Essentially, the developed MRM projectiles are a key element that makes it possible to implement the entire concept of building a promising light tank MCS "Fighting system of the future" (magazine "Weapon, "3, 2011). The developed HM360 tank gun (magazine “Weapon”, No.5, 2011) and the automatic loader for the MCS tank make it possible to shoot with all existing 120-mm projectiles, as well as with all the new 120-mm ammunition currently under development, including new MRM self-guided munitions. In the future, MRM projectiles can also be used on Abrams series tanks to improve their fire capabilities, without significant technical changes.
Even more than 25 years ago, studies by foreign experts showed that the US and NATO armed forces, and in particular their tanks, would have much more advantages and be more efficient if they could use high-precision extended-range ammunition. In this regard, since the middle of the 1980-ies., The United States are working on the creation of these munitions.
In 1982-1984 The US Defense Department’s research centers selected a number of promising areas for the development of new types of weapons, including the creation of a “smart, projectile-targeted projectile that provides the principle of“ fired and forgotten ”. Leading defense companies such as Alliant Techsystems Inc. (ATK), Raytheon, General Dynamics, and a number of other companies have begun to develop a new “smart” (self-aiming or self-guiding) projectile for an 120-mm tank gun. The companies developed their versions of the projectile, one of which would later be selected on the basis of competitive selection for the final stage of development and supply to the army.
Created by ATK, the new 120-mm self-targeting tank projectile is called Smart (smart) Target Activated Fire and Forget (STAFF) and XM943 index. In 1990, demonstrations were held to confirm the performance of the principles laid down in the projectile. The STAFF projectile was supposed to hit a target in flight with the aid of a “shock core”. To this end, the warhead, which forms the "shock core", was located perpendicular to the axis of the projectile. Target search was carried out using a millimeter radar. During the rotation of the projectile, if an attack object hit the target sensor's field of view, the warhead was undermined and a “strike core” -type compact striking element was formed. In addition to the destruction of armored targets, including those located in shelters, the projectile was also intended to destroy low-flying helicopters flying over them. The firing range was 4 km.
In parallel with the STAFF program, ATK was working to create an 120-mm controlled X-Rod kinetic projectile. The X-Rod (Rod) program was launched by the DARPA (Defense Advanced Research Projects Agency) agency in the middle of the 1980s. The STAFF and X-rod shells were considered by the US Army as applicants for the further development of the extended-range tank projectile, but under the new TERM Extended Range Munition program. The final choice between competing projectiles was planned for 1998. As a result, in 1998, it was decided to stop work on the STAFF projectile, and to continue the development of X-Rod kinetic ammunition as part of the TERM program. The program began to be designated as TERM-KE (Tank Extended Range Munition-Kinetic Energy - Extended Tank Kinetic Ammunition). Finally, the STAFF program was closed in the 2000 fiscal year.
In 2002, a new program for the development of MRM long-range tank shells was launched. The development of basic MRM ammunition technology is carried out on a competitive basis by ATK and Raytheon in conjunction with General Dynamics Corporation, creating their own variants of projectiles and components of the homing heads. Their main difference lies in the principles of hitting the target. One projectile, designated as Mid Range Munition - Kinetic Energy (MRM-KE), hits a target like a regular tempered projectile due to the high kinetic energy of an elongated rod. The other - Mid Range Munition - Chemical Energy (MRM-CE) hits a target with a tandem-shaped cumulative warhead. The ATK company develops MRM-KE projectile, in the homing head (GOS) of which the millimeter-range radar is used, which allows to “see” through smoke, clouds and fog. The Raytheon and General Dynamics firms are developing an MRM-CE projectile induced by an infrared (IR) 7,62-cm camera. Both projectiles can also be guided with a laser pointer.
US military experts have considered the principle of destruction of armored targets with kinetic munitions containing an armor-piercing core inside and accelerated using a solid propellant rocket engine (RDTT) for a long time. Back at the start of the 80, the army was developing long-range tank munitions with a rocket engine, known as RAKE (Rocket Assisted Kinetic Energy). However, at longer distances in 3 km and more unguided projectile was ineffective due to the lack of accuracy of shooting. From the middle of 80-x, they tried to solve this problem with the help of a guided projectile - “Managed RAKE” within the framework of the X-Rod program, launched by DARPA. First, the development of XNUM X-Rod high-precision armored-piercing active-rocket projectile for the 120-mm smooth-bore tank gun was conducted by two concerns: AAI Inc. and Hercules Defense Electronics Systems Inc., which are currently part of ATK. ATK is an aerospace and defense company that has gained authority in the development of rocket engines, composite materials, and ammunition. The company is also developing for the US Army 120-mm Precision Guided Mortar Munition (PGMM) guided mortar ammunition and a Precision Attack Missile (PAM) engine for the NLOS-LS rocket launcher.
The defeat of the tank on top of the "shock core"
120-mm tank ammunition HM943 STAFF: at the top of the projectile after exiting the barrel, at the bottom of the shot assembly
The layout of ammunition MRM-KE
MRM-KE ammunition: at the top of a guided projectile, at the bottom of a shot assembled with a cut sleeve
The X-Rod projectile began to be developed to extend the life of the Abrams М1А1 tank in the fight against promising tanks and to increase the tank's effectiveness at ranges of 4 km and more. The X-Rod program envisioned the creation of a kinetic guided munition with an accelerating engine, a millimeter-range homing head, which allows for the principle of “fired and forgotten”, and capable of hitting targets at ranges of at least 4 km. According to the designers, the principle of operation of the munition should be as follows. The crew of the machine manually or through the fire control system entered the parameters of the distance to the target. After a shot with an initial speed of 800 ... 900 m / s, the projectile flew along the ballistic curve for most of the trajectory. The rocket engine was activated near the target, accelerating the projectile to a speed of ~ 1650 m / s. The homing head detected the target and guided almost until the collision with the target. On approaching the goal, the GOS and the RDTT were separated from the projectile, and the armor-piercing core was included in the armor. The control technology, which was supposed to be equipped with X-Rod, has already been used on other missiles launched from a helicopter along the ground, and on air-to-air missiles. By May 1992, two GOS and guidance systems had successfully passed tests as part of Maverick air-to-surface homing missiles. For economic reasons, the army closed the X-Rod program, but ATK continued to work on controlled kinetic ammunition in the new TERM-KE program. The program envisaged the creation of the XM1007 projectile, which, unlike the X-Rod projectile, already had a dual-mode homing head (millimeter-wave radar and semi-active laser homing) and an increased firing range to 8 km. The TERM-KE projectile also had to provide a greater likelihood of hitting at increased ranges, both in the line of sight and beyond, an increased probability of hitting and expanding the combat space.
Projectile MRM-KE in flight
Sequential shots of approaching the MRM-KE projectile to the tank and hitting the target
At the end of 2001, the TERM-KE program was also closed. From 2002, further work on kinetic ammunition for a tank gun was carried out within the framework of the Mid Range Munition program, and the projectile was given the name MRM-KE.
The projectile developed by ATK uses the technologies previously used in the X-Rod and TERM-KE programs. The projectile was intended primarily for the tank MCS FCS - a promising combat vehicle developed under the program "Fighting System of the Future", but can also be used on the Abrams М1А1 / 2 tank without constructive changes in weapons. The combined guidance system, like TERM-KE, implements the concept of “shot-forget” and includes a millimeter radar and a semi-active laser homing head. The use of passive laser guidance makes it possible to external target designation, for example, from a T-Hawk class I or a Fire Scout class IV, with which the MCS combat vehicles will operate, which will increase the effectiveness of the projectile (noise immunity and firing accuracy). In the line of sight, target designation can be carried out directly from the side of the tank with a laser target designator-rangefinder.
Scheme of use of the MRM-CE projectile beyond the direct line of sight
The image of the target, obtained by the IR-head of the MRM-CE projectile as it approaches
The MRM-KE is a unitary shot - a single assembly of length 984 mm, consisting of a rocket inside a partially burning cartridge filled with high density (1,45 g / cc) gunpowder elements of artillery charge. The length of the rocket itself with folded 970 plumage mm. In foreign sources, it is noted that "the mass of the rocket is about twice as large as the mass of conventional 120-mm projectiles." If we assume that “normal” means the feathered piercing projectile M829А1, developed by ATK, weighing 9 kg (mass of uranium penetrator (rod) 4,6 kg), then the mass of the rocket should be close to 18 kg.
In order to reduce weight and increase the initial speed of the rocket body is made of composite material. In the tail of the rocket is located plumage and obturiruyuschy (sealing) belt. Since the body is made of composite material and cannot withstand high pressures of the shot, a unique sequential charge ignition system was developed that slows down the ignition of the main charge, allowing the projectile to leave the chamber before the main charge is completely ignited. At the same time, until the obturator belt moves approximately 400 mm and, entering the main part of the barrel, does not block the possibility of high pressure of the powder gases on the rocket body, the pressure in the chamber part should not exceed 70 MPa (about 700 atm.) - pressure that the rocket’s composite hull can withstand.
In the rocket the main place is occupied by solid propellant rocket motors, inside of which there is a long rod - the penetrator, intended for penetration through the armor barrier. In front of the engine there is a compartment with a block of radial impulse correction engines. The power supply battery, instrumental compartment and dual-mode homing are located in the bow.
According to the information available in domestic sources, the projectile should be fired from a gun at a speed of about 1100 m / s and fly to the target along a ballistic trajectory. Next, the solid propellant rocket motor should accelerate the rocket to the speed of 1650 m / s However, given that the rocket occupies more than half of the internal volume of the liner, leaving little space for the igniter and the main charge, obtaining such a high initial velocity is a rather complicated technical task. Nevertheless, preliminary evaluation ballistic calculations carried out showed that the achievement of the stated speeds is quite possible with the mass of the core-penetrator in 3,7 kg, and the mass of the entire rocket around 14,5 kg. So far, on tests, a significantly lower maximum speed was achieved - only in Mach 4, i.e. about 1330 m / s.
Depending on the target range, several modes of solid-propellant rocket motors are possible. The engine can be turned on either immediately after the launch of the rocket from the barrel, or at the peak of the trajectory, or at the final segment. The maximum application range claimed by the developers is 12 km. In the middle part of the trajectory, GPS is controlled by autopilot GPS. In flight, the projectile rotates due to the aerodynamic forces created by the plumage. Accelerometers, located on board, allow you to obtain data on the movement of the projectile, necessary to ensure the correct dynamics of the process of reviewing the search area for the homing head.
The maneuvering of the projectile is due to the pulse correction engines, with a radial arrangement of nozzles. The absence of moving parts in the correction engines allows us to withstand the high overloads that occur during a shot, to ensure high reliability and reduce the cost of the projectile.
According to an ATK representative, Eric Vokman, made in April 2007 at the 42-th annual conference “Weapons and Missile Systems” (Charlotte, North Carolina), “MRM-KE has 2,5 times more kinetic energy than kinetic projectiles for 120 mm guns. The tests showed the effectiveness of the projectile against modern tanks, including those equipped with dynamic protection. ”
MRM-CE ammunition at AUSA 2006, Washington. Shot in the foreground, followed by the projectile itself.
The layout of the ammunition MRM-CE
Tom Wilson, president of the Missile Systems division of ATK, believes that "... with MRM-KE, field commanders will have the opportunity to hit the target with a high probability - one shot, one defeat, at unprecedented distances."
Tests In April, 2004 was successfully tested for the first time in the Yuma, Arizona test site of the MRM-KE. The projectile autonomously conducted a search, aimed, and hit the tank at a distance of more than 4,8 km, while the target was out of sight.
In 2005, during the MRM-KE test at the Yuma test site, ATK became the only company to demonstrate the direct hit of its high-precision projectile on the target. 21 March 2005 ATK received a contract for 23 million USD for the development of a dual-mode seeker. The visual result of the financial support received was the successful test of the projectile in April 2006.
In May, 2006, the ATK company, announced the successful testing of MRM-KE high-precision kinetic energy munitions, conducted in April at the Hume test site. Shooting was conducted from the main battle tank Abrams M1. After flying out of the barrel, the rocket engine dispersed the projectile to a speed around Mach 4. In a test flight, a series of pre-programmed maneuvers were performed, aimed at assessing the projectile's ability to maneuver at high speed. The projectile reached a target at a distance of more than 8,7 km. All test tasks have been completed. The tests also showed the ability of the MRM-KE projectile to withstand overloads more than 13000 d. According to American experts, the level of overloads that the electronics in modern guided artillery shells can withstand is 15500 d. mechanical parts.
The MRM-KE projectile was also tested when firing a new XM360 tank cannon developed for the advanced MCS light tank and showed the declared 12 km range, having actually reached the 12,8 km range at an elevation angle of the 30 cannon. After passing through the muzzle brake, the plumage of the projectile opened normally.
In the summer of 2007, the ATK conducts a series of three shots at the Yuma test site. During the flights, the shells performed a series of programmed maneuvers, fixed by onboard telemetry equipment. All three shells successfully demonstrated the operation of the impulse correction system and the airframe. The tests were carried out in preparation for the competition, which was to be held at the end of autumn 2007. At the same time, in order to increase its competitiveness in the fight for the creation of the XM1111 projectile under the Mid Range Munition program, ATK forms the “MRM Team”, in which included leading armament firms such as Lockheed Martin, BAE Systems, HR Textron, and others.
However, despite such a powerful team and successful preliminary tests, the competition held in December of 2007 was won by Raytheon with its MRM-CE projectile.
At the end of 2007, Raytheon won a competitive trial that allowed it to enter into a contract to complete the development of its version of the projectile. The company has been developing in the field of electronics, space systems, artificial intelligence systems, communications, etc. For the past 50 years, Raytheon has supplied the army with more than 1,3 million high-precision ammunition. The company is also a prime contractor for the Excalibur 155-mm guided missile developed for the US Army and the Extended Range Guided Munition (ERGM) guided munition being developed for the US Navy.
The elements of the main charge cumulative: MRM-CE missile warhead
The MRM-CE projectile in flight with the rudders not yet opened and the head fairing not dropped
MRM-CE dual-mode propulsion seeker on a test bench
Tank Abrams M1A2, prepared for firing beyond the line of sight at the land of Yuma
Just like ATK, in July 2007. Raytheon creates its “team”, teaming up with General Dynamics Ordnance and Tactical Systems to further develop the MRM-CE munition for the US Army. The contract for this program was initially announced by the 21 December 2007 2. 2008. The US Army officially chose Raytheon and General Dynamics to develop the HM1111 munition for the Fighting System of the Future MRS-CE. The contract involves the development and implementation of the system during 63 months, until the second half of 2013.
The MRM-CE projectile is designed to hit modern targets, ranging from heavy armor to bunkers and fortifications. It has a tandem cumulative warhead and a combined homing head. For firing out of the line of sight, a cumulative warhead with its proven ability reliably hits the main armored targets and better effectiveness against secondary targets - buildings, fortifications, and lightly armored vehicles, to date for the US military turned out to be more preferable than the less universal kinetic ammunition.
The projectile is made according to the aerodynamic scheme "duck". Three rudders are located in the front, and the plumage - in the tail. In the bow is placed a dual-mode seeker, closed by a fairing that is discharged after a shot, then the steering unit goes, followed by the leading charge of the tandem warhead, the control unit and the main warhead charge.
The projectile does not have a rocket engine. Due to the presence of moving mechanical parts sensitive to high overloads, the MRM-CE is fired from the barrel at a slower speed than the MRM-KE projectile.
The dual-mode combined homing system consists of an uncooled 7,62-cm IR camera and a digital semi-active laser homing device. When the IR camera is in operation, the head compares images of objects in sight with images of targets stored in its electronic library. The company Raytheon in the head MRM-CE uses the technology obtained during the development of the PAM rocket for the NLOS-LS rocket launcher and the guidance system from the Javelin rocket tested in combat conditions.
The dual-mode head has the unique ability to automatically switch from one target tracking mode to another. For example, initially, the operator, being at the forefront, or UAV, or unmanned reconnaissance vehicle, in the “biased target designation” mode, illuminates with the laser target designator not the target itself, but the area next to the target. Since modern armored vehicles have sensors for detecting laser radiation, highlighting not the target itself, but some of the area next to it, allows the operator not to detect himself. The MRM-CE head is first guided to the laser spot, which highlights the area near the intended target, and then the IR head using the “combining function”, matching the IR images obtained with the images stored in the electronic memory unit, automatically finds a suitable target nearest to stain.
When firing within the line of sight, the projectile will be guided almost in a straight path using laser illumination, or in an image given by an uncooled infrared homing vessel. When firing beyond the line of sight, the projectile is fired at the ballistic trajectory and searches for the target autonomously, either with the help of a laser target designator, or in the “shifted target designation” mode.
Tests The first reports of shooting tests refer to October 2005, when the MRM-CE successfully demonstrated the ability to maneuver according to a given program. Prior to this, the projectile was repeatedly tested in wind tunnels and at various stands.
Approach (highlighted by the oval) and hit by the MRM-CE projectile in the T-72 tank at the Yuma test site
4 in May 2006 was successfully tested on the Hume test site of the MRM-CE semi-active laser projectile head. The purpose of the test was to assess the performance of the laser homing after exposure to overload shots. The shooting was carried out from a tank gun at a moving illuminated target at distances beyond the line of sight. The shot was made in the direction of the T-72 tank, moving at a distance of 8,7 km. The head withstood the load, captured and took on the tracking of the illuminated target and, issuing control commands, sent the projectile to the moving tank. It was the first shot of the planned series of shots from the M1A2 Abrams tank, in order to improve the capabilities of the semi-active laser seeker.
In the next series of tests 25 September 2006, the very first shot of the MRM-CE projectile beyond the line of sight hit the target. The Abrams М1А2 tank fired a projectile with a semi-active laser seeker (in laser guidance mode), which reached an increased range and hit a moving T-72 tank at a range of 8,7 km. The tests have once again demonstrated the capabilities of the laser seeker to successfully detect, capture and escort a moving tank and control the ammunition to intercept the target at the desired range.
In the shooting tests conducted by 1 in March of 2007 at the Hume test site, the MRM-CE projectile demonstrated the most flexible dual-mode homing operation - using the “combining function”. During the flight, the projectile successfully captured the laser spot of the target designator and transferred the function of tracking the target to the infrared camera. The infrared head sent ammunition to a direct collision with a T-72 tank at a distance of 5,2 km. During this test, the target was designated through the procedure of "shifted target designation", minimizing the possibility of exposing and preventing the enemy tank. The laser spot was first used to indicate a location near the intended target. Then, using the “combining function”, IR-GOS found the target closest to the laser spot, corresponding to the target images in its electronic library. According to Rthek Williams, MRM program manager at Raytheon, the projectile fell within inches from the aiming point. Successfully completing the task, ... The MRM-CE demonstrated all the required modes of operation.
December 2007 g. On the Hume test site, tests were carried out to prove the performance of the guidance system after exposure to various factors as a result of a shot. During the December tests, only the IR head was used for the first time. She destroyed the target without preliminary laser target designation. According to the test results, Raytheon and General Dynamics are winning the contract for the development of the XM1111 ammunition for the MCS FCS tank based on the MRM-CE projectile.
19 January 2009 on the Hume test site completed the first series of tests to test the performance of the head in all guidance modes. Two main modes of operation were tested on tests: target designation mode and autonomous. In the target designation mode, the projectile was initially sent to the target using a laser pointer, then switched to the IR targeting mode. In offline mode, a shot was fired in the right direction to the target, then the IR head searched for and captured the target. Shooting was conducted at a distance of 5,2 km outside the line of sight of the target.
Despite the closure of the MRM-KE program at 2007, the principle of killing a tank with the help of kinetic energy will become more and more relevant in the future, as the developed active tank protection systems such as Trophy (Israel), Iron Fist (Israel), Qiuck Kill ( USA), Arena (Russia) will be practically ineffective against kinetic ammunition because of its high speed and mass. Therefore, as has happened more than once before, with the proliferation and improvement of active protection systems capable of fighting only relatively slow-moving ammunition, it is possible that the project to create a kinetic homing projectile in the United States will be further continued.
As for the MRM-CE projectile, then, in the opinion of James Riley, vice-president of one of the divisions of Raytheon Missile Systems, “the ability of the MRM-CE projectile to hit targets beyond direct visibility will give soldiers of the future combat brigade group and Abrams tank the opportunity to engage in battle without contact and win battles while minimizing the loss of friendly forces. "
The MRM-CE projectile has recently been repeatedly exposed at arms exhibitions in various countries. Deliveries of new ammunition for American tanks are expected to begin in 2012. Serial production is planned to be deployed with 2016. The US Army expects to purchase at least 36000 120-mm MRM-CE guided missiles. The cost of the projectile is expected to be around 25-30 thousand USD.
MRM-CE shot at Eurosatory 2008, Paris
Projectile (top) and MRM-CE shot at IDEX-2009. United Arab Emirates, Abu Dhabi