When the North American XF-108 Rapier was announced as the winner of the LRI-X contest in April 1958, the Hughes entries were redesignated GAR-9 and AN/ASG-18 on the same day.

Growing much larger, the missile's range was extended to 100 miles (160 km), using the Aerojet-General XM59 solid-fuel motor.

Some consideration was given to the addition of a passive infrared homing seeker to improve terminal performance but that would have required the missile to grow by 180 lb (82 kg) and two inches in diameter, making it too large for the F-108's weapon bay.

Instead, B-58 Hustler s/n 55-665 was modified to house the AN/ASG-18 radar in a large protruding radome that gave it the nickname "Snoopy", and in-flight launches started in May 1962.

The missile was renamed AIM-47 in late 1962 as part of the transition to common naming for aerospace vehicles across the U.S. Department of Defense in 1962.

This project was also canceled in 1968, but the weapon system finally found a home on the F-14 Tomcat, entering service in the early 1970s.

In 1966, the basic airframe was adapted with the seeker from the AGM-45 Shrike and the 250 lb (110 kg) warhead from the Mk 81 bomb to create the high-speed AGM-76 Falcon anti-radar missile, although this did not see service.