I must admit that I never saw Blackstar, due largely to the fact that I was more interested in NBC's lineup during the 1981-2 season. Meh, my bad, so there's no rating to be had for this show.
A quick summation. The concept of the show appears to be a variation of Edgar Rice Burroughs' John Carter, Warlord of Mars, except that Blackstar is set in the future, specific period unknown. John Blackstar (George DiCenzo) is an astronaut, pulled into a black hole which sweeps him to another dimension, specifically, to the planet Sagar, where he is thrust into a battle against the evil Overlord (Alan Oppenheimer). If this last part sounds somewhat familiar, well, Filmation mined the vein again 2 years later for their adaptation of He-Man.
Superherocartoonsite uploaded the open, narrated by DiCenzo:
Could this be revived? Dreamworks Classic now holds the rights, so anything's possible, except that a lot of Filmation's properties have been ignored of late.