The program was intended to produce standoff delivery systems to allow for the release of torpedoes from outside of the range of enemy defenses, specifically calling for "radar-controlled, subsonic, self-homing, air-borne missiles...to deliver explosive charge [sic] below water line of floating targets".

[9] Its payload was intended to be a plunge bomb, an unguided projectile that upon release would glide briefly along a ballistic trajectory before sinking alongside a target and detonating underwater.

As designed, Petrel was essentially a Mark 21 Mod 2 torpedo fitted with flying surfaces and a Fairchild J44 turbojet; the missile had a range of 20 nautical miles (23 mi; 37 km) at Mach 0.5, and used semi-active radar homing for guidance.

[8] By the time Petrel entered operational service in 1956,[1] the Mark 41 torpedo had been selected as its definitive warload;[10] launched by the P2V Neptune patrol aircraft, Petrel was withdrawn from operational use by 1959, as it was useless against submerged submarines and the U.S. Navy placed a low priority on defense against surface vessels, considering them an insignificant threat by comparison.

Construction of Grebe was contracted to the Goodyear Aircraft Company; it was powered by a solid-propellant rocket in its base version, while pulsejet-powered variants were planned to extend the range of the weapon to 40,000 yards (23 mi; 37 km).