US Air Force sees early 2030s rollout for revamped Sentinel nuclear missile

The U.S. Air Force said Tuesday it expects its next-generation LGM-35A Sentinel nuclear missile to reach initial capability in the early 2030s, following a revamp of the over-budget program’s acquisition plan set to finish this year.

The Northrop Grumman-made Sentinel intercontinental ballistic missile is intended to replace the Cold War-era Minuteman III missiles, which were first introduced more than 50 years ago and are well past their expected service life.

But Sentinel’s cost, which was originally expected to be about $77.7 billion, ballooned, largely due to the rising price of constructing a vast network of missile silos and launch control centers, spread out over thousands of miles in the Great Plains region.

Sentinel was on track to cost about $160 billion, well over twice the original estimate, when the Pentagon in January 2024 declared a cost overrun process called a critical Nunn-McCurdy breach and launched a review process.

The Sentinel program was also originally expected to reach initial operational capability in 2029, but that deadline first slid to 2030 and is now dropping further behind schedule.

In July 2024, the Pentagon decided the LGM-30G Minuteman III replacement was too critical to national security to cancel. But while Sentinel would continue, the Pentagon told the Air Force to restructure the program and bring its costs under control.

The Sentinel program’s Milestone B approval, which was originally made in September 2020 and authorized the program to move into its engineering and manufacturing development phase, was also revoked by the Pentagon at that time.

The Air Force said Tuesday that the restructuring of the Sentinel program is now projected to finish by the end of 2026, along with a new Milestone B decision. The service said it has “leverag[ed] considerable progress over the last 12-18 months,” and is carrying out a “transformed acquisition strategy” allowing it to move quickly.

“Modernizing our nuclear deterrent is a critical priority!” Air Force Secretary Troy Meink said in a post on X. “The Sentinel program is on a data-driven path to deliver this capability, replacing a 1970s-era system to guarantee Peace through Strength for decades to come.”

Defense Secretary Pete Hegseth last August created a position dubbed the direct reporting portfolio manager, or DRPM, for critical major weapon systems — including the Sentinel and Minuteman III, the F-47 sixth-generation fighter and the B-21 Raider stealth bomber — to oversee the Air Force’s major programs.

That DRPM official, Gen. Dale White, is intended to be able to “cut through bureaucracy” and make decisions faster to rapidly deliver major capabilities at large scales, the Air Force said.

“The DRPM has the direct authority to make decisions, informed by integrated inputs across the enterprise and in alignment with the mission priorities set by the Secretary of War and the Secretary for the Air Force,” White said. “That construct allows us to resolve tradeoffs quickly and move with the speed required to deliver credible deterrence, while preserving the discipline this mission demands.”

The Air Force said that after taking the new DRPM role, White and the Sentinel team conducted a detailed review of the program, and decided it was on track to finish its restructuring phase this year and to deliver initial capability in the early 2030s.

A new cost estimate for Sentinel was not immediately available, but a U.S. official told Defense News that the Milestone B process typically involves an independent cost estimate from the Pentagon’s Office of Cost Assessment and Program Evaluation, or CAPE. The Pentagon said in July 2024 that Sentinel could cost $140.9 billion with a revamped acquisition process.