The merculite rocket was a projectile weapon mounted aboard Talarian vessels, considered obsolete by 24th century Federation standards. The merculite rockets aboard the Batris were used by three Klingon criminals to destroy the IKS T'Acog after it lowered its shields. (TNG: "Heart of Glory")

Talarian warships such as the Q'Maire were armed with merculite rockets, although they posed little threat to starships such as the USS Enterprise-D. (TNG: "Suddenly Human")