Declassified: The GBU‑57 “Super‑Bunker Buster” & Its First Combat Debut

In the early hours of June 22, 2025, the United States launched a historic strike on three Iranian nuclear facilities—Fordow, Natanz, and Isfahan—deploying a powerful arsenal that included six GBU‑57 Massive Ordnance Penetrator (MOP) bombs and 30 Tomahawk cruise missiles. This operation marked the first-ever combat use of the GBU‑57, the world’s most formidable non‑nuclear bunker buster.

What is the GBU‑57 MOP?

Massive Ordnance Penetrator: A GPS/INS‑guided bomb, weighing approximately 30,000 lb (13,600 kg)
Designed to penetrate up to ~60 m of earth or 18 m of reinforced concrete before detonation
Composed of a BLU‑127 bomb body (~27,125 lb) filled with high explosives (~5,342 lb AFX‑757 & PBXN‑114), encased in hardened steel
Delivery Platform: Exclusively carried by the stealthy B‑2 Spirit, which can house two MOPs per aircraft

Why Fordow Required Such Firepower

The Fordow Fuel Enrichment Plant, located near Qom and buried approximately 300 ft (or ~60 m) deep in a mountain, was long considered virtually "impenetrable" by conventional ordnance. According to Al Jazeera, only the GBU‑57’s deep penetration capability could threaten such fortifications—an assessment echoed by military analysts

The Execution of the Mission

Aircraft deployment: At least six B‑2 Spirit bombers launched from Whiteman AFB in Missouri, possibly staging through Diego Garcia.
Bombing sequence: Twelve MOPs were dropped on Fordow, and two on Natanz, sequentially to achieve maximum structural collapse
Missile campaign: Concurrently, 30 Tomahawk missiles struck Natanz and Isfahan

Presidential claim: President Trump called the strikes “a spectacular military success,” declaring that Iran’s primary nuclear facilities had been “completely and totally obliterated”

The Technical Edge & Its Limits

The GBU‑57’s breakthrough lies in longevity and penetration:

Size Matters: At 20 ft long and weighing 13.6 tonnes, it's purpose-built to breach fortified, subterranean structures
Sequential Deepening: Dropping multiple bombs serves to amplify the crater and collapse; it's a hydraulic excavation at scale .
No Void-Sensing Fuze: Lacking a void-sensor, blasts detonate only after the bomb stops, which may limit maximum effect.

Advanced Countermeasures: Iran potentially uses ultra-high-strength concrete (>30,000 psi) and guidance-jamming abilities that might blunt effectiveness

What's Next?

Potential Further Strikes: Trump has warned of more attacks if Iran doesn't move toward peace
Iran's Response: Tehran insists there were no radiation leaks and maintains its nuclear program is peaceful
Diplomatic Tensions: Regional actors like Turkey have offered mediation; others warn of war escalation.
Strategic Calculus: The strike marks a turning point in US engagement—abandoning defense in favor of offensive intervention.

Broader Implications

Combat Deployments: The deployment in real-world conflict after years of development could shape future bunker-buster doctrine.
Nuclear Proliferation Risk: Destroying nuclear infrastructure may incentivize underground dispersal or turbocharge Iran’s nuclear resolve.
War Ethics & International Law: Debates around legality, proportionality, and civilian impact loom large.

Technological Arms Race: Iran may boost underground hardening efforts; the U.S. and allies may push next-gen earth-penetrating weapons for B‑21 bomber integration .

Final Word

The use of the GBU‑57 MOP against deeply buried nuclear infrastructure represents a seismic shift in strategic warfare—blurring lines between conventional and escalatory force. While it delivers unprecedented destructive capability, it raises equally profound questions on nuclear deterrence, global security architecture, and the future of aerial warfare.

As the dust settles in Iran and Washington recounts the aftermath, the world braces for what's unfolding next—a complicated mix of retaliation, diplomacy, and perhaps another leap in military escalation.

Declassified: The GBU‑57 “Super‑Bunker Buster” & Its First Combat Debut