GBU-57/B Massive Ordnance Penetrator (MOP)

On 25 July 2012, Air Force Secretary Michael Donley told the Capitol Hill Club that if required the GBU-57/B MOP would be available for use, though testing of the weapon to refine its capabilities was continuing.

The MOP is a technology demonstration program funded by the Defense Threat Reduction Agency [DTRA] to develop a 30,000-pound conventional penetrating weapon that will defeat a specialized set of hard and deeply buried targets. The MOP is designed specifically to attack hardened concrete bunkers and tunnel facilities. Designed to be carried aboard B-2 and B-52 bombers and deployed at high altitudes, the MOP's innovative design features include a Global Positioning System navigation system.

The MOP is approximately 20.5 feet long, with a 31.5-inch diameter. The weapon will carry over 5,300 pounds of explosive material and will deliver more than 10 times the explosive power of its predecessor, the BLU-109. The MOP features short-span wings and trellis-type tails. The 13,600 kg (30,000 lb) weapon contains a 2,700 kg (6,000 lb) explosive charge (some sources report "more than 5,300 pounds" of explosives). MOP is designed to go deeper than any nuclear bunker buster and take out 25 percent of the underground and deeply buried targets worldwide. It is designed to penetrate up to 200 feet underground before exploding. By some reports, it was expected to penetrate as much as 60 meters (200 feet) through 5,000 psi reinforced concrete, and 8 meters (25 feet) into 10,000 psi reinforced concrete (these number seem suspiciously high and may in fact be first in feet, not meters).

On 31 March 2006 Dr. James A. Tegnelia, the director of the Defense Threat Reduction Agency told American Forces Press Service [AFPS] that the MOP is a test article meant to understand the design principles on which a country might build a weapon to counter hard targets. "We are not in the process to convince anybody to field a large earth penetrator," he said. But the FY 2008 Global War on Terror Amendment of October 2007 stated [page 44-45] that "The Department requests $5.3 billion to procure equipment to replenish that consumed during combat and support operations in the theater. ... The Replenishment category also includes $0.3 billion for the development of specific technologies to improve the survivability of U.S. personnel and equipment. This includes funding for the Massive Ordnance Penetrator (MOP) for use on the B-2 bomber... " On 23 October 2007, John M. Donnelly reported in Congressional Quarterly that the request includes "$88 million to modify B-2 bombers so they can drop a Massive Ordnance Penetrator" and that White House stated the request for money to modify bombers was in response to "an urgent operational need from theater commanders."

Boeing's Phantom Works is leading the effort to demonstrate the Massive Ordnance Penetrator (MOP). Northrop Grumman is working on with Boeing to develop this conventional bunker buster. They are under contract to Air Force Research Laboratory's Munitions Directorate at Eglin Air Force Base, Florida, and Defense Threat Reduction Agency. The three-phase technology demonstration built on design studies that Boeing had conducted for the laboratory.

While complete physical destruction may be desired, for some hard and deeply buried targets this effect isn't practicable with current weapons and employment techniques. It may be possible, however, to deny or disrupt the mission or function of a facility. Functional defeat is facilitated through better data collection and intelligence preparation against the potential targets. The defeat process includes finding and identifying a facility, characterizing its function and physical layout, determining its vulnerabilities to available weapons, planning an attack, applying force, assessing damage, and, if necessary, suppressing reconstitution efforts and re-striking the facility. New more lethal defeat options for Hard and Deeply Buried Targets (HDBTs) like the Massive Ordnance Penetrator, that can overwhelm target characterization uncertainties, are being developed and demonstrated to provide a 10x increase in weapon lethality and improved penetration capability compared to inventory weapons.