After the Luftwaffe lost the Battle of Britain in 1940, Hermann Goering ordered an ambitious new project he called the "3x1000" fighter. Goering wanted a plane that could deliver 1,000 kilograms of ordnance to a target 1,000 kilometers and fly 1,000 kilometers per hour.
Two brothers, Walter and Reimar Horten, proposed a design that not only would satisfy the ambitious concept, but that would also be the first stealth fighter.
The Horten 229 was the first blended-wing jet fighter ever built, but it only flew a handful of times in World War II. While its body looks similar to modern stealth planes like the B-2 Spirit, the 229 was never tested against radar.
The first prototype was destroyed in a crash during testing and the second was captured by the Allies who boxed it up and sent it to the U.S.
A team of Northrup Grumman model builders created a mockup of the 229 so that engineers could test the design against the types of radar used for the defense of Britain.
The results spelled probable doom for the British if the Horten had entered full production. Its reduced cross section could have allowed it to get closer to the coast before detection, and its speed might have gotten it to its target well before it could have been intercepted.
And, even if fighters or coastal artillery did reach the Horten before it destroyed the radar station and flew off, its speed and maneuverability would have made in nearly unstoppable in a fight.
See the full story of the engineers who rebuilt the Horten body and how the plane could have reshaped history in the National Geographic video below: