Virtually every modern US stealth aircraft was developed and tested at Area 51.

The base served as a giant laboratory for radar-evading technology. Engineers used mathematical formulas from a Russian scientist to design shapes that radar could not see. From the early A-12 spy plane to the angular F-117 Nighthawk, every major American stealth plane was tested in the Nevada desert. The strange shapes and lights of these secret flights are what likely started the local UFO rumors.