Battlestar Galactica (1978)

The Human Colonial forces have agreed to peace with their mortal enemies the Robotic Cylons when a surprise attack destroys most of the Colonial Fleet. The remnants of the Colonials form up a "ragtag group of ships" on the surviving major ship, the Battlestar Galactica. They decide to go off in a search for the planet founded by missing tribe of the Colonials, a planet called earth as the Cylons continue to search for them.