Continuity mistake: In a few episode we'll hear about "Hodgkin's Law of Parallel Development," but here Spock claims the odds of a planet developing similar to Earth's Nazi culture are "virtually impossible." Why was it so likely as to be easily accepted there, but impossible here?
Continuity mistake: The blood dripping from Isak's mouth changes sides.
Chosen answer: If they're in orbit, they're being pulled along by the planet's gravity well, therefore, impulse engines would only be used for minor corrections and would be "on standby" while in orbit, but not active. (Like keeping your car idling without revving the engine and creating plumes of exhaust).
Captain Defenestrator
Thank you for the info.
Movie Nut