Closed Caption wrote:
I misunderstood you probably because people on the board have debated whether or not the TOS Enterprise was really on a five year mission of exploration during the events of TOS, since it was never said so inside an episode. I'm not sure, but perhaps STID is the first time in the franchise when such a thing was said about an Enterprise on screen (outside of the voiceover narration).
No; in ST:TMP, Kirk cited "my five years out there" as the reason why he was more qualified than Decker to command the mission, and in Voyager
: "Q2," Icheb gave a report on what he described as Kirk's "historic five-year mission." So there are two canonical references to the TOS mission being 5 years long -- it's just that neither of them are in TOS (or TAS) proper, titles aside. And neither of them proves whether there were other
5-year missions before, simultaneous with, or after that one. If anything, the fact that Icheb specifically mentioned the mission's duration implies that five years may not have been the default, or at least that it was only one specific category of mission.
But both those references, if you disregard the opening narration, could simply indicate that the mission was open-ended in its planned duration and just happened to end five years after it began. So STID is the first canonical, in-story reference to a starship mission being planned in advance to be five years long, or to "a five-year mission" being a specific category of starship assignment.