ARLINGTON, VA. — The Northrop Grumman-led Sentinel intercontinental ballistic missile program likely will get an updated cost and scheduled estimate in 1.5 to two years, an Air Force civilian official said at an industry conference here this week.
The service announced in January that Sentinel had shattered projections put together in 2020 for the program’s Milestone B, the point in Air Force project management where a program passes into what is known as the engineering and manufacturing development stage and receives formal cost and schedule estimates.
The increase was well in excess of the 25% threshold that triggers mandatory reporting to Congress under a law known as Nunn-McCurdy. The Air Force has blamed the overrun on Sentinel’s ground infrastructure, silos and command bunkers, for example, rather than the missile itself.
“I’ve visited the missile fields before, but now, in the context of Nunn-McCurdy, you look at things with new eyes,” Air Force acquisition chief Andrew Hunter said at a Defense News conference here Wednesday.
The Air Force’s Sentinel restructuring plans to change the design of the ground segment of the missile to be “simpler” and “more affordable,” Hunter said. The service would essentially need to tweak the program through an intensive, months-long re-examination of line item requirements to meet presidential and Pentagon guidance for system safety, security, maturity, and survivability.
“What’s striking is the complexity of what we ask the ground infrastructure of the Sentinel to do. The tendency is to focus on the missile, and that was how we did the program initially. We neglected the complexity of the ground infrastructure,” Hunter said.
In July, the Air Force said Sentinel’s costs have soared even more since the service announced the Nunn-McCurdy breach, clocking in now at about $140.9 billion, or 81% higher than the program’s first Milestone B estimate.
The Air Force had targeted May 2029 for initial operational capability for Sentinel, but that date will be several years later, the service has said.
Pentagon acquisition boss William LaPlante, who led the Nunn-McCurdy program review, said that DoD should not have approved Sentinel for EMD in 2020 and that “knowledge” around the ground segment in 2020 “was insufficient in hindsight to have a high-quality cost estimate.” That knowledge is more mature now, he said.
LaPlante said that DoD will scale down the Sentinel launch facilities and make them less complex to aid the transition from Boeing‘s Minuteman III to Sentinel. The new missile will initially carry W87-0 warheads provided by the National Nuclear Security Administration’s Lawrence Livermore National Laboratory in California.
Later Sentinels will use W87-1 warheads, a replacement warhead for the W78 now used on Minuteman III. W87-1 warheads will also include freshly cast plutonium pits, fissile first stage nuclear weapon cores, from the Los Alamos National Laboratory in New Mexico. Lab officials have said they planned to start casting pits this spring and should have a small stockpile built up by year’s end, pending certification of finished product.
A version of this story first appeared in Nuclear Security & Deterrence Monitor affiliate publication Defense Daily.
