Rickover-class fast frigates. It was on active duty in Starfleet during at least the late 23rd and early 24th centuries. (Starfleet Dynamics, 2291 edition)USS Rickover (NCC-1890) was the lead ship and prototype of the
- This registry conflicts with that of the lead ship and prototype of the Cyane-class heavy frigates. Perhaps they exist in different continuities, or one or two vessels of the Avenger-class were rescheduled and refit to Rickover-class configuration instead of the Cyane class one.