The LGM-35 Sentinel, also known as the Ground Based Strategic Deterrent (GBSD), is a future American land-based intercontinental ballistic missile system (ICBM) currently in the early stages of development. It is slated to replace all 450 Minuteman II missiles from 2029 through 2075. The Minuteman missiles are currently stationed in North Dakota, Wyoming, Montana, and Nebraska.
In 2020, the Department of the Air Force awarded defense contractor Northrop Grumman a $13.3 billion sole-source contract for development of the LGM-35 after Boeing withdrew its proposal. Northrop Grumman’s subcontractors on the LGM-35 include Lockheed Martin, General Dynamics, Bechtel, Honeywell, Aerojet Rocketdyne, Parsons, Textron, and others.
On January 19th, 2024, the USAF announced that the program’s costs had risen to over $125 billion—37% above the initial $95.3 billion budget—and its deployment would be delayed by two years. A revised cost estimate released by the Department of Defense on July 8th, 2024, put total program acquisition costs for the Sentinel program at $140.9 billion.
The United States Air Force plans to procure 634 Sentinel missiles, plus an additional 25 missiles to support development and testing, to enable the deployment of 400 missiles. According to the Air Force, the program also includes modernizing “450 silos and more than 600 facilities across almost 40,000 square miles”
Several months ago, the National Interest published an article discussing the Sentinel ICBM initiative, outlining the impact the updated missile program will have on our national defense, as well as cost overruns and slipping milestones the program has faced since inception. They also point out that not only are new missiles being developed but so too is the infrastructure, which in most cases date back to the Cold War and the use of old analog technology. According to the National Interest, “the program plans to produce over 600 new missiles, upgrade or construct hundreds of facilities, and lay nearly 8,000 miles of new, underground fiber optic cabling for command and control. This massive enterprise spans 40,000 square miles and involves six states. Assumptions were made during early cost estimates that some of the facilities currently in use could be refurbished and reused to save money and time, which has compounded the cost overruns.”
While Congress will have to review the escalating costs of the program, its doubtful they will cut or even cancel the Sentinel since it makes up the all-important land leg of our nuclear triad system — a defensive strategy that has been in effect for over seventy years. The other two legs of our nuclear triad strategy involves long-range bombers flown to the target from deep within the continental US and submarine-based missiles that are submerged and moved about the oceans to help them avoid detection. The three systems are designed to work in concert with one another should an adversary hack or destroy our missiles with a massive first strike. As such, its unlikely the DoD will revamp what has become the bedrock of our offensive ICBM system, one that is meant to deter an adversary from launching their own missiles at the continental US.