LIVERMORE, Ca. — With development of the Sentinel missile largely paused, the Lawrence Livermore National Laboratory here is doing what “relevant flight testing” it can on the missile’s W87-0 warhead, a senior lab official at the Lawrence Livermore National Laboratory told the Exchange Monitor Tuesday.
“There have not been Sentinel flights associated with it [the W87-0],” Brad Wallin, deputy director for strategic deterrence, told the Monitor at a planned press tour of the Lawrence Livermore and Nevada National Security Site. “Although we are doing relevant flight testing to help us inform what that transition is going to look like, to take us from the Minuteman III to the Sentinel.”
“[T]here will be” flight tests with the W87-0, but it is not clear when, Dave Hoagland, executive principal assistant deputy administrator for defense programs at the National Nuclear Security Administration said.
Sentinel, being built by Northrop Grumman, will eventually replace the Boeing-made Minuteman III as the Air Force’s silo-based, nuclear-armed intercontinental ballistic missile. The Sentinel program, managed by the Department of Defense, this year began a congressionally mandated review in the wake of soaring costs.
The ongoing review had a cascading effect on other programs tied to the missile, including W87-0.
In its 2025 budget request, released in March this year two months after the service acknowledged Sentinel’s cost increases, the Air Force said the missile’s first development test flight would launch in February 2026. At one point, Sentinel’s first test flight was on the books for December 2023.
Asked how the missile rebaseline would affect the flight tests, Wallin said, “it’s affecting it in the sense that we are thinking, again, with this incredible toolkit that we have about how, if there’s a delay in our ultimate Sentinel flight test, how can we do our best to qualify the warhead itself?”
W87-0 warheads will be the first to tip Sentinel when the missile deploys sometime next decade or later. These warheads will be harvested from existing Minuteman III missiles and adapted for the successor missile.
Later Sentinel missiles will use W87-1 warheads. These weapons will be replacements for the W78 that tips Minuteman III now. The W87-1s will have freshly made plutonium pits cast at the Los Alamos National Laboratory.
Livermore owns both the Sentinel warhead programs.
The Air Force disclosed in January that the Sentinel program was facing a Nunn-McCurdy breach, which happens when a Pentagon program’s costs exceed early estimates by 25%. The Sentinel program’s current cost as of July is $140.9 billion, or 81% higher than its original Milestone B estimate, as of September.
