It originally aired from September 28, 1987, to May 23, 1994, in syndication, spanning 178 episodes over seven seasons. The third series in the Star Trek franchise, it was inspired by Star Trek: The Original Series. Set in the latter third of the 24th century, when Earth is part of the United Federation of Planets, it follows the adventures of a Starfleet starship, the USS Enterprise (NCC-1701-D), in its exploration of the Alpha quadrant and Beta quadrant in the Milky Way galaxy.