The FIM-92 Stinger is an American man-portable air-defense system (MANPADS) that operates as an infrared homing surface-to-air missile (SAM). It can be adapted to fire from a wide variety of ground vehicles, and from helicopters and drones as the Air-to-Air Stinger (ATAS). It entered service in 1981 and is used by the militaries of the United States and 29 other countries.