World superpowers like Russia and China are interested in the B-21 Raider because of its reputation as a stealth bomber. At least six of the next-generation stealth bombers are now in some stage of production, as announced by the Air Force a few months ago.
It is anticipated that when the B-21 Raider enters service later this decade, it will be the most sophisticated stealth bomber ever flown. The Raider, developed and manufactured by Northrop Grumman, the company also responsible for the B-2 Spirit stealth bomber, is meant to improve upon the Spirit's stealth capabilities for use in the modern battlefield.
The first completed B-21 Raider is currently undergoing ground testing, though this doesn't necessarily indicate that the plane will be airborne anytime soon. Tests on the ground are extensive and involve checking every aspect of the plane, from the mechanical operation of the control surfaces (flaps, ailerons, and rudders) to the activation of various electronic systems to ensure their functionality and lack of interference.
Since the B-21 will be carrying state-of-the-art technology, rigorous ground testing is almost certain to take years. Northrop Grumman still plans on revealing the plane to the public later this year, and the first flight is anticipated to take place soon after.
Air Force Global Strike Command's top general, Maj. Gen. Jason R. Armagost, explained earlier this year that the rapid development time was due in large part to the Air Force's adoption of a digital approach to design and development.
"We are taking advantage of the revolution in digital—model-based systems engineering and open mission systems architecture software," Armagost explained.
Because of model-based systems engineering, "a fairly complex thing like the software for the fuel control system is completely done on an aircraft that hasn't even flown yet as a test article." They simulated the fuel system in order to test the program, and it passed all the tests with flying colors.
The B-21, like its forerunner, will be able to carry a wide array of nuclear weapons, including the B-61 variable-yield nuclear gravity bomb and the Long Range Stand-Off (LRSO) nuclear cruise missile. Soon after its release, the B-21 will be able to contribute to military operations all over the world thanks to the wide range of conventional weapons it can carry.
The Air Force has recently shown an interest in developing a second long-range stealth bomber, this time a cheaper uncrewed platform that can fly in support of the B-21, utilizing systems in development to pair fighters with highly capable UCAV wingmen. During the fiscal year 2024, this new drone stealth bomber concept will likely enter the design phase.
