"to boldly go where no one has gone before"
The third starship to bear the name The Enterprise-B was launched under the command of Captain John Harriman from a drydock orbiting Earth in 2293. The ship was christened with a bottle of Dom Pérignon, vintage 2265. Honored guests aboard for the ship's maiden voyage included Captains James T. Kirk, Montgomery Scott, and Commander Pavel Chekov, along with many journalists. The vessel was still incomplete at the time of launch and did not have a medical staff, photon torpedoes, or a tractor beam, all of which were scheduled for delivery the following Tuesday. The dignitaries were given a tour of the ship, which impressed even Scotty. Captain Kirk gave the order to get underway.
the third ship to bear the name enterprise
Its first journey was mostly for publicity purposes, and the ship was not scheduled to venture much past Pluto. However, the Enterprise-B was the only ship in range capable of responding to a distress call from two Federation transport ships, the Lakul and the Robert Fox. The ships, which were carrying El-Aurian refugees, had become trapped in an energy distortion called the Nexus. Because the Enterprise-B lacked equipment necessary to rescue the ships, the Robert Fox was destroyed before the Enterprise could transport its passengers. Only 47 were brought aboard from the Lakul before it too was destroyed. Chekov served as a makeshift medical officer, enlisting several journalists to help treat survivors including Guinan and Tolian Soran.
The Enterprise itself became ensnared within the Nexus when it maneuvered within transporter range of the Lakul. Scotty devised a plan to use a resonance burst from the deflector dish in order to simulate an antimatter explosion and free the Enterprise. Kirk went to deflector control to make necessary modifications as the Enterprise's engineering hull was struck by an energy tendril. The Enterprise escaped with minor casualties and a hull breach along sections 20 through 28 on decks 13 through 15. Captain Kirk's heroic actions saved the ship. Unfortanatly Kirk was apparently killed in the incident, unknown at the time he was living in the Nexus for the next 78 years.
The fate of the Enterprise-B is unknown. It was definitely removed from service by 2344, when the Enterprise-C was lost at Narendra III. The Enterprise-B was important in exploration beyond the Gourami sector, charting 142 star systems and making first contact with seventeen new civilizations.