Precision mortar mines are gaining increasing attention from the US military, who see such advantages as increased accuracy, reduced indirect losses, and a simplified supply chain
At the moment, in the field of high-precision mortar mines, two main contracts of the US Department of Defense are being fulfilled, which are at different stages of development. The Marine Corps contract for the Precision Extended Range Munition (PERM) was awarded to Raytheon at the end of 2015, while several companies carry out the Army's High Explosive Guided Munition (HEGM) high-explosive guided mortar program. While there are some differences between the two projects, they are similar in that they strive to meet the need for a high-precision 120mm mortar system.
Benefits
According to Pat Farrell, Head of Precision Systems in the Ammunition Program Development and Execution Department at Picatinny Arsenal, "The HEGM project is currently in preliminary stages of development, with three companies awarded initial contracts to develop and test prototypes of their systems."
The Defense Ordnance Technology Consortium (DOTC) last summer awarded contracts to BAE Systems, General Dynamics Ordnance and Tactical Systems, and Orbital ATK. These initial contracts will last 15 months and end in October 2018. During this time, tests of projectiles in a controlled flight of each of the applicants must be carried out. Further, the DOTC consortium should organize a full-fledged open tender for the continuation of the development and production preparation stage of the HEGM system, for which other companies can also apply.
All applicants are expected to submit bids for this stage in the spring, and at the end of 2018 a contract will be issued to the winning company. According to the plan, serial production will begin in 2021 and a total of about 14,000 HEGM shells should be manufactured.
“What will the HEGM system provide? This is increased range and increased accuracy for 120mm mortars at the battalion and company commander level, Farrell explained. "It will give these commanders the ability to deliver accurate strikes at extended distances."
HEGM will give the army a number of advantages: the required impact will require fewer mines than standard high-explosive fragmentation shells; increased damaging effect due to its accuracy; and reduction of indirect losses.
"Every time you are fighting, for example, in an urban area, you want to get as close to the target as possible and this solution will give you that opportunity."
The HEGM mortar will be integrated with GPS technology, including M-code (with increased noise immunity) and multi-channel options for working in conditions of a weak signal. According to Farrell, the projectile will have a circular probable deviation (CEP) of about three meters, and possibly even less. This will not only increase lethality and reduce indirect losses, but also reduce the logistical burden on soldiers. “If you are firing fewer projectiles, then you need to carry fewer projectiles and fewer propellants with you. In this case, you have the same or greater impact on the target, and this is an increase in combat effectiveness."
Major Kenneth Fowler, Deputy Program Manager for HEGM, also highlighted the logistical benefits. “Now, in order to achieve the necessary impact, you need to shoot not two or three shells, but to make only one shot,” he explained. "This reduces the required amount of material and technical support, which means less fatigue of the personnel, plus the range of targets to be fired is significantly expanded."
One of the main features of the HEGM projectile will be the inclusion of a semi-active laser guidance system in its composition, which will complement the GPS guidance system. The laser will not only increase the overall accuracy of the system, it will also allow you to change the trajectory of the projectile during flight in order to hit a moving target. This is due to the fact that the laser is aimed at a specific object, and not according to GPS coordinates. In addition, a semi-active laser guidance system will increase the capabilities of the HEGM projectile in conditions of a weak or no GPS signal, which is one of the main requirements of the program.
“The increased functionality of the HEGM ammunition will allow soldiers to engage moving targets or targets that have changed position since the call of fire,” said Anthony Gibbs, Farrell's predecessor in the department of development and execution of programs for ammunition. "If the target has moved, you can hit it, because the laser system is able to lock it for tracking."
Component development
In parallel with developments in the field of guided mortar shells, the development of subsystems and components for them, including guidance units, is also in full swing.
MTS Industries and Research manufactures CAS (Canard Actuation Steering) front rudder drives, with the help of which projectiles and other aerial platforms are directed precisely to their targets. According to Nir Eldar, commercial director of MTS, several directions of development have emerged in recent years, especially when it comes to affordability and meeting customer needs.
In addition, Eldar pointed to a breakthrough in the integration of mechanical and electronic systems in CAS units, resulting in highly accurate systems, proven in dozens of experiments. CAS can be embedded not only in ammunition of different calibers, but also in other platforms.
The newest model created by MTS is the CAS-2603 system. The system includes four separate brushless DC motors driving four steering surfaces, Eldar said, while "a position sensor measures the angular position of each wing, and an electronic microcontroller determines the speed of the motor." The system comes with folded wings, which are locked in this position; after the shot, a special mechanism opens and fixes the steering surfaces in the open position.
According to the company MTS, its new development, called a "roll gyro sensor" can be integrated into the CAS unit in order to monitor the roll of a rocket or other platform. Also, the CAS system "is highly resistant to the most adverse environmental conditions and is compatible with the US Department of Defense MIL-STD 810, which describes the requirements for military equipment."
Eldar noted that MTS "carries out a full cycle: manufacturing, assembly, testing, comprehensive technical support." The systems are covered with special coatings developed in the company's own metallurgical laboratory. He also mentioned "specially designed locking and opening mechanisms for steering surfaces, as well as special electric motors with high power and high torque."
Out of acceleration
The HEGM project is a further development of the army's APMI (Accelerated Precision Mortar Initiative) program. Mortar mines were purchased in 2010 as part of urgent operational requirements.
According to Farrell, the APMI projectile has a KBO of 10 meters, which means it is less accurate than the HEGM projectile. However, "the APMI projectile showed good results, which was the impetus for the implementation of a new program for the HEGM projectile." APMI ammunition is now available for deployment as part of a planned procurement process.
Gibbs, for his part, noted that “the APMI decision was a lifesaver for our soldiers in Afghanistan. It has helped meet the urgent need for accurate mortar return fire from dispatched combat posts across the country … We're going to improve existing technology and include next-generation updates to HEGM, such as increased resistance to interference and improved maneuverability."
The APMI solution provided several advantages that will be further improved in the HEGM projectile, Gibbs noted. “High accuracy allows mortars to be used in areas where fears of indirect losses may limit their use, that is, mortars are now always in business. Having the ability to fire from a mortar with high accuracy, you are able to quickly take a position, install a mortar, fire and achieve the desired success with one shell. In the event of a possible return fire, a high-precision projectile gives you the opportunity to get the desired result and then quickly change position."
The requirements of the APMI program were met by the XM395 high-precision targeting projectile developed by Orbital ATK. When developing the XM395, the company followed the beaten path. As in the case of the program to improve the accuracy of 155-mm artillery shells, when the M1156 PGK (Precision Guidance Kit) is screwed in instead of the usual fuse, the standard M394 mortar round is also equipped with a fuse with bow rudders and a guidance unit.
According to Orbital ATK, the XM395 projectile "provides combat commanders with high-precision capabilities when firing indirect fire while neutralizing targets on reverse slopes, in narrow hollows, in urban areas and in other difficult conditions where they are inaccessible for flat fire." The increased accuracy of the system also “allows the commander to hit moving targets more likely and reduces the number of projectiles needed to successfully engage them. In the XM395 projectile, a GPS guidance system and controlled steering surfaces are combined in one block, which replaces the standard fuses. The kit for a relatively low price allows you to transform existing 120-mm mortar rounds into high-precision ammunition."
The PGK was originally designed to give the commander more flexibility. On the battlefield, where terrain and environmental conditions are constantly changing, "it is very important to reduce the risks of casualties among your forces and civilians, as well as indirect damage to infrastructure." This combination of restrictions "in combination with the characteristics of traditional artillery ammunition often limited the commander's options for action and sometimes took the artillery out of action." The PGK system is designed to provide the necessary accuracy and flexibility and "at a price that allows it to be used in the necessary and large quantities, including for combat training."
Problem solving
One of the companies participating in the HEGM program is Orbital ATK. Dan Olson is vice president of weapons systems at Orbital ATK. pointed out many differences between this program and the previous APMI. "The HEGM project requires a more accurate, more maneuverable projectile that has the ability to overcome various countermeasures, such as being anti-jamming."
He also noted the fact that the new projectile should be able to work in the absence of a GPS signal. “APMI only works on GPS signal. Silencers are increasingly appearing on the battlefield as many systems run on GPS, from phones to vehicles and guided weapons.”
This is a major problem for military operators.“What happens on the battlefield if there is a problem with the GPS signal? How to keep all these systems working? Olson asks.
Orbital ATK strives to improve the performance of the HEGM system in a number of ways over the APMI system. The American army now believes that giving this capability to the fighter at the tactical level really gives superiority on the battlefield. Not all potential adversaries have such systems, says Olson. "High-precision mortar shells can really significantly increase the combat effectiveness of our units."
Olson also noted the development of precision guided munitions, which allowed the transition to the HEGM system. “Our expertise in precision targeting, fuses, warheads and system integration gives us the experience we need to work with the army to develop and qualify HEGMs. With all the experience we have gained in the development of the Precision Guidance Kit for artillery, we understand how important new technologies such as HEGM are to give our soldiers the superiority they need over potential adversaries."
Logistic impulse
The Marine Corps PERM contract is at a more advanced stage than the HEGM contract; Raytheon received it at the end of 2015. PERM is the Defense Department's first precision mortar round. They will be fired by the existing Expeditionary Fire Support System mortar complex. “This highly effective weapon system is designed for the Marines,” said Allen Horman, Program Manager for Precision Mortar Systems at Raytheon. "The use of the PERM projectile will significantly increase the accuracy of this complex."
PERM is currently in the design and development phase, and Raytheon is collaborating on this system with Israel's IMI Systems. The American company says that PERM will have a range of twice the existing mortar shells, while reducing indirect damage and the volume of logistics.
Raytheon sees the need to improve the accuracy of more than just mortar shells, as demand for its other products, such as the Excalibur guided artillery shell, is growing.
“Accuracy has certain benefits,” Horman said. - For example, the use of high-precision systems with one projectile instead of several. It shortens your logistic tail as well as lightens the weight of your transportation system. And this is of great importance, since the actions of the Marine Corps are mainly expeditionary in nature."
Raytheon plans to present a modified version of its PERM system for the military's HEGM program. According to Horman, the biggest difference between the two projects is that the army requires the HEGM system to be capable of destroying targets using a semi-active laser guidance system. Raytheon, if successful, will be able to "quickly enter the market and use the familiar laser semi-active homing technology."
Horman also said that the demand for high-precision guidance is growing for all calibers and types of ammunition, mentioning in this regard the Excalibur artillery shell, as well as the Pike 40-mm grenade, which can be fired from the M320 grenade launcher at a distance of more than 1500 meters. "We would prefer each caliber to be highly accurate - that's what we really do."
In the future, Horman expects an inevitable increase in the accuracy and damaging effects of mortar systems. “One of the areas that we continue to develop is the angle of attack. I believe this is an area where accuracy will continue to improve."
There was always a price to be paid for accuracy, but "the legitimacy of spending should be handled by the Ministry of Defense and at the same time taking into account the interests of the military and, at the same time, the state," added Horman. As a former Marine, he believes that accuracy and lethality “are of the utmost importance to your infantry, your soldiers and special operations units that operate in close proximity to each other. But with the new weapon, you are now able to fire at targets with the required precision and impact, giving yourself an edge on the battlefield."
Precision mortar mines and other precision munitions will be in increasing demand as the military gains a number of advantages with them. However, these systems face serious problems, since a technologically advanced enemy can jam GPS signals. In this regard, the inclusion of a semi-active laser homing system in the HEGM projectile looks logical, which also increases the target designation capabilities.
The development process of the HEGM mortar shell is closely watched by the most influential players in the defense industry. Although this contract, like the PERM system, is attractive in itself, it is quite possible that the potential of high-precision ammunition in general and guided mortar shells in particular in the future will be appreciated by the leading armies of the world.
