Skunk Works Hopeless Diamond Experimental Stealth Aircraft

In the mid-1970s, the Pentagon's Defense Advanced Research Project Agency (DARPA) began investigating how an aircraft's radar signature might be minimized by faceting its exterior. One of the Lockheed Skunkworks' contributions to this effort was the "Hopeless Diamond," a proposed tail-less stealth fighter with a fuselage composed of sharply angular panels. Radar tests on a 10-foot model resulted in a radar signature "as small as an eagle's eyeball." Although an operational Hopeless Diamond wa