All seasons
3 seasons - 93 episodes
Season 2
1978
In the year 2202, a restored Earth faces a new threat: The Comet Empire, bent on conquest of the universe i sheading straight to Earth.
Season 1
1974
In the year 2199, a starship must make a dangerous voyage to the distant planet Iscandar and back to save Earth from an alien invasion.
Specials
1977