Sentinel

The construction of new silos for the U.S. Air Force’s future LGM-35A Sentinel intercontinental ballistic missiles (ICBM) means that units charged with defending them will have to update their tactics, techniques, and procedures (TTPs). Air Force Security Forces personnel regularly train to protect existing silos housing LGM-30G Minuteman III ICBMs, as well as associated launch facilities, or even recapture them if necessary. The need for totally new silos and other infrastructure has been a major issue for the Sentinel program, contributing significantly to delays and cost overruns that triggered a total restructuring that is still ongoing.

The Government Accountability Office (GAO), a congressional watchdog, highlighted how Sentinel will impact Air Force Security Forces units in a brief report released earlier today. This comes a day after the Air Force put out its own update on the new ICBM program, stating that the current goal is for the restructuring effort to wrap up before the end of the year and for the first launch of a prototype LGM-35A to occur in 2027. The hope now is that Sentinel will begin entering operational service sometime in the early 2030s. The original schedule had called for the missiles to reach initial operational capability in 2029.

“DOD will need to complete Sentinel launch facility test and evaluation activities early in the transition to inform DOD and Air Force security policy updates,” the GAO report says. “Because security forces incorporate these updates into unit-level operating instructions, these policy updates will be needed to train Air Force security forces for the transition.”

The report does not elaborate on the changes that will be required. As noted, Security Forces personnel currently assigned to Air Force Missile wings train to protect the Minuteman III force above and below ground. There are currently 400 LGM-30Gs loaded into silos spread across five states. Sentinel is said to offer greater range and improved accuracy, as well as reliability and sustainability benefits, over the aging Minuteman IIIs, which first entered service in 1970. The development of a new ICBM also offers the opportunity for the inclusion of survivability improvements and other additional capabilities.

An Air Force news release from 2019 describes one potential “recapture and recovery” scenario used in a routine training:

“The training simulated a hostile’s attempt to capture a nuclear asset. Security forces Airmen, who arrived by both Humvee and helicopter, began to combat the threat and worked their way toward retaking control of the launch facility. After neutralizing the threat, recapturing and securing the launch facility, the Airmen performed self-aid buddy care and tactical combat casualty care.”

The video below shows scenes from a recapture and recovery exercise conducted as part of the larger Global Thunder 23 exercise.

91st Missile Wing participates in Global Thunder 23

Terrorists or other hostile actors could also seek to break into silos or launch facilities just to damage or destroy them. Even if they could not trigger a nuclear detonation, blowing up an ICBM inside its silo would have significant operational, environmental, and other ramifications.

The Air Force had originally said it would reuse Minuteman III silos and other existing infrastructure for Sentinel, but subsequently determined that was no longer a viable course of action. As such, new silos and launch control facilities could easily come with substantially different physical layouts that would affect the tactics, techniques, and procedures for securing them. The LGM-35A missiles will also be completely different from the existing LGM-30Gs, and there could be additional notable differences in how the Sentinels are married together with their new ground-based infrastructure. All of this could further impact how Security Forces personnel prepare themselves for a variety of contingencies, including any potential for accidental detonations or launches.

In its update about Sentinel yesterday, the Air Force shared that prime contractor Northrop Grumman is set to start building a prototype launch silo at the company’s facility in Promontory, Utah, this month. “This crucial effort will allow engineers to test and refine modern construction techniques, validating the new silo design before work begins in the missile fields,” according to the release.

There’s a strong possibility that a prototype silo could also be used to help develop and refine new Security Forces TTPs in future, as well.

Site defense is also just one aspect of the elaborate and costly security ecosystem in place now for the Minuteman III force. This includes protection for ICBMs while they are being transported via transporter-erector trucks, as well as loaded or unloaded into silos. All of this will also have to adapt to the future Sentinel missiles and their new facilities. The Air Force has already been modernizing certain aspects of nuclear force protection capabilities, including the acquisition of new MH-139A Grey Wolf helicopters to replace aging UH-1Ns used to provide air support over the silo fields and for convoys on the move. An MH-139A was used to escort a Minuteman III convoy for the first time in January.

In terms of other Sentinel-related infrastructure work, “this summer, prototyping activities at F.E. Warren AFB [Air Force Base, in Wyoming] will validate innovative utility corridor construction methods, which are key to streamlining the installation of thousands of miles of secure infrastructure and fielding the system faster,” the Air Force’s release added. “Meanwhile, foundational construction on permanent facilities is already well underway. The first of three new Wing Command Centers is taking shape at F.E. Warren AFB, and critical test facilities are being erected at Vandenberg SFB [Space Force Base, in California] to support the future flight test campaign.”

So-called Site Activation Task Force (SATAF) detachments are also helping lay the groundwork for the transition from Minuteman III to Sentinel at F.E. Warren and Vandenberg, as well as Malmstrom Air Force Base in Montana and Minot Air Force Base in North Dakota. It should be noted that Vandenberg does not currently host operational ICBMs, and is not set to do so in the future, but is used for routine test launches. The Air Force also says that the planned first launch of a Sentinel in 2027 will be from a pad rather than a silo.

US Air Force launches Minuteman III ICBM from Vandenberg in unarmed test

The Air Force is otherwise hopeful that the ongoing restructuring effort will reduce the chance for further schedule risks to the Sentinel program and, by extension, cost growth.

“We certainly have not lowered the bar, and we certainly have not taken on any risk by doing this,” Air Force Gen. Dale White, the new Direct Reporting Portfolio Manager (DRPM) for Critical Major Weapon Systems (CMWS), told Breaking Defense in an interview published yesterday. The DRPM CMWS role was established last August to create a “single empowered leader” to manage Sentinel and other top-priority Air Force weapon systems programs, including the F-47 sixth-generation fighter and B-21 Raider stealth bomber.

“The restructured program incorporates key lessons learned to ensure maximum efficiency,” the Air Force’s release explained. “The decision to build new silos, for example, avoids the unpredictable costs and safety hazards of excavating and retrofitting 450 unique structures built over 50 years ago, and is a prime example of choosing a path that delivers capability with greater speed and less risk.”

“Sentinel program officials continue to evaluate options to potentially redesign portions of the weapon system for cost reductions and are looking at avenues to minimize further schedule delays,” GAO’s report today also noted. “For example, the Air Force is reevaluating system requirements and evaluating changes to the acquisition strategy – both of which could limit further cost and schedule growth.”

GAO’s report did still highlight continued concerns about potential challenges for Sentinel, including in relation to software development for the missiles and work on the extensive new ground infrastructure. As noted, the need for all-new silos has already been a central factor in delays and cost overruns, despite the hope that this will prove less risky in the long run. There are also concerns about sustaining the Minuteman III force beyond 2036, when the transition to Sentinel was originally supposed to be complete. A seamless replacement process is critical to ensuring that the land-based leg of America’s nuclear triad remains a credible deterrent capability throughout.

“I think Sentinel is going to be a bit easier with some of the things we’re designing into the program, the digital infrastructure, the open architecture,” Air Force Gen. Stephen Davis, head of Air Force Global Strike Command (AFGSC), told TWZ in an interview last month. “I think it will make it easier to upgrade and keep that missile relevant. I don’t have any worries about being able to do that in the future.”

Overall, the Sentinel is categorized as “megaproject” by GAO, defined as something that “costs $1 billion or more, affects 1 million or more people, and runs for years.” Such efforts “are extremely risky ventures, notoriously difficult to manage, and often fail to achieve their original objectives,” according to the Congressional watchdog.

A revised cost for Sentinel has yet to be released. However, when the Air Force announced the restructuring effort back in 2024, the total acquisition costs were projected to rise to approximately $140.9 billion, an 81 percent increase over the original estimates.

Even if the restructured Sentinel plan holds going forward, the program will still be immensely complex and resource-intensive, and have many different facets, including changes to how Security Forces units operate going forward.

Contact the author: joe@twz.com

Lockheed Martin has offered a very rare confirmation of the RQ-170 Sentinel stealth drone‘s operational exploits, in this case, in support of the recent mission to capture Venezuelan dictator Nicolas Maduro.

“This is what you can expect from Lockheed Martin: continued significant investment to advance technology development and produce proven major weapon systems at ever greater scale. We build on this momentum with a powerful start to 2026,” CEO Jim Taiclet said during a quarterly earnings call this morning. “Lockheed Martin products, once again, proved critical to the U.S. military’s most demanding missions. The recent Operation Absolute Resolve [in Venezuela] included F-35 and F-22 fighter jets, RQ-170 Sentinel stealth drones, and Sikorsky Black Hawk helicopters, which helped ensure mission success while bringing the men and women of our armed forces home safely.”

After the conclusion of Operation Absolute Resolve on January 3, video footage had emerged showing at least one, and possibly two, RQ-170s arriving at the former Naval Station Roosevelt Roads in Puerto Rico. This was a major hub for aircraft employed in the operation and had already offered very strong evidence of the Sentinel’s involvement.

The U.S. military subsequently confirmed that F-35s, F-22s, and Black Hawks – the latter belonging to the U.S. Army’s elite 160th Special Operations Aviation Regiment, the Night Stalkers – among many other types of aircraft had taken part in the operation. While mention was also made of the use of drones, the RQ-170 was not explicitly named.

A now-deleted post in December 2025 from Air Forces Southern (AFSOUTH) on X, which included a picture of an individual wearing a name patch with an RQ-170 silhouette and the sleeve insignia of the 432nd Wing, had prompted earlier questions about whether the drones were operating in the region. The only units known to fly Sentinel are the 30th and 44th Reconnaissance Squadrons, both of which are assigned to the 432nd Wing at Creech Air Force Base in Nevada. A total of between 20 and 30 RQ-170s are said to be in the Air Force’s inventory.

The exact role the RQ-170 played in Operation Absolute Resolve remains unclear, and Lockheed Martin CEO Jim Taiclet offered no further details. TWZ has previously detailed how the mission and the lead-up to it are exactly what the Sentinel was designed for. As we wrote:

“RQ-170s would have provided a valuable way to discreetly track Maduro’s movements and otherwise establish his ‘patterns of life,’ as well as those of the forces guarding him, for an extended period of time in the lead-up to the actual launch of the operation to capture him. During the mission itself, having one of the drones orbiting overhead would have provided an indispensable source of real-time information, including to help spot threats that might unexpectedly appear. Those same feeds would also have given senior leaders, including President Donald Trump, a way to watch the operation as it happened.”

…

“With all this in mind, RQ-170s could also have surveilled Venezuelan military bases and other sites that U.S. forces struck as part of the operation overnight, and helped with post-strike assessments. The Air Force has disclosed having at least conducted tests in the past of the Sentinel in the bomb damage assessment role in combination with B-2 bombers.”

Since then, it has also emerged that the U.S. military planning for the mission included preparations to destroy three airfields in the country if it appeared that fighters belonging to the Venezuelan Air Force were attempting to scramble and intercept the raiding force. That threat did not materialize, and none of those facilities were ultimately struck, but it would have been necessary to closely monitor them to be sure.

Substations were also targeted to cut power to the Fuerte Tiuna (Fort Tiuna), a sprawling military base in Venezuela’s capital, Caracas, housing Maduro’s fortress-like compound.

Multiple Venezuelan air defense assets were also struck at various locations in the country during the operation. TWZ has also highlighted previously how suppression and destruction of enemy air defenses (SEAD/DEAD) would have been a key mission for the F-22s and F-35s in the force package. U.S. Navy EA-18G Growlers, and likely at least one U.S. Air Force EC-130H Compass Call aircraft, also contributed electronic warfare support to this mission and other aspects of the operation.

The RQ-170’s participation in Operation Absolute Resolve adds to the still relatively limited publicly available information (and even less that is officially confirmed) about the use of these drones over the years. The U.S. Air Force only officially acknowledged the Sentinel’s existence in 2009, two years after it was first spotted in Afghanistan and had been dubbed the “Beast of Kandahar.”

RQ-170s were used to monitor aspects of Iran’s nuclear program, something that was thrust into the public eye after one of the drones went down in that country in 2011, a major intelligence loss. RQ-170s likely also played a role in relation to the Operation Midnight Hammer strikes on Iranian nuclear sites last year, where they could have provided direct overhead coverage and intelligence for post-mission bomb damage assessments.

Sentinels are understood to have surveilled Al Qaeda founder Osama Bin Laden’s compound in Pakistan in the lead-up to the raid that led to his death, which also occurred in 2011. This, as well as operations over Iran, are prime examples of the Sentinel’s ability to persistently surveil key sites even in denied areas. The preparations for and execution of Operation Absolute Resolve also followed a playbook with direct parallels, as well as notable differences, to the Bin Laden mission.

The stealthy RQ-170s have also deployed to South Korea in the past, from where they likely conducted flights at least very near to North Korean airspace. The drones have also been at least deployed elsewhere in the Pacific, as well.

Between 2022 and 2023, Sentinels may have flown missions in the Black Sea region, gathering intelligence on Russian forces on the heavily-defended occupied Crimean Peninsula. A satellite image available through Apple Maps showing an RQ-170 at Naval Air Station Sigonella in Italy has lent some further credence to those reports. Sigonella has been and continues to be a hub for intelligence, surveillance, and reconnaissance flights over the Black Sea. It is unclear when the image was taken, but it looks to be from a relevant timeframe based on the visible state of construction elsewhere at the base.

Though much still remains to be learned, the remarks today from Lockheed Martin CEO Taiclet have added a small, but notable addition to the story of the RQ-170.

Contact the author: joe@twz.com

The U.S. Air Force general who oversees America’s intercontinental ballistic missile (ICBM) force sees a long future ahead for the new LGM-35A Sentinel after it eventually enters service. At the same time, he has acknowledged challenges surrounding the Sentinel program, which is still being restructured nearly two years after huge cost overruns triggered a full review. Northrop Grumman, the prime contractor for the missile, says it is now working with the Air Force to try to re-accelerate the program, which is now years, if not decades, behind schedule.

Air Force Gen. Stephen Davis, head of Air Force Global Strike Command (AFGSC), recently discussed Sentinel, as well as the existing Minuteman III ICBMs the new missile is set to replace, among other topics, with TWZ‘s Howard Altman. This was Davis’ first interview since taking command of AFGSC in November.

Today, there are 400 Minuteman IIIs loaded in silos spread across five states. The Air Force’s goal is to replace them, one-for-one, with new Sentinels. In 2020, the Air Force declared Northrop Grumman as the winner of the Ground Based Strategic Deterrent (GBSD) competition that led to Sentinel.

“Sentinel is probably the biggest program going on in the Department of War right now, certainly in the Department of the Air Force,” Davis said. “Sentinel brings some important new capabilities that we actually have to deliver for the warfighter, for USSTRATCOM [U.S. Strategic Command].”

Much about the new LGM-35A is classified. The Air Force and Northrop Grumman have talked broadly in the past about it offering greater range and improved accuracy, as well as reliability and sustainability benefits, over the aging Minuteman IIIs. The stated plan is for each Sentinel to carry a single W87-1 nuclear warhead inside a Mk 21A re-entry vehicle, but that loading may change in the future, as you can read more about here.

Enabling Peace Through Deterrence

Gen. Davis also called attention to the benefits that are expected to come from Sentinel’s use of open-architecture systems and a supporting infrastructure that is more digital in nature. In general, open architectures, especially software-defined ones, are intended to make it easier to integrate new and improved capabilities and functionality down the line.

“I think Sentinel is going to be a bit easier with some of the things we’re designing into the program, the digital infrastructure, the open architecture,” Davis said. “I think it will make it easier to upgrade and keep that missile relevant. I don’t have any worries about being able to do that in the future.”

The Minuteman III, also known by the designation LGM-30G, first entered operational service in 1970. The missiles, as well as their supporting infrastructure, have received incremental upgrades since then. The design is an evolution of the earlier Minuteman I and II types that entered service in the 1960s. The Air Force did field a newer ICBM, the LGM-118 Peacekeeper, in the 1980s, but withdrew the last of those missiles from service in 2005 as a result of U.S.-Russian arms control agreements. 

LGM-118 MX Peacekeeper ICBM

“We have the challenge of continuing to sustain Minuteman III until we can get Sentinel up online,” Davis said. “We’ve continued to modernize that to keep it relevant. It will continue to sustain it until Sentinel comes on.”

The original program timeline for the Sentinel called for it to begin entering service in 2029. The Minuteman III would continue to serve into 2036 as the Air Force transitioned fully to the new missile.

What the current timeline for Sentinel is now is unknown. In 2024, delays and cost overruns triggered a formal legal requirement for a review of the program, referred to as a Nunn-McCurdy breach, as you can read more about here. This, in turn, prompted an effort to restructure the program that was expected to take 18 to 24 months. At that time, the Pentagon’s Office of Cost Assessment and Program Evaluation (CAPE) projected the total acquisition costs could soar to approximately $140.9 billion, an 81 percent increase over the original estimates, even with the restructuring.

Even then, it had begun to emerge that the bulk of the issues with the Sentinel program were tied to the ground-based infrastructure rather than the missile itself. It has since become clear that the Air Force did not have a full understanding of the magnitude of the physical construction that would be required. This has been compounded by the determination that reusing existing Minuteman III silos is no longer viable, and that entirely new silos will have to be built.

The understanding that it would be possible to reuse substantial parts of the existing Minuteman III infrastructure factored heavily into the original basing plan for Sentinel. The Air Force had considered and rejected a wide range of alternatives, including launchers positioned at the bottom of lakes or in tunnels.

With the Nunn-McCurdy breach, the timeline for replacing Minuteman III has fallen into limbo, at least publicly. Last September, the Government Accountability Office (GAO), a Congressional watchdog, released a report saying the Air Force was considering options for extending the service life of Minuteman III out as far as 2050.

During a quarterly earnings call today, Northrop Grumman CEO Kathy Warden discussed Sentinel and said that the restructuring effort is still underway, creating continued timeline uncertainty.

“We are in the middle of supporting the U.S. Air Force as they restructure the Sentinel Program,” Warden said. “Coming out of that, they will firm [up] a schedule that both locks in new time ranges for milestone B [entry into the engineering and manufacturing development phase], initial operating capability, final operating capability.”

“I don’t want to get ahead of the Air Force in talking about that, but certainly, as I have shared, and the Air Force has, as well, we are working to accelerate the timelines that were published coming out of the Nunn-McCurdy breach two years ago,” she continued. “So that is the goal, and we’re making good progress to identifying options to do so. We still believe that the program will be in development for several years and not transitioning into production until later in the decade, and that production will very much be guided by the milestone achievement during development.”

Overall, the Air Force and Pentagon leadership continue to view the Sentinel program as a top national security imperative. The announcement of the GBSD effort to replace Minuteman III and the selection of Northrop Grumman’s design had prompted new discussions about the utility of the ground-based leg of America’s nuclear triad. As it stands now, the primary purpose of America’s silo-based ICBMs is to act as a ‘warhead sponge’ that would force any opponent to expend substantial resources on trying to neutralize it in a future nuclear exchange. It also stands as the fastest nuclear response option in the Pentagon’s strategic portfolio. A the same time, the deterioration in the security situation around the globe, with China drastically expanding its nuclear arsenal and Russia at war with its neighbor in Europe, among other proliferation and strategic weapons development concerns, have bolstered the case for Sentinel and nuclear modernization as a whole.

As AFGSC’s Gen. Davis has now told us, the hope is also that the benefits the Sentinels will bring when they finally do enter service will ensure they remain on guard for decades to come.

Contact the author: joe@twz.com