GBU-28 "Bunker Buster" Laser-Guided Bomb

The Guided Bomb Unit 28 (GBU-28) is a 5,000 pound / 2268 kg. laser-guided "bunker busting" bomb nicknamed "deep throat" produced originally by the Texas Instruments division Defense Systems and Electronics Group (division since sold to Raytheon). It was specifically developed for US Military use in Operation Desert Storm to penetrate hardened Iraqi command centres located deep under ground. However, only two of these weapons were dropped in Desert Storm, both by F-111Fs.

The initial batch of GBU-28s were built from modified 8 inch/203 mm. artillery barrels (principally from deactivated M110 howitzers), but later warheads were purpose-built. They weigh 4,700 pounds/2132 kg. and contain 630 pounds / 286 kg. of high explosive. The operator illuminates a target with a laser designator and then the munition guides to a spot of laser energy reflected from the target.

The bomb underwent critical testing in Nevada at the Tonopah Test Range, a major test facility for United States Department of Energy funded weapon programs. It proved capable of penetrating over 30 metres (100 ft) of earth or 6 metres (20 ft) of solid concrete. The GBU-28 is unique in that the total development time from conception to the first drop test took only 12 weeks, and the weapon went into active service after only one test drop.

The first foreign sale of the GBU-28 was the acquisition of 100 units by Israel, authorized in April 2005. Delivery of the weapons was accelerated at the request of Israel in July 2006. According to Israeli Military sources, Iran or Syria are possible targets for the weapons.