Precision Guided Mortar Munition (PGMM)

To effectively control the battle space beyond the direct fire fight, the battalion maneuver commander must have an organic extended range precision strike capability. The 120mm Precision Guided Mortar Munition (PGMM) will provide the battalion with a lethal, surgical strike capability to destroy high value targets beyond line of sight direct fire weapons. The PGMM is a multi-mission, multi-mode precision munition capable of defeating high value point targets at double the range of conventional 120mm mortar ammunition (12km required, 15km desired). Its modes of operation include laser designation and/or autonomous fire and forget, depending on the needs of the mission. Its infrared seeker detects and classifies targets, and inputs information through its processor to its guidance & control subsystems to ensure a direct hit on the target. The shaped charge warhead will defeat both soft and hard targets. The use of operational experiments and high resolution computer simulation are key components in the development of PGMM.

The Precision-Guided Mortar Munition (PGMM) ATD will demonstrate, through live fire and simulation, the ability of a guided mortar munition to defeat armored as well as high–value point targets. It will also demonstrate longer range, more accurate and more timely response to requests for fire through the integration of a lightweight fire control system. As part of the RFPI, the PGMM and fire control will be an advanced concept standoff killer in the RFPI ACTD. The ATD program consists of a 120–mm PGMM capable of finding and defeating enemy armor and other high–priority targets in an autonomous role, and a lightweight fire control to improve the accuracy and response time of fielded mortar systems. An initial test bed is being integrated on a HMMWV, with a follow–on effort to reduce the size and weight of the components. The program will focus on the azimuth reference unit and the software required to integrate the components completely and fire a PGMM against moving targets.

The PGMM will provide the maneuver Commander with an organic capability for precision attack of critical point targets, to include those in urban environments or restrictive terrain, under all weather conditions to ranges beyond current 120mm mortar capabilities. PGMM is intended to incapacitate personnel in standard brick over block masonry structures, collapse earth and timber bunkers or incapacitate personnel inside, and defeat stationary lightly-armored vehicles or incapacitate personnel inside. PGMM will be compatible with all current and future mortar and mortar fire control systems. PGMM's terminal guidance will employ a man-in-the-loop laser designator to ensure precision engagement and to minimize collateral damage.

In June 1995 the U.S. Army selected a team led by Lockheed Martin Missiles & Space to design and test the Precision Guided Mortar Munition (PGMM), a long-range mortar munition for use against bunkers, tanks, and other targets requiring precision attack. The U.S. Army, Armament, Research, Development and Engineering Center (ARDEC), Picatinny Arsenal, NJ, awarded continuation of the $10.8 million contract to the Lockheed Martin-Diehl team. Diehl is a German defense contractor that specializes in munitions. The decision allowed the team to move into Phase II of the Advanced Technology Demonstration (ATD) contract.

The 38-pound PGMM is about one meter long, and is designed to penetrate reinforced concrete, modern armor, and known reactive armors. Immediately after launch from its canister, the munition deploys four tail fins for stability. At apogee, (the point of maximum altitude) PGMM deploys four wings that glide and steer the munition to its target. The munition provides a man-in-the-loop discrimination option, in which the round guides toward laser-designated targets when specific target selection is critical. The PGMM also utilizes an imaging infrared guidance capability for autonomous navigation to the target, thus providing a "fire-and-forget" precision guided weapon. The PGMM is compatible with both the conventional steel 120mm mortar canister and the new lightweight composite 120mm mortar canister being developed under Lockheed Martin funding. PGMM is capable of being launched either from ground-mounted or armored mortar carrier-mounted systems.

The weapon platform for this munition is the US Army's 120mm Battalion Mortar System (nomenclature M120 and M121) and the Interim Armored Vehicle -- Mortar Carrier (IAV-MC). The 120mm Battalion Mortar System has been fielded in two configurations: the towed M120 and the carrier mounted M121. The towed M120 is pulled on a carriage behind a High Mobility Multi-purpose Wheeled Vehicle (HMMWV), and also transports mortar ammunition in its cargo bed. The carrier mounted M121 is the same mortar system, but mounted and fired from a tracked vehicle, designated as the M1064/A3 (mortar version of the M113). The IAV-MC is a new 120mm platform, managed by the Office of the Project Manager for the Brigade Combat Team. Although the weapon system may be different from the M120 or M121, it is required to be compatible (fire the same family of US ammunition).

The initial goal of the acquisition program is to develop, demonstrate, and qualify for production an initial Block 1 capability no later than the end of FY06. The Blocked tactical configuration must be able to satisfy the following requirements (Threshold requirements at a minimum, with Objective requirements as the Desired goal): Block 1 systems compatibility requirement is to be able to be fired from the M120, M121 or IAV-MC mortar systems and utilize the XM95 Mortar Fire Control System (MFCS); Block 1 maximum range requirement is 7.2km. Block 1 lethality requirement is to incapacitate personnel behind protective cover (earth & timber bunkers, brick over block masonry construction, and stationary Lightly Armored Vehicles).

Given the target sizes and signatures, man in the loop terminal guidance (laser designation) is a Block 1 requirement. Subsequent Block improvements must extend the range of the PGMM to 12km (Threshold) and 15km (Objective). Subsequent Block improvements also add to the target set (incapacitate personnel behind triple brick walls, reinforced concrete, and moving lightly armored vehicles). Additionally, subsequent block improvements must provide the capability to maneuver off of the gun target line defeat targets outside of traditional man-in-the-loop designation ?Angle T? (angle between Forward Observer, target, and gun positions) boundaries.

The Government was interested in an operational live fire demonstration of a production configuration no later than FY06. Live firing must demonstrate Block 1 system compatibility, range requirements, and high probability of defeat of each of the targets.

By mid-2002 the Army planned to move up the date for fielding the XM-395 Precision Guided Mortar Munition by two years-from 2008 to 2006.

Because soldiers had not previously employed laser designators for the terminal guidance of mortar munitions, DOT&E's system evaluation will include an assessment of the effectiveness of the tactics, techniques, and procedures for the employment of PGMM, to include limitations on laser designator employment.

Since the PGMM requires the minimization of collateral damage, as compared to that caused by other available munitions, DOT&E will require a detailed plan to assess this capability. The January 2003 PGMM Acquisition Strategy and Acquisition Plan stated that the Army plans to award an FRP contract through full and open competition. Should a contractor other than the SDD/LRIP contractor be selected for this award, additional testing will be required for an adequate assessment of operational effectiveness and suitability.

In January 2006 Alliant Techsystems and the U.S. Army successfully completed the preliminary design review (PDR) of the company's precision guided mortar munition (PGMM). During the PDR, all elements of the system design were thoroughly vetted to ensure the design has the performance capability to meet requirements and the program remains on schedule and on cost. The PDR is one of two critical milestones prior to Milestone C in ATK's PGMM system design and development contract. The next milestone was the critical design review in 2006. ATK intends to begin low rate initial production in 2008 and field the system by 2010.

In February 2006, in a series of flight tests conducted at the Yuma Proving Grounds, Alliant Techsystems successfully demonstrated the ballistic characteristics of the most advanced mortar round ever developed for the U.S. Army - ATK's precision guided mortar munition (PGMM). A total of 49 rounds were shot over three days from a 120mm mortar, achieving all test objectives. The primary objectives of the test included establishing the appropriate charge weight to ensure proper muzzle velocity when the round exits the mortar tube; evaluating range performance, obtaining aeroballistics data and verifying structural integrity at hot, cold and ambient temperatures. Secondary objectives included feedback from mortar operators on the handling of the new PGMM round and collection of mortar interior environment data.

As of 2006, ATK and the U.S. Army had established an extensive test regimen to ensure that the first PGMM production rounds will be ready for delivery no later than 2010, reflecting a four year slip from the 2002 plan. The Army was considering an earlier fielding date of 2009 given success in system demos planned for 2006-07.