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This page details Constitution class in the primary universe; for the Constitution class in the mirror universe see Constitution class (mirror); for the Constitution class in the Kelvin timeline created by Nero's temporal incursion, see Constitution class (Kelvin timeline); for the Constitution class in the mirror universe created by Nero's temporal incursion see Constitution class (mirror) (Kelvin timeline); for the Constitution class in all other alternate universes see Constitution class (alternates).

The Constitution-class was a Federation heavy cruiser starship in Starfleet service in the mid-to-late 23rd century. The design underwent several refits in its many decades of service. The original configuration and refit variants of this class influenced starship design significantly, and accelerated the standardization of the fleet.

Celebrated members of the class included the USS Enterprise and the USS Enterprise-A—two of the most venerated starships in Federation history, having risen to prominence under the captaincy of James T. Kirk.



Development of the Constitution-class began in the 2230s when key Fleet personnel, including Admiral William Jefferies and Captain Robert April, came to see the necessity of an all-purpose vessel that could explore space while protecting Federation interests and expanding its reach. When a design team led by Doctor Lawrence Marvick finished plans late in that decade for just such a ship, a new class was swiftly approved by Starfleet Command.

Starfleet authorized its Fleet Yards in San Francisco to build two vessels, with Admiral Jefferies overseeing NX 1700 -- christened Constitution -- and Captain April supervising its sister ship 1701, as yet unnamed. (TOS novel: Final Frontier)

The USS Constitution's hull was completed in 2244, with enhanced sensor and deflector shield systems installed. When hostilities broke out late in the year, Jefferies pulled her from drydock to take decisive part in the Battle of Donatu V. Blunting the Klingon invasion force -- without weaponry -- she rescued USS Yorkshire but was badly damaged and required extensive repairs. (TOS - Errand of Vengeance novel: Killing Blow)

The USS Enterprise (NCC-1701)

Construction on NX 1701 continued apace, employing new Duotronic computer systems designed by Doctor Richard Daystrom, which afforded 1701 better control of her systems. After a secret mission into the Romulan Neutral Zone, April christened her the Enterprise. (TOS novel: Final Frontier)

By 2245, both the Constitution and the Enterprise had begun their first five-year missions of exploration, the results of which led Starfleet to order nine more ships of the class. (TOS reference: Star Fleet Technical Manual)

Even after over a decade of service, the Constitution-class was known for its hardiness, and posting on one of them was considered a privilege. The Constitution-class was largely kept away from the battlefield during the Federation-Klingon War, ostensibly as a weapon of last resort, the only known exception being the USS Defiant which patrolled Sector 006. By this stage, however, the Constitution-class was beginning to show its age compared to newer models such as the Crossfield-class. (DSC episodes: "Lethe", "Despite Yourself", "Brother")

Often sent on long-term missions far from Federation space, Constitution-class ships were equipped to operate alone for extended periods of time and could go for long periods of time without seeing a sister ship. Noted exceptions occurred in 2267 when several of them were docked at Starbase 11 (TOS episode: "Court Martial") and in the brief war that took place over Organia where eleven of the class fought off the Klingon fleet until the Organians forced a ceasefire. (TOS episode: "Errand of Mercy" & TOS comic: "Against Their Nature")

The following year, five Constitution-classes were used in the testing of the M-5 computer only for the computer's malfunctions to result in the destruction of the USS Excalibur and the USS Lexington being severely damaged. (TOS episode: "The Ultimate Computer")

After the Enterprise had stolen a Romulan cloaking device, the Constitution-class was used to test Federation built copies of the device. While the Enterprise's cloak initially malfunctioned, the cloaks of five others had been properly refined and were used to scare of Kor's fleet before the Treaty of Algeron prevented any further usage of cloaking technology by the Federation. (TOS - Year Four: The Enterprise Experiment comics: "Part 4", "Part 5" & TNG episode: "The Pegasus")

Their long-term missions meant that the Constitution-classes often missed out on upgrades such that, by 2270, their technology was considered ancient by fleetwide standards. (TOS - Year Five comic: "Issue 1")


One of many proposals for the Constitution refit project

It was in the 2270s, after decades of continued service with only minor modifications, that the Constitution-class underwent a significant refit. Upgrade proposals all shared a more efficient power plant, with some versions streamlining the hull for better warpfield geometry, and others emphasizing enhanced weaponry or science capability with the final design merging many of the proposals. (ST reference: Ships of the Line)

The refitted USS Enterprise

The first major refit was Enterprise, and its success ensured the refit of the rest, bringing the fleet in line with newer technologies and extending its life. (ST reference: Starship Spotter; WizKids module: Attack Wing)

Refit USS Explorer

Later service

A Constitution-class ship served into the late 24th century and was destroyed in battle at Wolf 359; others, reactivated or still in service, fought in the Dominion War, and took part in the task force to retake Deep Space 9. (TNG episode: "The Best of Both Worlds"; ST reference: Fact Files)

At least one decommissioned Constitution-class ship was sold to a private entity; later known as Glory, it was acquired by Romulans and given to privateer Deigo DeBlazio to harass Federation shipping. (TNG novel: Blaze of Glory) Another Constitution-class survived in a fleet museum. (TNG episode: "Relics")

The construction of the Constitution-class started again in late 24th and early 25th centuries, it was designated as a standard cruiser and the commanding officer was commonly a Lieutenant Commander. When the Alpha Quadrant Alliance began to get involved in Temporal Cold War, Starfleet commissioned new vessels with experimental molecular reconstruction technology that allowed the vessels to assume their original, refit, Vesper, Excalibur and Exeter appearances, and allowed the ship to assume offensive, defensive and support configurations during combat. These variants were designated Temporal Light Cruisers and were commandeered by a select group of Admirals.(STO video game: Star Trek Online)


Aft view, with a shuttle exiting the open hangar bay

The largest and most elaborate vessel class Starfleet had yet fielded, with an unprecedented fourteen research labs each, ships of the Constitution-class became the most extensive mobile research platforms ever deployed by the Federation, and were responsible for expanding known space by thousands of cubic parsecs.

The class utilized a greater level of modularity, which allowed for incremental changes to configuration -- so flexible that it became standard starship design practice. As other classes began to employ such modularity, Fleet design became increasingly more uniform. (ST reference: Starship Spotter)

The Enterprise en route to Starbase 13 after a saucer separation

The Constitution class were also among the first to allow for primary-hull saucer separation -- though only in emergencies, since the separation's use of explosive bolts required starbase facilities for reconnection. By the 24th century, the saucer separation had become a routine maneuver with Galaxy-class starships having the ability to separate their saucers, and reconnect them. (TOS comic: "'Til Death"; TOS episode: "The Apple"; TNG novelization: Encounter at Farpoint)

The USS Enterprise landed in 2266

The saucer section of the class was also capable of making an emergency planetary landing using retractable landing gear. A boarding ramp could be lowered from the dorsal connector point to allow crew on and off the ship. (TOS comic: "UK comic strips, first story arc"; TOS reference: Mr. Scott's Guide to the Enterprise)

Constitution-class ships were normally crewed by roughly 400 people (TOS episode: "Who Mourns for Adonais?" & ENT episode: "In a Mirror, Darkly") but could be crewed by less should the need arise. At minimum, discounting any special modifications to aid in operating the ship, twenty-three crewmembers were required. (TAS - Star Trek vs. Transformers comic: "Issue 4")


Some Constitution subclasses.

Tactical summary

subseries beam armaments launcher armaments defensive arrangement
Constitution (mk I) FL-6 laser weapons (6 in 3 banks, port, starboard, fore) FAC-3 accelerator cannons (2, fore) FSG deflector shield
Bonhomme Richard (Constitution mk II) FH-3 phasers (6 in 3 banks, port and starboard or aft, fore) FP-1 torpedo launchers (2, fore or fore and aft) FSN deflector shield
Achernar (Constitution mk III) FH-3 phasers (6 in 3 banks, port, starboard, fore) FP-1 torpedo launchers (2, fore) FSO deflector shield
Tikopai (Constitution mk IV) FH-3 phasers (6 in 3 banks, port, starboard, fore) FP-1 torpedo launchers (2, fore) FSO deflector shield
Enterprise (mk I) FH-11 phasers (6 in 3 banks, port, starboard, fore) FP-4 torpedo launchers (2, fore) FSP deflector shield
Enterprise (mk II) FH-11 phasers (6 in 3 banks, port, starboard, fore) FP-4 torpedo launchers (2, fore) FSP deflector shield
Enterprise (mk III) FH-11 phasers (8 in 4 banks, port, starboard, fore, aft) FP-4 torpedo launchers (3, fore, aft) FSP deflector shield
Enterprise (mk IV) FH-11 phasers (8 in 4 banks, port, starboard, fore, aft) FP-4 torpedo launchers (4, fore, aft) FSP deflector shield

The Constitution vessels of the original series had slightly different features than the succeeding subclasses Bonhomme Richard, Achernar, Tikopai and Enterprise, with early laser and phaser weapons available to security teams onboard as hand-held weapons, as well as ship-mounted emplacements, in concert with accelerator cannons and photon torpedo launchers. The Constitution vessels of the 2240s and 2250s began the use of the class's standard emplacements, with forward arcs of fire. Most early Constitution variants had 6 phasers, usually dual mounted, in 3 or more phaser banks, although some variation exists between the various subseries. For example, the one modifications of the Enterprise modification had a series with 8 phasers in 4 banks. (FASA RPG module: Federation Ship Recognition Manual)

Starships of the Bonhomme Richard modification, such as the Enterprise, had forward firing phaser banks that could fire beams or pulses, located on the lower saucer section, just above the sensor dome and a torpedo launcher. The Defiant was noted to use, with dramatic effect, its rear firing phaser and torpedoes located above the secondary hull's shuttlebay, as well as the upper saucer banks. (ENT episode: "In a Mirror, Darkly")

Some vessels of the Achernar series, such as the USS Constitution had port and starboard upper saucer phasers as well as a forward firing phaser on the lower saucer and upper and lower saucer torpedo tubes. All of the Achernar series weapons were forward or side firing, leaving the rear arc uncovered. (TOS reference: Star Fleet Technical Manual)

The Enterprise-subclass, with one more launcher than the preceding series, had a move in the torpedo launchers to an outrigged tube control room at the separation between the secondary hull and the connecting hull. By subsequent Enterprise modifications, the rear arcs had been restored. (TOS movie:[citation needed])

Known vessels

The USS Defiant

The USS Intrepid

Various Constitution configuration

Constitution (mk I)

Bonhomme Richard (Constitution mk II)

Achernar (Constitution mk III)

Tikopai (Constitution mk IV)

Various Enterprise configuration

Enterprise (mk I)

Enterprise (mk II)

Enterprise (mk III)

Mirror universe



Variants and sub-classes of the Constitution-class starship
Emblem of the United Federation of Planets. Constitution-class (mk I) • Bonhomme Richard-class (mk II) • Achernar-class (mk III) • Tikopai-class (mk IV) • Enterprise-classes (mk I-III refits) • Excalibur-class (24th century) • Vesper-class (24th century) • Exeter-class (25th century) • Kirk-class (31st century) • Constitution-class (Kelvin timeline) • Constitution-class (mirror universe) Seal of the Federation Starfleet.
Starship classes of the Federation Starfleet
subclass groups

Akira (AlitaArmitageThunderchild) • Ambassador (AlaskaNarendraYamaguchi) • Apollo (Akula frigate / light cruiser) • Cardenas (Buran) • Chesapeake (Mongrel) • Cheyenne (DakotaStargazer) • Concorde (Geneva battlecruiserPresidio) • Constellation (Challenger deep space explorer) • Chimera heavy destroyer (Manticore) • Constitution (AchernarBonhomme RichardTikopaiEnterpriseExeterExcaliburVesperKirkCrossfield (Glenn32nd century refit) • Danube (Yellowstone) • Decatur (Dreadnought) • Defiant (GallantIncursionNachthexenSao PauloValiantVigilant escort) • Dervish (GryphonHermes escortMaelstromTempest) • Destiny (NimbusOracleTrident) • Engle (Earhart) • Excelsior (BismarckCurryKirovNew JerseyResolute) • Galaxy (Andromeda (25th century)CelestialEnvoyGalaxy XMonarch cruiserRossVenture cruiserYamato dreadnought) • Hermes scout (CygnusMonoceros) • Inquiry (Avenger battlecruiserArbiter) • Hoover (Edison) • Intrepid (BellerophonCochrane science vesselDiscovery (science vessel)JanewayPathfinderTrailblazerYeager) • Kumari (CharalKhyzon) • Luna (CometPolarisSolTitan) • Magee (Shran (escort)) • Malachowski (Helios (tug)) • Miranda (AntonReliantSoyuz) • Merian (Merian (dreadnought)) • Nebula (Magellan) • New Orleans (Lafayette) • Nimitz (Europa) • Norway (Oslo) • Nova (AuroraQuasarRhode Island) • NX (ColumbiaPoseidon) • Oberth (ClarkeGagarin (23rd century)GrissomSagan) • Odyssey (VerityYorktown (cruiser)) • Olympic (HopeHorizon science vessel) • Prometheus (CerberusHephaestusHestiaPhoenix) • Ptolemy (DollondDopplerKeppler) • Remora (Charger) • Saladin (CochiseSiva) • Santa Fe (Newport) • Saber (GladiusRapierUshaan) • Sentinel (EmissaryNomad cruiserVanguard) • Shepard (Gagarin (25th century)) • Solanae (HeliosMontgomeryOmega) • Sovereign (ArchonImperialMajesticNoble cruiserRegent) • Steamrunner (AppalachiaZephyr) • Vesta (AventineRademaker) • Walker (GeorgiouShenzhou ) • Wells (EternalOuroborosVerne)

Emblem of the United Federation of Planets. Seal of the Federation Starfleet.
other named classes

AA classAakennAchillesAdvanceAegianAeolusAerieAkula destroyer / escortAmbassador HardinAndesAndorAndromeda (24th century)AngelouAntaresApacheAquariusArcherArchimedesArk RoyalArielAscendantAtroxAvenger (scout)BabcockBaderBakerBaton RougeBerenaBodeBolarusBonaventureBradburyBrentonCaliforniaCanadaCanopusCapellaCastorCentaurCentaurusCeresCestusChallengerChandleyChariotChimerChimera fast frigateChristopherClarke (25th century)Cle DanCochrane transportColumbiaCondor (raider)ContinentContortrixCopernicusCourageDaedalusDauntlessDeckerDefenderDeltaD'KyrDenevaDerfDrexlerDurrettEagleEclipseEdwardEinsteinEisenbergEl Doradofuture EnterpriseEpochEpsilonErewonEternalFederationFenlonFermiFijiFreedomFriendshipFrontierGagarin (24th century)GalenGallantGangesGenevaGenserGracefulGraysonGriffonGuardianGeminiHaleHermes fast cruiserHestonHoganHokule'aHorizon cruiserIcarusIlthirinIndomitableIntrepid (light cruiser)IowaIstanbulIwo JimaClass JJupiterKarekhKeithKethkinKievK'KmarakKolm-AnKorolevLarsonLauroLaweyaLegacyLenthalLexingtonLibertyLokiLoknarLondonMadisonMakinMannMarklinMarsMarshallM'BengaMediterraneanMercedMercury (courier)Mercury (escort)MerianMerian (dreadnought)MessierMeteorMidwayMissionMissouriMobulaiMoKalMoscowMulciberNarcineNautilusNelsonNiagaraNoble laboratory vesselNomad escortNorthamptonOberonOdinOdysseusOkinawaOppenheimerOrionOsakaOverfieldPaladin battlecruiserPaladin destroyerParliamentPaladin (24th century)PerseusPioneerPhalanxPhantomPhiladelphiaPinnaclePiperPolluxPortsmithPralimPremonitionProximaPyotr VelikiyPyreneesRakotaRanger battlecruiserRanger explorerRanger scoutRenaissanceRickenbackerRigelRochesterRoyal SovereignSagittariusSamsonSaturnSawyerScorpioScryerScyllaSequoiaSevaijenShiKahrSierraSolarSpringfieldSulekSurakSydneyTangentTheophrastusThomas PaineThucydidesThufirTiberiusTiconderogaUniverseTheseusTripperTritiumTyphonTyphoonUkoraUlyssesUralUtahVenture scoutVigilant scoutVoyagerWallenbergWambunduWei-FaWellingtonWilkersonWizardYamatoYorkshireYorktownZodiacunnamed

general type

Defiant pathfinderRaging QueenSun TzuValley ForgeFederation assault shipFederation cargo shipFederation colony shipFederation construction shipFederation cruiserdeep galaxy shipFederation freighterFederation frigateFederation galaxy shipFederation holoshipFederation heavy cruiser (2380s heavy cruiser) • Federation light cruiser (Constitution-variant light cruiserIntrepid-variant light cruiser) • Federation medium cruiser (Excelsior-variant medium cruiser) • Federation mining freighterFederation repair shipStarfleet tanker


The Constitution class appeared as the USS Enterprise (NCC-1701) and USS Enterprise (NCC-1701-A) and a handful of other vessels throughout TOS and other TOS subseries including TAS, Early Voyages and Untold Voyages in all media. Appearances, apart from the Enterprise in TOS and related series include:

External link

References and notes