The working title of this film was Running Silent. As noted by Filmfacts, the title Silent Running refers to a nautical term describing a submarine "running silent" by lying on the ocean's floor with its engines cut in order to prevent detection. Sometimes the submarine will jettison debris and fluids in order to make the enemy think that it has been damaged. In the ending credits, a written acknowledgment thanks a number of companies, including American Airlines, which lent its logo for the "American Airline Space Freighter" sign on the U.S.S. Valley Forge space freighter, and the U.S. Dept. of Agriculture, Forest Service. The names of the three drones—Huey, Dewey and Louie—were the names of the nephews of Disney cartoon character Donald Duck.
       1969 and 1970 news items noted that the film was to be made within the independent unit overseen by Ned Tanen, a vice-president at Universal Studios. As with other films supervised by Tanen, Silent Running was given a $1,000,000 budget and a guarantee of final cut to first-time director Douglas Trumbull, who had previously worked on the special and visual effects for films such as the 1968 release 2001: A Space Odyssey and the 1971 production The Andromeda Strain (see entries below and above).
       Although a 21 Aug 1970 HR news item reported that Robert Dillon and Dennis Clark had written the screenplay, which contemporary sources noted was based on a story by Trumbull, the extent of Dillon’s and Clark’s contribution, if any, to the completed film has not been determined. Contemporary sources reported that the majority of the film was shot on location inside the U.S.S. Valley Forge, a decommissioned aircraft carrier moored at the Terminal Island Naval Station off Long Beach Harbor in Southern California. The interior of the carrier was extensively remodeled, using styrene vacuum forms, plywood, rubber and other materials, to make it look like a space freighter, according to a 1972 documentary on the film's making, which was included in the 2001 DVD release of Silent Running. The documentary also reported that the forest scenes were shot in an airplane hanger at the Van Nuys Airport in California. In a modern interview included on the DVD, Trumbull related that he personally photographed the brief scenes of Lowell’s recollection of a real forest in the Muir Woods, near San Francisco. Producer Michael Gruskoff, a former agent, had been Bruce Dern’s first agent and recommended him for the role of “Freeman Lowell,” according to the DVD commentary, to which Trumbull added that Larry Hagman was among the actors considered for the role.
       As reported by the 1972 documentary, the costumes for the drone units were vacuum-formed, styrene plastic shells. The lightweight costumes were worn by bilateral amputees (double amputees without legs), whose arms fit into the legs of the drones. The amputees walked on their arms and breathed through the slotted fronts of the costumes. In a modern interview, Trumbull stated that he had been inspired to cast real actors as the drones after seeing the 1932 Tod Browning-directed film Freaks (see above), which features an actor known as "The Living Torso."
       Trumbull also related that the geodesic domes housing the forests used in the film were inspired by a dome designed by Buckminster Fuller located at the Missouri Botanical Gardens in St. Louis, MO, and that the design of the spaceship was inspired by a tower at the 1970 Osaka World Expo. Many of the special effects for the picture were created “in camera,” according to Trumbull, by using front projection equipment to project still photographic plates of stars, the domes and other images in front of the actors or models while the live-action sequences were being shot, as opposed to optical visual effects being inserted after principal photography was completed. The model for the Valley Forge was approximately twenty-five feet long, according to the 1972 documentary, with the domes being twenty-seven inches in diameter.
       According to contemporary sources, the film was initially rated GP--the rating listed by Filmfacts and several preview reviews--but was re-edited before its general release in order to receive a G rating. According to the 13 Mar 1972 Box review, two minutes were cut from the film in order for it to qualify for the G rating. The picture won the 1972 Golden Astroid for best picture at the International Science-Fiction Film Festival in Trieste, Italy. The 1972 making of documentary about Silent Running also received an award at the Trieste festival in 1974. Silent Running received generally warm reviews, with many critics comparing it to 2001: A Space Odyssey, because of Trumbull’s connection to both productions. Time magazine’s critic, Jay Cocks, praised Silent Running for having the earlier film’s “same kind of technical virtuosity, the same sense of still, vast symmetry of the galaxies.” The Washington Post reviewer pronounced Silent Running “a new classic of the genre” and asserted that he preferred its “scaled-down secular, humane perspective” to the “philosophic-mythic-religious dimensions of 2001.”
       Paul D. Zimmerman, writing for Newsweek, asserted that the picture “beyond being a good family film, will become the object of cult worship by the young romantics of the Tolkien-Vonnegut generation.” Despite modest box-office returns, as Zimmerman predicted, Silent Running went on to become a cult hit after being discovered on television by a new generation of fans.
       Wardrobe advisor Ann Vidor married Trumbull after Silent Running finished production. Although Trumbull did not make another feature film until the 1983 release Brainstorm, he continued to work in visual effects, including on the Academy-Award nominated pictures Close Encounters of the Third Kind (1977) and Blade Runner (1982), as well as creating interactive theme park rides such as the Back to the Future attraction at Universal Studios. Don Trumbull (1909—2004), the director's father, had worked in motion picture special effects in the 1930s, but moved into a career in the aerospace industry. Trumbull requested his father's help with Silent Running, and the elder Trumbull aided with the design of the drones and the transmissions of the motorized carts in which the astronauts race. The carts became the prototypes for the four-wheel, all-terrain vehicles that soon became popular. Don Trumbull went on to design much of the photographic equipment used in Star Wars (1977). Composer Peter Schickele, who had worked with singer Joan Baez previously as an arranger on her albums, also performed under the name P. D. Q. Bach.
       Silent Running marked the feature film debuts of writer Michael Cimino, billed onscreen as Mike Cimino, and special effects designer John Dykstra. Cimino, who became a director and producer as well as a screenplay author, became well-known for films such as 1978's The Deer Hunter and 1980's Heaven's Gate. Dykstra, an influential special effects supervisor, worked on Star Wars as well as 2002's Spider-Man and its 2004 sequel, Spider-Man 2.
       According to a 14 Aug 1981 HR article, Universal sued Twentieth Century-Fox, claiming that the droid “R2-D2” in Star Wars was an infringement upon the design of drones Huey, Dewey and Louie. Judge Irving Hill of the U.S. District Court in Los Angeles dismissed the case before trial, however, stating that “no one has a monopoly on the use of robots in art,” and that the robots in question were not similar. Universal appealed the decision, but the Court of Appeals also dismissed the case. Although Trumbull and Dern revealed in their DVD commentary for the film that both a sequel to and a remake of Silent Running have been contemplated, with a completed sequel screenplay having been written by John Curtis, neither project has been made as of 2007.