U.S. Air Force to Unveil the B-21 Raider, America's New Stealth Nuclear Bomber. "Most Advanced Military Aircraft Ever Built." 

The Air Force will introduce its next-generation stealth bomber this week, upgrading its current 30-year-old model to become even more difficult for enemy radar to spot. It's being called the most advanced military aircraft ever built. The B-21 Raider will be unveiled Friday in Palmdale, California, to an invitation-only audience of 800. The host is Northrop Grumman, the company that has been developing the futuristic bomber since 2015. Read on to find out more about the sixth-generation fighter jet—including its features, cost, and the military heroes who gave the plane its name.

Photos of the Raider have not been released, only renderings. The craft is expected to be similar in shape to the B-2 Spirit bomber, which was introduced more than three decades ago. But it will be smaller and more difficult for enemy radar to pick up. It's expected to be even stealthier than the revolutionary Stealth bomber—barely visible in operation.

+The plane has been designed with the next generation of stealth technology to evade radar detection, Defense One reports. The Air Force has kept the B-21 project a secret so America's adversaries wouldn't be able to copy the design or come up with ways to shoot it down.

Like the B-2, which has been used in nearly every conflict in the past 30 years, including Kosovo, Iraq, and Afghanistan, the B-21 can carry precision-guided conventional and nuclear weapons, the UK Times reports. The craft was "optimized for operations in highly contested environments," said Northrop president Tom Jones.

The company used digital engineering and advanced manufacturing to create the plane, making it a reality much faster than most military development projects. "The B-21 is the most advanced military aircraft ever built and is a product of pioneering innovation and technological excellence," said Northrop sector vice president and general manager Doug ​​Young. 

According to reports, at least 100 B-21s will be built at a cost of $550 million each. An initial order of six is in various stages of development and testing, the company said. The first planes are expected to be operational in 2023, and the B-21 will eventually replace the B-2 and B-1 bombers. "With the capability to hold targets at risk anywhere in the world, this weapon system is critical to our national security," said Young.

The B-21 Raider was named after a group of World War II bomber pilots and crewmen known as the Doolittle Raiders. These 80 Air Force members volunteered to attack Tokyo on April 18, 1942, mere months after Japan attacked Pearl Harbor and the U.S. joined World War II. Led by Lt. Col. James Doolittle, the bombing mission involved 16 B-25 bombers launched from the aircraft carrier USS Hornet.

"The raid acted as a catalyst to many future innovations in U.S. air superiority from land or sea," Northrop says on its website. "That bold, innovative and courageous spirit of the Doolittle Raiders has been the inspiration behind the name of America's next-generation bomber, the B-21 Raider."

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B-21 production didn't shut down during the pandemic, with a crew working consistently at the top-secret hangar to get the plane built. "They didn't have the opportunity to work at home, either because of the classification or they were working in a factory—they were coming in every day, couldn't tell their families why they were coming in, just they have to go in when a lot of the rest of the world was able to work at home," said Jones. "Working through all the turmoil of that and still successfully putting this aircraft together. I'm just so proud of the work that they've done."