Weapon System Features
The LGM-35A Sentinel is the weapon system being developed to replace the aging LGM-30 Minuteman III intercontinental ballistic missile. The Sentinel program represents a comprehensive modernization of the land-based leg of the U.S. nuclear triad. It will be deployed at F.E. Warren Air Force Base, Wyoming; Malmstrom Air Force Base, Montana; and Minot Air Force Base, North Dakota.
Note: The LGM-35A Sentinel was originally called the Ground Based Strategic Deterrent, or GBSD.
Background
Nuclear deterrence is the Department of War's highest priority mission and the foundation of our national defense. After more than 50 years of service, the Minuteman III and its 1970s-era infrastructure require replacement.
After extensive analysis, the Air Force determined it will build new, modern launch silos, launch centers, communications systems and infrastructure rather than reusing the existing Minuteman III silos.
What We Do
The Air Force Nuclear Weapons Center is responsible for the complete life-cycle management of the Sentinel weapon system.
Program Status and Future Role
The Sentinel program is a deliberate, multi-year effort involving the largest construction project in Air Force history. The first Minuteman III silo at F.E. Warren was taken offline in September 2025 to prepare for this transition, marking a tangible first step in the construction process.
Due to the scale of this new construction, the Minuteman III will remain in service to ensure a continuous and credible deterrent until the Sentinel system is fully deployed. The total number of land-based nuclear missiles on alert in the continental United States will remain the same.