This is a Petrel, an air-to-surface or air-to-underwater missile developed by the National Bureau of Standards for the U.S. Naval Bureau of Ordnance. The missile is basically a 2,000 pound airborne torpedo with semi-active automatic radar homing guidance in its warhead. The main propulsion system is a J-44 Fairchild turbojet engine and it was also fitted with a solid fuel booster. Prior to impact, the Petrel jettisoned its turbojet and attachments. The torpedo then entered the water unencumbered and made a normal run at the submarine or surface ship target. The Petrel had a brief operational life. It became operational in 1958 but target-seeking was difficult and it was cancelled in the same year. The missile was transferred to the Smithsonian in 1968 from the U.S. Navy.
Transferred from U.S. Navy, Naval Supply Depot, Mechanicsberg, Pa., to Smithsonian, by way of National Armed Forces Museum Advisory Board (NAFMAB) on 1 March 1967