Aerojet SD-2 Overseer

The Aerojet SD-2 Overseer was an unmanned aerial vehicle developed by Aerojet General in the late 1950s for use by the United States Army. Built in limited numbers, it never saw operational service.

Design and development
Development of the SD-2 drone was begun in 1957 by the Rheem Manufacturing Company; in 1959, the company was acquired by Aerojet General, who continued work on the project. Developed as part of the AN/USD-2 surveillance system, the SD-2 was designed for truck launch using two solid rocket boosters; following launch, a piston engine provided propulsion. At the end of its mission, the drone would be recovered via parachute. Control was provided from a translateration system for navigation, which allowed the aircraft to steer on a pre-programmed course.

The SD-2 was designed to use a modular sensor system, allowing equipment to be switched between missions according to requirements. Available payloads included cameras for either recovered or real-time photography, an AN/AAD-2 infrared sensor, AN/DPD-2 side looking airborne radar, or equipment for the dispensing of biological or chemical warfare agents from tanks mounted under the wings of the aircraft.

Operational history
35 production SD-2s were produced; poor results of the navigation system resulted in the system's cancellation in 1966, and the program was terminated without any Overseers having seen operational service. In 1963, the SD-2 was given the designation MQM-58A under the revised designation system.