Advanced gun system for DD-X to expand commander's options.

The U.S. Navy's future destroyer, the DD-X, will change radically the concepts associated with naval surface fire support.

The DD-X will accomplish fire-support missions with the Advanced Gun System, which will launch precision-guided projectiles at a range of up to 100 nautical miles.

The highly automated 155 mm (6.1-inch) gun will answer Marines' call for fire as they move further inland faster. AGS also will support joint and coalition expeditionary ground units, including Marines, Army and special operations forces.

"With the increased range and speed of expeditionary mobility assets, the landward area of influence of naval forces has increased by an order of magnitude. Consequently, the nation requires weapon systems with correspondingly greater range, lethality, flexibility and tactical mobility," said Gen. Michael W. Hagee, commandant of the Marine Corps. "Our expeditionary forces ashore will remain at considerable risk for want of suitable sea-based fire support until DD-X joins the fleet in significant numbers."

The new gun, which can be described as a "trainable rocket launcher," will fire a GPS (Global Positioning System) guided, rocket-assisted round called the Long Range Land Attack Projectile, among other munitions, at targets up to 100 nautical miles away, with a sustained firing rate of up to 12 rounds per minute.

By comparison, the maximum range of the 5-inch/54-caliber Mk 45 naval gun currently used in the fleet is 13 nautical miles. The Navy now is installing the 5-inch/62-caliber, Mk45 Mod 4 naval gun on new Arleigh Burke (DDG 51)-class destroyers and will back-fit it on Aegis cruisers as part of the cruiser conversion program. The improved 5-inch/62 will shoot the Extended Range Guided Munition, currently being developed by Raytheon, to a maximum range of 63 nautical miles.

The Long Range Land Attack Projectile planned for DD-X will deploy from a fully automated gun and magazine, will contain three times the ERGM payload, and will have 60 percent more range, as well as other advanced features.

"AGS has a multiple round simultaneous impact capability to coordinate simultaneous delivery of multiple rounds," says Scott Leitch, of United Defense, the AGS manufacturer. "You can fire six rounds, one right after the other, at the same target, with slightly different trajectories, so each round impacts the target at the same moment."

The multiple round simultaneous impact capability can be used against targets up to 75 percent of the gun's maximum range, says Leitch. For AGS, that means multiple rounds can be fired simultaneously at targets up to 75 nautical miles away.

Two different loading systems ate being considered for the advanced gun. The standard loading system can fire 12 rounds per minute. A vertical load version is 38 tons lighter than the standard loading system and rakes up less space, but has a slightly reduced rate of fire. Both loading systems will fire the same rounds. The magazines in both options are highly automated. The Navy has not decided yet which loading system will be employed.

Concept of Operations 

Naval fires complement and augment the capabilities of the Marine Air Ground Task Force. The range and capabilities of the new naval guns will prepare the battlefield before expeditionary forces arrive, and will deliver rapid and accurate close support once they have arrived.

The AGS is being developed as a part of the DD-X program. Completion of the gun system's preliminary design review is expected later this year. A design review for the LRLAP projectile is scheduled for fiscal year 2004. The first AGS installation on DD-X is planned for fiscal 2008, and will achieve its initial operating capability in 2013.

Under development by SAIC and Lockheed Martin, the seven-foot long, 155 mm LRLAP will contain 24 pounds of explosives, considerably larger than the seven pounds of explosives in the 5-inch ERGM. Initial LRLAP rounds will be GPS guided, but future rounds may be laser guided, or employ submunitions similar to XM-80 bomblets or sense and destroy armor (SADARM) munitions.

The AGS-equipped DD-X will complement the towed M198 howitzer, now in-service with the Army and Marine Corps, and the Army's M109 tracked howitzer. All these guns may one day share common 155 mm ordnance.

In addition to the AGS, DD-X will carry the next-generation Tactical Tomahawk cruise missiles, along with the gun-launched projectiles to support expeditionary maneuver forces.

The TACTOM will provide a precision strike capability for targets more than 1,000 nautical miles away. The TACTOM, made by Raytheon, features an in-flight reprogramming capability to strike preprogrammed alternate targets or to redirect the missile to new GPS target coordinates. In addition to its unique ability to loiter over a target area for several hours, the missile uses a built-in television camera, allowing commanders to assess battle damage in real time. A spotter on the ground also can illuminate a target with a laser to guide the TACTOM to it. The missile recently completed successful demonstration test flight trials. It will join the fleet in 2004, and will be deployed in both surface combatants and submarines.

DD-X will employ an Advanced Vertical Launch System, which is a different concept than the MK41 Vertical Launch System currently used in the fleet. The AVLS cells surround the ship in separate four-cell launcher compartments along the periphery of the ship's hull, improving the ship's survivability and war-fighting capability. AVLS will support a variety of offensive and defensive missiles.

The DD-X will have a local area air defense capability, anti-surface and anti-submarine capabilities delivered by a package of traditional organic sensors, unmanned vehicles, and two armed SH-60 Seahawk helicopters. The Cooperative Engagement Capability system will assist in the theater ballistic missile defense mission, and will employ a detachment of unmanned aerial vehicles.

"Our naval surface fire support programs will contribute critical precision and volume fire support to maneuvering forces ashore from the sea, complementing aviation assets and ground-based artillery," said Rear Adm. Donald Loren, the Navy's deputy director for surface ships.

DD-X will be followed on the construction ways by the CG-X cruiser, which will be designed with a common or scalable hull. Larger, faster and longer-range missiles will allow CG-X to counter state-of-the-art air threats hundreds of miles over operating areas ashore and to perform other missions well in the littoral. Equipped with a new generation of air defense radars under development to counter low-radar cross section threats at extended ranges, CG-X will detect, track and engage ballistic missiles outside of the atmosphere.

RELATED ARTICLE: Survivability not just about heavy armor, says Cebrowski.

The Pentagon's transformation chief, retired Vice Adm. Arthur Cebrowski, endorsed the U.S. Army's Future Combat System for its emphasis on information-based warfare and speed. The FCS, he said, will help prove that heavy armor is no longer the dominant in a ground war.

Recent battles in Iraq, Cebrowski said, proved that speed and integrated information networks were key to defeating the enemy.

"I look at these marvelous Navy and Air Force munitions and what they do to armor. I look at what one of our own tank rounds does to everyone else's armor in the world," he said at a breakfast with defense reporters. "I go, well, you know the notion that steel protects you, just doesn't seem to be there, because it doesn't protect in the absolute. Nothing protects in the absolute. What you, therefore, want is a mix of things.

"Do I want to take all tanks out of the force? No. Do I want to take tanks as we know them out of the force? Probably yes," he noted. "If I can have a 35-ton tank [...], a lighter tank with same protection and lethality, I'd much rather have the lighter one, because I can move it faster.... That is one of the reason why I like Army's transformation program in the FCS."

Armor is not the only answer to the survivability problem, he added. "Just as in some cases, it is really nice to have armor, in a lot of cases it doesn't help you. It didn't help 17 dead sailors on board the [USS] Cole, for example. That is a steel ship. And so you don't see Navy talking about adding more steel to its destroyers. Instead it reaches for other things to create the protective environment."--Roxana Tiron

Edward Lundquist is the communications director at the Center for Security Strategies and Operations of Anteon Corporation. The company provides information technology and engineering services to the Defense Department and other government agencies.