The U.S. Army got a rush delivery of 72 GMLRS (Guided Multiple Launch Rocket System) rockets, armed  with a unitary warhead (containing 196 pounds of explosives). This rocket is used in the MLRS system. The GMLRS uses GPS guidance, and the army wanted the new rocket in a hurry for use against time-sensitive enemy targets. Examples of such targets would be a bunch of Iraqis firing mortar shells at a U.S. base, or groups of gunmen in a town or city, holding out in a building. 

There is another version of the GMLRS available, which contains a cluster bomb warhead (with 404 bomblets). In some situations, the unitary warhead, which does more damage in a smaller area, is considered a more suitable weapon. The cluster bomb spreads its bomblets over  a hundred meters in every direction. The unitary warhead is also the only one you would want to use against targets in an inhabited urban area. The unitary rocket will enter mass production next year. The GMLRS has a range of 70 kilometers, meaning that one MLRS vehicle could support many operations spread over a wide area.