HIMARS is Great, but it's no Miracle Weapon
From scanning newspaper coverage of the US deployment of rocket artillery systems to combat ISIS one might believe the HIMARS rocket system will collapse ISIS on its own. So what is this system and and why is the media so fascinated with it? Certainly not a new weapon, a veteran of the Gulf War through present conflicts, this multi-barreled behemoth is seemingly unknown to the US public.
HIMARS (pronounced: High-Mars), or High Mobility Artillery Rocket System, is the modern lighter six barreled version of the 12 barreled M270 Multiple Launch Rocket Launcher (MLRS) introduced to the US military in the 1980s. Firing 227mm caliber 13 foot long telephone poles of explosives, the system is mounted on the back a US Army FMTV five ton truck. Introduced in the late 90s as a lighter and more mobile version of its heavier Desert Storm relative, the HIMARS system hosts a variety of guided and unguided rockets, as well as a 3700 lb ballistic missile.
Soviet era BM-21 122mm rocket launchers fire a volley of unguided rockets
In contrast to Soviet and Russian rocket artillery doctrine which favored cheap and easy to produce multi-barreled rocket launchers like the lighter 122mm BM-21 Grad or 220mm BM-27 Uragan, which operate on the principle of massed fire saturating an area and sacrifice precision accuracy, the M270 and follow on HIMARS launchers put a focus on precision. While the unguided M26 through M28A1 rockets can be salvo fired 6 or 12 at a time (depending on launcher) and similarly saturate a given target zone, their true strength is in the use of their GMLRS (pronounced: Gim-lerz) Guided Multiple Launch Rocket System rounds.
M270 MLRS twelve barreled launcher
Traditional dumb rockets depend on conventional ballistic calculation and target plotting to strike their target, with reasonable accuracy comparable, depending on range, to artillery like the M777 howitzer. Once the rocket leaves the launcher it's flight path is determined and only environmental factors impact its final point of impact. In contrast, the GMLRS series of rockets are programmable to a GPS coordinate and continue to correct their flight path via an inertial guidance package and canards on the nose of the rocket. The result is nearly 200 lb warhead that can be fired from up to 70km aways and hit a target with smart bomb accuracy. The benefits of such a system should be immediately evident, particularly when one remembers that a single launcher can launch six of these before needing to reload. In circumstances that prevent airstrikes (thunderstorms, sandstorms, hostile anti-aircraft weapons), if one is within range of a given target, the ability to pepper the target with multiple heavy rockets that offer PGM (precision guided munition - smart bomb) levels of accuracy while putting no pilots or friendly troops at risk is indeed an attractive option.
ATACMS surface to surface missile fired from an M270 MLRS
Where the news outlets go wrong is in confusing the maximum abilities of these systems with their regular usage capabilities. Less often spoken about when discussing the M270 and HIMARS are the 3,700 lb MGM-140 ATACMS (Army Tactical Missile System) surface to surface missiles the launchers are capable of firing (two missiles for the M270 and one for the HIMARS). Such a system is similar to the Russian OTR-21 Tochka fielded by many former Soviet client states. Initially designed to carry and disperse huge quantities of cluster-munitions, the variants fielded today are generally the MGM-168 variety, carrying a 500 lb warhead. A GPS guided ballistic missile, these systems can reach out to as far as 300km. That 300km figure seems to figure heavily into the articles like one put out by Foreign Policy where the system is presented as being a 300km rocket artillery system, rather than a 30-70km rocket artillery system that *can* be extended to 300km when the need calls for it and a supply of ATACMS missiles are present. The general usage of the HIMARS system requires it to be substantially closer to its target than the 300km maximum range of its single shot ATACMS option.
The HIMARS is an incredible asset that will aid Iraqi military forces as they push the envelope on ISIS and require precision strikes from US assets to keep up the pressure. Their increased usage in Iraq and soon to be Syria signals the serious nature of the US admin to bring the most capable weapons, short of ground troops, to bear on ISIS. But at the end of the day, the HIMARS is just another tool, in the overworked tool-chest of the American military efforts to combat ISIS.