Ground Based Strategic Deterrent EMD

The Ground Based Strategic Deterrent Engineering and Manufacturing Development (GBSD EMD) program, now designated as the LGM-35A Sentinel, is a major Air Force initiative focused on modernizing the United States' ground-based nuclear deterrent. The program's primary goal is to replace the aging Minuteman III Intercontinental Ballistic Missile (ICBM) system with a fully integrated, technologically advanced ICBM weapon system. This modernization effort aims to enhance safety, security, reliability, and effectiveness, while reducing lifecycle costs and addressing vulnerabilities identified in previous assessments. The Sentinel program operates under the ICBM Systems Directorate and is managed by the Sentinel Systems Program Office, with key integration across related programs such as ICBM Reentry Vehicles and Fuze Modernization.

Flight Systems objectives center on maturing the design and technology of the missile boosters, re-entry vehicles, and guidance systems. FY 2026 activities include implementing updated specifications, conducting design reviews, and refining critical components such as air vehicle equipment, cybersecurity, and nuclear surety architectures. The program leverages extensive modeling, simulation, and trade studies to assess performance against evolving threats. Integration with government agencies ensures seamless incorporation of cryptographic systems and Department of Energy technologies. Lifecycle sustainment strategies are developed for reentry vehicles and logistics data.

Command & Launch efforts focus on developing robust, secure, and reliable command and control systems for the Sentinel weapon system. FY 2026 priorities include refining mission equipment, cryptographic systems, and interfaces for wing command centers and launch silos. The program advances launch guidance control systems, communications subsystems, and ground mechanical systems, emphasizing cybersecurity and operator/maintenance systems. Collaboration with the Department of Defense and NSA supports cryptographic asset integration. Systems engineering processes establish technical baselines and supportability analyses for logistics and sustainment.

Infrastructure & Deployment activities are dedicated to planning and executing the development and modernization of facilities required for Sentinel deployment. FY 2026 objectives include constructing utility corridors, overseeing real estate acquisition, and designing launch silos and centers for both operational and test deployments. Environmental impact assessments and agreements are executed to ensure compliance. Integration with the NC3 Directorate supports future command and control capabilities. The program continually assesses fielding requirements and transition timelines from Minuteman III to Sentinel, aiming to optimize scheduling and minimize lifecycle costs.

Software development under the GBSD EMD program focuses on establishing a resilient software ecosystem, managing the Sentinel software baseline, architecture, and modularity. FY 2026 plans involve maturing weapon system software, expanding data ingestion capabilities for flight test analysis, and leveraging Model-Based Systems Engineering tools. The effort supports comprehensive software sustainment strategies and assesses fielding requirements for the transition to Sentinel. Control of the technical baseline is maintained through government resources and partnerships.

Systems Engineering objectives include maturing specifications, architecture, and design through rigorous testing, modeling, and simulation. FY 2026 activities emphasize modular architectures, external interface management, and survivability certification planning, particularly for nuclear survivability and hardening requirements. Specialty engineering expertise is leveraged to deliver a secure, reliable, and sustainable weapon system. Proactive processes and program-wide collaboration ensure quality and cost-effectiveness.

Test and Government Support lines ensure robust test strategies and program management. FY 2026 test efforts focus on developing and modernizing test capabilities, including flight, cyber, and environmental testing at key ranges such as Vandenberg Space Force Base. Government support activities provide the necessary manpower, technical expertise, IT infrastructure, and cybersecurity capabilities, expanding digital engineering and DevSecOps environments. The acquisition strategy, currently being restructured following the July 2024 Nunn-McCurdy recertification, aims to deliver a low-risk, technologically mature weapon system with flexible architecture and government ownership of key interfaces and data rights. These efforts support the ground-based leg of the nuclear triad through 2075.