No decision made yet on reusing Minuteman siloes for Sentinel, commander says

Gen. Thomas Bussiere, commander of the Air Force Global Strike Command at Barksdale Air Force Base, La., said reusing the Minuteman III intercontinental ballistic missile siloes for the replacement Sentinel in the future might not be “more efficient” or “cost effective.”

Bussiere’s comments came at the April 30 Advanced Nuclear Weapons Alliance Deterrence Center virtual forum “Modernizing the U.S. Strategic Nuclear Deterrent: Air and Land-based Legs of the Triad.” 

“Part of this process, post Nunn-McCurdy, is to look at the viability of using the same landscape, but potentially looking at maybe doing a different hole for the weapon, versus using, reusing the current hole,” Bussiere said. “Now a decision hasn’t been made. We haven’t taken it to the program decision makers in the Pentagon, but the team is working very hard – operators, maintainers, acquisition professionals, industry professionals, engineers – to make sure we get this right.”

Bussiere told the Exchange Monitor in February at a forum in Washington that Global Command was looking at analysis into whether new siloes will be needed.

In January 2024, the Air Force said it notified Congress that Sentinel had breached Nunn-McCurdy guidelines, primarily due to construction design changes, and then DoD acquisition chief William LaPlante ordered a root-cause analysis. The latter led last summer to the DoD decision to continue the program, due to its stated importance to strategic deterrence, but also to the rescinding of the Sentinel Milestone B engineering and manufacturing development (EMD) go-ahead.

Last summer, the Air Force pegged Sentinel cost at $140.9 billion, 81% higher than the September 2020 estimate when the program was approved for EMD–a rise that DoD said has less to do with the missile than the command-and-control segment, including silos, launch centers, “and the process, duration, staffing, and facilities to execute the conversion from Minuteman III to Sentinel.”

Sentinel, being built by Northrop Grumman, will eventually replace the Boeing-made Minuteman III as the Air Force’s silo-based, nuclear-armed intercontinental ballistic missile sometime in the 2030s while the Minuteman III is still commissioned. At the virtual forum last week, Bussiere also said it would be a “few years” before the entire Minuteman III weapon system can be replaced by the Sentinel weapon system. 

Maj. Gen. Stacy Jo Huser, commander of the 20th Air Force in the Air Force Global Strike Command, said at a workshop preceding the Exchange Monitor’s annual Nuclear Deterrence Summit there would likely be a 15-year overlap between Sentinel and the last Minuteman III. Huser told the Monitor that the Minuteman III, originally expected to be decommissioned by the mid-2030s, would now be decommissioned by 2050 or later.