One of the best science-fiction films of the 1970s, Silent Running is a story of man's relationship with machines, with nature, and with himself in the face of total isolation.
Freeman Lowell (Bruce Dern), a botanist, has spent eight years aboard the space freighter, 'Valley Forge', participating in a program to preserve the only botanical specimens extant from Earth, where all vegetation has died. His hope is that the forests, protected under huge geodesic domes, will survive until Earth's environment can support the forests once again.
The apathy of the three younger astronauts who are assigned to help him, reflects the prevalent attitude on Earth toward the program. When orders are received that the project has been terminated, the forests are to be destroyed and the men returned to Earth, Lowell tries to save the forests by pirating the Valley Forge. His action kills his three companions and plummets the freighter into the gaseous Rings of Saturn. Lowell is injured but survives with two robots to continue his mission.