According to an Air Force news release, a full-scale qualification static fire test of the Sentinel intercontinental ballistic missile, or ICBM, stage-one solid-propellant rocket motor was completed March 6 at Northrop Grumman’s Promontory facility.

“As we modernize our nuclear triad, the ICBM Systems Directorate is driven to securely deliver America’s ICBM capabilities,” said Brig. Gen. William Rogers, Air Force program executive officer for ICBMs and director of the Air Force Nuclear Weapon Center’s ICBM Systems Directorate, following the successful test.

“This brings us one step closer to fielding the Sentinel weapon system, a vital component of our nation’s strategic deterrence and a testament to our unwavering commitment to national security.”

The successful test “confirms the accuracy of digital engineering models and brings the stage-one solid rocket motor closer to achieving full qualification,” according to the Air Force, and follows second- and third-stage static fire tests.

Operating out of Hill Air Force Base, the ICBM Systems Directorate is overseeing the production and rollout of the LGM-35A Sentinel ICBM, which will replace the aging LGM-30 Minuteman III. The Minuteman III has been in service since 1970.

Northrop Grumman was awarded a $13.3 billion contract for the engineering, development and manufacturing of the next-gen Sentinel ICBM in 2020. However, the program has not been without its hiccups.

A June 2023 report from the US Government Accountability Office indicated that the Sentinel program was behind schedule due to “staffing shortfalls, delays with clearance processing and classified information technology infrastructure challenges.”

Supply chain issues/material shortages were also observed.

More recently, the Sentinel program was subjected to a formal review amid cost overruns, which resulted in a critical Nunn-McCurdy breach.

The Nunn-McCurdy Act requires the Department of Defense to report to Congress when defense programs experience overruns exceeding certain thresholds. A “critical” breach occurs when the cost increases by 25% or more over the current baseline estimate or more than 50% over the original baseline estimate.

In July 2024, the resulting DoD review deemed that the Sentinel program was essential to national security and “met the statutory criteria to continue.”

After the latest test, the Air Force stated that the Sentinel program “is essential to ensuring a safe, secure and effective strategic nuclear deterrent for decades to come.”