The Nimitz class strike carriers were a type of United Federation of Planets starship on active duty in Starfleet during at least the late 23rd century. (Task Force Games: UFP: The Federation Sourcebook for Prime Directive) Outwardly similar in appearance on Constitution-class heavy cruisers, the Nimitzes were built during the General War (in the Star Fleet Battles timeline) in 2278. The larger rear hull holds a full squadron of attack fighters. As mainline combat vessels, carriers did not have Prime Teams assigned on a regular basis.