The ambitious program to replace the Minuteman III intercontinental ballistic missiles (ICBMs) with a brand new, modern version has blown over its budget limit, triggering a Pentagon review, according to the Air Force.
Because the Sentinel project exceeded its initial costs, the Office of the Secretary of Defense (OSD) will review the project and determine whether to restructure or terminate it.
“Work under the current contract will continue until OSD completes its review of the Sentinel program,” an Air Force spokesperson said Friday.
While it’s not clear what the Defense Department will decide, the spokesperson said “maintaining a strong nuclear deterrent is critical to safeguarding our nation and protecting our allies from a nuclear attack.”
The U.S. awarded the Sentinel project in 2020 to defense contractor Northrop Grumman with an initial program acquisition unit cost of $118 million, according to the Air Force.
The program’s per unit cost has since soared at least 37 percent, with a new price tag of about $162 million.
That triggered a critical breach of the 1980s law known as the Nunn-McCurdy Act, which requires the Pentagon to review any major defense acquisition program that exceeds its initial cost projections.
The Sentinel program is a $96 billion overhaul to completely replace the land-based component of the U.S. nuclear triad, which also includes bomber planes and submarines.
The Air Force is working to modernize 400 missiles, 450 launch silos and more than 600 facilities across the U.S., totaling more than 40,000 square miles.
The Sentinel program will replace the Minuteman III ICBMs, which first became operational in the 1970s.
Sentinel is expected to deploy by 2030 and last until 2075. But the program has faced significant hurdles.
The Air Force said Friday it expects at least a two-year delay on operational deployment.
Air Force Secretary Frank Kendall said in November that Sentinel was “struggling” amid rising costs and unique challenges, because it involves a “vast real estate civil engineering program” along with missile development.
“Sentinel is one of the most large, complex programs I’ve ever seen,” he said. “It’s probably one of the biggest thing in some ways the Air Force has ever taken on.”
Rep. Mike Rogers (R-Ala.), chair of the House Armed Services Committee, said he was committed to conducting oversight of the program to ensure it makes necessary changes to meet its goals.
“The Department must ensure that Sentinel is ready in time to replace the current ICBMs before they reach the end of their lives,” Rogers said in a statement. “Failure is not an option.”
The Defense Department is also racing to modernize its other triads, unveiling the B-21 Raider, the first new strategic bomber plane in more than three decades, in 2022. The plane conducted its first test flight in November.
Updated at 12:57 p.m. ET