The Starship Enterprise was a Constitution class ship, launched from the San Francisco fleet yeards in 2245. The ship was first commanded by Captain Robert April from 2245-2250. Captain Christoper Pike took command in 2251 and commanded the ship until 2262, leading 2 five year missions, before becoming a fleet captain. The Enterprise was slightly upgraded before James T. Kirk took command in 2264 and commanded the most famous five year mission of all.

The Enterprise frequently faced many dangers in outer space, from meteorites, other ships, and all kinds of spacial hazards. It was fitted with photon torpedos, phasers and shields. The ship had 4 shuttlecraft that the crew could use in case of transporter problems or short range space missions, and had several science and research labs on board as well as a state of the art M4 computer. The Enterprise had a crew of 432, had 23 decks and was 951 feet long, 420 feet wide and weighed about 195,000 tonnes.

In 2269, after Kirk's five year mission was over, the Enterprise returned to dock to be completely rebuilt. The warp engines and nacelle pylons were replaced, the main deflector was redesigned, the hull was enlarged and new equipment was installed. The refitted Enterprise was 1002 feet long, 457 feet wide and weighed 210,000 tonnes. In 2271, the Enterprise, now fully redesigned was ordered to stop V'ger reaching Earth. The Enterprise had not even been flight tested and many new systems were not expected to work properly, but the ship performed well and began a second 5 year mission under Kirk.

The ship was retired from active service in 2278, and was used to train cadets instead. The ship was not downgraded however so could be easily put back into service.

In 2285, the Genesis device was stolen by Khan, Kirk's old enemy and the Enterprise was heavily damaged. It returned to Earth and was to be decomissioned, but Kirk stole the ship to return to Genesis and save Spock. The ship was destroyed above Genesis to stop the Klingons getting their hands on it.

A new Enterprise was launched under Kirk's command in 2286, which was simply a renamed Constitution class ship. That ship was then retired after the Khitomer mission, and replaced by the Excelsior-class Enterprise-B. The launch of that ship turned into a rescue mission, and during which, Captain Kirk apprently died.