On February 13, 2026, the US Air Force and Northrop Grumman broke ground on a prototype launch silo for the LGM-35A Sentinel intercontinental ballistic missile at Northrop Grumman’s Strategic Missile Test and Production Complex in Promontory, Utah. This full-scale prototype enables engineers to test modern construction techniques, validate the new silo design, and refine processes before operational deployment across missile fields.
The program has shifted from refurbishing 60-year-old Minuteman III silos, which would near 150 years old by Sentinel’s 70-year service life end. Building new silos avoids unpredictable costs and safety risks of retrofitting 450 unique structures from the 1960s. A second prototyping phase is scheduled for summer 2026 at F.E. Warren Air Force Base in Wyoming to test utility corridor methods for thousands of miles of secure infrastructure.
Sentinel infrastructure spans 32,000 square miles in five states, including 24 launch centers, three missile wing command centers, and roughly 5,000 miles of fiber-optic cable. Construction is underway on the first Wing Command Center at F.E. Warren and test facilities at Vandenberg Space Force Base.
Missile development advances in parallel: Stage-1 solid rocket motor qualified in March 2025, Stage-2 in July 2025. The first complete three-stage ground test missile was assembled late 2025 for transportation and emplacement testing. The initial pad launch is planned for 2027.
This follows a 2024 Nunn-McCurdy breach after costs doubled from the $77.7 billion 2020 contract. Restructuring targets Milestone B by end-2026 and initial operational capability in the early 2030s. Minuteman III transition began September 2025 with the first silo offline; Site Activation Task Force detachments are at F.E. Warren, Malmstrom, Minot, and Vandenberg bases, planning a 15-year overlap.