To help contain procurement and running maintenance costs of a key battlefield piece, the U.S. military moved ahead with adopting the M142 "High Mobility Artillery Rocket System" (HIMARS) - a lightweight, wheeled derivative of the successful Cold War-era Vought M270 "Multiple Launch Rocket System" (MLRS). The M270 itself was debuted in 1983 and was the tracked M993 Carrier Vehicle (Bradley IFV) coupled to the traversable M269 Loader Launcher Module (LLM). Together, with its crew of three, the system could launch variable-warhead munitions some 40 miles away through its twin, six-round mounted launcher - all twelve rockets could clear the launch module in less than 40 seconds. By the end of production in 2003, approximately 1,300 units had been produced and shipped to many US-aligned customers including the United Kingdom, South Korea and France.
The M142 HIMARS retains the M270's crew of three though the M993 tracked carrier is now replaced by the Medium Tactical Vehicle (MTV), a 6x6 wheeled multipurpose heavy hauler. To this was added one six-shot launcher module of the M270 atop the flatbed area, producing a complete rocket-projecting system that is less than half the weight of its tracked counterpart - 24,000lbs versus 55,000lbs. Dimensions include a length of 23 feet, a width of 10.5 feet and a height of 10.5 feet, allowing for it to be air-transported in the hold of a Lockheed C-130 Hercules. Comparatively, the M270 fielded a running length of 22.5 feet, a width of 10 feet and a height of 8.5 feet.
The MTV itself is based on the Austrian Steyr 12M18 military truck and makes up a portion of the U.S. Army's "Family of Medium Tactical Vehicles" (FMTVs). The carriers are six-wheeled, mult-irole performers with a forward-set crew cabin seated atop the front axle. The remaining axle pair is at the rear, charged with handling much of the cargo weight. The MTV was selected by the US Army to replace its aged stock of M35 and M939 service trucks and were produced by BAe Systems Land and Armaments up until 2011 to which then production shifted under the Oshkosh Corporation brand label. Lockheed Martin Missiles and Fire Control is responsible for the launcher module and its rockets - the M142 can make use of 6 x 227mm M270 rockets or a single (though guided) MGM-140 "Army TACtical Missile System" (ATACMS) battlefield missile.
Having lost its M993 tracked nature (with its inherent armor protection at the superstructure), the M142 relies on a light armor protection scheme encompassing the whole crew cabin. This saves on weight while reducing complexity of a track-and-wheel arrangement while its diesel truck engine can be repaired and maintained through easy-to-procure off-the-shelf components. Road speeds reach 53 miles per hour with an operational range out to 300 miles. The M270 is listed with a road speed of 64 miles per hour and an operational road range out to 400 miles.
The 18th Field Artillery Brigade (Airborne) of the US Army was the first American unit granted use of the M142. Trials preceded its 2005 acceptance year and the system has since seen combat service in the fields of Iraq where its lethal payload could be brought to bear on unsuspecting rebels. The series has also gone on to showcase its strengths in the Afghanistan Theater where ranged engagements have proven the norm. Currently, the US military features the M142 across three Army Fires Brigades (17th, 18th, and 214th) as well as seven through its Army National Guard. The US Marine Corps 11th and 14th Marine Regiments are also given control of the type.
Other operators beyond the United States include Singapore (18 units), the United Arab Emirates (20 units) and Jordan (12 units). Other national powers holding some interest in the M142 system include Canada, Qatar, Thailand and the United Kingdom - though procurement has not been forthcoming (as of February 2014).