In 1955, Radioplane developed the Model RP-7l Falconer as a derivative of the OQ-19/MQM-33 series of target drones. The drone was launched by a solid rocket booster from a zero-length launcher, and was recovered by parachute. The RP-7l had onboard still picture (and optional TV) cameras, and was used by the US Army as the surveillance drone of the AN/USD-l system.
The drone itself was either known as AN/USD-l (although this was really the designation of the whole drone surveillance system, including ground equipment) or as SD-l (as an abbreviation of AN/USD-l, with SD conveniently being interpreted as “Surveillance Drone”). Series production of the SD-l for the US Army started in 1959. In June 1963, the RP-71 drones of the AN/USD-lA and AN/USD-lB surveillance systems were designated as MQM-57A and MQM-57B, respectively. The MQM-57 remained in service until the mid-1970s, and a total of about 1500 MQM-57s of all versions were built by Northrop Ventura (formerly Radioplane).