Silent Running (1971)

Synopsis
Bruce Dern stars as the caretaker of a greenhouse located on a group of space stations that are sent into orbit. The Earth has been stripped clean of foliage, and the greenhouse contains the last remaining greenery from the planet. Dern's staff includes three human beings and a trio of endearing robots named Huey, Dewey, and Louie. When word arrives from the Powers the Be that the greenhouse is to be destroyed (the space station is more valuable to man when hauling cargo and not "preserving the ecology of the universe"), Dern decides to ignore the order. He also decides to kill his colleagues, "circle the wagons" with Huey and Dewey, and fend off all outside attempts to eliminate his ecological paradise. Special-effects maven Douglas Trumbull directs, Michael Cimino was one of the screenwriters, and Peter "PDQ Bach" Schickele wrote the musical score. ~ Hal Erickson, All Movie Guide