Robert Moriarty, the Deputy Assistant Secretary of the U.S. Air Force for Installations, has given the go-ahead to start the support construction phase for the Northrop Grumman [NOC] LGM-35A Sentinel ICBM.

The Department of the Air Force’s (DAF) 450 missile silos–launch facilities (LFs)–and 45 missile alert facilities (MAFs) “would be updated extensively to completely refurbished condition to meet the requirements of the Sentinel system,” according to a May 19th final Environmental Impact Statement Record of Decision signed by Moriarty. “Sentinel system deployment and MMIII [Minuteman III] disposal activities are scheduled to sequentially begin in late 2023, starting at Main Operating Base (MOB)-1, F.E. Warren AFB, [Wyo.], then at MOB-2, Malmstrom AFB, [Mont.], and finally at MOB-3, Minot AFB, [N.D.].”

Building of the installation command center and the material handling complex at F.E. Warren is to begin this year, while construction is to start at Malmstrom in 2026 and Minot in 2029. The Air Force’s Record of Decision said that F.E. Warren is to be the first MOB as the base “has the best local industrial capacity because of its proximity to Denver, the ICBM Program Office and depot at Hill AFB, two major interstate highways, a railway hub, and a major airport that would be used for movement of supplies, equipment, and personnel.”

The Air Force selected option for Sentinel support infrastructure is the “Reduced Utility Corridors Alternative,” which would build 626 fewer miles of new utility corridors than the original proposal to build 3,126 miles of new utility corridors, and which would reuse “marginally fewer miles of existing utility corridors” than the original proposal, according to the Record of Decision.

The Reduced Utility Corridors Alternative “does not include the generation or disposal of nuclear material,” the decision said. “No nuclear material would be generated or disposed of by the Sentinel program. The DAF will decommission and dispose of all MMIII missiles and associated equipment, including removing each missile from its LF, transporting it to the main operating base for temporary storage, and preparing it for transport to Hill AFB, UTTR [Utah Training Range], Camp Navajo, or a contractor facility. The DAF will remove MMIII-related technology and support equipment from the MAFs, LFs, and on-base support facilities and transport, sort, declassify, and dispose of the materials based on standardized protocols.”

“The Sentinel deployment program and MMIII decommissioning, and disposal process are both geographically and temporally extensive, reaching into seven states and more than 15 years into the future,” according to the Record of Decision.

A summary of the final EIS said that “a launch center (LC) would be constructed at 24 of the existing MAF sites, and the remaining 21 MAF sites would be decommissioned and razed.”

During the public comment period, the Air Force said that it held two virtual forums and seven in-person meetings at the Fort Berthold Indian Reservation, N.D., and in Minot, N.D.; Great Falls and Lewistown, Mont.; Kimball, Neb.; Raymer, Colo.; and Cheyenne, Wyo.

Air Force Secretary Frank Kendall told the House Armed Services Committee in April that it will be a challenge for Sentinel to reach initial operational capability (IOC) on time (Defense Daily, Apr. 27).

DoD has targeted Sentinel IOC for May 2029. Kendall is not permitted to make decisions on Sentinel because of his previous consulting work for Northrop Grumman.

A Defense Department report sent to Congress in September indicated a possible 10-month delay in the estimated $95.8 billion Sentinel development effort, yet Air Force Brig. Gen. Ty Neuman, the service’s director of concepts, said in February that Northrop Grumman is still on track to perform a full-scale inaugural flight test this year.

Sentinel features a three-stage booster rocket. Northrop Grumman, which has an in-house solid rocket motor business, will make the missile’s first- and second-stage solid motors.

Aerojet Rocketdyne [AJRD] will make the third-stage motor.

Sentinel will initially carry the W87-0 thermonuclear warhead, refurbished versions of the W87 from the Minuteman III missiles it will replace. Later in its fielding, the new missiles will be tipped with the W87-1 warhead, a newly manufactured copy of the Minuteman’s W78 warhead, but with a fresh plutonium pit. The National Nuclear Security Administration’s Lawrence Livermore National Laboratory will provide both warheads.