The Massive Ordnance Penetrator (MOP) GBU-57A/B is a U.S. Air Force massive, precision-guided, 30,000-pound (13,608 kg) “bunker buster” bomb. This is substantially larger than the deepest penetrating bunker busters previously available, the 5,000-pound (2,268 kg) GBU-28 and GBU-37.
The U.S. Air Force has no specific military requirement for an ultra-large bomb, but it does have a concept for a collection of massively sized penetrator and blast weapons, the so-called “Big BLU” collection, which includes the MOAB (Massive Ordnance Air Burst) bomb. Development of the MOP is now underway at the Air Force Research Laboratory, Munitions Directorate, Eglin Air Force Base, Florida. Design and testing work is also being performed by Boeing. It is intended that the bomb will be deployed on the B-2 bomber, and will be guided by the use of GPS.
A test release from a B-52 bomber
The push for accelerated deployment is due to the increased perceived nuclear threats from Iran and North Korea. It’s believed that many of their nuclear programs could be in development underground, below levels of current bunker-busting bombs’ range. The Pentagon intends the rapid deployment to send a message that the United States is tweaking strategies to address new threats.
The Air Force took delivery of 20 bombs, designed to be delivered by the B-2 bomber, in September 2011. In February 2012, Congress approved $81.6 million to further develop and improve the weapon.
On 25 June 2010, USAF Lt. Gen. Phillip Breedlove said that the Next-generation Penetrator Munition should be about a third the size of the Massive Ordnance Penetrator so it could be carried by affordable aircraft. In December 2010, the USAF had a Broad Agency Announcement (BAA) for the Next Generation Penetrator (NGP).
Global Strike Command has indicated that one of the objectives for the Next-Generation Bomber is for it to carry a weapon with the effects of the Massive Ordnance Penetrator. This would either be with the same weapon or a smaller weapon that uses rocket power to reach sufficient speed to match the penetrating power of the larger weapon.
Israel doesn’t have military jets big enough to carry the MOP. But they have been working on their own penetrators which are much smaller than MOP, and therefore could be carried by Israel’s F-15I Strike Eagles and Jericho missiles. As one official reported, “You would be surprised at their accuracy” and that the high explosives involved is a special mix of chemical explosives that could conceivably penetrate the Iranian fortifications.