In an interview with Starlog magazine in the late 1970s, Douglas Trumbull revealed that the plot of the movie in the original version of the script was quite a bit different from what was actually filmed. In the original version the space freighters were on permanent duty, carrying biological domes.

When they are finally told to blow the domes and return to Earth, it is because the freighters are going to be scrapped. The Freeman Lowell character in the original version was an older, more curmudgeonly man who simply did not want to return to Earth and be forced into retirement, so he steals the Valley Forge and heads off into deep space.

As in the filmed version, he reprograms the robots for some companionship. The subplot involving the plants dying due to a lack of light was involved, but his main interest in the plants was simply as a means of extending his limited food supplies.

Eventually he receives a signal from an alien ship and decides to approach it, making humanity's first contact with aliens. The conclusion was a race between Lowell, who was trying to contact the aliens, and the human boarding party trying to retake the ship.

Finally, in desperation, Lowell detaches one of the domes with one of the robots aboard seconds before he is killed by the boarding party. The dome drifts off into deep space, where it is found by the aliens.

The film would have ended with a confused Dewey "introducing" itself to the equally baffled aliens by presenting them with a "family photo" of Lowell and the drones taken earlier in the story. Trumbull had been involved with creating effects for 2001: A Space Odyssey.

Director Stanley Kubrick wanted the Stargate sequence of that film to be centered around Saturn, but there were technical difficulties in getting the special effects for it finished in the limited timeframe. The Saturn idea was scrapped, and Kubrick substituted Jupiter instead.

Trumbull developed the sequence after production, and it was recreated for Saturn in Silent Running. The interiors were filmed aboard the decommissioned Korean War aircraft carrier USS Valley Forge (LPH-8), which was docked at the Long Beach Naval Shipyard in Long Beach, California. Shortly after filming was completed, the carrier was scrapped.

The forest environments were originally intended to be filmed in the Mitchell Park Domes in Milwaukee, Wisconsin, but the production budget forced the sequences to be shot in a newly completed aircraft hangar in Van Nuys, California.

Trumbull stated in the commentary accompanying the DVD release that the geodesic domes containing the last forests of Earth's future on the Valley Forge were based on the Missouri Botanical Garden Climatron dome. Three freighters are shown in the film, the Valley Forge, the Berkshire, and the Sequoia.

Five other ships that carried domes – the Yellowstone, Acadia, Blue Ridge, Glacier, and Mojave — are also mentioned. Each ship features a designation on the hull which notes the area from which some of the flora and fauna samples were taken.

The Valley Forge is listed as "Bahia Honda Subtropical", indicating at least some specimens were taken from this area of the Florida Keys. The model of the Valley Forge was 26 feet (8 m) long, and took six months to build from a combination of custom castings and the contents of approximately 800 prefabricated model aircraft or tank kits.

After filming was completed, American Airlines expressed an interest in sending the model on the tour circuit, but this was not feasible due to the fragile nature of the model (in fact, during filming pieces of the model kept falling off). The ship was subsequently disassembled after several years sitting in Douglas Trumbull's personal storage facility.

Several pieces, including the domes, wound up in the hands of collectors. Several domes survive, including one that now rests in the Science Fiction Museum and Hall of Fame in Seattle, Washington, and another which was sold at auction in 2008.

The three drones were played by four bilateral amputees, an idea inspired by Johnny Eck, a sideshow performer of the early 20th century who had been born without lower limbs.[citation needed] The 20-pound (9-kg) drone suits were custom-tailored for the different actors.

The suits are in Douglas Trumbull's personal collection. The sound effects, including the drones, were created by uncredited composer Joseph Byrd. They were generated on a modified ARP 2600 synthesizer with added Oberheim Expander Modules.

Resources: Wikipedia.org, imdb.com

Silent Running - 1971

Silent Running takes place in the not-so-distant future, at a time in which Earth's plant life has been decimated. Only a few specimens of flora have been preserved, and are currently in space in a fleet of orbiting greenhouses. Freeman Lowell (played by Bruce Dern) is the main character, one of four extraterrestrial forest rangers aboard the Valley Forge, one of the 2,000 metre-long green house freighters.

He is passionately dedicated to preserving the orbiting forests and their natural inhabitants, and eventual returning them to Earth for reforestation of his now-barren planet more so than his crewmates, whose main priority seems to be returning to Earth after their one-year deployment to space. The main conflict comes when Lowell and his crew are ordered to destroy the orbiting greenhouses and redeploy the freighters to commercial service.

Lowell decides to disobey orders and save the forests he has worked so hard to preserve. Lowell's crewmates manage to jettison and detonate four of the six greenhouse domes on the Valley Forge. Lowell kills one of his crewmates in a struggle to save the two remaining domes, during which he seriously injures his leg. He then manages to trap the other two crewmen in the other remaining dome, which he then jettisons and destroys.

With help from the ship's three robots, Lowell feigns a premature dome detonation to fool his superiors, then alters the orbit of the Valley Forge , redirecting it towards Saturn in an attempt to preserve the last forest dome. Injured and alone with three robots, Lowell programs them to perform surgery on his leg.

Still in communication with the rest of the fleet, Lowell is informed that the Valley Forge is on a collision course with Saturn's rings, and there is nothing he can do to stop the catastrophic event. The ship will likely be destroyed. With communications failing due to the distance now between the Valley Forge and the rest of the fleet, the ship passes through the rings of Saturn.

While the three robots are outside the ship on maintenance duty, one is blown away from the ship, leaving two remaining robots. The ship, and its single greenhouse dome, emerge undamaged on the other side of the rings. Lowell and the two remaining robots chart a course into deep space, far away from the fleet. Alone except for his accompanying drones, Lowell befriends them and renames them Huey, Dewey and (posthumously) Louie.

He teaches them to play poker, plant trees, and bury the killed crewmember. Lowell soon realizes that despite all his efforts, his forest is dying from unknown causes. In a desperate and rushed attempt to save the dome he badly damages Huey in an accident with one of the ship's buggies. Repairs are unsuccessful, the forest continues dying, and Lowell begins to come to realize that his mission to save the forest is bound to fail.

After weeks alone in space, faint radio chatter is heard from a rescue party mounted from the Valley Forge's sister ship, the Berkshire, which has located the freighter after a long search. Finally able to communicate with Lowell, they inform him that they will be able to reach him within six hours he must jettison the dome but not detonate the nuclear charge, as it is too dark to do so safely.

At this point it dawns upon Lowell that what was killing the forest was lack of sunlight. With little time to work, he activates a series of lights to simulate the sun and instructs his last active robot, Dewey, to "just maintain the forest." Realizing that his crime will be uncovered when the Berkshire finds him, Lowell jettisons the last dome to safety with the words "take good care of the forest, Dewey."

With the Berkshire only two hours away from docking, Lowell and the damaged Huey sit facing each other while he arms the last of the six nuclear charges. As he prepares to destroy himself and preserve the last dome, Lowell says to Huey: "When I was a kid, I put a note into a bottle, and it had my name and address on it. And then I threw the bottle into the ocean. And I never knew if anyone ever found it."

With that, Lowell destroys the Valley Forge with the last of the onboard nuclear charges. The final scene is of a well-lit forest greenhouse drifting into space, tended by the sole remaining robot with a battered watering can. The scene is accompanied by Joan Baez's rendition of the film's theme song.