Annotations We can see the wireframe drawing of the ISS Defiant on a display in DIS: "Despite Yourself". Curiously, it is still labeled as "USS Defiant", although the depiction shows the ship after many years with many modifications in Terran service. The Defiant is meant to be the very same ship that vanished in TOS: "The Tholian Web" and resurfaced in the Mirror Universe more than 100 years earlier, in ENT: "In a Mirror, Darkly". The depiction in the episode is rather coarse, but it includes two changes to the design that point to a redesign of the ship, rather than to a reimagination. The nacelle pylons are not straight any more but have a kink with an embedded pod, much like the phaser pods on the Miranda class. There are also four cut-outs in the saucer edge. Overall, the wireframe with its short neck and rounded engineering hull matches a bit better with the proportions of the reimagined DIS-style Constitution than with the look of the ship in classic Star Trek. It appears that the ship was not clearly shown for a reason, either to save the surprise about the redesign of the original Constitution for a later occasion, or because it was not yet finally decided to what extent the ship would be altered. The anachronistic technology of the USS Defiant supposedly allowed Captain Archer and later Empress Sato to defeat the alien rebellion. Despite this technology leap, the Mirror Universe itself developed standard Constitution-class ships as late as at the same time as in the Prime Universe, as evidenced by TOS: "Mirror, Mirror". Since DIS rewrites "only" the visuals and not the "facts" of the old Star Trek, it is safe to say that the standard Constitution class also exists in the Mirror Universe of the reboot series and looks much like the reimagined USS Enterprise as first seen in DIS: "Will You Take My Hand?". See also Starfleet Ship Classes A-K, Mirror Universe Ships, Discovery Federation Ship Classes

Class specifications Length: 442m