The Air Force said it has no plans to publicly disclose the cost estimate for the aircraft touted as the "backbone" of the U.S.'s future strike and deterrence capabilities, arguing it would reveal too much information to potential adversaries and compromise a classified program.
That's infuriated some lawmakers, including Sen. John McCain, who argue that the public deserves to see the price tag because so many defense projects have blown their budgets due to waste and fraud.
Officials have been tight-lipped as to the specific capability expectations for the B-21, but indications are that it will be stealthy, able to carry conventional and nuclear weapons, and could possibly operate with or without a pilot.
"Releasing that [data], releasing other things that may be more insightful to our adversaries, I don't think helps the taxpayer and I don't think it helps -- certainly -- the warfighter," Randall Walden, program executive officer of the Air Force's Rapid Capabilities Office, said at an event earlier this month hosted by the Mitchell Institute for Aerospace Studies.
"All we're doing is putting in that risk and we're showing our hand of what we believe this nation and the states' workers can deliver this particular weapon system for," added Walden, whose office is responsible for procuring the bomber and other classified weapons systems.
But the service has faced pressure from several lawmakers to release the data, including the fees paid to defense contractor Northrup Grumman, which is building the sophisticated, nuclear-capable bomber, so that the taxpayers can see if the program is being properly managed.
"At a time of growing threats and fiscal constraints, American taxpayers want to know if the Pentagon is spending their hard-earned money effectively and efficiently," McCain, one of the program's harshest critics, told CNN. "The Air Force must release the total contract award value of the Long Range Strike Bomber to ensure this program and the people managing it are held accountable."
The Air Force has already released some financial info, but it's not the whole picture, by any means. It was disclosed that the B-21's per-plane cost is expected to come in at roughly $560 million, although that was a preliminary estimate made by the Department of Defense before Northrup Grumman had even won the contract to build the plane. The amount that the government is paying the defense contractor for the new stealth program is secret.
The Pentagon also made public an artist's conception of the aircraft, which some lawmakers argue would be more useful to a foreign intelligence agency than the overall contract cost.
Recent programs to upgrade stealth air capabilities, including the F-35 Joint Strike Fighter, have been plagued by schedule delays, technology glitches and cost overruns.
But the flaws of some past defense programs have not swayed most of McCain's colleagues to join his call for more transparency when it comes to the B-21's price tag.
The Senate House Armed Services Committee recently voted 19-7 to limit revealing the B-21 program's total cost estimate to only members of congressional defense committees, rather than full public disclosure, during a closed-door session to discuss the details of its annual defense policy bill.
Voting in favor of keeping the number a secret from the public were Republicans James Inhofe, Jeff Sessions, Roger Wicker, Deb Fischer, Mike Rounds, Thom Tillis, and Mike Lee. They were joined Democrats Jack Reed, Bill Nelson, Richard Blumenthal, Claire McCaskill, Joe Manchin, Jeanne Shaheen, Kirsten Gillibrand, Joe Donnelly, Mazie Hirono, Tim Kaine and Martin Heinrich.
Republican Senators Kelly Ayotte, Tom Cotton, Joni Ernst, Dan Sullivan, Lindsay Graham and Ted Cruz joined McCain in opposition to the secrecy.
"The Air Force has repeatedly said, citing National Security concerns, that it will not declassify the amount of Northrop Grumman's bid for the project because, as has been demonstrated in the past, doing so would allow our adversaries to use the costs associated with the program to glean information about the B-21 such as what equipment is going on it, its weight, how high it can fly, how fast it can go and how far it can travel," said a spokesman for Sen. Bill Nelson.
"Sen. McCain introduced a provision during the Armed Services Committee mark-up of the National Defense Authorization Act that would have, in effect, killed the B-21 program unless the Air Force publicly disclosed how much Northrop bid to win the project," the aide added.
Northrop Grumman, the developer of the Air Force's current bomber, the B-2, beat out a partnership between aeronautic juggernauts Boeing and Lockheed Martin last year for the right to build the next generation of long-range aircraft.
The Air Force said it plans to start testing the plane sometime in the mid-2020s and hope to replace the B-1 bomber when they retire sometime in the 2040s.