The M142 High Mobility Artillery Rocket System (HIMARS) is a light multiple rocket launcher developed in the late 1990s for the United States Army, mounted on a standard Army M1140 (6×6 FMTV) truck frame. The purpose of HIMARS is to engage and defeat artillery, air defence concentrations, trucks, light armour and personnel carriers, as well as support troop and supply concentrations. HIMARS launches its weapons and moves away from the area at high speed before enemy forces locate the launch site. HIMARS was developed by Lockheed Martin Missiles and Fire Control under an advanced concept technology demonstration (ACTD) programme, placed in 1996.
The HIMARS carries six rockets or one MGM-140 ATACMS missile on the Family of Medium Tactical Vehicles (FMTV) five-ton truck, and can launch the entire Multiple Launch Rocket System Family of Munitions (MFOM). HIMARS ammunition is interchangeable with the MLRS M270A1, however it is only able to carry one pod rather than the standard two for the M270 and A1 variants. The HIMARS (launcher) consists of a carrier and a Fire Control system (FCS) that computes all fire mission data and a Launcher-Loader Module (LLM) portion that performs all operations necessary to complete a fire mission. The HIMARS can firing the standard MLRS round, but also entire MLRS family of munitions, including the extended-range rocket, the reduced-range practice rocket and all future variants.
In addition to the standard MLRS round, HIMARS is capable of launching the entire MLRS family of munitions, including the extended-range rocket, the reduced-range practice rocket and all future variants. The extended-range MLRS rocket (ER-MLRS) improves the basic M26 range of 32km to more than 45km and the area of influence by 107%. The Lockheed Martin GMLRS rocket has a GPS (global positioning system) and inertial guidance package and small canards on the rocket nose to enhance accuracy. HIMARS is capable of firing the long-range ATACMS (army tactical missile system) guided missile. The ATACMS family includes the Block 1, Block 1A and Block 1A Unitary missiles.
The front of the M142 HIMARS is fitted whith a fully enclosed and armoured cab, which provided a protection against small arms firing and shell splinters. The FMTV standard cargo truck is motorised with a Caterpillar C7 engine coupled to an automatic Allison 3700SP transmission with 7 speed. It was designed as a small, mobile, MLRS, with the ability to ‘shoot-and-scoot’. The chassis is produced by BAE Systems Mobility & Protection Systems (formerly Armor Holdings Aerospace and Defense Group Tactical Vehicle Systems Division), the OEM of the FMTV. The rocket launching system is produced by Lockheed Martin Missiles & Fire Control. HIMARS is C-130 transportable and can be deployed into areas previously inaccessible to heavier launchers. It also incorporates the self-loading, autonomous features that have made MLRS the premier rocket artillery system in the world.