Star Trek: The Original Series the 23rd century bearing a crew dedicated to exploring the Milky Way Galaxy. Roddenberry noted a number of influences on his idea, some of which includes A. E. van Vogt's tales of the spaceship "Space Beagle", Eric Frank Russell's "Marathon" series of stories, and the film "Forbidden Planet" (1956). Some have also drawn parallels with the television series "Rocky Jones, Space Ranger" (1954), a space opera which included many of the elements that were integral to "Star Trek"—the organization, crew relationships, missions, part of the bridge layout, and some technology. Roddenberry also drew heavily from C. S. Forester's Horatio Hornblower
Star Trek: The Original Series had a "quality audience" including "upper-income, better-educated males", and other NBC shows had lower overall ratings. The show was unusual at the time in its serious discussion of contemporary societal issues in a futuristic context, unlike "Lost in Space" which was more "campy" in nature. The enthusiasm of "Star Trek"s viewers surprised NBC. The network had already received 29,000 fan letters for the show during its first season, more than for any other except "The Monkees". When rumors spread in late 1967 that "Star Trek" was at risk of cancellation, Roddenberry secretly began and funded an effort by Bjo Trimble,