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