The head of U.S. Strategic Command (STRATCOM) acknowledged ongoing challenges with the Ground Based Strategic Deterrent replacement program, emphasizing the need to carefully balance testing demands with the realities of an aging legacy system.

During a recent House Armed Services Committee hearing, Rep. Salud Carbajal (D-Calif.) pressed STRATCOM Commander Adm. Richard Correll on how the command is managing finite test assets for the LGM-35 Northrop Grumman Sentinel intercontinental ballistic missile (ICBM) program while the current LGM-30 Minuteman III continues to age beyond its originally planned service life.

The Sentinel ICBM, being built by Northrop Grumman, will eventually replace the 56-year-old Boeing-made Minuteman III as the Air Force’s silo-based, nuclear-armed ICBM sometime in the 2030s while the Minuteman III is still commissioned. Either the W78 warhead or the W87-0 warhead, with plutonium pits made by the National Nuclear Security Administration, currently tips each of the Minuteman III missiles, though the missile was originally designed for multiple reentry vehicles.

The last Minuteman III was originally expected to be decommissioned by the mid-2030s, but an Air Force official told the Exchange Monitor in 2024 that it would now be decommissioned by at least 2050, with both Sentinel and Minuteman III being fielded at the same time while Minuteman III is phased out.

Carbajal noted that Sentinel was initially expected to be ready by the end of the decade but now faces delays of at least several years, raising concerns about the availability of test bodies and the long-term viability of the existing intercontinental ballistic missile force.

Correll said STRATCOM is actively managing what he described as a “risk balance” between sustaining Minuteman III and accelerating Sentinel’s development and deployment. He underscored close coordination with Sentinel program leadership, including regular engagements with the Air Force’s portfolio manager overseeing the effort.

“We have weekly conversations on where the opportunities are to accelerate delivery,” Correll said, adding those discussions also address sustainment risks tied to Minuteman III.

Correll also said as the combatant commander responsible for the nation’s strategic deterrent, his role is to clearly communicate risk within the Defense Department and outline mitigation efforts as the transition unfolds.

Despite ongoing program pressures, Correll expressed confidence that the Minuteman III force can be sustained through the transition period. He also pointed to steady progress within the Sentinel program office, signaling cautious optimism even as schedule uncertainty remains.

The exchange highlights continued congressional concern over the pace of nuclear modernization and the strain placed on legacy systems as next-generation capabilities face delays and cost overruns. The Sentinel program underwent a review in 2024 through a law known as Nunn-McCurdy, wherein the Pentagon must disclose when a program passes a certain cost threshold. Sentinel triggered a “critical” Nunn-McCurdy breach, as costs escalated over 50% past the original baseline at 81%.