Star Trek is an American science fiction television series created by Gene Roddenberrythat follows the adventures of the starship USS Enterprise (NCC-1701) and its crew, led by Captain James T. Kirk (William Shatner), first officer Spock (Leonard Nimoy), and chief medical officer Dr. Leonard McCoy (DeForest Kelley), in the 23rd century. 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 1966-67 by Desilu Productions, and by Paramount Television from 1968-69. Star Trek aired on NBC from September 8, 1966 to June 3, 1969. Although this television series had the title of Star Trek, it later acquired theretronym of Star Trek: The Original Series (Star Trek: TOS or TOS) to distinguish the show within the media franchise that it began. Star Trek's Nielsen ratings while on NBC were low, and the network canceled it after three seasons and 79 episodes. Nevertheless, the show had a major influence on popular culture and it became a cult classic in broadcast syndication during the 1970s. The show eventually spawned afranchise, consisting of five additional television series, 11 theatrical films, and numerous books, games, and other products.