For more than twenty years, the B-52 bomber was the ol’ reliable, flying missions from Korea to Vietnam and everywhere in between. By the 1970s, however, much of its technical edge disappeared — Russian fighters and surface-to-air missiles were by then quite capable of intercepting the aircraft. The search for a replacement brought the Air Force to the defense department’s R&D lab, called Defense Advanced Research Projects Agency, which was developing a new type of bomber that would fly undetected by enemy radar.

On this day, July 17, 1989, the first widely-used test bomber in the United, the B-2 Spirit Stealth bomber made its public debut, flying from an air force base in Palmdale, California.

Much of what gives the stealth bomber its stealth remains classified. What is known is that its unique profile – it looks essentially like a flying wing – combined with radar wave-absorbing paint makes it practically invisible to radar, and its hot exhaust gases are cooled to ambient temperature before being released into the sky, to throw off enemy heat-seekers.