What is America's GBU-57, the only bomb that can hit Iran's deep nuclear sites?

Hindustan Times

4 hours ago

Amid escalating tensions between Iran and Israel, the GBU-57, a powerful American bunker-buster bomb, is the only known weapon capable of destroying Tehran's deeply buried nuclear facilities.
The 30,000-pound (13,607 kg) bomb is designed to penetrate up to 200 feet (61 metres) underground before detonation. It is not part of Israel's arsenal, despite the country's stated objective of preventing Iran from developing a nuclear weapon.
Donald Trump is considering whether the United States should join the ongoing conflict between Israel and Iran. In a meeting with his National Security Council on Monday, officials discussed the option of targeting Iran's underground nuclear site at Fordo, which is used for uranium enrichment.
Speaking to reporters at the G7 Summit in Canada on Monday, Trump said that Iran 'will not win' in the ongoing confrontation and urged Tehran to return to negotiations 'before it's too late.'
In the wake of Israel's recent strikes on Iranian targets, experts say only one conventional weapon, the GBU-57 bunker-buster bomb,can take out Iran's most heavily fortified nuclear site, Fordo, which remains untouched.
'In less than a week, the regime's missile stockpiles, launchers, military bases, production facilities, nuclear scientists, military command and control has taken a very severe beating,' Behnam Ben Taleblu, director of the Iran program at the Foundation for Defense of Democracies (FDD) told news agency AFP.
'But there are still outsized questions as to how efficacious of a strike Israel had against the beating hearts of Iran's nuclear program,' he added.
The International Atomic Energy Agency (IAEA) has confirmed that no damage was done to Fordo, the underground uranium enrichment site south of Tehran. Unlike other facilities like Natanz or Isfahan, Fordo is buried deep—far too deep for Israeli airstrikes to reach.
'All eyes will be on Fordo, which is buried under about 300 feet of rock in central Iran,' Taleblu said.
That's why analysts are pointing to the US-made GBU-57, a 30,000-pound non-nuclear bomb designed to penetrate such depths.
The US military says the GBU-57, also known as the Massive Ordnance Penetrator, 'is designed to penetrate up to 200 feet underground before exploding,' allowing it to break through layers of rock and concrete.
Unlike conventional missiles or bombs that detonate on or near impact, this weapon is built specifically to strike deeply buried targets.
'To defeat these deeply buried targets, these weapons need to be designed with rather thick casings of steel, hardened steel, to sort of punch through these layers of rock,' said Masao Dahlgren, a fellow focused on missile defence at the Center for Strategic and International Studies (CSIS), a Washington-based think tank.
The GBU-57, which is 6.6 metres long, also uses a special fuse. 'You need an explosive that's not going to immediately explode under that much shock and pressure,' Dahlgren explained.
The design of the bomb began in the early 2000s, and Boeing received an order for 20 units in 2009.
The only aircraft capable of carrying the powerful GBU-57 bomb is the American B-2 stealth bomber. Some B-2s were deployed in early May to the joint UK-US base at Diego Garcia, but 'were no longer visible by mid-June,' according to AFP's analysis of satellite images from Planet Labs.
'With their long-range capabilities, B-2s departing from the United States are able to fly all the way to the Middle East to do bombing runs. That's been done before,' said Masao Dahlgren of the Center for Strategic and International Studies.
Each B-2 can carry two GBU-57s. 'They're not going to just be one and done,' added military analyst Peter Schwartz, noting that multiple bombs would likely be needed. He also said Israel's air superiority over Iran reduces the risk for the bombers.
With AFP inputs