Updated: August 07, 2022

Star Trek is an American science-fiction television series created by Gene Roddenberry that follows the adventures of the starship USS Enterprise (NCC-1701) and its crew. It later acquired the retronym of Star Trek: The Original Series (TOS) to distinguish the show within the media franchise that it began.

The show is set in the Milky Way galaxy, roughly during the 2260s. The ship and crew are led by Captain James T. Kirk (William Shatner), First Officer and Science Officer Spock (Leonard Nimoy), and Chief Medical Officer Leonard 'Bones' McCoy (DeForest Kelley). Shatner's voice-over introduction during each episode's opening credits stated the starship's purpose:

Space: the final frontier. These are the voyages of the starship Enterprise. Its five-year mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no man has gone before.

The series was produced from September 1966 to December 1967 by Norway Productions and Desilu Productions, and by Paramount Television from January 1968 to June 1969. Star Trek aired on NBC from September 8, 1966, to June 3, 1969, and was actually seen first on September 6, 1966, on Canada's CTV network. Star Trek's overall Nielsen ratings while on NBC were considered low by studio executives ( despite the show's high ratings amongst its target audience of teenagers through adults of middle-age ), and the network cancelled it after three seasons and 79 episodes. Within just a few years, the series became a hit in broadcast syndication, remaining so throughout the 1970s, and rapidly achieved cult classic status and a developing influence on popular culture. Star Trek eventually spawned a franchise, consisting of eight television series, 13 feature films, and numerous books, games, art, fan films, toys, collectible props, and various yet numerous other media, and is now widely considered one of the most popular and influential television series of all time. The series contains significant elements which could categorize it as a Space Western, as described by Roddenberry and the general audience.

On March 11, 1964, Gene Roddenberry, a long-time fan of science fiction, drafted a short treatment for a science-fiction television series that he called Star Trek. This was to be set on board a large interstellar spaceship named S.S. Yorktown in 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 that included many of the elements 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 novels that depict a daring sea captain who exercises broad discretionary authority on distant sea missions of noble purpose. He often humorously referred to Captain Kirk as "Horatio Hornblower in Space".

Roddenberry had extensive experience in writing for series about the Old West that had been popular television fare in the 1950s and 1960s. Armed with this background, the first draft characterized the new show as "Wagon Train to the stars." Like the familiar Wagon Train, each episode was to be a self-contained adventure story, set within the structure of a continuing voyage through space. Most future television and movie realizations of the franchise adhered to the "Wagon Train" paradigm of the continuing journey, with the notable exception of the serialized Star Trek: Deep Space Nine, Star Trek: Discovery, Star Trek: Picard, and the third season of Star Trek: Enterprise.

In Roddenberry's original concept, the protagonist was Captain Robert April of the starship S.S. Yorktown. This character was developed into Captain Christopher Pike, first portrayed by Jeffrey Hunter. April is listed in the Star Trek Chronology, The Star Trek Encyclopedia, and at startrek.com as the Enterprise's first commanding officer, preceding Captain Pike. The character's only television/movie appearance is in the Star Trek: The In April 1964, Roddenberry presented the Star Trek draft to Desilu Productions, a leading independent television production company. He met with Herbert F. Solow, Desilu's director of production. Solow saw promise in the idea and signed a three-year program-development contract with Roddenberry. Lucille Ball, head of Desilu, was not familiar with the nature of the project, but she was instrumental in getting the pilot produced.

The idea was extensively revised and fleshed out during this time "The Cage" pilot filmed in late 1964 differs in many respects from the March 1964 treatment. Solow, for example, added the "stardate" concept.

Desilu Productions had a first-look deal with CBS. Oscar Katz, Desilu's Vice President of Production, went with Roddenberry to pitch the series to the network. They refused to purchase the show, as they already had a similar show in development, the 1965 Irwin Allen series Lost in Space.

In May 1964, Solow, who had previously worked at NBC, met with Grant Tinker, then head of the network's West Coast programming department. Tinker commissioned the first pilotâ€"which became "The Cage". NBC turned down the resulting pilot, stating that it was "too cerebral". However, the NBC executives were still impressed with the concept, and they understood that its perceived faults had been partly because of the script that they had selected themselves.

NBC made the unusual decision to pay for a second pilot, using the script called "Where No Man Has Gone Before". Only the character of Spock, played by Leonard Nimoy, was retained from the first pilot, and only two cast members, Majel Barrett and Nimoy, were carried forward into the series. This second pilot proved to be satisfactory to NBC, and the network selected Star Trek to be in its upcoming television schedule for the fall of 1966.

The second pilot introduced most of the other main characters: Captain Kirk (William Shatner), Chief Engineer Lt. Commander Scott (James Doohan) and Lt. Sulu (George Takei), who served as a physicist on the ship in the second pilot, but subsequently became a helmsman throughout the rest of the series. Paul Fix played Dr. Mark Piper in the second pilot; ship's doctor Leonard McCoy (DeForest Kelley) joined the cast when filming began for the first season, and he remained for the rest of the series, achieving billing as the third star of the series. Also joining the ship's permanent crew during the first season were the communications officer, Lt. Nyota Uhura (Nichelle Nichols), the first African-American woman to hold such an important role in an American television series; the captain's yeoman, Janice Rand (Grace Lee Whitney), who departed midway through the first season; and Christine Chapel (Majel Barrett), the ship's nurse and assistant to McCoy. Walter Koenig joined the cast as Ensign Pavel Chekov in the series second season.

In February 1966, before the first episode was aired, Star Trek was nearly cancelled by Desilu Productions. Desilu had gone from making just one half-hour show (The Lucy Show) to deficit-financing a portion of two expensive hour-long shows, Mission: Impossible and Star Trek. Solow was able to convince Lucille Ball that both shows should continue.