The U.S. Army's MLRS (Multiple Launcher Rocket System) used its new "smart rocket" ( GMLRS) in combat for the first time during the September fighting in central Iraq. This version, which weighs 680 pounds, carries 200 pounds of explosives, and can deliver it with the accuracy of a smart bomb, at ranges of over 60 kilometers. There are two versions of the GMLRS, the other one contains 404 bomblets that kill troops, or damage vehicles, over a wide area. The high explosive one is most in demand, for destroying structures where hostile gunmen are holding out. The GMLRS is the first of several guided projectiles American artillery forces are getting. Next Summer comes the 155mm Excalibur smart shell, which also uses GPS guidance. While the army likes the smart bombs, the smallest one available is 500 pounds, which is sometimes more than the troops on the ground want. This is because hurting civilians in adjacent buildings can cause problems later on, and the larger the bomb, the farther away friendly troops have to be until it goes off. The air force is developing a 250 pound JDAM (smart bomb), but it is not ready for service yet. Meanwhile, the GMLRS does the job, and you don't need a bomber overhead, or an air force ground controller nearby, to use it. The army likes that kind of convenience a lot. But this does not come cheap. The Excalibur shells will cost $50,000 each, but GMLRS is more cost effective, the GPS guidance package costing about as much as the JDAM guidance system the air force fits to dumb bombs to make them smart bombs. But the air force can deliver a 250 pound smart bomb at a total cost of under $30,000 (including the cost of operating the aircraft). Convenience always comes at a cost, and cost does matter in the long run.