Silent Running

Silent Running is a 1972 environmentallythemed American postapocalyptic science fiction film starring Bruce Dern, featuring Cliff Potts, Ron Rifkin and Jesse Vint. It was directed by Douglas Trumbull, who had previously worked as a special effects supervisor on science fiction films, including 2001 A Space Odyssey and The Andromeda Strain.

Orders come from Earth to jettison and destroy the domes with nuclear charges and return the freighters to commercial service. After four of the six domes are jettisoned and blown up Lowell rebels and opts instead to save the plants and animals on his ship. Lowell kills one of his crewmates who arrives to plant explosives in his favorite dome, with his right knee seriously injured in the process. He traps the remaining two crewmen in the other dome, just as it is jettisoned and destroyed.Enlisting the aid of the ships three service robots, called drones, Lowell stages a fake premature explosion as a ruse and sends the Valley Forge careening towards Saturn in an attempt to hijack the ship and flee with the last forest dome. He then reprograms the drones to perform surgery on his leg and sets the Valley Forge on a risky course through Saturns rings. Later, as the ship endures the rough passage, Dronelater nicknamed Louie is lost, but the ship and its remaining dome emerge relatively undamaged on the other side of the rings. ........

Source: Wikipedia