Neither of these questions are related to each other, but sometimes when watching an episode you need to know the answer. First, in "Mirror, Mirror," they seem to refer to both Starfleet Command and The Empire as the overseeing body in the Mirror Universe. Are they interchangeable or is it one or the other? Seems like a script continuity thing. The other question revolves around Sulu and Chekov and may have been answered before. How many episodes did Chekov and Sulu actually share the helm together? I wonder if Mr. Blackburn had seen more screen time?