The Ambassador Class was developed during the 2320’s as a replacement for the aging Excelsior Class as Starfleet’s front-line explorer type vessel. Several innovative features were included in the design, most notably for diplomatic and scientific missions. The USS Ambassador included high-quality guest quarters and was equipped with elaborate conference facilities. Many of these areas were capable of maintaining a wide range of environments, a vital prerequisite for a vessel that would spend a great deal of its life dealing with non-standard life forms. These facilities allowed her to host a much wider range of diplomatic functions than the more cramped Excelsior Class.
The scientific facilities of the Ambassador Class were equally well equipped. The ships contained the most powerful spaceborne sensor arrays of their time, including eighteen modular sensor pallets for mission-specific equipment. Twenty-eight large dedicated laboratory facilities are included in the ship, along with facilities to convert three of the cargo bays to hold extra scientific equipment if necessary. This gave the Ambassador an estimated 325% increase in research capabilities over an Excelsior.
While the primary purpose of a starship is exploratory and scientific, the Ambassadors also have teeth. The class introduced phaser arrays to Starfleet in place of the ball turret ports carried by previous designs. This measure greatly increased the ability of the Ambassador Class to fire sustained bursts, and greatly reduced the recharge and cool downtimes. The use of an independent power system for every group of ten emitter segments in the array triples the survivability of the array compared to a ball turret, while there are also benefits to the reaction time, greater control of thermal effects, field halos and target impact. Overall the phaser arrays of the Ambassador are over 50% more effective than ball turrets of similar power.
The USS Ambassador was launched in 2328 and commissioned in 2330. Overall the class performed well and was deemed a success, although production was suspended in 2355 in favor of the new Galaxy Class, then under development. The remaining Ambassador Class vessels still serve as capable explorers and are expected to stay in service until at least 2405.