LGM-35 Sentinel delays may push Minuteman III to 80 years retiring in 2050
September 12, 2025
The LGM-30 Minuteman III missile is currently the only land-launched nuclear ICBM in the US arsenal. First introduced in 1970, the ageing missile may have to continue to uphold the land-based leg of the American nuclear triad until 2050.
Minuteman III may remain in service until 2050
The new LGM-35 Sentinel missile is expected to start replacing the Minuteman around 2029. Originally, the transition had been planned to start in fiscal 2025 with the Minuteman III reaching the end of its service in 2036.
Now, according to officials interviewed by the US Government Accountability Office (GAO) watchdog, the Air Force may need to prepare to keep these Boeing Minuteman missiles in operation for another 25 years.
The information comes from the public version of the now-released April 2025 report, with some sensitive information on the missiles being redacted.
The US Air Force currently fields more than 600 facilities that include 450 missile silos in five states. The Air Force has a total of 400 Minuteman III missiles in inventory.
Minuteman III to reach 80 years of service
The missiles have already been in service for 55 years and were originally only intended to remain in operation for ten years. If they do remain in service until 2050, then the type would have served an impressive 80 years.
One of the challenges with keeping the old missiles in service is sustainment, including finding needed spare parts. While old, the missiles are refurbished and are still able to perform the task they were originally designed to do.
For some, the Minuteman III may remind readers of the B-52 strategic bomber that refuses to retire. The Air Force had looked at replacing the aircraft early on and developed the B-1 Lancer to replace it, and then developed the B-2 Spirit to replace both. Now the B-52 is set to outlive both successors and serve alongside the next-generation B-21 Raider.
The Minuteman III was to be succeeded by the large LGM-118 Peacekeeper, which became operational in 1986. The Peacekeeper was a MIRV-capable ICBM, meaning it was able to carry multiple warheads.
As fate would have it, the Peackeeper fell victim to the START II Treaty, which stipulated ICBMs could only carry a single warhead. The type was fully withdrawn from service in 2005. Only 50 Peacekeepers were ever procured.
Delays and cost overruns with the Sentinel
The US Air Force plans to procure 634 Sentinel missiles, another 25 missiles for testing and development, to replace its stock of around 400 Minuteman IIIs. Significantly, the Sentinel was planned to use the Minuteman silos, but that hasn’t worked out, and new silos need to be built.
Northrop Grumman was contracted to replace the Boeing Minuteman III missiles in 2020. The programme was originally expected to cost $77.7 billion. That number has now increased to $140 billion after restructuring.
The Sentinel programme is in stark contrast to Northrop Grumman’s other mega-Air Force contract. The next-generation B-21 Raider stealth bomber appears to be on time and on budget.
There are reports that some of the costs of retrofitting Trump’s new ‘free’ Qatari Boeing 747-8i as an interim Air Force One aircraft are being hidden in the Sentinel programme. Almost $1 billion was recently mysteriously transferred from the nuclear missile programme.
