Northrop XST Stealth Demonstrator 3D model

In 1974, DARPA established a competition to develop the first low-observable -- or stealth -- fighter, one capable of evading enemy radar systems. Virtually all of America's top aviation defense contractors entered the contest, although by 1975 the competition came down to just two: Lockheed, with its multi-faceted Hopeless Diamond, and Northrop, with its simpler diamond-delta wing platform.Although most DARPA evaluators believed that the Northrop XST (Experimental Survivable Testbed) looked like a more plausible flying machine, its shape only became stealthy when viewed from the front or rear. Lockheed's design, while more problematic, presented a smaller signature from every angle, and thus won the competition.Lockheed's triumph went to its winning the contract for what ultimately became the F-117 Nighthawk. Northrop, on the other hand, ultimately won an even bigger contract for what became the B-2 "Spirit