system can fire rockets or MGM-140 ATACMS missiles, which are contained in interchangeable pods. Each pod contains six standard rockets or one guided ATACMS missile; the two types cannot be mixed. The LLM can hold two pods at a time, which are hand-loaded using an integrated winch system. All twelve rockets or two ATACMS missiles can be fired in under a minute. One launcher firing twelve rockets can completely blanket one square kilometer with submunitions. A typical MLRS cluster salvo consisted of three M270 vehicles each firing all 12 rockets. With each rocket containing 644 M77 grenades, the entire salvo would drop 23,184 grenades in the target area. However, with a two percent dud rate, that would leave approximately 400 undetonated bombs scattered over the area, which could endanger friendly troops and civilians. Production of the M270 ended in 2003, when a last batch was delivered to the Egyptian Army. In 2003, the U.S. Army began low-rate production of the M142 HIMARS. The HIMARS fires all of the munitions of the MLRS, but is based on the chassis of the Family of Medium Tactical Vehicles. As of 2012, BAE Systems still had the capability to restart production of the MLRS. In 2006, MLRS was upgraded to fire guided rounds. Phase I testing of a guided unitary round (XM31) was completed on an accelerated schedule in March 2006. Due to an Urgent Need Statement, the guided unitary round was quickly fielded and used in action in Iraq. Lockheed Martin also received a contract to convert existing M30 Dual-Purpose Improved Conventional Munition (DPICM) GMLRS rockets to the XM31 unitary variant. The M31 GMLRS Unitary rocket transformed the M270 into a point target artillery system for the first time. Due to GPS guidance and a single high-explosive warhead, the M31 could hit targets accurately with less chance of collateral damage while needing fewer rockets to be fired, reducing logistical requirements. The unitary warhead also made the MLRS able to be used in urban environments. The M31 had a dual-mode fuse with point detonation and delay options to defeat soft targets and lightly fortified bunkers respectively, with the upgraded M31A1 equipped with a multi-mode fuse adding a proximity airburst mode for use against personnel in the open; proximity mode can be set for Height Of Burst (HOB). The GMLRS has a minimum engagement range of and can hit a target out to , impacting