GBSD Finally Gets a Name: ‘Sentinel’

The Air Force announced a name and designation for the intercontinental ballistic missile system long known as the Ground-Based Strategic Deterrent: LGM-35A Sentinel. The name recycles one already given to one of the Air Force’s secret spy drones.

The Sentinel, being developed by Northrop Grumman, is set to replace the Minuteman III as the land leg of the U.S. nuclear triad, beginning with initial operational capability in 2029 and full operational capability by 2036.

“The name Sentinel recognizes the mindset that thousands of Airmen, past and present, have brought to the deterrence mission” over decades, said Air Force Secretary Frank Kendall in an official release. As those Airmen have “kept the watch; always vigilant and ready,” the name will “serve as a reminder for those who operate, secure, and maintain this system in the future about the discipline and responsibility their duty entails.”

Sentinel joins the ranks of Atlas, Titan, Minuteman, and Peacekeeper as the land-based ICBM missiles that have maintained America’s nuclear deterrent since the early 1960s. Its nomenclature—LGM-35A—is a bit puzzling, however, as the Minuteman was the LGM-30 and the LGM-118 was the successor Peacekeeper. The Air Force could not immediately explain the derivation of the nomenclature.

The GBSD name has been assigned to the new missile program for years now as the Air Force’s modernization efforts have wound their way through Congress and the Pentagon. In February 2021, then-Vice Chairman of the Joint Chiefs of Staff Gen. John E. Hyten lamented the lack of an official name for the project.

“We’ve got to find a name for the GBSD,” Hyten said. “GBSD just doesn’t hack it. … Because GBSD is very hard to explain to the American people … GBSD requires me to define the term before I actually get into it, so for God’s sakes, Air Force, let’s get a name for the thing and start moving forward.”

The missile will, however, have to share the “Sentinel” moniker. The Air Force named its stealthy RQ-170 intelligence, surveillance, and reconnaissance drone the Sentinel in the mid-2000s. The Sentinel, built by Lockheed Martin, was considered a key element in locating and tracking Osama bin Laden, leading to the special operations raid that killed him in Pakistan in 2011. An RQ-170 also crashed in Iran, where that government claimed to have back-engineered it and built their own version. An Air Force spokeswoman told Air Force Magazine there are no plans as yet to rename the RQ-170.

The LGM-35A will be stationed at missile bases where the Minuteman III is already emplaced—F.E. Warren Air Force Base, Wyo.; Malmstrom Air Force Base, Mont.; and Minot Air Force Base, N.D.