The Galaxy Class began it's development in 2345. This class was designed as the most advanced of it's time. Three vessels, the prototype [NX-70637 (later NCC-70637)] and two production models, were initially authorized for construction. NX-70637 was commissioned as USS Galaxy in 2358. The second production model was commissioned in 2363 as the fifth vessel to bear the name, Enterprise with the registry number NCC-1701-D. The first model, USS Yamato, NCC-71807, was commissioned about 2360. Ships of this class measured about 642 meters long and were designed with three isolinear computer cores; two in the saucer section and one in the engineering section. These vessels are armed with twelve Type X phaser arrays and three photon torpedo launchers for their defense. Galaxy class ships are capable of separated flight, which means the saucer section (module) and the engineering (battle) section can operate independently of each other. This allows the bulk of the ship's population to remain outside a combat area. If in an absolute emergency, the saucer can make an emergency landing on a habitable planet's surface. Of the first three vessels of the class, only the Galaxy would survive to complete it's first decade of service. By 2375, a total of eight known ships of this class have served or are serving in Starfleet.
NOTE: Challenger may or may not exist since to was a part of an alternate timeline from ST: Voyager episode "Timeless". Magellan and Trinculo are seen in the seventh season of ST: Deep Space Nine and are listed at the ST Archive's Expanded Ship section.
