Direct and indirect fire: the Multi-Role Armament and Ammunition System (MRAAS) for the multi-mission FCS.

The following article describes one of several possible scenarios for the design and operation of the future combat systems (FCS) for the Objective Force. The technologies described in this article are still under development and have not been tested on an FCS prototype. In FY03, the Army will make the decision as to the design of the FCS, including the type and calibers of the weapon systems and which technologies to incorporate. Ed.

In 1999, the Defense Advanced Research Projects Agency, (DARPA), Arlington, Virginia, in conjunction with the US Army Training and Doctrine Command (TRADOC) with its headquarters at Fort Monroe, Virginia, initiated the FCS Program for the Objective Force. This program will leverage advanced technologies in platforms, sensors, communications, lethality and unmanned systems, including robotic ground vehicles and unmanned aerial vehicles (UAVs).

The FCS force has specific goals for strategic deployability, lethality and sustainability. For example, the FCS unit of action (brigade-sized) has a deployment goal of weighing only 25 percent of today's heavy brigade. Additionally, this force must be more lethal, emphasize standoff precision engagement and be capable of closing with and destroying the enemy. FCS must be effective across the spectrum of conflict, including stability and support operations (SASO), and operate in all environments, including urban.

About this same time, the Assistant Secretary of the Army for Acquisition, Logistics and Technology approved an Advanced Technology Demonstration (ATD) to be run by the Tank-Automotive and Armament Command-Army Research, Development and Engineering Center (TACOM-ARDEC) at Picatinny Arsenal, New Jersey. The ATD is designated the Multi-Role Armament and Ammunition System (MRAAS), the subject of this article, and includes developing an integrated direct and indirect firing capability on a common chassis.

MRAAS will be mounted on an FCS chassis to produce an advanced strike system to perform multiple functions on the battlefield of 100-by-100 kilometers. TRADOC provided initial guidance for MRAAS to be capable of providing lethality overmatch in the direct fire mission and full-spectrum lethality in both the red zone and shaping zone fights. (The red zone is the FCS-based force's standoff engagement area approximately 12 kilometers away from the enemy.)

TACOM-ARDEC began working with DARPA, TRADOC and industry to develop a high-technology armament system that will serve as one of the key FCS strike platforms and underpin the Objective Force's ability to dominate maneuver and fires throughout the battlespace.

Operational Concept. Developing an operational concept facilitated understanding the multi-role tactical requirements of the MRAAS system. The concept exploration scenario was one in which a joint task force (JTF) commander requested an FCS force for a rapid deployment mission. The force included MRAAS and other platforms consistent with emerging FCS concepts.

The scenario investigated the actions of a notional decisive operations unit (DOU) consisting of MRAASs, reconnaissance and surveillance (R&S) platforms, infantry fighting vehicles (IFVs) and responsive accurate munitions modules (RAMM). RAMM is another TACOM-ARDEC science and technology objective investigating a fully robotic indirect fire module that shoots conventional and special purpose 120-mm mortar munitions out to 15 kilometers.

In this operational concept, systems were inserted by parachute or immediate follow-on air transport landing on unimproved combat runways at a distance of about 75 kilometers from the threat force. The threat provided a robust baseline of battlefield targets, including tanks, light armored vehicles, cannons, rockets, missiles, trucks, helicopters, mortars and soldiers in the open and in fortified fighting positions.

Immediately after landing, the DOU dispersed. Due to limited airlift, the force did not bring UAVs. Instead, a RAMM launched a limited-dwell UAV, called QuickLook, that flew to the threat area and provided a live feed for targeting purposes.

MRAAS oriented and commenced standoff engagements at ranges out to 50 kilometers. Each FCS system had a predetermined mixture of munitions that was weighted toward attacking the threat through long-range standoff fires while maintaining an air defense and direct fire capability.

MRAAS steadily moved toward the enemy, continuing to destroy enemy targets. Based on his systems' ammunition expenditure and movement rates, the DOU commander requested precision airdrop resupply between his force and the threat; MRAAS systems independently moved to dispersed pallets and resupplied.

The fight had unfolded rapidly, and MRAAS guns needed a quick ammo resupply. Resupplying ammunition at this point allowed systems to tailor the load for the last 25 kilometers of the fight when beyond-line-of-sight (BLOS) and direct fire engagements would prevail, but long-range engagements also might be needed. As a three-gun MRAAS platoon resupplied, the other platoon continued to rain lethal fires on the threat.

Soon all MRAAS systems had resupplied and moved to within 25 kilometers of the threat force. As FCS IFV systems repositioned to assault the flank of the enemy, RAMM systems robotically followed, providing what amounted to hip-pocket fire support to the infantry.

Quite predictably, the threat launched a helicopter counterattack. JTF assets detected this launch, and DOU assets were cued where to look.

When picked up by the R&S platform and MRAAS sensors, systems designated for the short-range air defense role immediately received the necessary targeting information. When the threat helicopters arrived within 12 kilometers of the flank MRAAS systems, the helicopter blips disappeared from the joint surveillance and target attack radar system (JSTARS) operator's screen. Soon, MRAAS closed with and executed direct fire engagements to destroy the enemy systems attempting to escape the RAMM and FCS IFV assault.

MRAAS Capabilities. The concept exploration highlighted a number of capabilities MRAAS should have. First, the scenario showed the special logistical implications of the fight. The wide range of targets suggested the need for MRAAS to have an ammunition suite both tailorable and multipurpose. C-130 precision delivery and MRAAS' ability to self-upload ammunition was an underpinning capability. The log platform and the MRAAS platform should be designed to fully automate re-supply of ammunition, fuel and water.

But the overriding lesson from the scenario was the utility of a single platform's ability to provide fires across a full-spectrum of targets throughout the depths of the battlespace. But is this possible... a single platform that can serve as a direct fire, indirect fire and an air defense system?

Assessing this possibility lies in investigating the technologies of the armament and ammunition subsystems that underpin this vision.

MRAAS Subsystems. Trade studies conducted at TACOM-ARDEC selected a 105-mm cannon as the primary armament system for MRAAS because the cannon met future lethality requirements on the lightest platform. A 25-mm objective crew-served weapon is the secondary armament system.

MRAAS has five armament subsystems: ammo handling/resupply, weapon control, chassis integration, turret design and launcher.

Ammo-Handling/Resupply. Central to the MRAAS resupply vision are advances in resupply packaging, materials delivery and platform reloading. As described in the scenario, there should be a precision air-delivery capability to insert ammunition.

Work on precision parachute delivery is being done at Natick Labs in Massachusetts. Initial studies show a load equipped with a global positioning system (GPS) receiver likely could be delivered to within 10 meters of a specified location, thereby facilitating pinpoint and dispersed enroute resupply during MRAAS unit movement.

Under development today is the enhanced delivery system-air (EDS-A), a modular transportation platform to be used by air, land or airdrop delivery systems. Up to three MRAAS vehicle loads of water, fuel and ammo will fit on each modular platform. Analysis suggests this configuration will require 40 percent fewer aircraft sorties over the current 463L system configuration.

Ammunition will be prepackaged in five-round clips weighing less than 350 pounds or about half the weight of equivalent lethality in missiles.

Although the initial deployment weight of a gun platform may be slightly higher than a missile platform, that difference is more than made up with the first resupply. For equivalent stowed-kills, follow-on resupply loads of 105-mm munitions will weigh about one-half that of missile loads.

This suggests that, overall, MRAAS will be significantly less burdensome on the logistics system.

And resupply will be easier on the individual soldier, too. Advances in robotic technologies will allow the MRAAS chassis to have manipulators that will move ammunition clips from the modular platform into position to refill the platform's magazine. While TACOM-ARDEC engineers are investigating different concepts for this capability, initial modeling analysis suggests an ability to upload ammunition in about one-third of the time it takes now. The system also will be able to be reloaded manually.

Weapon Control. Technical weapon fire control capabilities will be vastly superior to current systems--MRAAS will engage targets more accurately than ever before. The key to this will be the advanced stabilization of the tube and a closed-loop sensor system. A dynamic muzzle and tube reference sensor will provide information to computer controllers that will direct electric motors to dampen tube movement. Other sensors will monitor the entire system's status continuously, including mechanical problems, such as boresight alignment, tube wear and tube movement.

Embedded passive radio frequency sensor tags will provide ammunition identification and instantaneous propelling charge temperature to the fire control and inventory management systems. Environmental sensor tags inside the case telescoped ammunition (CTA) rounds will update the status of the munition as it rests in the magazine as well as allow for total asset visibility and unprecedented inventory control.

Enhanced stabilization and continuously updated system status will allow predictable weapons performance and accurate firing computations and enable accurate direct and indirect fires while on the move.

Electro-thermal chemical (ETC) is an advanced technology that features the conversion of electrical energy to a high-temperature plasma that is used to augment ignition of the propellant bed. ETC will allow the precision ignition of the propulsion system.

The temperature of the propellant and projectile determines the amount of energy required to ensure a predictable, repeatable performance for every round fired across the operational temperature range. A new advanced propellant (Gen II) is being developed that features a high-energy formulation with a progressive burning configuration and decreased sensitivity.

Chassis Integration. TACOM-ARDEC's vision is that it will be possible for MRAAS to fit on the platform selected for FCS but also will integrate onto others. The MRAAS module will weigh five tons and comprise about one-third of the weight of the overall platform. Fully combat loaded with weapons systems' basic loads and fuel, the platform will weigh approximately 16 to 18 tons, be C-130 transportable and have platform mobility and agility equivalent to other FCS platforms.

Turret Design. The current FCS design calls for a compartment with a two-man crew to operate the vehicle and serve as a man-in-the-loop for the fully automated firing process but be totally separate from the firing event.

A second compartment will house the MRAAS. This arrangement facilitates future transitions to teleoperated and, ultimately, a fully robotic capability.

MRAAS Launcher. The launcher assemblies are some of the most interesting technological advances. Perhaps most challenging are those techniques to manage recoil.

The current MRAAS design envisions a variable recoil mechanism. Traditional recoil designs allow very rapid controlled rearward motion of the cannon assembly to absorb the energy of the fired munition.

Variable recoil will use advanced cylinder designs and valve switching technologies to control system hydraulics. Variable recoil will adjust and shorten the recoil stroke, accommodating the nature of the munition and the elevation fired.

Shortening recoil will mean less intrusion of the gun and chamber into the body of the vehicle. This will have three benefits. First, there will be more space for stowed rounds. The gun will be able to fire at higher elevations. And last, the gun will be smaller, more compact and lighter.

However, significant pressure and energy still will be transferred during firing. To move from the existing 40- to 60-ton systems of today to an 18-ton system of the future is no minor challenge. The gun mount and cradle still will undergo significant stress and, therefore, must be built of high strength/strong materials.

The tube must have consistent pointing performance. If too rigid, the tube is subject to structural failure during firing. If too flexible, the variable directional pointing of the tube throws inaccuracies into the firing computations.

New technologies and better engineering has resulted in the development of high-quality forged and rolled steel that is selectively wrapped and specially bonded with composites for increased strength, predictable rigidity and less weight.

Handling this stress also requires unique applications of many other advanced materials. But how does one achieve the strength of steel without incurring the weight? One technology of particular note is isogrid structures that have the high strength-to-weight characteristics of honeycomb structures.

These structures will offer the strength and hardness (stiffness) of steel plate at a fraction of the weight. By specifically designing the shape of the honeycomb structure, the material will be matched to the magnitude and direction of the force being applied. What results will be a very efficient structure, ultimately allowing tremendous overall weight reductions.

Within the launcher, an autoloader and swing-chamber mechanism will translate the projectile from the ammo magazine to the loader to the breech. The autoloader will work at any of MRAAS' firing elevations and permit loading on the move. A controlled velocity rammer will result in consistent ramming and also eject empty casings.

While swing-chamber mechanisms have been demonstrated in smaller caliber systems, the development of cased ammo capable of sealing the chamber to the gun tube in this dynamic environment is challenging. Nevertheless, the benefits of a swing-chamber mechanism make it an extremely desirable characteristic.

It will require smaller space than fixed chambers and associated autoloading mechanisms, resulting in more room available for ammunition storage. This also will contribute to achieving an operating elevating range of minus-10 to plus-55 degrees--not insignificant in urban operations. Swing-chamber mechanisms have demonstrated burst rates in excess of 20 rounds per minute.

MRAAS Ammunition Suite. The overall objective of the MRAAS munition suite program is to develop mature concepts and technologies for a small family of munitions capable of defeating the full spectrum of threat targets. TACOM-ARDEC established a baseline ammunition suite comprised of three fundamental types of rounds: an advanced kinetic energy (KB) precision round, a multipurpose extended-range munition (MP-ERM) and a smart cargo round. At the time of this writing, TACOM-ARDEC was in the process of selecting up to two industry teams to begin developing and demonstrating these rounds.

Precision munitions will be key to MRAAS as they improve both the probability of hit and probability of kill for each engagement. The capability to destroy targets beyond the effective standoff of the enemy will be particularly important for the survivability of the MRAAS platform as aggressive weight goals limit the amount of platform armoring. Instead of a heavy armored outer shell, platform survivability will be enhanced by a combination of an active protection system (APS), reduced system signature and enhanced situational awareness that enables standoff engagement.

Among precision munitions, there are common technological advances. First, all the projectiles are being designed to fit within the CTA cartridge case, thereby producing munitions that are self-contained and shorter than the current 105-mm munitions. Breech and chamber seals are an important element of the CTA system, so the cartridge case will incorporate composite casing with a self-sealing capability. After firing, the empty case simply will eject as part of the autoloader function.

Other common technologies include the ETC ignition and Gen II propellant previously discussed.

Advanced KE Round. For line-of-sight (LOS) defeat of heavy armor threats, MRAAS will fire an advanced KE round. The key technologies associated with the advanced KE munition will include composite sabot and a novel penetrator, which will be designed to defeat the current and future heavy armor threat.

MP-ERM Round. This round will offer an exciting capability to deliver short time-of-flight, multi-mode effects from two to 15 kilometers. This round will incorporate an on-board target acquisition capability enabling accurate engagement of LOS, BLOS and non-line-of-sight (NLOS) targets.

The projected target set goes beyond that mentioned in the scenario. Defeating a wide-range of targets with a single munition is a key challenge. To accomplish this, TACOM-ARDEC currently is developing two multipurpose warhead technologies. In one technology, explosively formed projectile (EFP), tactical fire commands inform the projectile to take on one of four selectable configurations: single-slug anti-armor; multiple-slug anti-armored personnel carrier; small-pellet anti-vehicle/UAV/helicopter; and anti-personnel fragmentation. In the other technology, an advanced shaped charge forms an explosive jet into either a single or multiple fragment effect.

In both of these technologies, the development priorities are to get the right level of armor penetration, add the multipurpose capability and then improve the round with more powerful explosives that occupy less volume.

Smart Cargo Round. This will be the final member of the ammunition suite. This munition will be used to attack armored systems, urban structures, bunkers and infantry formations and assembly areas.

The concept for the smart cargo round is to develop a lightweight round capable of carrying multiple payloads deep into the shaping zone. Possible payloads include unitary munitions, dual-purpose improved conventional munitions (DPICM), smart submunitions and nonlethal munitions, such as incapacitants.

To achieve the desired range, the smart cargo round will be fired to a given altitude and then glide to the target. In-flight updates on the target location are essential to modify the round's trajectory and achieve a high probability of target engagement at great distances. To accomplish this, the smart cargo program is leveraging technological advances involving novel applications of antennae to receive updates and advanced guidance systems coupled with GPS.

Challenges. Integrating a capability of MRAAS' significance has its challenges. There are many operational, technical and institutional issues to overcome. Issues can be as simple as planning the proper ammunition mixes or as complicated as integrating a cooperative engagement capability within the MRAAS weapon control system in order to attack air defense targets.

Technological challenges include hardening sensitive electronics--such as those associated with guidance and control or electronic safe and arming--to withstand the high forces associated with a gun launch. Another challenge is miniaturization of munition guidance systems; one promising example is a micro-electromechanical system inertial measurement unit (MEMS IMU).

Maintaining 155-mm equivalent lethality in cargo rounds with a 105-mm projectile requires a number of these technologies to merge. As with any system, there will be significant software and hardware integration issues.

There also are considerations as to the technical, tactical management and leadership skills required in the young lieutenants and NCOs who will command the multi-role systems. Their skill sets will be subsets of those capabilities found in today's Infantry, Armor, Field Artillery and Air Defense leaders. The impact on the institutional training base and across doctrine, organizations, materiel, leader development, personnel and facilities will be enormous.

While MRAAS will contribute significantly to accomplishing the FCS goal of providing a rapid deployment and early access capability to Army forces, it also will have relevance in other areas. It will have particular utility in economy-of-force operations. Because of its multi-role capability, MRAAS will be able to serve as the central strike platform in a variety of missions, including reconnaissance and surveillance, force screening and rear area combat operations. MRAAS would be particularly useful to forces conducting deep raids or other special missions. Because MRAAS will be relatively light, resupply will be an enormous plus, especially when conducting distributed offensive operations.

This system will have no limitations across the full range of special environments in which Army forces will be asked to operate. Its multi-role capability will make it particularly relevant in military operations in urban terrain (MOUT) and SASO.

MRAAS will not only be key to FCS brigades, but also it likely will have immediate application to special capability forces--airborne, air assault, special operations forces (SOF) and Marine expeditionary forces (MEFs).

Yes--it's possible for a single platform to serve as a direct fire, indirect fire and air defense system. In terms of indirect fire, we will be able to achieve a range out to 50 kilometers using an 105-mm cannon mounted on a 18-ton common platform to provide effects throughout the 100-by- 100 kilometer battlefield. If the Army selects MRAAS for its objective system, it could begin fielding by 2012.

With its baseline ammunition suite and its multi-role mission capability, MRAAS will underpin the FCS concept and provide the Objective Force the ability to dominate maneuver and fires.

Mark A. Ford is the Project Manager for the Multi-Role Armament and Ammunition System (MRAAS) Advanced Technology Demonstration (ATD) at the Tank-Automotive and Armament Command-Army Research, Development and Engineering Command (TACOM-ARDEC) at Picatinny Arsenal, New Jersey. He has coordinated the design, modeling, analysis and demonstration of lethality concepts for Crusader, the Future Scout and Cavalry System (FSCS) and many other programs, several with robotic applications. He joined ARDEC in 1984, working first in the Fire Support Center on missile control systems. He holds a Master of Science in Electrical Engineering from Polytechnic University in Brooklyn. He was named the Distinguished Engineer of the Year 2000 by the North Jersey Section of the American Society of Mechanical Engineers and is a certified member of the Army Acquisition Corps.

Colonel (Retired) John H. Northrop, under contract with TACOM-ARDEC at Picatinny Arsenal, is responsible for identifying the relevance of MRAAS to future operational concepts and system requirements and MRAAS' relationship to the Future Combat Systems. Before he retired in 1998, he was the Chief of the Joint Requirements and Assessments Division of Force Development (FDJ) in the Office of the Deputy Chief of Staff for Operations and Plans at the Pentagon. He commanded the 3d Battalion, 7th Field Artillery, 25th infantry Division (Light) at Schofield Barracks, Hawaii, and commanded a firing battery. He was the S3 and then Executive Officer in the 3d Battalion, 319th Field Artillery in the 82d Airborne Division, Fort Bragg, North Carolina. He is a graduate of the National War College, Washington, DC, and holds a Master of Science in Organic Chemistry from the Georgia Institute of Technology.