Aviation Week l Big Advances Seen For GMLRS
February 20, 2012 § Leave a comment
Even with the drawdown of U.S. forces in Iraq and Afghanistan, where combat conditions have placed a premium on both precision and volume of fire, the Guided Multiple Launch Rocket System (GMLRS) will evolve to meet new requirements.
Lockheed Martin is considering various options to sustain production and introduce upgrades, building on U.S. Army and Marine Corps plans to keep the rocket and its launchers in service until 2050. Meanwhile, a number of allied customers also are expected to extend the life of their own launchers.
The M31E1 Phase II unitary warhead rocket—which weighs 302 kg (666 lb.), is 3.94 meters (12.9 ft.) long and has a 227-mm diameter—is the current production standard. Lockheed Martin received its latest order in June 2011 for $445 million, covering 735 rocket pods (each with six rockets), as well as 508 reduced-range practice rocket pods, for delivery starting in December.
While additional orders for M31s fitted with the 89-kg unitary warhead are expected, a new major acquisition program is likely due to the need to replace the M30 rocket, which is fitted with the Dual-Purpose Improved Conventional Munitions (DPICM) bomblet warhead. That weapon is slated for retirement under the Pentagon’s Cluster Munitions Policy that bans any ammunition that produces a combined unexploded ordnance rate of more than 1% as of 2018. The M30’s rate is around 3.5%.
While DPICM bomblets, designed to defeat area targets, have become less useful in recent years, the Pentagon’s recent defense strategic guidance indicates that “conventional” high-intensity conflicts could come back into fashion. For soldiers and Marines ashore, the answer will come in a new variant of the GMLRS, which replaces the DPICM with a new unitary warhead under the Alternate Warhead Program (AWP). This warhead is intended to provide the same destructive effects against area targets, including inaccurately located targets, but with a single munition over a similar area versus the DPICM. This comes, in part, due to the increased precision that the M31 rocket offers compared with the M30—unofficially its circular error probable (CEP) rate is in the two-meter range compared with five meters for the older rocket.
The U.S. Army started its AWP effort in 2009 by awarding three integration and demonstration contracts to develop concepts. The 17-month contracts led to live demonstration and flight tests in 2010 and then selection of the Alliant Techsystems (ATK) design in mid-2011. ATK had self-funded two AWP designs in 2008 and chosen the most promising one for the Army research effort. The program has completed the technical demonstration phase and will be ready for Milestone B review by the end of the first quarter of 2012. Lockheed Martin will be the prime for the expected engineering and manufacturing development phase. The M31 with AWP warhead will be one of the first examples of a “legal” area weapon.
The company, meanwhile, continues self-funding refinements for a so-called GMLRS+ rocket, which combines an extended-range capability with a new warhead. With extended range, a smaller number of rocket launchers can cover a greater area. The official GMLRS range is 15-70 km, but with just a little improvement to the standard rocket, up to 92 km was achieved. Then in August 2011, a GMLRS+ attained a record distance of 120 km under a combined Lockheed and Aerojet effort, which brought an improved and longer rocket motor, increased accuracy and new rocket flight profile. All of this comes while keeping it compatible with existing six-round rocket pods and current launchers—the 12-round tracked M270A1/B launcher and six-round wheeled High-Mobility Artillery Rocket System.
Lockheed Martin also has tapped Aerojet to develop the scalable-effects warhead, an advanced fragmentation unit whose explosive effects target can be programmed before the launch, depending on the target. The new warhead was tested on a GMLRS+ rocket in November 2011 at White Sands Missile Range, N.M., with the detonation power set on low yield and scored a direct hit. No details are available yet on the chosen approach, but one of the concepts considered involves an exterior “band” wrapped around the warhead, which “shrinks” the warhead case at the proper time during the flight. When coupled with appropriate fuzing, it makes the effects tunable and widens the potential target set.
By Andy Nativi
February 17th, 2012