The USS Vengeance was a 23rd century Federation Dreadnought-Class Starship operated in secret by Section 31. Unlike other ships operated by the Federation or Starfleet, the vessel was completely unmarked with no Registry number or nomenclature visible on the hull. The ship was launched in 2259 from the Lo Facility, a spacedock in orbit of the Jupiter moon lo. The Ship's commanding officer was Admiral Alexander Marcus.