The Hughes AN/ASG-18 Fire Control System was a prototype airborne fire control radar system for the planned North American XF-108 Rapier interceptor aircraft, and the Lockheed YF-12 for the United States Air Force.
The installation itself was massive, weighing 2,100 pounds (950 kg), and taking up most of the nose of the aircraft.
While development work was done with the XF-108, the AN/ASG-18 and Falcon missiles were first tested on a highly modified Convair B-58 Hustler bomber.
To fit the radar, the nose was lengthened nearly 7 feet (2.1 m), and the infrared sensors were mounted on either side of the forward fuselage.
Before the test "Snoopy" could fly, the XF-108 program was cancelled, and the proposed Lockheed YF-12 interceptor was to instead receive the radar/missile system pair.