An artist rendering of the B-21 released by Deborah Lee James, Secretary of the Air Force.

That so-called "open-architecture system" of the aircraft is significant given each B-21 stealth bomber is expected to cost about $500 million and will likely be in service for decades. Having a more open platform will allow the electronics and software to be upgraded much more rapidly.

As a result, the military will be able to upgrade the aircraft's software systems as technology evolves or make changes as adversaries evolve, Air Force Lt. Gen Arnold Bunch Jr., military deputy of the office of the assistant secretary of the Air Force for acquisition, told the Senate Armed Services Subcommittee on Airland.

The Air Force's super-secret B-21 long-range strike bomber under development will feature flexible technology that will allow its capabilities to be modernized over time to stave off obsolescence, a top acquisition general testified Wednesday to a Senate panel.

Northrop Grumman is the prime contractor on development of the B-21, an aircraft nicknamed the Raider. The B-21 will replace the Air Force's aging B-52 Stratofortress bombers and the B-1B Lancer.



Bunch also said the B-21 bomber is being outfitted with additional power, space and other features "so that we can grow the platform for the future. We can do it in a more efficient manner because we won't need to test as much, and I personally believe we will increase our cyber security as we go through that process."



There's also been more scrutiny of the B-21 given the history of cost overruns on other large military contracts, including the F-35 Joint Strike Fighter program from Lockheed Martin.



The general said preliminary design review on the B-21 was completed and the Air Force was now going into "detailed design review."



"The contractor [Northrop] is hiring people at the appropriate level to get the work done," he said. "We're tracking what they're doing. Everything right now to me indicates that we haven't slipped anything."

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