Constitution class
The Constitution-class starships were the premier front-line Starfleet vessels in the latter half of the 23rd century. They were designed for long duration missions with minimal outside support and are best known for their celebrated missions of galactic exploration and diplomacy which typically lasted up to five years.
History
The Constitution class lineage was launched in 2245, and served as Starfleet's front-line vessels for the rest of the century. The Constitution class also served as a mighty deterrent to both the Klingon and Romulan Empires, several times taking part in combat actions which determined the fate of the entire Federation if not the Alpha Quadrant itself.
The Constitution class design was refurbished some time between 2254, when the USS Enterprise had a crew complement of 203, and 2266, when the Enterprise held an increased crew complement of over 400.
The most famous Constitution class starship was the USS Enterprise, launched under the command of Captain Robert April in 2245. The Enterprise gained its reputation during its historic five year mission (2265-2270) under the command of Captain James T. Kirk.
In 2266, on stardate 1709, the Enterprise was instrumental in preventing a war between the Federation and the Romulan Star Empire. When a Romulan Bird-of-Prey crossed the Romulan Neutral Zone and destroyed several Earth Outpost Stations, Captain Kirk barely managed to outwit the enemy commander and stop his vessel from returning to Romulus and reporting on the Federation's weakness.
In late-2268, the Constitution class vessels Excalibur, Hood, Lexington and Potemkin took part in the disastrous testing of the M-5 computer, which was in control of the Enterprise. The Excalibur was severely damaged, with all hands lost. The Lexington also was brutally assaulted by the M-5 computer when the unit became unstable.
Later that year, the Constitution class starship Defiant responded to a distress call from an unexplored sector of space, claimed by the Tholian Assembly. Shortly upon entering the region, the Defiant crew began experiencing sensory distortion, and insanity quickly spread throughout the ship. The ship's medical surgeon was unable to determine what was happening, and eventually the insanity induced by the phenomenon lead the crew to kill each other.
Three weeks later, Starfleet ordered the Enterprise to mount a search mission to locate the Defiant. On stardate 5693.2, the Enterprise located her adrift, lost between universes in a space warp. As a result of a later phaser exchange between the Enterprise and several Tholian vessels, a hole was created through the spatial interphase, pushing the Defiant to parts unknown. As it turned out, the Defiant emerged in the 22nd century Mirror Universe, where the Tholians of that universe had created the interphase rift by detonating a tri-cobalt warhead within the gravity well of a dead star. It appeared that the Defiant would go on to play a major role in Empress Sato's rule over the Earth. However, it is unclear whether Sato's bid to become Empress actually succeeded, or what the final disposition of the Defiant in that universe was, as the Mirror Universe of the 23rd Century exhibited no significant advances in technology nor any evidence of knowledge of the 'real' universe.
Refit configuration
In the late 2260s to early 2270s, the Constitution class starships underwent a major refit program. The actual refitting took eighteen months of work and essentially a new vessel was built onto the bones of the old, replacing virtually every major system. Thus the Constitution class continued in service for a further twenty years.
Essential upgrades were made to the Constitution class' warp systems; the old cylindrical nacelles were replaced with new angular ones, and also the warp nacelle struts were new, as they were connected to the engineering hull much closer to the neck than before. The engineering hull roughly retained its original shape -- while the original hull was essentially a conical cylinder, the refit was much more rounded. As for the interior of the hull, the most obvious upgrades were the enlargement of the shuttle deck and landing bay, as well as the addition of a horizontal matter-antimatter reaction assembly and a vertical intermix chamber.
New also was the installment of the double photon torpedo launcher with its rectangular housing in the neck of the vessel. Furthermore, the saucer section was considerably extended (almost 20 meters), while the rest of the surface remained about the same. Major changes were made to the interior of the Constitution class starship; however, many new systems were added and existing ones upgraded. Summarizing, only the internal structure of the saucer and very little of the engineering hull and neck may have survived the 2271 upgrade.
Technical data
Physical arrangement
The Constitution class starships were one of the first to feature the saucer-engineering hull design, which would later become recognizable for most other Starfleet vessels. The hulls were capable of saucer separation in case of emergency; the crew would than evacuate to the saucer module, while personnel unable to escape in time could abandon the engineering hull through way of escape pods. The Main Bridge was located on top of the primary hull, while an emergency bridge was located deep within the saucer. The superstructure on top of which the bridge was located featured science labs on the original configuration Constitution class, but would be the location of the officers' lounge and dining area on the refit configuration vessel.
If necessary, a Constitution class starship is capable of entering a Class M planet's atmosphere and flying through it for an extended period of time.