The LGM-35A Sentinel intercontinental ballistic missile program is moving from digital design to reality, marked by the recent groundbreaking for a full-scale launch silo prototype in Promontory, Utah.
Developed in partnership with Northrop Grumman, the silo prototype will validate a modular, repeatable construction approach designed to accelerate fielding, reduce cost growth and enable learning before full-rate production. The shift to building new silos—rather than refurbishing legacy Minuteman III infrastructure—preserves uninterrupted alert coverage while enabling a modern, adaptable architecture.
The silo prototype builds on a series of milestones demonstrating continued program momentum. Construction is underway on a new Wing Command Center at F.E. Warren Air Force Base, Wyoming, and the program has demonstrated all propulsive elements of the Sentinel missile. These include test firing stages-one, two and –three and completing a hot fire test of the post boost propulsion system, reducing technical risk as the program advances toward a planned 2027 flight test.
Sentinel remains on track to field initial capability in the early 2030s, ensuring a safe, secure, and credible land-based deterrent for decades to come.
U.S. Air Force
