A cruise missile is a guided missile the major portion of whose flight path to its target (a land-based or sea-based target) is conducted at approximately constant velocity; that relies on the dynamic reaction of air for lift and upon propulsion forces to balance drag. Cruise missiles are designed to deliver a large warhead over long distances with high accuracy. Modern cruise missiles can travel at supersonic or high subsonic speeds, are self-navigating, and can fly on a non-ballistic, extremely low altitude trajectory. They are distinct from unmanned aerial vehicles (UAV) in that they are used only as weapons and not for reconnaissance. In a cruise missile, the warhead is integrated into the vehicle and the vehicle is always sacrificed in the mission.
Cruise missile designs fundamentally derive from the German V-1 of World War II. Advances in transistor and computer technology have contributed to self-correcting avionic and aeronautical designs that allow missiles to be guided in flight, as opposed to only at launch. These advances developed into guided missiles and guided bombs, and later into the modern cruise missile.
In 2011, it was estimated that a single Tomahawk cruise missile costs US$1,410,000.