U.S. Orders New GBU-57 Bunker Buster Bombs After B-2 Bombers Strike on Iran Nuclear Sites.

The U.S. Air Force has awarded Boeing a sole-source contract to produce additional GBU-57 Massive Ordnance Penetrator bombs following their use in June 2025 strikes on Iranian nuclear facilities. The move is intended to rapidly restore strategic bunker buster inventories critical to Air Force Global Strike Command’s long-range strike mission.

The U.S. Air Force has formally awarded Boeing a sole- source contract to manufacture additional GBU-57 Massive Ordnance Penetrator bombs, replenishing weapons expended during the June 2025 B-2 Spirit strikes on hardened Iranian nuclear sites, including the deeply buried Fordo enrichment facility. The decision was confirmed in a publicly released justification notice, which states that Boeing remains the only qualified producer of the 30,000-pound class precision-guided munition. Air Force officials warned that any delay in contracting would directly affect operational readiness within Air Force Global Strike Command, which maintains the nation’s penetrating long-range strike capability.
Follow Army Recognition on Google News at this link

The contract, whose total value exceeds 100 million dollars, although the exact figure remains redacted, covers the production of additional all-up-round components and new guidance tail kits. Deliveries are scheduled to begin in January 2028. The sole-source justification emphasizes the urgency of restoring the inventory of Massive Ordnance Penetrators within Air Force Global Strike Command, which is responsible for the nation’s long-range strike and strategic deterrence missions. The command oversees both the B-2 Spirit and the B-52H Stratofortress fleets, although the MOP is operationally integrated with the B-2 due to weight and carriage constraints.

The GBU-57 Massive Ordnance Penetrator represents the most powerful conventional bunker-defeating weapon in the U.S. inventory. Weighing approximately 30,000 pounds, or roughly 13,600 kilograms, it is designed to engage deeply-buried and heavily-fortified targets such as underground command centers, weapons laboratories, and reinforced storage complexes. Its hardened steel casing enables the weapon to penetrate up to 60 meters of earth or an estimated 200 feet of rock before detonation, depending on target composition. Unlike area-effect munitions, the MOP is optimized for concentrated kinetic penetration followed by a delayed explosive effect, maximizing structural collapse within subterranean facilities.

Guidance is provided through a satellite-aided inertial navigation system, combining GPS updates with internal inertial measurement to ensure high accuracy against fixed coordinates. This architecture enables precision strikes against hardened points with limited circular error probability, even when released from high altitude. The bomb’s mass and penetration profile require release from strategic bombers capable of carrying its weight internally. The B-2 Spirit, powered by four General Electric F118 turbofan engines and designed with low-observable shaping and materials, provides the necessary range and survivability to deliver the MOP against heavily-defended targets. With an unrefueled range exceeding 6,000 nautical miles and the ability to operate with aerial refueling, the B-2 allows intercontinental strike options while minimizing exposure to advanced integrated air-defense systems.

The June 2025 operation against Iranian nuclear infrastructure demonstrated the operational niche of the MOP. Multiple weapons were reportedly employed against Fordo, a facility constructed deep within a mountain to protect centrifuge halls from conventional air attack. In that context, the MOP’s penetration capability becomes central: rather than relying on repeated strikes or stand-off missiles with limited penetration, a single precisely placed munition can achieve structural defeat of underground chambers. The weapon thus complements cruise missiles and smaller precision-guided bombs within the broader strike portfolio.

The MOP offers a distinct effect within the U.S. conventional deterrence framework. Its mass and penetration capacity enable the neutralization of targets previously considered resistant to non-nuclear attack. When integrated into a strike package, the B-2 can ingress under low-observable conditions, release the weapon from altitude, and egress before adversary air-defense networks can effectively respond. The reliance on GPS introduces a constraint in heavily-jammed environments, although the inertial navigation backup mitigates degradation. The requirement for specialized aircraft also limits sortie generation compared to lighter munitions. Even so, the presence of an operational bunker-buster capable of defeating deeply-buried facilities complicates adversary planning and forces potential opponents to reassess the survivability of underground assets.

The replenishment decision therefore extends beyond inventory management. It reflects an assessment that hardened and deeply-buried targets will remain central to future contingency planning across multiple theaters. Air Force Global Strike Command must maintain sufficient stockpiles to support operational plans assigned to geographic Combatant Commands, whether in the Middle East, the Indo-Pacific, or Europe. The exclusive reliance on Boeing for production highlights the narrow industrial base supporting such niche capabilities, as well as the lead times involved in manufacturing specialized penetrator casings and guidance assemblies.

The renewed procurement signals that conventional long-range strike remains a pillar of U.S. strategy. By sustaining the GBU-57 inventory, Washington preserves an option that sits below the nuclear threshold yet retains the ability to threaten strategic infrastructure. For states investing in hardened facilities, including underground missile silos or enrichment plants, the message is clear: physical depth alone no longer guarantees immunity. As rival powers expand their own anti-access and area-denial architectures, the interaction between stealth platforms, precision guidance, and advanced penetration munitions will continue to shape the balance between fortification and strike. In that evolving landscape, the Massive Ordnance Penetrator occupies a narrow but decisive role within the architecture of deterrence and coercive power projection.