The United States Air Force has taken the first step in building infrastructure for the new LGM-35A Sentinel intercontinental ballistic missile (ICBM).
The U.S. plans to replace its existing Minuteman III missile fleet with the Sentinel, building silos across fields from Colorado to North Dakota. The previous plan for the Sentinel program called for refurbishing the 55-year-old Minuteman silos, which number about 450, according to Breaking Defense.
The service ceased operation of launch facility LF 5E10 at F.E. Warren Air Force Base in Wyoming, marking the “first operational [Minuteman III] silo to be taken offline” to prepare for its replacement, an Air Force Global Strike Command (AFGSC) spokesman confirmed to news site Breaking Defense in September 2025.
U.S. Air Force Gen. Anthony Cotton, Commander of U.S. Strategic Command (USSTRATCOM), has called the Sentinel essential to national security, telling the U.S. Senate Armed Service Committee in March 2025 that it will “ensure the ICBM force remains a potent … nuclear deterrent through at least 2080.” USSTRATCOM’s responsibilities include strategic deterrence, nuclear command, control and communications, and global strike operations.
U.S. Air Force Lt. Gen. Andrew Gebara, the service’s deputy chief of staff for strategic deterrence and nuclear integration, said the shift to building new silos should save money because it will quicken Sentinel deployment. “In some small cases, we may need to make purchases [of land],” Gebara said, according to an August 2025 Breaking Defense story. “But I believe building all new silos is actually … saving time and cost.”
Gebara made his remarks during an online forum hosted by the Mitchell Institute for Aerospace Studies, where he also mentioned another component in U.S. nuclear modernization: the B-21 Raider stealth bomber. Gebara said the Air Force expects to see a second B-21 fly before the end of 2025, and that the service has conducted more flight tests of the Long-Range Standoff cruise missile that will be a key weapon for the upcoming bomber, according to Breaking Defense.
The “administrative decertification” of the Wyoming launch facility, meanwhile, will not affect the number of Minuteman missiles on alert, the AFGSC spokesperson told Breaking Defense. “This decertification does not pose any threat to our ability to respond decisively if called upon,” the spokesperson said.
The Air Force maintains 400 ICBMs at the ready — meaning 50 of the service’s 450 silos are empty, Breaking Defense said. Matt Korda, associate director of the Nuclear Information Project at the Federation of American Scientists, told Breaking Defense that it’s likely the silo was empty as it would make sense to start decommissioning vacant launch facilities. Korda called the silo’s shuttering “an early step” in what will be a long road to replacing the Minuteman.
The AFGSC spokesperson likened the project to another in U.S. history.
“[T]his is one of the largest modernization efforts ever undertaken by the U.S. government,” the spokesperson told Breaking Defense.