Starfleet records. Federation starships. Constitution class (alternate reality): The Constitution-class was launched by Starfleet in the latter half of the 23rd century in the alternate reality. The Constitution-class was shipping the flag of starships' Starfleet. Source: Star Trek. Star Trek Star Trek Online Star Trek. Live the experience. | Starfleet Command

Starfleet records. Federation starships. The Ambassador-class starship. Physical arrangement: The Ambassador-class featured the saucer section-engineering section-warp nacelle layout common to most Starfleet vessels. It was intermediate in size between the Excelsior-class and the Galaxy-class. In addition, the class boasted at least three engineering levels. Source: TNG: "Yesterday's Enterprise". | Starfleet Command