The "Tacit Rainbow" is a small, jet powered unmanned “mini” drone that was conceived and developed by General Thomas P. Stafford during his time as the Air Force’s Deputy Chief of Staff for Research, Development and Acquisition at the Pentagon in the late 1970’s.
The "Tacit Rainbow" was a "smart" weapon designed to be small enough to be carried by bombers and fighter aircraft to within striking distance of a potential target. When launched, the drone’s wings and horizontal tail would unfold out of the fuselage, and its small 70-lb thrust jet engine would fire up. An onboard computer was pre-programmed to steer the craft to a designated target area where it would loiter, waiting for an enemy radar site to be turned on. As soon as a radar signal was detected, it would immediately attack the radar installation. If the radar was turned off to avoid detection, the “Tacit Rainbow” would return to orbit the site and wait for the radar to be turned back on. It would continue to do this until the radar installation was either destroyed, or until it ran out of fuel.
The "Tacit Rainbow" is extremely rare, with less than five still known to exist. (Actual Artifact)