It was a time when computers were in their infancy. They were incredibly expensive and enormous with less processing power than an iPhone. Using little more than slide rules and pencils, a group of engineers designed one of the most advanced aircraft in aviation history. The year was 1958 and the aircraft they created was the SR-71 Blackbird.For exclusive content, check out our show notes at lockheedmartin.com/insideskunkworksEmail us at insideskunkworks.lm@lmco.comProduced by Theresa Hoey & Claire WhitfieldArtwork by Becca Smith