Here are the bunker-buster bombs used on Iran’s Fordo nuclear facility

In inserting itself into Israel’s war against Iran , the U.S. unleashed its massive “bunker-buster” bombs on Iran’s Fordo fuel enrichment plant .

Those bombs were widely seen as the best chance of damaging or destroying Fordo, built deep into a mountain and untouched during Israel’s weeklong offensive.

A U.S. official, speaking on condition of anonymity to discuss the operation before an official briefing, confirmed their use in Sunday’s attack.

The U.S. is the only military capable of dropping the weapons, and the movement of B-2 stealth bombers toward Asia on Saturday had signaled possible activity by the U.S. Israeli leaders had made no secret of their hopes that President Donald Trump would join their week-old war against Iran, though they had also suggested they had backup plans for destroying the site.

It remained unclear early Sunday how much damage had been inflicted upon Fordo. The mission could have wide-ranging ramifications, including jeopardizing any chance of Iran engaging in Trump’s desired talks on its nuclear program and dragging the U.S. into another Mideast war.

Here’s a closer look.

“Bunker buster” is a broad term used to describe bombs that are designed to penetrate deep below the surface before exploding.

In this case, it refers to the latest GBU-57 A/B Massive Ordnance Penetrator bomb in the American arsenal. The roughly 30,000 pound precision-guided bomb is designed to attack deeply buried and hardened bunkers and tunnels, according to the U.S. Air Force.

It’s believed to be able to penetrate about 200 feet (61 meters) below the surface before exploding, and the bombs can be dropped one after another, effectively drilling deeper and deeper with each successive blast. It was not immediately known how many were used in the Sunday morning strike.

The bomb carries a conventional warhead, but the International Atomic Energy Agency has confirmed that Iran is producing highly enriched uranium at Fordo, raising the possibility that nuclear material could be released into the area if the GBU-57 A/B were used to hit the facility.

However, Israeli strikes at another Iranian nuclear site, Natanz, on a centrifuge site have caused contamination only at the site itself, not the surrounding area, the IAEA has said. U.S. warplanes also hit Natanz.

Fordo is Iran’s second nuclear enrichment facility after Natanz, its main facility, which already has been targeted by Israeli airstrikes. The IAEA says it believes those strikes have had “direct impacts” on the facility’s underground centrifuge halls.

Satellite image of the Fordo enrichment facility in Iran on Jan. 24, 2025. (Maxar Technologies via AP)

Fordo is smaller than Natanz, and is built into the side of a mountain near the city of Qom, about 60 miles (95 kilometers) southwest of Tehran. Construction is believed to have started around 2006 and it became operational in 2009 — the same year Tehran publicly acknowledged its existence.

In addition to being an estimated 80 meters (260 feet) under rock and soil, the site is reportedly protected by Iranian and Russian surface-to-air missile systems. Those air defenses, however, likely have already been struck in the Israeli campaign, which claims to have knocked out most of Iran’s air defenses.

Still, Israeli Prime Minister Benjamin Netanyahu has said the goal of attacking Iran was to eliminate its missile and nuclear program, which he described as an existential threat to Israel , and officials have said Fordo was part of that plan.

“This entire operation ... really has to be completed with the elimination of Fordo,” Yechiel Leiter, Israel’s ambassador to the U.S., told Fox News.

In theory, the GBU-57 A/B could be dropped by any bomber capable of carrying the weight, but at the moment the U.S. has only configured and programed its B-2 Spirit stealth bomber to deliver the bomb, according to the Air Force.

The B-2 is only flown by the Air Force, and is produced by Northrop Grumman.

The B-2 Spirit is a stealth bomber that can penetrate enemy defenses undetected and deliver nuclear munitions. (Bobbie Garcia/Air Force)

According to the manufacturer, the B-2 can carry a payload of 40,000 pounds (18,000 kilograms) but the U.S. Air Force has said it has successfully tested the B-2 loaded with two GBU-57 A/B bunker busters — a total weight of some 60,000 pounds (27,200 kilograms).

The strategic long-range heavy bomber has a range of about 7,000 miles (11,000 kilometers) without refueling and 11,500 miles (18,500 kilometers) with one refueling, and can reach any point in the world within hours, according to Northrop Grumman.

Whether the U.S. would get involved had been unclear in recent days.

At the G7 meeting in Canada, Trump was asked what it would take for Washington to become involved militarily and he said: “I don’t want to talk about that.”

Then on Thursday, Trump said he would decide within “two weeks” whether to get involved to give another chance to the possibility of negotiations with Iran over its nuclear program. In the end, it took just two days to decide.

美国介入以色列对伊朗的战争，向伊朗的福尔多燃料浓缩厂投放了威力巨大的“掩体炸弹”。

这些炸弹被普遍认为是破坏或摧毁福尔多堡垒的最佳机会，该堡垒建在山体深处，在以色列长达一周的进攻中未受影响。

一位美国官员在正式简报会前匿名透露了此次行动的情况，并证实了他们在周日的袭击中使用了这些武器。

美国是唯一有能力投放这些武器的军队，而周六B-2隐形轰炸机向亚洲的调动表明了美国可能采取的行动。以色列领导人毫不掩饰地希望美国总统唐纳德·特朗普加入他们一周前开始的对伊朗的战争，尽管他们也暗示他们有摧毁该设施的备用计划。

周日清晨，福尔多遭受的损失程度仍不清楚。此次袭击可能产生广泛影响，包括危及伊朗参与特朗普所期望的核计划谈判的任何机会，以及将美国拖入另一场中东战争。

让我们仔细看看。

“掩体克星”是一个宽泛的术语，用来描述那些设计成能够穿透地表深处并爆炸的炸弹。

这里指的是美国军火库中最新的GBU-57 A/B型大型穿透炸弹。据美国空军称，这种重约3万磅的精确制导炸弹旨在攻击深埋地下的加固掩体和隧道。

据信，这种炸弹在爆炸前能够穿透地表以下约200英尺（61米），而且可以连续投放，每次爆炸都能有效地钻入更深的地下。目前尚不清楚周日早晨的袭击中使用了多少枚这种炸弹。

该炸弹携带常规弹头，但国际原子能机构已证实伊朗在福尔多生产高浓缩铀，因此如果使用 GBU-57 A/B 炸弹袭击该设施，核材料可能会释放到该地区。

然而，国际原子能机构表示，以色列对伊朗另一处核设施纳坦兹离心机设施的袭击仅造成该设施本身污染，并未波及周边地区。美国战机也曾袭击过纳坦兹。

福尔多是伊朗继纳坦兹之后的第二个核浓缩设施，纳坦兹是伊朗的主要核设施，此前已遭到以色列空袭。国际原子能机构表示，他们认为这些空袭对该设施的地下离心机大厅产生了“直接影响”。

2025年1月24日，伊朗福尔多浓缩铀设施的卫星图像。（Maxar Technologies via AP）

福尔多监狱比纳坦兹监狱小，建在库姆市附近的一座山腰上，位于德黑兰西南约 95 公里（60 英里）处。据信，福尔多监狱的建设始于 2006 年左右，并于 2009 年投入使用——同年，德黑兰公开承认了该监狱的存在。

据报道，该遗址位于地下约80米（260英尺）深处，被岩石和土壤覆盖，并受到伊朗和俄罗斯地对空导弹系统的保护。然而，这些防空系统很可能已经在以色列的军事行动中遭到摧毁，以色列声称已摧毁了伊朗的大部分防空系统。

不过，以色列总理本雅明·内塔尼亚胡表示，攻击伊朗的目标是消除其导弹和核计划，他称该计划对以色列构成生存威胁，而官员们也表示，福尔多是该计划的一部分。

“整个行动……必须以消灭福尔多为最终目标才算完成，”以色列驻美国大使耶希尔·莱特告诉福克斯新闻。

理论上，任何能够携带该重量的轰炸机都可以投放 GBU-57 A/B 炸弹，但据美国空军称，目前美国只对其 B-2“幽灵”隐形轰炸机进行了配置和编程，使其能够投放该炸弹。

B-2轰炸机仅由美国空军使用，由诺斯罗普·格鲁曼公司生产。

B-2“幽灵”隐形轰炸机能够突破敌方防御而不被发现，并投掷核弹药。（鲍比·加西亚/美国空军）

据制造商称，B-2 可以携带 40,000 磅（18,000 公斤）的有效载荷，但美国空军表示，他们已经成功测试了装载两枚 GBU-57 A/B 掩体炸弹的 B-2——总重量约为 60,000 磅（27,200 公斤）。

据诺斯罗普·格鲁曼公司称，这款战略远程重型轰炸机不加油航程约为 7,000 英里（11,000 公里），加油一次后航程可达 11,500 英里（18,500 公里），可在数小时内到达世界任何地点。

近几天来，美国是否会介入一直不明朗。

在加拿大举行的七国集团会议上，有人问特朗普，华盛顿需要什么条件才会进行军事介入，他回答说：“我不想谈论这个问题。”

周四，特朗普表示他将在“两周内”决定是否介入，再次尝试与伊朗就其核计划展开谈判。最终，他只用了两天时间就做出了决定。