: A Space Odyssey from three years prior. It was shot and written on a tight budget and schedule, though it was certainly visually impressive. It was also written in a hurry, by an up and coming young Steven Bochco, who hated the way his script was treated so much that he stayed away from movies for the rest of his career, becoming a prominent TV producer instead. It got good reviews from critics, who praised its depth and environmental message, but filmgoers remained largely unimpressed, and the film was not a box-office success. The film was called Silent Running and today, it is one of the most influential genre films ever made.

Silent Running’s plot is simple: in an effort to save future-Earth's flora from extinction, the US government sends ships containing large greenhouses into space, in the hope that some day the project will allow restoration of plant life on the planet.

Freeman Lowell (Bruce Dern), a crew member on one such ship called Valley Forge, makes it his mission to take care and nurture the greenhouses aboard and the wildlife attracted to them, and is treated with ridicule and even open hostility by his comrades, who consider his obsession with nature – and their mission – a waste of time. They cheer when word comes from Earth about the cancellation of the project, followed by orders to destroy the greenhouses and return home, but these orders prove too much for Lowell. In a desperate attempt to fulfill what he now considers his life mission, he murders the other crew members, takes over the Valley Forge, and flies it deep into space.

Silent Running (1972) dir. Douglas Trumbull

From this point on, Silent Running becomes a slow, almost meditative film, focusing on its protagonist's mental breakdown – his desperate attempts to take care of the greenhouses in the ship under the emotional burden of guilt over the crime he committed and loneliness. This part of the film is largely devoid of action and for the most part also tension – it is about Lowell's inner conflict, which is superbly portrayed by Dern, but does not exactly contain the stuff that blockbusters are made of.

And yet, blockbuster films in Hollywood and all over the word, have made direct references to Trumbull's film. What is it about Silent Running that keeps capturing the imagination of so many filmmakers? As noted above, the film's designs stand out, and had strong influence on subsequent productions, but a closer examination reveals how fans of Trumbull's film in the filmmaking community have also absorbed the film's deeper themes.

Silent Running (1972) dir. Douglas Trumbull

Living off the Land

Silent Running's environmental message about the importance of protecting the flora and fauna of our world is clear, although the film also poses moral questions as to how far the struggle for such protection can go. Strangely enough, though, the film also promotes reaching beyond our world, deep into space, and in fact argues that doing so will help preserve Earth's ecosystem. Nowhere in the film is this approach made clearer than in its memorable closing shot: a single greenhouse dome, filled with trees, plants, and wildlife, tended by a single robot, floating in space.

A direct reference to this scene is found in Hayao Miyazaki's 1986 steampunk anime feature Castle in the Sky. The film, a tale of adventure revolving around the search for the mythical flying island of Laputa, ends with the island again flying away from the reach of mortal beings, its beautiful evergreen gardens lovingly tended by a robot.

Miyazaki, however, did not completely buy into Trumbull's vision about the need to preserve nature's beauty at all costs. On the contrary: Laputa, his version of Silent Running's flying greenhouse dome, is not only something that will never be achieved by mortals, but something that shouldn't be aspired for. He does not consider the prospect of paradise that is devoid of human presence as ideal. Rather, he believes that coexistence with nature on Earth, for all its hardships, is the true ideal.

Similarly, princess Nausicaa of Miyazaki's early ecological fable Nausicaa of the Valley of Wind (a manga serialized by Miyazaki between 1982 and 1994, adapted by him into an animated feature in 1984) and Lady Eboshi of his later film Princess Mononoke (1997) both follow in the footsteps of Silent Running's Lowell in maintaining their own garden.

Silent Running (1972) dir. Douglas Trumbull

Nausicaa's garden preserves plant life free from the pollution of the environmental apocalypse in the outside world whereas Lady Eboshi's garden is a little piece of paradise surrounded by war between men and nature (with Eboshi herself, ironically, leading the men on this struggle). Both characters, again, learn by the end of their respective stories that they have invested their efforts in a fruitless project: the beauty and riches of nature should be sought for in the post-apocalyptic world or the burnt, post-war forests, and should be shared with everyone rather than kept a secret.

Like Miyazaki, Hollywood also found a way to channel Trumbull's environmental vision into optimism, albeit of a different kind. Two of the previous decade's "lone man in space" epics, Christopher Nolan's Interstellar (2014) and Ridley Scott's The Martian (2015) owe a huge debt to Silent Running, primarily in the choice of their protagonists' occupation – a farmer and a botanist, respectively.

In Interstellar, protagonist Joseph Cooper (Matthew McConaughey) is sent by NASA to find a new home planet for mankind after Earth became a barren planet, unable to support its population. As in Silent Running, Cooper is accompanied in his quest by a helpful robot. The film ends with Cooper making the vision of ecological paradise from Trumbull's film available for all humankind, essentially turning it into a race of space explorers that can thrive all throughout space.

Silent Running (1972) dir. Douglas Trumbull

In The Martian, protagonist Mark Watney (Matt Damon), who finds himself marooned on Mars, starts a large-scale agricultural experiment in order to survive on the planet's harsh surface while waiting for his rescue, but in the process leads the way for future explorers and colonists of the planet, demonstrating how long-term existence on the planet is possible.

If Miyazaki borrowed visual and narrative ideas from Trumbull's film while rejecting his ideal of "empty ecological paradise in space", insisting that problems should be solved on Earth, Hollywood referred to Silent Running while rejecting the same ideal from the opposite direction – arguing that such paradise does not need to be empty.

Silent Running (1972) dir. Douglas Trumbull

Counterculture and Robot Utopia

Silent Running's environmental subtext is strongly influenced, of course, by the counterculture of the 1960s and the 1970s, but an even stronger legacy of the same counterculture in the film can be found in one seemingly unexpected place: the film's love for technology.

As noted above, the film did promote space exploration – and the US space program was, and is, very much a government operation at the time the film was made – but such exploration, in the film's context, can also be a metaphor for other things: the expansion of both the physical and mental boundaries.

Less metaphorical is one of the most recognized and beloved tech toys that populate Trumbull's film: the small "Drone" robots that accompany the protagonist on his quest. The drones – played by amputee actors – have long been considered the leading example for the longstanding influence of Silent Running on genre cinema, with R2-D2 of George Lucas' Star Wars (1977) seen as a prime example. Indeed, in what is perhaps the most charming and lighthearted scene in Trumbull's otherwise grim film, Lowell programs the drones to play poker with him, a clear inspiration for the holographic chess game between R2-D2 and Chewbacca in Lucas' film.

The similarities between Lucas' droids and Trumbull's drones go deeper. In showing how Lowell re-programs the drones not just to play poker but also to help him in his gardening operation, Trumbull has inspired not only Lucas' droids behavior but also their lifecycle. After all, the droids in Star Wars are initially bought second-hand from a shady dealer so that they can be reprogrammed – much like the drones in Silent Running – to work at the farm.

This concept further links both films to the counterculture movement: the love for technology that's based on used components, spare parts and home-made modifications. One person who promoted such sustainable use of technology, paired with a strong sense of ecological responsibility, and became an admired figure in counterculture circles and publications as Whole Earth Catalog was architect and designer Buckminster Fuller – who, unsurprisingly, was also the pioneer of geodesic domes design, the same kind of design seen on the Valley Forge's greenhouses.

Silent Running (1972) dir. Douglas Trumbull

The Pragmatic Ideologist

In one of the film's early scenes, which demonstrates the ideological difference between Lowell and the other crew members of the Valley Forge, Lowell makes an argument about the value of his work in the greenhouses aboard the ship. The damage from the destruction of Earth's flora, he says, was not only environmental but also social, as it bred conformity and indifference among people.

He makes this argument when he is having a meal with the other crew members, and the scene is strongly echoed in future genre films that used a discussion over meal between members of a futuristic ship as a narrative device to demonstrate ideological rifts and tensions. The mistrust between the working class and the upper class among the crew of the Nostromo during the waking-up meal in Alien (1979) and the discussion about the pros and cons of living in the real world aboard the Nebuchadnezzar in The Matrix (1999) are direct descendants of the scene in Trumbull's film.

Silent Running (1972) dir. Douglas Trumbull

As the film progresses, though, the good/evil dichotomy between the counterculture idealism of Lowell and the establishment represented by the other crew members, becomes less clear. After killing the other crew members, Lowell discovers that another ship from Earth is after him – with the best intentions of bringing him back (in his transmissions, Lowell gave his Earth superiors the impression that he committed an act of heroic sacrifice by taking the ship deep into space). Already feeling guilty for the murders he committed, Lowell now realizes that his home planet, which he betrayed, is not willing to give up on trying to rescue him.

And it is here, in the film's closing scenes that show Lowell taking his own life while simultaneously releasing the ship's last greenhouse into space, to be tended by the remaining drone, that Silent Running reveals complexity far beyond that of any of its successors. While the many works influenced by Trumbull's films offered answers to the world's problems, Silent Running ends with the notions that no easy answers to those problems exist – that neither idealism nor pragmatism can solve everything, leaving the responsibility of finding the right balance between them with its audience.

Raz Greenberg is an animation researcher and a teaching fellow at the Tel Aviv and Hebrew Universities. Features and reviews by him have appeared on Strange Horizons, Tablet Magazine and All the Anime. He is the author of Hayao Miyazaki: Exploring the Early Work of Japan's Greatest Animator published by Bloomsbury Academic.