The GBU-43/B is large, powerful and accurately delivered. high explosive. The GBU-43/B Massive Ordnance Air Blast Bomb [MOAB] weapon is a 21,000 lbs total weight GPS-guided munition with fins and inertial gyro for pitch and roll control. It is probable that this munition was initially nick-named the “Mother Of All Bombs” with the retronymic expansion of MOAB following later.
MOAB is a guided bomb which delivers the 18,700 lb BLU-120/B warhead bomb with KMU-593/B GPS/INS. The MOAB is the largest-ever satellite-guided, air-delivered weapon in history [not the largest ever, but the largest satellite guided]. The 21,600-pound MOAB is an improved replacement for the unguided 15,000-pound BLU-82 Daisy Cutter. It is 30 feet long with a diameter of 40.5 inches. The warhead is a blast-type warhead. It was developed in only nine weeks to be available for the Iraq campaign, but it was not used in combat.
The 21,700-pound [9,500 kilogram] bomb contains 18,700 pounds of H6, an explosive that is a mixture of RDX (Cyclotrimethylene trinitramine), TNT, and aluminum. H6 is used by the military for general purpose bombs. H6 is an Australian produced explosive composition. Composition H6 is a widely used main charge filling for underwater blast weapons such as mines, depth charges, torpedoes and mine disposal charges. HBX compositions (HBX-1, HBX-3, and H6) are aluminized (powdered aluminum) explosives used primarily as a replacement for the obsolete explosive, torpex. They are employed as bursting charges in mines, depth bombs, depth charges, and torpedoes. HBX-3 and H-6 have lower sensitivity to impact and much higher explosion test temperatures than torpex. The MOAB weapon produces a very large explosive blast, with lesser fragmentation effects due to a thin-walled aluminum casing.
Contrary to some published claims, it most certainly is not an Ethylene-Oxide Fuel-Air Explosive (FAE). Some initial reports had stated that this replacement for the BLU-82 bomb uses more of the slurry of ammonium nitrate and powdered aluminum used in the BLU-82. Other reports indicated that the MOAB might use tritonal explosive as opposed to the gelled slurry explosive of the BLU-82. Contrary to some reports, it is not capable of deep ground penetration.
Like the BLU-82, the MOAB rests in a cradle on an airdrop platform inside a C-130 aircraft. Due to the size of the ordnance, the item is extracted from either an MC-130 Talon II or “Slick” C-130 Hercules by way of a parachute. A drogue parachute extracts the weapon, cradle and platform—and the weapon is quickly released to maintain maximum forward momentum. The grid fins then open and begin guiding the weapon to its target.
The MOAB weapon is based upon the same principle as the BLU-82 “Daisy Cutter”, except that it is larger and has a guidance system. The weapon is expected to produce a tremendous explosion that would be effective against hard-target entrances, soft-to-medium surface targets, and for anti-personnel purposes. Because of the size of the explosion, it is also effective at LZ clearance and mine and beach obstacle clearance. Injury or death to persons will be primarily caused by blast or fragmentation. It is expected that the weapon will have a substantial psychological effect on those who witness its use. The massive weapon provides a capability to perform psychological operations, attack large area targets, or hold at-risk threats hidden within tunnels or caves.
The weapon is intended to have a high altitude release, allowing for greater stand-off range for the delivery vehicle. Following deployment from the aircraft via drogue parachute, the MOAB weapon is guided approximately 3 nautical miles through a GPS system (with inertial gyros for pitch and roll control), JDAM actuators, and is stabilized by series of fixed wings and grid fins. The weapon, which uses the aircraft’s GPS prior to launch, takes several seconds to reconnect to the GPS signal after it has been deployed, which is normal for GPS weapons.
The US Air Force developed the satellite-guided Massive Ordnance Air Blast Bombs (MOAB) as a successor to the the 15,000-lb. “Daisy Cutters” used in Vietnam and Afghanistan. The Air Force is said to call MOABs (pronounced MOE-ab) the Mother Of All Bombs. As with the earlier Daisy Cutter, these huge bombs are dropped out of the rear of the C-130 cargo plane. Unlike the Daisy Cutter, the MOAB falls to the ground without the use of a retarding parachute. As a result, the aircraft releasing the bomb can fly at higher altitudes, thus making it safer for US pilots.
Source: Global Security