Massive Ordnance Penetrator (MOP)
Direct Strike Hard Target Weapon / Big BLU

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. 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.

Direct Strike Hard Target Weapon

The Direct Strike Hard Target Weapon was described in 1997 as a 20,000 lb. class precision guided, adverse weather, direct attack bomb employed on the B-52 and B-2 aircraft. It would make use of the GCU developed by the JDAM program which uses GPS aided INS for adverse weather guidance. Precision accuracy will be attained by using differential GPS (DGPS) technology demonstrated on programs such as Enhanced Differential GPS for Guidance Enhancement (EDGE) and Miniature Munition Technology Demonstration (MMTD).

The weapon would make use of the JDAM interface under development for the B-52 and B-2 aircraft and would be carried internally using new suspension hardware within the bay. The warhead was to be a 20,000 lb. penetrator with dense metal ballast. This concept uses the Hard Target Smart Fuze (HTSF), an accelerometer based electronic fuze which allows control of the detonation point by layer counting, distance or time. The accelerometer senses G loads on the bomb due to deceleration as it penetrates through to the target. The fuze can distinguish between earth, concrete, rock and air.

The Air Force also investigated whether a similar size weapon could be used in a blast-only configuration, to replace the BLU-82 Daisy Cutter blast weapon dropped from the MC-130. This was eventually realized as the GBU-43/B "Mother Of All Bombs" MOAB - Massive Ordnance Air Blast Bomb.

Big BLU

Although the Direct Strike Hard Target Weapon concept was unfunded as of 1997, in early 2002 it was reported that Northrop-Grumman and Lockheed Martin were working on a 30,000-lb. earth penetrating guided conventional weapon, said to be known as "Big BLU" or "Big Blue" [which is also the nickname of the 15,000-lb surface burst BLU-82]. Flight testing was initially envisaged around 2006. Big BLU will be GPS guided and feature cobalt-alloy penetrator bomb body that enables it to penetrate to depths of up to 100 feet below the surface before detonating. The bombs are so large that a bomber such as the B-2 could carry one of them. As of March 2002 reportedly three Big BLUs had been ordered by the Air Force on an urgent basis ["Inside The Ring," By Bill Gertz and Rowan Scarborough, Washington Times March 15, 2002 Pg. 10].

Defense Science Board on Future Strategic Strike Forces

The February 2004 Defense Science Board Summer Study Task Force on Future Strategic Strike Forces looked to the 30-year future with the objective of providing the President with a broad range of strike options to * Protect the United States and our forces abroad, * Assure friends and allies of our future commitment, and * Deal with future adversaries on terms favorable to the United States. The Task Force identified currently planned systems that will still be relevant and recommended new systems for development.

The DSB Task Force recommended that USD(AT&L) immediately undertake an Advanced Concept Technology Demonstration (ACTD) for a bomber-delivered massive penetrator. A family of massive ordnance payloads (20-30 klb.), both penetrator and blast variants, would be developed to improve conventional attack effectiveness against deep, expansive, underground tunnel facilities.

A deep underground tunnel facility in a rock geology poses a significant challenge for non-nuclear weapons. Such a target is difficult to penetrate, except possibly near an adit, and the likelihood of damaging critical functional components deep within the facility from an energy release at the adit is low. Past test experience has shown that 2,000 lb. penetrators carrying 500 lbs. of high explosive are relatively ineffective against tunnels, even when skipped directly into the tunnel entrance.

Instead, several thousand pounds of high explosives coupled to the tunnel are needed to blow down blast doors and propagate a lethal airblast throughout a typical tunnel complex. This can be achieved either by an accurate blast weapon situated in front of the tunnel entrance or a penetrator that has burrowed directly into the tunnel. In both cases, the munition must be on the order of 20- to 30- klb. to couple a sufficient amount of energy to the tunnel.

The penetrator requires the weight for penetration; the blast weapon requires the weight for carrying high explosives. Optimized penetrators of this size may penetrate about 5 to 8 times farther than an existing 2,000 lb. class weapon and may also be suitable for housing a clean, low-yield nuclear weapon. Using the tactic of optimum dual delivery, where a second penetrator follows immediately behind the first, and boosting the penetrator velocity with a rocket motor, a depth of up to 40 meters can be achieved in moderately hard rock. In view of the promise of such a massive penetrator for both conventional and nuclear payloads, the DSB Task Force recommended an immediate start on an ACTD-like demonstration of this capability.