Bunker-busting behemoth: Pentagon upgrades bomb with Iranian nukes in mind

In this 2007 file photo the Massive Ordnance Penetrator conventional bomb is off-loaded at White Sands Missile Range, N.M. (The Boeing Company/DTRA)

The Pentagon's biggest bunker-busting bomb has been upgraded with one task in mind: taking out suspected Iranian nuclear facilities built deep under the mountains of the Islamic Republic's northern region.

At 30,000 pounds, the Massive Ordnance Penetrator packs brute force and advanced features meant to enable it to destroy Iran's most fortified nuclear site. The bomb is nearly a third bigger than the MOAB, or so-called "Mother of all Bombs," the 22,000-pound previous generation of bunker busters first built in 2003 but never used outside of tests. Officials are confident the newest bunker-buster can dismantle even the deepest and most fortified nuclear facility.

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"Hopefully we never have to use it," a senior U.S. official familiar with the development of the new version told The Wall Street Journal. "But if we had to, it would work."

The Pentagon redesigned the bomb with more advanced features intended to enable it to penetrate even deeper, giving it the ability to destroy Iran's most heavily fortified and defended nuclear site. U.S. officials see development of the weapon as critical to convincing Israel that the U.S. has the ability to prevent Iran from getting a nuclear bomb if diplomacy fails, and also that Israel's military can't do that on its own.

American officials have shown Israeli military and civilian leaders secret Air Force video of an earlier version of the bomb hitting its target, according to diplomats who spoke to the newspaper. In the video, the weapon penetrating the ground within inches of its target, then detonates underground, according to people who have seen the footage.

The new and improved MOP, has adjusted fuses to maximize its burrowing power, upgraded guidance systems to improve its precision and high-tech equipment intended to allow it to evade Iranian air defenses in order to reach and destroy the Fordow nuclear enrichment complex, which is buried under a mountain near the Iranian city of Qom. The upgraded MOP designed for Fordow hasn't been dropped from a plane yet.

Iran's Fordow Uranium Enrichment Facility, built under a mountain near the city of Qom, has long been seen as a nearly impenetrable target using conventional weapons. In January 2012, U.S. officials said didn't think their largest bomb could penetrate the bunker where centrifuges enrich the material needed for nuclear bombs.

According to the website of defense contractor and maker Boeing, the MOP includes a GPS navigation system and more than 5,300 pounds of explosives. It measures 20 feet long and is “designed specifically to attack hardened concrete bunkers and tunnel facilities.”

In March, Pentagon officials are spoke publicly about the MOP bombs, which are from Boeing and designed to fit exclusively with the B-2 and B-52 bombers, for the first time. The paper reports U.S. officials have demonstrated an earlier version of the bomb's capabilities to Israeli leaders several times recently by showing them a video of the bomb hitting its target in high-altitude testing.

Pentagon officials view the development of the weapon as critical to convincing Israel it can rely on the U.S. to stop Iran from developing nukes, and that the Israeli military cannot do so on its own.

According to the Wall Street Journal, the new version of the MOP has advanced components that would allow it to evade Iranian defense systems to reach the Fordow nuclear complex, which is by numerous accounts buried under a mountain in Iran. This upgraded version has not yet been dropped from a plane.

"It gives us a far greater capability to reach and destroy an enemy's weapons of mass destruction that are located in well protected underground facilities... to a magnitude far greater than we have now," Pentagon Spokesman Capt. John Kirby said.

Kirby denied the bombs are designed to target Iran, even though it is the only country known to have buried its nuclear weapons program.

"The system is not aimed at any one country, it's to develop a capability we believe we need," Kirby said. That remark was met by audible groans and various comments of disbelief from the Pentagon press corps.

Boeing successfully tested the bomb on March 17, 2007 at White Sands Missile Range in New Mexico.

Pentagon Spokesman George Little says the MOP is far more powerful than its predecessor, the BLU-109. Some estimate it’s as much as 10 times more powerful.

The Pentagon says it has contracted for a total of 20 bombs from Boeing, some of which were delivered in the fall. But, for purposes of operational security it won’t disclose how many.

On August 2, 2011 the Air Force signed a contract for eight more, meaning it's unlikely it has more than 12 bombs.

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