Fordo Versus GBU-57 “Bunker Buster” and B-2 Stealth

The temperature of conflict in the Middle East shows no signs of cooling. On the contrary, it is becoming increasingly heated. Although it had been predicted earlier, the world remains shocked by the United States' attack on Iran. Moreover, the U.S. targeted three of Iran's main nuclear sites, namely Fordo, Natanz, and Isfahan. So far, there have been no detailed reports regarding the condition of these three sites.

In a recent report, Sunday (22/6/2025), the Saudi Arabian Nuclear and Radiological Regulatory Commission stated on X that no radioactive impacts were detected in the Gulf region following the US attack. A similar statement was made by the Kuwait National Guard. "Radiation levels in the air and waters of Kuwait are stable, and the situation is normal," the agency wrote on X.

Previously, the President of the United States, Donald Trump, on Saturday (21/6/2025) Washington DC time, or Sunday (22/6/2025), announced that the US had attacked Fordo, Natanz, and Isfahan. In the attack, the US deployed stealth bombers, B-2 Spirit. The aircraft dropped bunker-busting bombs GBU-57 to damage the three Iranian nuclear sites.

Is the US military equipment relied on in this attack really that tough?

Several experts have previously stated that Israel would not be able to damage Fordo without assistance from the United States. Why? Because only American bombs are capable of penetrating Fordo.

Referring to The Associated Press, the GBU-57 MOP (Massive Ordnance Penetrator) is indeed designed to destroy underground bunkers. After being dropped, the bomb strikes the surface, penetrates deep into the ground, and then explodes, destroying tunnels or bunkers that are buried and reinforced underground.

The precision-guided bomb weighs approximately 13.6 tons and is believed to be capable of penetrating the ground to a depth of 61 meters. The bomb can be dropped one at a time, effectively "drilling" deeper with each successive explosion.

Referring to The War Zone, the Channel News Asia website states that the GBU-57 is approximately 6.2 meters long. The bomb carries a warhead of type AFX-757 and PBXN-114 weighing 2.4 tons. The warhead is housed in a specially coated steel casing with high performance.

"GBU-57 is the only conventional weapon that has the potential to cause damage to Fordow," said Damien Tan, a research assistant at the Middle East Institute of the National University of Singapore, to CAN.

In addition to the GBU-57, the United States also possesses other bunker-busting bombs, namely the GBU-28 and BLU-109. The GBU-28 is a laser-guided weapon, weighing nearly 2,300 kilograms. This bomb can penetrate concrete up to 6 meters thick.

Another bomb, the BLU-109, weighs approximately 900 kilograms. This mini bomb can destroy reinforced concrete up to 1.2 to 1.8 meters thick. The BLU-109 carries a warhead weighing 240 kilograms. The GBU-28 was used by the United States during the Gulf War in 1991, while the BLU-109 was used by Israel to target Hezbollah leader Hassan Nasrallah.

In theory, the GBU-57 can be dropped by bombers capable of carrying such a heavy payload. However, the United States has specifically configured and programmed the stealth bomber B-2 Spirit to drop the GBU-57.

The B-2 Spirit, produced by Northrop Grumman, is capable of carrying a payload of up to 18 tons. However, the U.S. Air Force stated that they successfully tested the B-2 carrying two units of GBU-57, with a total weight of approximately 27.2 tons.

The strategic bomber is capable of flying up to 11,000 kilometers without in-flight refueling. When supported by a single in-flight refueling, the B-2 can fly as far as 18,500 kilometers. According to Northrop Grumman, with this capability, the B-2 can reach various points in different corners of the world in just a matter of hours from its base.

Fordo, one of the sites targeted by the United States, is estimated to be located 80 meters below the surface. The site, whose construction began in 2006, is also protected by air defense systems made by Iran and Russia.

However, the system is likely no longer operational following last week's Israeli attack.

Fordow is smaller than Natanz and is built among the mountains not far from the city of Qom. It is located approximately 95 kilometers from Tehran.

In this US attack, although the GBU-57 is equipped with a conventional warhead, due to the target being a nuclear enrichment site, the International Atomic Energy Agency (IAEA) has warned of the potential for radiation leaks. However, referring to Israel's previous attack on Natanz, contamination only occurred within the site itself.

If referring to the Russia Today page on X, it was reported that last Thursday, satellite imagery showed a convoy of 16 cargo trucks leaving Fordo. It is unknown what was being transported from Fordo.