This effort led to a 10-foot wooden model that the Skunk Works team dubbed the Hopeless Diamond. The design was stealthy enough for Rich to win a bet against legendary engineer Kelly Johnson ...

Inside was a 55-year-old model of the A-3, Lockheed’s first try at blending stealth with speed—and a direct predecessor of the triple-sonic A-12 Blackbird. It had been designed by Skunk Works ...