The Daedalus-class was an early class of Starfleet vessel that, unlike most Federation starship designs, was designed with a spherical primary hull, outwardly similar to the later Olympic-class. This class, which operated with a crew of approximately 229, was decommissioned by the year 2196. (TNG: "Power Play")
Operating out of Starbase 12, the USS Essex, under the command of Captain Bryce Shumar, was lost in 2167 when the ship was destroyed with all hands aboard by an electromagnetic storm in the atmosphere of an M-class moon of Mab-Bu VI. (TNG: "Power Play")
Ships commissioned Edit
Background information Edit
Note that ship design and the name "Daedalus" have never been connected in any canon production. "Power Play" is the only mention of a ship type called "Daedalus-class". The ship model as seen on DS9, and the USS Horizon it represents, was never stated to be a Daedalus-class starship. But since the model was initially built for Star Trek Chronology to depict the Daedalus-class, we assume it is the Daedalus-class design.
While not mentioned specifically, according to dialog in "These Are the Voyages...", new warp 7 starships came into service in or sometime soon after 2161. Since the Daedalus-class is known to have been in service since at least the 2160s, this suggests that the class was among the first new warp 7 starships.
A Daedalus-class starship named the USS Lovell is prominently featured in the Star Trek: SCE Foundations trilogy. The "Daedalus"-class starship on the book's cover is the USS Archon. The USS Lovell is also active in the Star Trek: Vanguard novels. The ship, Drexler's CGI model, is shown outside Starbase 47 (Vanguard) on the cover of the second book of the series Summon the Thunder (though Drexler had assigned the registry number NCC-129 to the USS Daedalus on his CGI model).
In Michael Jan Friedman's novel Starfleet: Year One, competition among the early Starfleet's captains for command of the first Daedalus was one of the main plot threads - though the events of this novel have been ignored by later novels, as it was contradicted by Star Trek: Enterprise.
In the Pocket ENT novels The Good That Men Do, Kobayashi Maru, and Beneath the Raptor's Wing the Daedalus-class is featured heavily as an older ship class refitted with modern technology, and the main replacement of the NX-class fleet. The NX ships were deemed too expensive and taking too long to build, shipyard personnel stated they could churn out three new Daedalus hulls in the same time it would take to build one NX vessel.