The Avenger class heavy frigate starship was introduced by the United Federation of Planets Starfleet in the 2270s, following the development of linear warp drive. Its spaceframe was derived from the Surya-class starships in service since the 2240s and 50s. (Federation Frontiers) The Reliant-class starships (FASA RPG: Federation Ship Recognition Manual) may be this class's nomenclature in an alternate timeline.