Development of the SD-2 drone began in 1957 by the Rheem Manufacturing Company, and the project continued through the company's acquisition by Aerojet General in 1959.[2] 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.[2] Control was provided from a translateration system for navigation (similar to the much later differential GPS technology), which allowed the aircraft to steer on a pre-programmed course.[3]
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.[3]
Thirty-five production SD-2s were produced. Poor results from the navigation system resulted in the system's cancellation in 1966, and the program was terminated without any Overseers having seen operational service.[3] In 1963, the SD-2 was given the designation MQM-58A under the revised designation system.[2]
Newcome, Lawrence R. (2004). Unmanned Aviation: A Brief History of Unmanned Aerial Vehicles. Reston, Virginia: American Institute of Aeronautics and Astronautics. ISBN978-1-56347-644-0.
Parsch, Andreas (2002). "Aerojet General SD-2/MQM-58 Overseer". Directory of U.S. Military Rockets and Missiles. designation-systems.net. Retrieved 2014-05-14.
Taylor, John W. R., ed. (1965). Jane's All the World's Aircraft, 1965-1966. London: Sampson Low,. Marston & Company Ltd.
