What are bunker buster bombs? US uses MOP, its largest non-nuclear missile, to strike Iran
Donald Trump revealed operational details, saying that six MOP bombs, each weighing 30,000 pounds, were deployed on Iran's Fordow.
The United States used its most powerful conventional weapon—the Massive Ordnance Penetrator (MOP), or bunker buster bomb—in a high-impact military operation targeting Iran’s underground nuclear facility at Fordow on Saturday.
US President Donald Trump, who in a social media post suggested, “Fordow is gone,” said that the attack targeted nuclear sites in Natanz and Isfahan too.
“We have completed our very successful attack on the three Nuclear sites in Iran. A full payload of BOMBS was dropped on the primary site, Fordow." Trump said, confirming that all planes are now outside of Iran air space. Follow Israel Iran war live updates.
In an interview with Fox News, Trump further revealed operational details, saying that six MOP bunnker buster bombs—each weighing 30,000 pounds—were deployed on Fordow. Meanwhile, 30 Tomahawk Land Attack Missiles (TLAMs) were fired by US Navy submarines to target Natanz and Esfahan, which he claimed “destroyed all three nuclear facilities completely.”
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The Fordow facility, long suspected of housing uranium enrichment infrastructure deep within the mountains near Qom, is widely considered one of Iran’s most fortified nuclear sites. Analysts believed it can only be effectively penetrated by the MOP, a weapon exclusively in the US arsenal.
What is the MOP and why is it so powerful?
The GBU-57 Massive Ordnance Penetrator is the largest non-nuclear bomb in the US inventory. Built by Boeing and guided by GPS, it is engineered specifically to target deeply buried and hardened bunkers.
According to a US air force fact sheet cited by CBS News, the MOP measures 20.5 feet in length and 31.5 inches in diameter, and weighs just under 30,000 pounds—including 5,300 pounds of high-explosive material.
The bomb can burrow more than 200 feet through reinforced concrete before detonating. Its casing, made from high-performance steel alloy, helps it withstand the immense impact forces upon penetration. The Air Force notes the MOP’s explosive yield is more than 10 times greater than that of its predecessor, the BLU-109.
Because of its size and weight, only the B-2 Spirit stealth bomber is capable of carrying and deploying the MOP.
The B-2’s stealth capability allows it to evade radar and air defenses, making it the ideal platform for strikes on heavily protected sites like Fordow. Each B-2 can carry up to two MOPs in its internal weapons bay.
An unconfirmed report by The New York Times claimed that the B-2 bombers which struck Iran's nuclear sites flew non-stop for 37 hours straight from their base in Missouri, refuelling multiple times mid-air during the long-range mission.
‘Only the US could have done this’
Defense analysts have long argued that Fordow's deeply buried infrastructure—shielded by 60 to 90 meters of rock—would require a weapon like the MOP to neutralize.
“Each bunker buster can be independently targeted and released, making it possible to deliver a MOP right on top of another MOP,” Bloomberg quoted Rebecca Grant of the Lexington Institute. She added that US drone surveillance likely played a role in refining the final strike coordinates.
Grant also emphasised that Fordow and other Iranian nuclear installations have been under US observation for years, helping planners build a precise targeting profile.
The MOP was developed by Boeing under a Pentagon contract, with at least 20 units built by 2015.
