The Massive Ordnance Penetrator is a 30,000-pound bunker buster bomb

The only bomb that can strike the heart of Iran's nuclear program.
Massive ordnance penetrator
That's one big bomb. (U.S. Air Force)

In “Top Gun: Maverick,” the Navy is tasked with destroying an underground uranium enrichment plant in an unnamed foreign country. Maverick’s plan requires two bombs to be dropped: the first to hit an exposed ventilation hatch and the second to travel down the shaft as the kill shot. This tandem strike wouldn’t be necessary if Maverick had been in the Air Force. The Air Force would have used it’s most powerful “bunker buster:” the 30,000-pound GBU-57 Massive Ordnance Penetrator.

It is the most powerful bunker buster bomb in the U.S. Air Force’s arsenal, and was designed following the poor performance of bunker buster bombs employed during the 2003 invasion of Iraq. Smaller bunker busters, such as the GBU-28 and GBU-37, yielded poor penetration and inadequate levels of destruction during the conflict. The Air Force Research Laboratory’s Munitions Directorate, with design and testing conducted by Boeing, developed the ultimate bunker buster for about $400 million.

GBU-57A/B MOP Massive Ordnance Penetrator in transit
A GBU-57 MOP is transported at Whiteman AFB (U.S. Air Force)

Weighing a total of 30,000 pounds while measuring 20.5 feet in length and 31.5 inches in diameter, the MOP is a massive weapon. Designed to be dropped by a strategic bomber, it uses GPS as well as Inertial Navigation System guidance to strike within meters of its target. A large penetrator smart fuze dictates the bomb’s detonation based on the impact depth to ensure the destruction of an underground structure.

The MOP can reportedly penetrate up to 200 feet of reinforced concrete or soil. This is accomplished by dropping the incredibly thick bomb from high altitude. Only 5,300 pounds of the 30,000-pound MOP is made up by its warhead of polymer-bonded explosives; the high-density steel alloy hull makes up about 80% of the bomb’s weight. Although testing was conducted with the B-52 Stratofortress, the MOB can only be employed operationally by the B-2 Spirit, which can carry two of the bombs.

Massive Ordnance Penetrator B-52 GBU-57A/B MOP
A B-52 releases a GBU-57 MOP during a weapons test over White Sands Missile Range, New Mexico. (Department of Defense)

As of November 2015, the Air Force reported that an initial 20 MOPs were contracted to be built. The service also announced that an operational stockpile is present at Whiteman Air Force Base, Missouri, the only operational B-2 Spirit base. The new B-21 Raider has been designed to employ the Massive Ordnance Penetrator, as well as the Next Generation Penetrator munition, which is intended to replace the large MOP.

To enable the NGP to be carried by smaller aircraft, the Air Force aims for the MOP’s replacement to be three times smaller than the explosive’s current size. This means that the NGP will have to be denser, which will retain a high overall weight, or it will need to be rocket-assisted to ensure the same penetration performance.

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Miguel Ortiz Avatar

Miguel Ortiz

Senior Contributor, US Army Veteran

Miguel Ortiz graduated from San Diego State University and commissioned as an Army Officer in 2017. His passion for military culture and history led him to freelance writing. He specializes in interesting and obscure military history. When he’s not writing, Miguel enjoys traveling and watch collecting.


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