The UGM-89 Perseus was a proposed U.S. Navy submarine-launched anti-ship (AShM) and anti-submarine (ASW) cruise missile that was developed under the Submarine Tactical Missile (STAM) project, which was also referred to as the Submarine Anti-ship Weapon System (STAWS). This missile system was to be the centerpiece for a proposed third-generation nuclear-powered cruise missile submarine championed by then-Vice Admiral Hyman G. Rickover, the influential but controversial head of the Navy's nuclear propulsion program.