Silent Running features another unhinged performance from Bruce Dern. He plays Freeman Lowell, a scientists aboard a spaceship looking after the only remaining examples of Earth's plant life as it heads off to Saturn.

Lowell has become attached to the eco-system in the spaceship and less with his crew mates who he kills when they receive orders to destroy the plant life.

On his own, alienated, staving off madness, all Lowell has are three droids for company and then his plants start to die as they get less sunlight as the craft nears Saturn.

Douglas Trumbull in some ways has directed a low fi science fiction film, in some ways the interior sets reminded me of a television series from the early 1970s. It also contains some folk songs to accompany its environmental message.

This was a thoughtful sci-fi story.
Bruce Dern appears as a bit of a deranged scientist in what may be his most likable role ever, which says a lot about the roles he has played.
He is a caring scientist, except he kills all his companions in a spacecraft. Well, can he still be likable?
He has a motivation for doing this which is more than the motivation for his other villains.
Here, he means to save plant life for Earth. His companions didn't even understand the need to save plant life, which tells you about the horrible times they live in.
All this happens fairly early in the film. Afterwards, his companions are robots whom he empathizes with as if they are human beings.
Earth has decided to destroy all plant life, so in essence, he plays a hero/villain, hard to tell. But does he manage to salvage something for humanity?

A botanist (Bruce Dern) on a deep space mission tries to stop the corporate machine from destroying his small "forest" aboard his inter-planetary freighter. When his shipmates decide to implement the order he takes matters into his own hands. It is vaguely portentous of events yet to come - and has a poignancy about not knowing what you've lost until you haven't got it any more. It's the first film I recall seeing where there are droids - in this case, drones - Huey, Dewey (Louie has broken) that are given some semblance of personality and they do inject some much needed bursts of humour into this rather slow-moving sci fi story. It certainly has a message (climate change, warming etc.), but after a while it becomes quite laboured and slows down to a snail's pace before quite an abrupt ending. Interesting, but no classic...