Back in 1975, Lockheed’s legendary Skunk Works started tooling around with the Experimental Survivable Testbed (XST) program, also known as Project Harvey. Harvey soon led to the Hopeless Diamond, a shape developed using computers that experts agreed would offer the smallest radar return possible under their current computational restrictions. The Hopeless Diamond led to Have Blue, the precursor program to what would become the world’s first operational stealth aircraft.

By 1981, only six years after the concept began to take shape, the XST program had matured into a flying F-117 airframe. Two years after that, the Nighthawk, America’s “stealth fighter” entered into service under a veil of secrecy. It would fly for five more years before the American government would even acknowledge it existed.

Could America's secretive B-21 Raider already be flying?
(Photo by Tech. Sgt. Marvin Lynchard, USAF)

In today’s world full of satellite imagery and cell phone video cameras, that type of secrecy seems all but impossible. With cameras ever-present and a global digital infrastructure capable of relaying leaked information or pictures to news outlets anywhere on the planet in a matter of seconds, keeping a big, triangular bomber a secret sounds downright improbable, but that doesn’t mean impossible.

According to Air Force officials, the B-21 Raider is expected to enter into service sometime in the mid-2020s and eventually replace both the aging B-2 Spirit and B-1B Lancer bombers. The Spirit, sometimes referred to as the “stealth bomber,” shares its flying-wing design with its forthcoming replacement, though beyond the general shape of the B-21, neither the U.S. government nor Northrop Grumman, the firm tasked with its development and production, have offered much in the way of details.