US Air Force and Northrop Grumman Assemble Inert Missile, Progress Toward Sentinel Flight Testing

• The US Air Force and Northrop Grumman vertically assembled a fully integrated inert Sentinel missile at Vandenberg Space Force Base in California and secured approval from the US Air Force on Sentinel design maturity for flight test in 2027

• These events mark crucial progress to modernize the ground-based leg of the strategic triad and accelerate initial capability of the system

• Northrop Grumman is acting with speed and scale to deliver this highly advanced weapon system to the Air Force

VANDENBERG SPACE FORCE BASE, Calif., Sep 14, 2026. America’s next-generation intercontinental ballistic missile moved another step closer to defending the nation when Northrop Grumman and the US Air Force fully assembled the Sentinel missile in its operational orientation. The vertical assembly demonstrates the design and integration of the missile and is a major step toward the Sentinel missile’s design and suitability evaluation for flight test in 2027.

Sentinel is making progress toward fielding, a key part of the nation’s strategic deterrence.

• In partnership with the US Air Force, Northrop Grumman engineers have completed the safe stacking of the Sentinel missile. This proves all missile stages, propulsion elements, the shroud, and associated components have been fully integrated into a single missile configuration.
• This milestone stacking operation is a critical step to demonstrate that every process and requirement for safely assembling the complete Sentinel missile is executable on the test pad. It validates that the team is ready to move forward to a live flight test.
• Every step – from specialized transport and mobile crane operations to full interface verification – proved the readiness to perform this complex vertical integration process.
• In parallel, Northrop Grumman and the US Air Force’s 719th Test Squadron completed the first flight test Critical Design Review, confirming the missile’s design maturity and hardware testing meet Air Force requirements for performance, safety, and schedule for flight test in 2027.
• As part of a rigorous four-month test event, Northrop Grumman safely transported missile components from across the country to Vandenberg Space Force Base, where the inert missile was safely stacked and de-stacked on a test pad.
• Together, these achievements demonstrate that Sentinel is moving from design into a tangible, fully integrated system that is closer to standing alert in an operational silo.

Amanda Davis, Vice President and General Manager, Strategic Deterrent Systems, Northrop Grumman: “This vertical assembly demonstrates the momentum toward test launching Sentinel in 2027 and having missiles on alert by the early 2030s, ensuring the United States’ ground-based nuclear capabilities remain strong and reliable for decades to come.”

Known as Pathfinder, this dry-run exercise included the transport of missile components on specially designed vehicles from across the US to VSFB, where Northrop Grumman engineers rigorously tested mechanical operations including transportation, mobile crane use and safe vertical integration while validating all interface connections on the test pad. Northrop Grumman engineers carefully coordinated every step of the process to meet the stringent Air Force requirements, including safely stacking the inert missile – a complex and precise operation critical to mission success.

The US Air Force’s Sentinel program is a modernization of the nation’s ground-based leg of the strategic nuclear triad. Northrop Grumman leads a nationwide team of more than 500 partners under an engineering and manufacturing development contract to deliver an all new, advanced and highly capable ICBM weapon system that will be viable through 2075. Northrop Grumman is achieving substantial progress across the Sentinel program, advancing toward flight test in 2027 and initial capability in the early 2030s. From missile testing and infrastructure prototyping to supply chain readiness and augmented by a nationwide workforce of more than 10,000 dedicated professionals, Sentinel is accelerating development enabled by a transformed acquisition approach.

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