US progresses in nuclear arsenal upgrade with Sentinel missile test

Americans Conduct Test of the Third Engine of LGM-35A Sentinel Nuclear Missile at Arnold Air Force Base

Defense News reported that Americans have conducted a test of the third engine of the LGM-35A Sentinel nuclear missile at Arnold Air Force Base in Tennessee. This trial marks "significant progress in the implementation of the Sentinel program," a key initiative aimed at introducing modern nuclear weapons into the U.S. military by 2031.

Gen. John Newberry, commander of the Air Force Nuclear Weapons Center, noted, “This test is the latest in our ground and flight test program and aims to help us refine the Sentinel weapon.” The Sentinel program is set to replace the aging LGM-30G Minuteman III intercontinental ballistic missiles, over 400 of which remain in service, serving as the backbone of America’s nuclear arsenal.

Sentinel set to replace aging Minuteman III missiles

The test involved not just the military but also key defense contractors such as Northrop Grumman and Aerojet Rocketdyne. Conducted in a secure chamber at a Tennessee military base, the specifics of the trial, including the duration of the engine firing and the test outcomes, remain undisclosed. However, it is known that recent weeks have seen tests on various other components of the missile, including its front and rear covers.

For the U.S., this represents another significant step in advancing its nuclear capabilities, acting as a "deterrent" among others against Russia. This development is part of ongoing efforts by the U.S. military to work on powerful weapons. Notably, in March 2024, the still-developing super missile AGM-183 was spotted at a U.S. Air Force base in Guam, which is expected to reach speeds of about 15.2 thousand mph.

Details on Sentinel's development phase

As the Sentinel is still under development, its exact specifications remain partially undisclosed. However, public information suggests the missile will likely use a thermonuclear W87 warhead in either the existing 300-kiloton TNT equivalent version 0 or a newer version 1 with an as-yet-unknown yield. Its propulsion will rely on a step motor, a three-stage solid-fuel propellant system, where each stage has its engine and fuel.

The development of the Sentinel remains a priority for the U.S., even as recent months have revealed the cost of a single Sentinel missile to be about 40 percent higher than initially estimated, now at around 160 million dollars. Despite rising costs, the development of this weapon continues to be a key focus.