Adam Quark, captains an interstellar garbage scow

Quark was a 1977 science fiction sitcom starring Richard Benjamin as Commander Adam Quark, who captains an interstellar garbage scow in the year 2226. Real-life twins Cyb and Patricia Barnstable played Betty I and Betty II, (a.k.a. “The Bettys”) who were the navigator and pilot. The joke was that one of them is a clone of the other, but each claims the other one is the clone.