USAF moves to hundreds of new Sentinel ICBM silos as B-21 second test aircraft approaches maiden flight

USAF moves to hundreds of new Sentinel ICBM silos as B-21 second test aircraft approaches maiden flight

Published:

September 6, 2025

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Updated:

September 6, 2025

Defense Infrastructure & Manufacturing

Peter Johansson

U.S. Air Force illustration

The U.S. Air Force is preparing to break ground on hundreds of new silos for its LGM-35A Sentinel program while pressing toward the next major test event for the B-21 Raider. Senior leaders point to time and cost gains from building fresh launch facilities instead of refitting 60-year-old Minuteman III sites. They also acknowledge a hard truth. Not every new location will fit neatly on federal land, so limited private land purchases may follow.

Sentinel ICBM new silos plan and land acquisition issues

At a public forum this week Lt. Gen. Andrew Gebara, the Air Force’s deputy chief of staff for strategic deterrence and nuclear integration, said the service now favors all-new silos. He said the shift would avoid disruption across missile fields that must remain on alert while Sentinel comes online. Building new silos lets teams work in parallel. It removes the need to carry out intrusive upgrades at active Minuteman III sites. Gebara said the approach saves time and money.

Most new silos should fit within existing government property, though some sites will not. In a small number of cases the government may purchase land to close gaps in the grid. Air Force public guidance notes access needs for surveys, easements, fiber routes and potential tower parcels. The U.S. Army Corps of Engineers handles real-estate actions at fair-market value.

Program planners are also re-examining field layouts to fix known problems at legacy sites. Some Minuteman locations now see seasonal flooding that wasn’t present decades ago. In other areas, tall wind turbines built near facilities complicate helicopter operations. New-build sites allow engineers to correct such issues from the start instead of living with inherited constraints.

The Air Force is preparing a supplemental environmental impact statement to update previous analyses and reflect the restructured facility plan. Its public Sentinel page says the supplement is due in August 2025 and outlines real-estate, access and construction steps in direct terms for landowners. Construction of certain supporting infrastructure has begun on base locations, with long-lead fiber work planned to start in 2027.

Community touchpoints and Minuteman III transition details

At a community town hall in Minot on August 26, service leaders emphasized two concurrent priorities. Keep Minuteman III forces credible throughout the changeover and stand up Sentinel locations on a predictable cadence. The director of ICBM modernization told attendees the remaining Minuteman fleet can benefit from parts salvaged as older hardware comes out of the ground. He also described a remark that caught local attention: the “first site at F.E. Warren has been taken down.” The service hasn’t clarified whether that line referred to a specific silo or preparatory site work, but it signals the early stages of physical transition are underway.

At a community town hall in Minot on August 26, service leaders laid out two priorities: keep Minuteman III forces credible during the changeover, and bring Sentinel locations online on a predictable cadence. The director of ICBM modernization told attendees the remaining Minuteman fleet could use parts salvaged from older hardware removed from the field. He also repeated a remark that caught local attention: “the first site at F.E. Warren has been taken down.” The service hasn’t clarified whether that referred to a specific silo or preparatory site work, but the comment indicates early stages of the physical transition are under way.

Minot is planned as the last of the three missile wings to transition and the job will not finish fast. Leaders told the community full project completion may run into the 2040s.

Here’s how the active missile wings line up right now:

F. E. Warren AFB, Wyoming – Early transition activity in focus. A senior official referenced one site already “taken down,” pending further clarification.

Malmstrom AFB, Montana – Part of the three-wing fielding plan and covered in the supplemental environmental review; supporting work proceeds on-base as schedules firm up.

Minot AFB, North Dakota – Last to convert under current planning; August 26 town hall covered property, safety and schedule questions from the community.
According to industry sources, recent contract adjustments have focused on infrastructure sequencing and work packages that limit ripple effects on security forces, maintenance crews and local roads.

B-21 Raider second aircraft target flight and event-based testing

Gebara offered a short update on the B-21 test fleet. He said the second test article is expected to achieve its first flight before the end of 2025, while stressing the program stays “event-based.” In other words, teams will not chase a public date if test points aren’t ready.

The first B-21 flew in November 2023 and has continued envelope expansion at Edwards. The focus now shifts to bringing aircraft two into the air to accelerate data collection and mature production-representative systems.

Defense officials confirm the added funding in this year’s reconciliation law supports an eventual production ramp once test data clears gateways. The service still plans for at least 100 aircraft, though senior leaders have publicly entertained a higher total as analysis of force needs continues.

As more jets join the fleet, avionics, mission systems and low-observable sustainment processes can move out at pace, which in turn informs training and basing milestones.

B-52 radar upgrade flight testing status and path to Edwards

The Air Force’s B-52 Radar Modernization Program is nearing flight test after a cost breach earlier this year forced a scrub of requirements. Leaders say the first radar shipment to Edwards AFB is very close, which would finally allow airborne testing to start. 

The upgrade replaces the mechanically scanned AN/APQ-166 with Raytheon’s AESA-based AN/APQ-188, also called the Bomber Modernized Radar System. Officials acknowledge the program trimmed some desired features to control costs, while preserving growth options later.

Built partly from APG-79 family technology, the new sensor delivers steadier performance and a sharper targeting and navigation image. It underpins the B-52J upgrade package, which combines new radar, avionics and engine changes through the 2030s. Schedule slips pushed flight testing out of the original window and into the second half of the decade, yet the first Edwards installation being described as “very close” marks a needed turn. According to industry sources, the integration plan now prioritizes minimum operational needs before layering in optional modes once test clears them.

Leaders drew a direct link between cost control and reuse of proven designs, noting an all-new bespoke radar would have driven both price and risk even higher. With requirements reset, teams can open the flight-test envelope, de-risk interfaces and aim for stable production lots.

Defense-Aerospace editorial team notes one more thread that ties these updates together. Sentinel’s decision to build new sites, the B-21’s event-driven test flow, and the B-52’s radar pivot all point to the same operating idea. Align engineering work with what units can absorb while they continue missions. Our analysis shows the Air Force is trying to retire avoidable friction, even if that requires buying slivers of private land in a few counties or trimming nice-to-have radar features to get test aircraft airborne.

REFERENCE SOURCES

https://defence-blog.com/second-b-21-stealth-bomber-poised-for-test-flight-in-2025/

https://www.twz.com/air/b-52-radar-upgrade-flight-testing-expected-to-finally-begin-soon

https://www.stripes.com/branches/air_force/2025-08-28/air-force-b-21-raider-18904487.html

https://www.afgsc.af.mil/Sentinel-GBSD/

https://www.minotdailynews.com/news/local-news/2025/08/sentinel-town-hall-tackles-public-questions/

https://www.minot.af.mil/News/Article-Display/Article/4288312/team-minot-connects-with-community-on-future-of-sentinel-icbm/

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https://www.northropgrumman.com/what-we-do/advanced-weapons/sentinel

https://www.northropgrumman.com/what-we-do/aircraft/b-21-raider

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https://www.defenseone.com/defense-systems/2025/08/second-b-21-will-fly-years-end-usaf-says/407726/

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https://interestingengineering.com/military/us-next-gen-sentinel-nuclear-missile

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