"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." This is where it all began. The Original Series (often abbreviated TOS) ran on NBC from 1966 through 1969, for a total of three seasons and 78 episodes (counting the two-part "The Menagerie" only once, and not counting the first commissioned pilot, "The Cage," which did not air during this time).