The Aerojet SD-2 Overseer was an
unmanned aerial vehicle
An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controll ...
developed by
Aerojet General
Aerojet was an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California, with divisions in Redmond, Washington, Orange and Gainesville in Virginia, and Camden, Arkansas. Aerojet was owned by GenCorp. I ...
and
Rheem Manufacturing Co.Mission ensured with a reliable Rheem drone system
// ''Aviation Week & Space Technology'', February 9, 1959, v. 70, no. 6, p. 76. in the late 1950s for use by the United States Army
The United States Army (USA) is the land warfare, land military branch, service branch of the United States Armed Forces. It is one of the eight Uniformed services of the United States, U.S. uniformed services, and is designated as the Army o ...
. Built in limited numbers, it never saw operational service.
Design and development
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.[Parsch 2002.] Developed as part of the AN/USD-2 surveillance system, the SD-2 was designed for truck launch using two solid rocket boosters
A solid rocket booster (SRB) is a large solid propellant motor used to provide thrust in spacecraft launches from initial launch through the first ascent. Many launch vehicles, including the Atlas V, SLS and space shuttle, have used SRBs to giv ...
; following launch, a piston engine provided propulsion. At the end of its mission, the drone would be recovered via parachute.differential GPS
Differential Global Positioning Systems (DGPSs) supplement and enhance the positional data available from global navigation satellite systems (GNSSs). A DGPS for GPS can increase accuracy by about a thousandfold, from approximately to .
DGPSs c ...
technology), which allowed the aircraft to steer on a pre-programmed course.[Newcome 2004, p.74.]
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
Side-looking airborne radar (SLAR) is an aircraft- or satellite-mounted imaging radar pointing perpendicular to the direction of flight (hence ''side-looking''). A squinted (nonperpendicular) mode is possible also. SLAR can be fitted with a st ...
, or equipment for the dispensing of biological or chemical warfare agents from tanks mounted under the wings of the aircraft.
Operational history
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.
Specifications
See also
References
;Citations
;Bibliography
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{{US missiles
SD-002
1950s United States military reconnaissance aircraft
Unmanned military aircraft of the United States
Single-engined tractor aircraft
High-wing aircraft
V-tail aircraft
Aircraft first flown in 1959