September 2,2008:  The U.S. Air Force has, after three years of development, introduced the LJDAM (Laser Joint Direct Attack Munition). The main difference between JDAM and LJDAM is the sensor unit. There are now two sensors, one for  GPS guidance, and a laser seeker sensor, turning the JDAM into the LJDAM. The aircraft dropping the bomb can now use its laser designator to track a moving target, and the LFDAM bomb hits it. A LJDAM can hit a vehicle moving at over 60 kilometers an hour. LJDAM was supposed to enter service last year, but there were several small reliability problems that had to be fixed.

The main reason for developing LJDAM was to give the air force an inexpensive weapon that can be used against enemy vehicles. Most specifically, against Iraqi terrorists who are discovered planting a roadside bomb, and then jump into their pickup truck and speed away. The smallest LJDAM, one using a 500 pound bomb, costs about $40,000. A 670 pound laser guided Maverick missile costs $150,000. Britain developed a version of the laser guided, 106 pound Hellfire (called Brimstone) that can be launched from "fast movers" (jet fighters), that costs about half as much as Maverick. The U.S. never adopted Brimstone. Hellfire size weapons are the preferred way to destroy fleeing enemy vehicles. That's because only a few pounds of explosives are involved, limiting the casualties to any nearby civilians. U.S. helicopters and UAVs carry Hellfire. A 500 pound bomb contains about a hundred times as much explosives (280 pounds) as a Hellfire.