The General Atomics MQ-1 Predator (often referred to as the Predator drone) is an American remotely piloted aerial vehicle (RPA) built by General Atomics and used primarily by the United States Air Force (USAF) and the Central Intelligence Agency (CIA). Conceived in the early 1990s for aerial reconnaissance and advanced surveillance, the Predator has cameras and other sensors. It has been modified and upgraded to carry and fire two AGM-114 Hellfire missiles or other munitions. The aircraft entered service in 1995 and participated in the war in Afghanistan, Pakistan, the NATO intervention in Bosnia, the NATO bombing of Yugoslavia, the war in Iraq, Yemen, the civil war in Libya in 2011, the 2014 intervention in Syria and Somalia. The US Air Force describes the Predator as a "Tier II" MALE UAS (medium-altitude long-endurance unmanned aerial system). A UAS consists of four aircraft or "aircraft" with sensors, a ground control station (GCS) and primary satellite communications. Powered by a Rotax engine and propeller drive, the aircraft can fly up to 400 nautical miles (460 mi; 740 km) to a target, stay overhead for 14 hours, and then return to its home base.