The LGM-35 Sentinel missile, successor to the aging LGM-30 Minuteman III that forms the ground leg of the US nuclear triad, is moving closer to its first flight test in 2027 after several delays.
The US Air Force (USAF) and Sentinel program prime contractor Northrop Grumman completed the vertical assembly of a fully integrated inert Sentinel missile at Vandenberg Space Force Base (VSFB) in California.
Northrop also secured USAF approval for the intercontinental ballistic missile’s design maturity, advancing the Sentinel to its inaugural flight test next year.
Missile Assembly
Completing the Sentinel’s assembly proves that all missile stages, propulsion elements, and associated components have been fully integrated into a single missile configuration.
The effort was conducted as part of a four-month test event known as Pathfinder.
Northrop Grumman transported missile components on specially designed vehicles across the country to VSFB.
Upon arrival, company engineers rigorously tested mechanical operations, including transportation, mobile crane use, and safe vertical integration.
The inert missile was also safely stacked and de-stacked on a test pad, ensuring that each step met the USAF’s requirements.
Sentinel Missile Progress
In 2020, the USAF awarded Northrop Grumman a contract to develop the LGM-35A Sentinel, targeting an initial capability in the early 2030s and keeping the missile viable through 2075.
The service and the defense contractor completed the critical design review for the Sentinel Launch Support System in October 2025, moving the program into the construction, testing, and qualification phase.
This year, they prototyped a new launch silo tube designed to accelerate fielding and improve maintainability.
Northrop also began expanding its Utah campus in July to support the Sentinel ICBM program.
