Pursuant to Starfleet Exploration Directives 902.3 & 914.5, Starfleet Defense Directives 138.6 & 141.1, and Federation Security Council General Policy, the following objectives have been established for an Ambassador Class Starship:

1. Provide a multi-mission mobile platform for a wide range of scientific and explorative research projects.

2. Augment Excelsior Class Starships as the primary instrument of Federation deep-space defense and exploration.

3. Provide autonomous capability for full execution of Federation defensive, cultural, scientific, and explorative policy in deep space or border territory.

4. Serve as a frontline support vehicle during times of war and emergencies.

Length: 526 meters
Width: 322 meters
Height: 128 meters
Weight: 3,700,00 metric tons
Cargo capacity: 42,500 metric tons

Hull: Duranium hull planting over duranium/tritanium structural members
Number of Decks: 26 Total, 25 Habitable


Length: 514 meters
Width: 322 meters
Height: 128 meters
Weight: 2,350,000 metric tons
Cargo capacity: 41,200 metric tons

Hull: Duranium hull planting over duranium/tritanium structural members
Number of Decks: 26 Total, 25 Habitable

Now an important footnote in the lineage of many a starship, the Ambassador Class is no longer the backbone of Starfleet's exploration nor defensive arms. Once the pride of the fleet and considered, at the time, to be the pinnacle of starship development, technology developed for the Ambassador class has exploded into common usage among other classes of starships, while the grand spaceframe has slipped from active production and is slowly being replaced by newer designs, it still remains a notable class of vessel that continues to serve with distinction.

The Ambassador Class starship was a large departure from current trends in ship design when it was conceived. Nearly twice as large as the current mainstay, the Excelsior Class starship, the Ambassador class would change the face of Starfleet and influence ship design for decades to come. Initial design concepts were developed and toyed with at the newly formed Advanced Starship Design Bureau, Mars in 2249; some of the first concept models and drawings are still on display at the ASDB Museum. However, given the scale of the craft, the concept would remain just that until 2292, when a dramatic shift in Galactic Politics occurred. A shift that would effect the Federation, the Romulan Star Empire and the Klingon Empire well into the next century.

In early 2290, a marked increase of hostilities along the Klingon and Federation border occurred. This disturbing trend reached a peak in 2291 when the USS Oberon (NCC 4998) was forced to withdraw from an engagement against 2 B'rel Class Birds of Prey. According to published reports, Captain Oded Hammlin believed the vessel to be an arms smuggling corvette enroute from Andor to Klingon Space, and stopped the vessel before entering the neutral zone. 2 B'Rel Class Birds of Prey intercepted the Oberon and threatened to defend the corvette, accusing the Oberon of piracy. When the Oberon refused to withdraw, the B'Rel vessels engaged and disabled the Oberon while taking minimal damage. The Klingon Council quickly learned of their new vessels clear advantages against the backbone of the Federation and became increasingly daring in their action in and around the Neutral Zone. Up until the Ambassador class was launched, several more incidents of Excelsior class starships being forced to withdraw from tense confrontations due to being outgunned and out shielded by the newer B’rel class Birds of Prey occurred. The withdrawals illustrated just how dated and stagnant the United Federations of Planets Starfleet had become. Immediately, the design teams at Utopia Planitia quickly addressed this situation and, blowing the dust off of their concept models, quickly began work on the Ambassador Class Starship. Official sanctioning by Starfleet occurred in 2311 after the Tomed incident and funding and resources were allocated for the development of a new Defense Cruiser.

The Ambassador project would prove to set a new standard in starship design for the Federation, giving Starfleet a starship that was better armed, better equipped and more diversely equipped than any other starship ever before. The design brief for the Ambassador class starship called for a heavily armed Battlecruiser which could also serve the non-combat roles of heavy transport and deep space exploration. The resulting design exceeded expectations and the Ambassador class was quickly put into service.

Several design aspects of the Ambassador class made the space frame unique and were carried over into future designs. Among these was the increased internal cargo, crew and fuel capacity combined with an increased lift capability that gave the Ambassador class not only great size, but an endurance that rivaled the Excelsior Class and crew amenities allowing for much longer on station and patrol times, meaning more Ambassador class starships could remain on patrol longer and with less crew fatigue. Some of the last Ambassador class starships also had thick duranium armor, the precursor to the Defiant Class ablative armor, added to protect the vulnerable areas of the ship. Finally, the development of Phaser Array, which replaced the traditional Phaser Turret found on previous hull types such as the Excelsior and Miranda class hulls, were made standard for the Ambassador class. The arrays allowed for quicker recharge times and the ability to fire at multiple targets out of one array, rather than targeting turrets individually.

So successful were the Ambassador Class vessels, that the production team began looking at designing an improved Ambassador Class vessel. While shaving nearly 15 meters of length, resulting in a much smaller cargo hauling capability, the team was able to make the already hearty Ambassador Class more nimble in combat situations. The addition of 4 more phaser arrays also gave the class more bite. Further improvements in shielding, sensor, and computer technology would be implemented in the Ambassador-Refit design, but these advancements would not be enough to warrant a further production contract beyond the initial 1000 starships ordered by Starfleet. While the final 150 Ambassador Class vessels were of the Refit variety, the improvements and advancements made by the Ambassadors would be short-lived as a new age of Starship production was about to begin.

However, with the advent of the successful Akira and the announcement of the "Grand Redesign of the Fleet" with the Cheyenne, Galaxy and Nebula class starships, production of the Ambassador class slipped markedly. The Nebula Class, the new workhorse of the fleet, could fill the same roles as the Ambassador class, and could do them more efficiently and with greater range. As a result, the Ambassador mission role became more and more limited to the role of border patrol and defensive specialist with fewer and fewer assigned to deep space exploration and diplomatic transport. Continued refits kept the majority of the Ambassador class starships in service, despite the end of their active production run. The currently active starships serve the Federation well, but the recent Borg incursions and war with the Dominion has cut down severely the number of Ambassador class starships that remain in active service. Most of the Ambassador class starships were lost or damaged beyond repair, resulting in the decommissioning of the majority of active Ambassador starships. The current trend in Starship has also phased the Ambassador class out, with less crew intensive starships being the order of the day.


Construction of the first hull for the as yet unnamed Ambassador Class, designated NXC-9331NA, began in early 2315 - a full four years after the project's official start date. The primary research team, being based out of Utopia Planitia while the engineering team being based out of San Francisco, let to a small increase in development and simulation testing times, along with an increased debate about final hull design and engineering assembly. This, despite the fact that the two teams were supplied with several completed hull structure simulations and theoretical spaceframe hull shapes through knowledge and experimentation gained from the Starfleet Experimental Propulsion Division. By the end of 2317, with the aide of computer models, sufficient progress had been made to the point that a working 1500 cochrane warp reactor - a version 3.5 NNEC Warp Core, the standard Excelsior Class warp core of the day - could be used to power a warp field capable of exceeding its design specifications for limited amounts of time.

Due to the increased tensions in the political arenas, and fearing the development of a comparable or superior craft to the NXC-9331NA project, and due to the hull's large size, Starfleet decided to announce the development of a new "Exploration Cruiser" and given the class name of Ambassador. This was done in the hopes that the title and benign nature of the class name would ease the tensions between the Federation and Klingons over rumors about the size and estimated capabilities of the new hull.

NXC-9331NA, the first Ambassador Class test hull, began warp flight tests within Sector 001 during Spring of 2318 and made use of an experimental deflector dish that preformed well in early test simulations and low-speed warp trials on Miranda and Oberth test hulls. After a year of rigorous warp testing, in which additional hull mass was added to the primary hull structure to simulate actual warp engine performance in a standard, estimated, Ambassador Class hull configuration, the Warp Core functioned admirably. The performance of the Scarbak IV impulse engines, standard for the Excelsior Class, was another matter. Acceleration was rated as poor, its sublight maneuverability was subpar, consuming far too much fuel far too quickly, and therefore deemed ineffective in simulations against Klingon threat vessels. Dwayne Lewis, an engineer with the NNEC (see Excelsior Class Warp Core specifications) who lead a team that specialized in theoretic impulse dynamics, proposed the addition of space time driver coil similar to the warp-field coils utilized in the standard warp drive nacelle. By pushing the energized plasma through a thermo-magnetic driver, the plasma energy is accelerated through the coil, thereby creating a subspace field around the vessel, which aids in negating the mass of the large hull and improve impulse engine performance.

The inclusion of the Sub-space driver coil in the Scarbak V impulse drives, called "Peacemakers" by the Scarbak Development team, was deemed a design breakthrough, and the first full production vessel, NX-10521, had its primary frame members gamma-welded at a brief ceremony at the San Francisco Fleet Yard. Hull NX-10521, being built from the ground up, saw further design improvements with the addition of the Duotronic Mk.20 Core and the newly designed Peacemaker Impulse Engines, designed specifically for the Ambassador class, along with the latest breakthrough in phaser technology - the strip phaser array - which allowed much more powerful and focused phaser beams to be discharged at multiple targets (See weapons discharge tests: Type IX discharge pattern). This meant that a Starship was no longer limited to targeting specific starships with individual phaser turrets, but could now strike any target in its firing arcs.

During the following year, NX-10521 saw rapid construction and the spaceframe was ready for testing in late 2319, two additional Ambassador spaceframes rested in drydock at Utopia Planitia as a ceremony was held at Earth's Spacedock 1 in November of 2320 as hull NX-10521, christened the U.S.S. Ambassador, left the space doors and warped out of the system to begin its shakedown cruise near the Tholian border. In December and January, the sister ships of the Ambassador, the U.S.S. Horatio NCC-10232 and the U.S.S. Farragut NCC-10233 launched from their drydocks, both bound for the Klingon border. The first real test of the Ambassador class against threat vessels occured in 2321 and would pit the U.S.S. Excalibur, responding to an SOS from a Neutronic Fuel carrier - the SS Haro Maru - against a Klingon raiding party of three B'rel class Birds-of-Prey led by the IKS Burunk. In a brief firefight, the Burunk was destroyed and a second Bird-of-Prey was severely damaged. This would be the beginning of numerous forays between the new Ambassador class vessels and the Klingons; the new vessels turning the tables against the IKC D-7's and Birds of Prey.

The numerous forays between the two entities would continue until 2344 when the USS Enterprise (NCC-1701-C), under the command of Captain Rachel Garret, responded to a distress call from a Klingon colony on Narendra III. Four Romulan Warbirds (of the D-7 design lineage) had engaged and destroyed the lone Bird of Prey and were systematically destroying the colony from orbit when the Enterprise arrived. The Enterprise engaged the Romulans, and succeeded in destroying two of the four Romulans while crippling a third before being destroyed by enemy fire. The bravery of the Enterprise crew was recorded by the Klingon taskforce approaching Narendra III and so impressed the Klingon High council that hostilities ended almost immediately between the Klingons and the Federation. A lasting peace agreement would not be reached until 2352, but the cessation of nearly 60 years of hostilities between the Klingons and the United Federation of Planets was a welcome step toward galactic peace.

The class would see production until 2359, and while it has taken heavy losses defending the Federation during its many wars, the Ambassdor Class is still a proud and familiar symbol of Starfleet's engineering ingenuity and imagination.

The lifetime of the Ambassador Class spaceframe had been projected to be some 80 years, with scheduled refits and major overhauls to take place at 40-year intervals. Unlike minor layovers, repairs and restocking missions to major fleet yards and bases, these major refits were intended to update the class with technologies that have since emerged after production of the class began. While the class is no longer in production, more then a hundred and fifty Ambassador Class Heavy Cruisers are still in use by Starfleet as of this publication, and the spaceframe was designed to allow for easy upgrades during its entire operational lifetime. To date, the Ambassador class starship has had two major refits after its initial launch.

First Refit: The first refit for the Ambassador-class took place in January of 2345 when the U.S.S. Yamaguchi entered drydock 10 at Starfleet's Utopia Planitia Fleet Yards in orbit around Mars. The average time for the refit was approximately 13 weeks, or roughly 3 months.

This upgrade included:

Installation of first-generation isolinear subprocessors throughout the vessel.
Removal of both torpedo launchers and related systems, followed by the installation of two fixed-focus rapid fire torpedo launchers capable of firing eight torpedoes at one time for simultaneous launch.
Enhanced warp plasma transfer conduits.
Installation of new Class-5 M/ARA.
Replacement of bridge module with upgraded design.
Upgraded living accommodations.
Installation of three holographic simulation chambers [later replaced with the standard holodeck after 2367].
Refurbished warp nacelles with variable warp field geometry capabilities.
Updated Warp Propulsion System (WPS) software to account for additional capabilities.
Installation of two additional Type IX Phaser Arrays on the starboard and port warp nacelles
Upgrade to Main Shuttlebay and service facilities.
Second Refit: Originally scheduled to take place around 2379, key events in the local galactic theater prompted an early review for the proposed second refit to the Ambassador class. In 2371, shortly after the discovery of the Dominion threat on the Gamma Quadrant side of the Bajoran Wormhole, Starfleet Intelligence and the Federation Council expressed major concerns over the status of Starfleet's assets. This concern became a reality when all out war broke loose along the Cardassian demilitarized zone when the Cardassian Empire joined the Dominion, and declared its intent to take over the Alpha Quadrant. Federation and ally ship production went into full sway, and efforts were made to upgrade all existing spaceframes currently active in the fleet inventory. In addition, a number of decommissioned and mothballed hulls were brought back to operational status, among them were several retired or incomplete Ambassador spaceframes decommissioned for various reasons during the past two decades. Rearmed with Type-X phaser emitters, improved M/ARA for increased power and various other upgrades, the Ambassador Class played an active role in the defense of the Federation. With many advances for the spaceframe already tested in the field, several ships saw refits during and immediately after the war to help maintain the capabilities of the fleet. This constitutes the final refit for the class.

This upgrade includes:

Installation of second-generation isolinear subprocessors throughout the vessel.
Replacement of both port and starboard main computer cores with updated systems.
Installation of Type-X phaser emitters.
Installation of a Class-6 M/ARA.
Refurbished warp nacelles with variable warp field geometry capabilities.
Updated Warp Propulsion System (WPS) software to account for additional capabilities.
Refurbishment of Impulse Propulsion System (IPS) and related systems.
Replacement of bridge module with upgraded design.
Replacement of primary and secondary graviton field generators.
Carpeting to cover metal floors through most high-traffic areas of the ship, most notably areas surround crew quarters and support systems.
Softer color palettes used on bulkheads and interior designs to coincide with planned uniform change expected to take place in the 2360's.


Phaser Array arrangement: Three dorsal arrays on the saucer section, one for the forward, starboard and port sides. These arrays are duplicated on the ventral side of the primary saucer. Two smaller arrays cover the aft side firing arcs, are mounted on the nacelle pylons. Two small arrays cover the aft firing arc and are located on the aft, dorsal portion of the saucer section.

Phaser Array Type: The Ambassador Class starship utilizes the Type IX system. The eight arrays are all type IX arrays. Each array fires a pulsed beam of phaser energy, discharging the phasers at speeds approaching .986c (which works out to about 182,520 miles per second - nearly warp one). The phaser array automatically rotates phaser frequency and attempts to lock onto the frequency and phase of a threat vehicle's shields for shield penetration.

Phaser Array Output: Each phaser array takes its energy directly from the impulse drive and auxiliary fusion generators. Individually, each type IX turret can discharge approximately 3 MW (megawatts).

Phaser Array Range: Maximum effective range is 300,000 kilometers.

Primary purpose: Assault

Secondary purpose: Defense/anti-spacecraft/anti-fighter


Arrangement: Two fixed-focus torpedo launchers, located just above the main deflector dish in the neck of the vessel. A third launcher is set to fire dead aft and is located on the rear of the engineering hull just below the aft shuttlebay. These launchers are the second generation of automated, high-speed launcher originally found on the Excelsior Class starships. Since the launch of the Ambassador Class, however, the vessel has had continuous upgrades to keep the vessel up to date with modern Torpedo Weapon technology.

Type: Mark XXV photon torpedo, capable of pattern firing (sierra, etc.) as well as independent launch. Independent targeting once launched from the ship, detonation on contact unless otherwise directed by the Chief Tactical Officer.

Payload: Ambassador Class starships can carry a maximum of 175 torpedoes.

Range: Maximum effective range is 3,000,000 kilometers.

Primary purpose: Assault

Secondary purpose: Anti-spacecraft


Type: Consolidated Fusion's version 8 Standard Matter/Anti-Matter Reaction Drive, developed by Utopia Planitia Warp Propulsion Laboratories. Information on this Warp Drive can be found in any Starfleet Library or Omnipedia.

Normal Cruising Speed: Warp 7

Cruising Speed as pursuant to Warp Limitations, as a cause of subspace pollution: Warp 6.6

Maximum Speed: Warp 9.4 for 12 hours

Note: Vessels equipped with the CF version 8 series M/ARA Drive System no longer have the maximum cruising speed limit of Warp 6.3, thanks to innovations discovered and utilized in the General Electric Type 8 M/ARA Warp Drive outfitted in the new Sovereign Class Starship. Pursuant to Starfleet Command Directive 12856.A, all Starships will receive upgrades to their Warp Core system to prevent further pollution of Subspace.


Type: Standard Scarbak V "Peacemakers" Ambassador Class mass drivers, developed specifically for the Ambassador Class

Output: The engine (there is one impulse engine, located on the neck) can propel the Ambassador Class at speeds within the area known as Standard impulse operations. These speeds are limited to a maximum speed of .25c, due to time dilation problems. Quarter impulse is rated at .0625c, half impulse being .125c and full impulse is rated at .25c or 1/4th the speed of light.

History based on information found in Star Trek: First Contact, Star Trek: Voyager, Star Trek Technical Manual, Star Trek: The Next Generation Technical Manual, Star Trek: Deep Space 9 Technical Manual, and Star Trek: The Magazine. The style of the history is based on histories presented in the Startrek Spaceflight Chronology by Stan Goldstein, Fred Goldstein, and Rick Sternbach. Please keep in mind that this is a history developed based on canon information presented in various sources and filled in with logical conjecture.

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