The Northrop Grumman MQ-4C Triton is an American high-altitude long endurance unmanned aerial vehicle (UAV) developed for and flown by the United States Navy as a surveillance aircraft. Together with its associated ground control station, it is an unmanned aircraft system (UAS). Developed under the Broad Area Maritime Surveillance (BAMS) program, the Triton is intended to provide real-time intelligence, surveillance and reconnaissance missions (ISR) over vast ocean and coastal regions, continuous maritime surveillance, conduct search and rescue missions, and to complement the Boeing P-8 Poseidon maritime patrol aircraft.

A high-altitude platform station also known as atmospheric satellite is a long endurance, high altitude aircraft able to offer observation or communication services similarly to artificial satellites. Mostly unmanned aerial vehicles (UAVs), they remain aloft through atmospheric lift, either aerodynamic like airplanes, or aerostatic like airships or balloons. High-altitude long endurance (HALE) military drones can fly above 60,000 ft over 32 hours, while civil HAPS are radio stations at an altitude of 20 to 50 km above waypoints, for weeks.