The Department of the Air Force has designated the Ground Based Strategic Deterrent next generation intercontinental ballistic missile under development by Northrop Grumman the LGM-35A Sentinel.
“The name Sentinel recognizes the mindset that thousands of airmen, past and present, have brought to the deterrence mission, and will serve as a reminder for those who operate, secure, and maintain this system in the future about the discipline and responsibility their duty entails,” Air Force Secretary Frank Kendall said in an Apr. 5 statement.
“The Air Force determined the LGM-35A Sentinel would provide continuity in strategic deterrence and cost less than extending the life of the current ICBM [intercontinental ballistic missile] fleet, comprised of the aging Minuteman III,” the Air Force said. “Replacing the 1970s-era missile modernizes the ground-based leg of the nuclear triad and brings the Minuteman’s more than 50 years of service to a close.”
Boeing built the Minuteman III missiles.
The LGM-35A “will incorporate low risk, technically mature components, feature a modular architecture that can easily incorporate emerging technology to adapt in rapidly evolving threat environments, and will be easier to maintain than the Minuteman system – all of which will enable cost-savings and ensure relevancy as the Sentinel operates well into the 2070s,” the Air Force said on Apr. 5.
The current missile bases of F.E. Warren AFB, Wyo., Malmstrom AFB, Mont., and Minot AFB, N.D. are to house the LGM-35As.
“Using infrastructure at current locations will allow both the Minuteman III and Sentinel weapons systems to continue meeting all nuclear surety and safety standards during the transition period,” the Air Force said on Apr. 5.
The Biden administration is conducting its Nuclear Posture Review and has opposed congressional efforts to prohibit a reduction below 400 Minuteman IIIs. The Air Force plans to retire the Minuteman IIIs by the mid-2030s or earlier, as Sentinel comes online.
Initial Sentinel missiles will use W87-0 warheads: a variant of the W87 warhead used on Minuteman III, but adapted for the newer ICBMs. The first Sentinel flight test had been scheduled for December 2023, the Air Force has said. Later Sentinel missiles are slated to use the W87-1: a replacement for Minuteman’s W78 that is supposed to use fresh plutonium pits, or first-stage warhead triggers, cast in a factory planned at the Los Alamos National Laboratory in New Mexico.
A version of this story first appeared in Exchange Monitor affiliate publication Defense Daily.
