M142 High Mobility Artillery Rocket System (HIMARS) Fire Mission. M142 High Mobility Artillery Rocket System is a U.S. light multiple rocket launcher mounted on a standard Army Medium Tactical Vehicle (MTV) truck frame. Features of launcher: The HIMARS carries six rockets or one Army Tactical Missile System (ATACMS) missile on the U.S. Army's new Family of Medium Tactical Vehicles five-ton truck, and can launch the entire M270 Multiple Launch Rocket System (MLRS) family of munitions. HIMARS is interchangeable with the MLRS M270A1, carrying half the rocket load.