The United States deployed more than a dozen 30,000-pound “bunker buster” bombs in a June 21 airstrike on Iranian nuclear sites—marking the first time the powerful weapons have been used in combat, according to the Pentagon.
Dubbed “Operation Midnight Hammer” by the Trump administration, the mission involved U.S. bombers dropping 14 Massive Ordnance Penetrators (MOPs) on three of Iran’s major nuclear facilities, Chairman of the Joint Chiefs of Staff Gen. Dan Caine confirmed on June 22.
Each bomb, also known as the GBU-57, weighs 30,000 pounds and is guided by GPS. Designed to punch deep into reinforced underground structures like tunnels and bunkers, MOPs measure about 20 feet in length and six feet in width.
The strikes targeted Iran’s Fordo, Natanz, and Isfahan nuclear facilities, causing “extremely severe damage and destruction,” Caine said, citing early assessments.
While other nations, including Israel, possess bunker-busting munitions, defense experts say only the MOP has the capacity to seriously damage or destroy Iran’s heavily fortified nuclear infrastructure.
Boeing’s Role in Bunker Buster Production
Though the exact unit cost of a MOP remains undisclosed, Pentagon contracts reveal the high price tag. In 2019, Boeing received $70 million to produce the bombs at its St. Louis site, followed by updated contracts worth more than $77 million in 2021.
Record-Breaking B-2 Mission
The B-2 stealth bomber is currently the only aircraft capable of delivering the massive MOPs—each bomber can carry two.
For the Iran strike, seven B-2 bombers flew the 14 bombs from Whiteman Air Force Base in Missouri to their targets, supported by over 125 aircraft involved in the overall mission, according to Caine.
“This was the largest B-2 operational strike in U.S. history and the second longest B-2 mission ever flown,”
— Gen. Dan Caine
The Air Force ran previously tested the MOP at White Sands Missile Range in New Mexico in 2012, with five successful drops—three using live warheads and two with inert versions.