The U.S. Air Force and Northrop Grumman have begun construction of a full-scale launch silo prototype for the LGM-35A Sentinel intercontinental ballistic missile program, underscoring an important advancement in modernizing the land-based leg of the nation's nuclear triad.
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What Is the Purpose of the Silo Prototype?
The prototype, located in Promontory, Utah, is intended to validate a modular construction approach designed for faster, more repeatable deployment, the Air Force said Friday. It is designed to support future production while allowing the program to assess performance before full-rate manufacturing begins. Additionally, the effort shifts away from refurbishing legacy Minuteman III silos, enabling the development of a new architecture while maintaining continuous alert coverage.
How Is the Sentinel Program Progressing?
Despite the potential risks identified by the Government Accountability Office in 2025, the transition from Minuteman III to Sentinel ICBM is progressing. The silo effort builds on recent program demonstrations, including successful test firings of all three missile stages and a hot fire test of the post-boost propulsion system. Construction is also underway on a Wing Command Center at F.E. Warren Air Force Base in Wyoming. These steps reduce technical risk as the program moves toward a planned 2027 flight test.
“The new silo design delivers operationally relevant capability on a predictable cost and schedule,” said Gen. Dale White, director of critical major weapon systems for the Department of War. “We are accelerating delivery while ensuring the system is sustainable and ready for Airmen to operate for decades.”
