Revealing mistake: Freeman Lowell has several cargo containers dumped off the spaceship, to make it appear the ship has suffered an accident. A wide shot shows the ship receding in the distance, with the containers rolling weightlessly in the foreground. As the foreground containers pass slightly in front of the more distant ones, they don't mask them; their images overlap. The containers were apparently composited into the shot with simple multiple exposures. (00:35:40)
Character mistake: Lowell points to Dewey as the robot that has the full house in the card game but it was Huey that had the full house.
Trivia: The space ship "Valley Forge" from Silent Running was re-used in one episode of the television series "Battlestar Galactica" (1978-1979). It was called the "agro-ship," used to grow food for the colonists.
Trivia: The interior shots of the American Airlines Space Freighter "Valley Forge" were actually filmed aboard the Korean-War-era aircraft carrier "USS Valley Forge" (LPH-8) at the Long Beach Naval Shipyard in California. After filming was completed, the decommissioned aircraft carrier "Valley Forge" was scrapped.Charles Austin Miller
Freeman Lowell: It calls back a time when there were flowers all over the Earth... and there were valleys. And there were plains of tall green grass that you could lie down in - you could go to sleep in. And there were blue skies, and there was fresh air... and there were things growing all over the place, not just in some domed enclosures blasted some millions of miles out in to space.