Northrop Grumman and the US Air Force are accelerating the Sentinel intercontinental ballistic missile (ICBM) program by prototyping a new launch silo tube designed to speed fielding and improve maintainability.
Developed by Northrop and construction partner Bechtel, the test article is the centerpiece of a modular launch silo concept, which intends to modernize the infrastructure that will house the future LGM-35A Sentinel missile.
The Sentinel is the planned replacement for the Minuteman III, which forms the land-based leg of the US nuclear triad. Its initial operational capability is expected in the early 2030s.
The silo prototyping effort also coincides with wider Sentinel transition planning across the force. Earlier this month, service leaders visited Minot Air Force Base to review infrastructure needs and operational preparations for the shift from Minuteman III to Sentinel.
Silo Modernization
According to the company, the new design is expected to improve maintainability, reduce program costs, and support the planned deployment of 450 Sentinel launch silos.
Northrop said the prototype launch silo tube moved from air force concept review to groundbreaking in about three months, a pace the company says reflects efforts to compress what is typically a multi-year infrastructure development timeline.
The prototype is intended to validate both the structural design and the construction approach before full-scale fielding.
Sentinel Progress
Northrop, the Sentinel program’s prime contractor, has also advanced several milestones tied to the missile’s development.
This includes carrying out a series of test-firings of the missile’s solid rocket motor and completing the critical design review for the Sentinel launch support system, clearing the way for system build, testing, and qualification.
However, the program has also been plagued by delays.
Its maiden flight, for example, was originally planned for December 2023, moved to February 2026, and rescheduled again to March 2028, according to the US Government Accountability Office.
