The Starfleet regestry number for the USS Enterprise.This ID has be suffixed with letters through the years as new Starship Enterprises replaced old ones.

The Starships Enterprise:
NCC-1701 Original Constitution Class, launched 2245, destroyed in 2285.
NCC-1701-A Modified Constitution Class, launched 2286, decomssioned sometime after stardate 9523.1
NCC-1701-B Excelsior Class, launched 2293, decommissioned ???
NCC-1701-C Ambassador Class, launched ???, destroyed 2344
NCC-1701-D Galaxy Class, launched 2363, destroyed 2371
NCC-1701-E Sovereign Class, launched 2372, still in service as of 2375

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