The M142 HIMARS (High Mobility Artillery Rocket System ) is a light multiple rocket launcher developed in the late 1990s for the US Army and mounted on a standard U.S. Army Family of Medium Tactical Vehicles (FMTV) M1140 truck frame developed by Oshkosh and powered by a Caterpillar 3116 ATAAC 6.6-liter Diesel Engine.