Sentinel still on course to achieve programme milestones following acoustic testing

The LGM-35A Sentinel undergoes acoustic testing at the company's Large Acoustic Test Facility in Redondo Beach, California. (Northrop Grumman)

The LGM-35A Sentinel intercontinental ballistic missile (ICBM) is still on track to reach its programme milestones following the completion of its acoustic testing, Matthew Dillow, director of government relations for the Strategic Deterrent Systems Division at Northrop Grumman, told Janes on 9 July.

The acoustic testing was done at Northrop Grumman's Large Acoustic Test Facility (LATF) in Redondo Beach, California in December 2025, Dillow said. The tests are just one step on the programme's path to reaching an initial operating capability in the 2030s.

He told Janes that previously stated timelines for the programme are still on track and continued confidence in the programme from US Air Force leaders is “well-merited”.

The USAF previously said in February 2026 it was looking to achieve a Milestone B programme decision by the end of 2026. Initial launch is still on track for 2027, followed by initial operating capabilities in the early 2030s.

The Sentinel's engineering, manufacturing, and development (EMD) certification had been revoked in July 2024 after the certification process revealed a projected budget breach of 81%.

The programme was eventually restructured and then re-certified by William A LaPlante, then serving as undersecretary of Defense for Acquisition and Sustainment, after a 120-day review deemed it essential to national security in July 2024.

Ahead of the 2027 test launch, Dillow said steps like the acoustic testing are about reducing risks and identifying issues prior to full launch of the rocket.

Dillow said acoustic testing is designed to validate whether the Sentinel is capable of withstanding the extreme conditions of a “hot launch” underground in its missile silos.