Cast of Silent Running

Bruce Dern plays Freeman Lowell, a dedicated botanist onboard the spacecraft Valley Forge who fights to protect the last remaining forests in space.

Cliff Potts portrays John Keenan, one of the crew members on the Valley Forge spacecraft who has a different perspective on the mission than Freeman Lowell.

Ron Rifkin takes on the role of Marty Barker, a crew member who interacts with Freeman Lowell and shares his concerns about the future.

Jesse Vint plays Andy Wolf, a crew member who becomes involved in the moral dilemmas faced by Freeman Lowell during the mission.

Mark Persons voices Grey Drone #1, also known as 'Dewey,' a robot onboard the Valley Forge that plays a significant role in the story.

Steven Brown voices Orange Drone #2, named 'Huey,' another robot onboard the spacecraft who interacts with the crew.

Cheryl Sparks provides the voice for Orange Drone #2, also known as 'Huey,' a companion robot to Freeman Lowell on the Valley Forge.

Larry Whisenhunt voices Green Drone #3, known as 'Louie,' a robot onboard the Valley Forge that aids Freeman Lowell in his mission.

Joseph Campanella provides the voice for Neal, the Captain of the spacecraft Berkshire, in an uncredited role in the film.

Roy Engel voices Anderson in an uncredited role, a character who communicates with the crew of the Valley Forge during the mission.