The U.S. Air Force, in partnership with Northrop Grumman, completed a full-scale qualification test of the stage-two solid rocket motor for the LGM-35A Sentinel intercontinental ballistic missile on July 20.

The test was completed by the 717th Test Squadron at the Arnold Engineering Development Complex, in a vacuum chamber to simulate high-altitude conditions, providing data on the motor’s thrust, burn profile, and steering capabilities via its thrust vector control system, according to the Air Force.

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“This test reflects our disciplined digital engineering approach and the continued momentum behind the Sentinel program,” Brig. Gen. William S. Rogers said in a release.

Rogers is the program executive officer for ICBMs and director of the ICBM Systems Directorate at the Air Force Nuclear Weapons Center.

“We’re not just testing hardware — we’re proving that our models are accurate, our development timeline is achievable and the system will be ready to deliver when called upon,” Rogers said.

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The stage-two motor is one of three booster segments that make up the three-stage Sentinel missile.

The test is one in a series intended to qualify the stage-two design and validate predictive performance models developed in a digital engineering environment, according to the Air Force.

The data gathered from this test will be used to refine design elements and reduce technical risk as the program moves toward production.

The test follows the stage-one rocket motor test conducted in March at Northrop Grumman’s facility in Utah. That test verified motor performance and alignment with digital models, setting the foundation for the next phase of qualification testing.

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“This isn’t just about one motor test,” Rogers said in a release. “It’s about building confidence — in our engineering; in our program schedule; and, most importantly, in our ability to deter aggression and defend the nation.”

The Sentinel program’s model-based design approach allows engineers to simulate system behavior, improve accuracy in performance predictions and reduce reliance on costly hardware prototypes. The Air Force and Northrop Grumman will continue stage-two qualification testing throughout the year, with upcoming tests planned to evaluate additional motor components under varied environmental conditions.