Star Trek: Every Starfleet Starship Class Ranked Worst To Best
56. Challenger
The Challenger class ship was a 'kitbash' design created the wreckage scene in the Best of Both Worlds. The USS Buran, depicted in the image above, was lost with all hands to the Borg.
The design shared elements of the Galaxy and Nebula class ships, with an oval shaped saucer section. This ship also had the dual nacelle design shared by most Starfleet vessels, though rather than side by side, these were ventral and dorsal.
Although other ships in the fleet were designated as Challenger class, the only one seen was the Buran. The Armstrong, from Deep Space Nine, was said to be a Challenger class ship as well. The class was retired not long after Wolf-359, quite possibly due to the fact that it was destroyed so easily.