Investments in science and technology today are shaping the battlefield of tomorrow. The Navy is conducting exciting research into futuristic and exotic weapons such as lasers, electromagnetic railguns, and hypersonic weapons. These weapons expand the range and reduce the time to target while reclaiming battlespace to counter high-speed, maneuverable threats.
While some of these systems may seem like science fiction, the research and development of such weapons means they may be ready sooner than many people think.
That’s why the Office of Naval Research (ONR) is investigating high-risk, high-payoff game-changing technologies that are disruptive in nature. “We may develop a material technology, or some software, or electronic warfare innovations that would then go into a program of record to be produced for future delivery to the fleet or the Marines,” said Rear Adm. Nevin P. Carr, Jr., chief of naval research.
Innovative Naval Prototypes (INPs), such as ONR’s electromagnetic railgun (EMRG), are examples of such disruptive technologies.
“INP efforts are often discontinuous, disruptive, radical departures from established requirements and operational concepts,” said Carr. “The goal is to prove the concepts and mature the technology within four to eight years, allowing informed decisions about reductions in technological risk to govern transition into an acquisition program.
Carr continued, “It’s not enough just to do interesting science. What matters is transitioning the products of that science to the warfighter.”
“The electromagnetic railgun is a totally different way of launching projectiles. It works off electromagnetic force. It’s extremely powerful. It does not involve any energetics in the projectiles, so you move all of the explosives out of the magazine,” said Carr. “Because of the way this technology works, we can accurately launch projectiles over 200 miles that arrive in about 6 minutes. The projectile leaves the barrel at about Mach 7 and arrives on target at about Mach 5, and its destructive power is based on that kinetic energy. The mass of a projectile is important, but it’s the square of the velocity that delivers far more destructive potential. The railgun may also have some applications for missile defense that we’re studying very closely, as well as long-range surface fires.”
Another example of a disruptive technology is directed energy. “The directed energy we’re focusing on right now is the Free Electron Laser [FEL],” Carr said. “You can tune it to wavelengths in the atmosphere that are less absorbent, and you can also scale it up to very high levels of power. So the FEL is an example of a disruptive technology that can change a lot of the way we do things, from sensing and tracking to countermeasures to kinetic defense and destruction of incoming targets.”
In congressional testimony last year, Carr stated, “The FEL INP will enable the Navy to fight at the speed of light by bringing high-power laser technology to sea for ship defense. This project will develop a laser for use in the maritime environment, consistent with Navy plans for an all-electric ship. The FEL provides intense beams of laser light tuned to atmosphere-penetrating wavelengths, allowing us to assess the potential of laser-based shipboard defense strategies.”
An FEL requires a linear accelerator. There has been significant research into nuclear physics and accelerator technology at various national laboratories such as Jefferson Labs in Newport News, Va., which conducts basic research of the atom’s nucleus at the quark level; Los Alamos National Laboratory, which conducts basic and applied research in accelerator and particle physics, space experimentation, nanotechnology, and materials; and the 2-mile-long Stanford Linear Accelerator in Menlo Park, Calif., which conducts astrophysics, photon science, accelerator and particle physics research; and at the Brookhaven National Laboratory on Long Island and the Oak Ridge Electron Linear Accelerator Pulsed Neutron Source in Tennessee. The challenge for the Navy is to put a linear accelerator inside a ship.
Even the fastest interceptor missiles take seconds to minutes to reach their targets, but a laser beam can focus on a target almost instantly.
“We invest in science and technology so that we will have the best weapons in the world,” said Dr. Quentin Saulter, directed energy program manager for the Office of Naval Research. “We want to have the ability to have speed-of-light engagements of targets, anytime, anyplace.”
The threat is real, and it’s growing. Agence France-Presse reported on Feb. 7, 2011, that “Iran is mass producing a new ballistic missile that can travel at more than three times the speed of sound and hit targets on the high seas.”
Press reports state that a Chinese Dong-Feng 21 anti-ship ballistic missile (ASBM) travels at Mach 10 and can reach targets 1,200 miles away in less than 12 minutes.
Despite superior capabilities today, the United States and its allies might lose a war of attrition. “We have $15 million missiles that can shoot down $5 million ICBMs [intercontinental ballistic missiles],” said Under Secretary of the Navy Bob Work. “We’re on the wrong side of that equation.”
“The ‘cost exchange ratio’ – the cost of the attacker’s weapon compared to the Navy’s marginal cost per shot for countering that weapon – currently often favor the attacker, sometimes very significantly,” said Ronald O’Rourke, a naval analyst with the Congressional Research Service in a December 2010 report to the Congress.
With lasers, a low marginal cost per shot could permit the Navy to dramatically improve the cost exchange ratio. “Converting unfavorable cost exchange ratios into favorable ones could be critical for the Navy’s ability in coming years to mount an affordable defense against adversaries that choose to deploy large numbers of small boats, UAVs [unmanned aerial vehicles], anti-ship cruise missiles (ASCMs), and ASBMs for possible use against U.S. Navy ships,” he said.
Electric weapons cost considerably less, basically the cost of fuel to generate the electricity to charge up the weapon. The power for the Navy’s December 2010 33- megajoule (MJ) electromagnetic railgun shot at Naval Surface Warfare Center in Dahlgren, Va., came from the local power utility, and cost about $7.00.
Carr said how you manage that energy, move it around the ship, switch it, and have it available becomes very, very important. “Sometimes you need a very large amount of energy in a short amount of time – as in launching a projectile – or sometimes you need lower amounts of energy over longer periods of time. So how you design and build that kind of environment in a ship is an area that requires some of our best and brightest research.”
“Compared to existing ship self-defense systems, such as missiles and guns, lasers could provide Navy surface ships with a more cost-effective means of countering certain surface, air, and ballistic missile targets,” O’Rourke said. “Ships equipped with a combination of lasers and existing self-defense systems might be able to defend themselves more effectively against a range of such targets. Equipping Navy surface ships with lasers could lead to changes in naval tactics, ship design, and procurement plans for ship-based weapons, bringing about a technological shift for the Navy – a ‘game changer’ – comparable to the advent of shipboard missiles in the 1950s.”
The Maritime Laser Demonstration (MLD) system, an ONR program that was tested last year at the Naval Surface Warfare Center (NSWC) in Port Hueneme, Calif., was able to track surface targets such as swarms of small, fast boats at long ranges in a marine environment.
“Such lasers would complement other defensive systems to address certain threats more effectively and at lower cost than traditional weapons,” said Steve Hixson, vice president of Space and Directed Energy Systems for Northrop Grumman Aerospace Systems, the MLD contractor.
Lasers are ultra-precise and can be used as both a sensor and a weapon. They offer unlimited magazine depth to defend ships against challenging threats such as hyper-velocity anti-ship cruise missiles. Because of their level of precision, targets can be engaged with minimal collateral damage, and the power output can be adjusted so that Navy ships can deliver nonlethal or lethal force to targets as appropriate. Power can be adjusted depending on range and size of the target and the desired effect.
“Precision” is a system concept, and laser systems (not just the lasers themselves) have their challenges when it comes to precision. A laser generates power, but that energy has to be sent through an optical system that must focus the beam on a small, distant target for several seconds to achieve its kill. This optical train is on a flexible structure, itself on a flexible ship that is indeed flexing in a moving sea. Also, atmospheric disturbances distort and move the beam around. “Because of these challenges, today’s lasers and those projected for intermediate term tactical application are best suited to slower moving, ‘soft’ targets such as UAVs and small boats,” said an industry source.
Unlike a weapon with a finite number of bullets, lasers have a “bottomless” magazine – as long as you can generate power, you can shoot. Because railgun projectiles have no propellant and no explosive warhead, a ship can carry many more of them in less sophisticated magazines. But what goes up must come down, so a bullet or missile that doesn’t destroy a target has to land somewhere. If over the ocean, it poses less of a problem, but over populated areas it can be an issue.
Solid state lasers (SSLs) are common in factories where they are used for cutting and welding metal, and they can be adapted for military purposes, as well.
The Navy is testing an SSL prototype called the Laser Weapon System (LaWS), which shows promise for soft and hard kills. (A “hard kill” involves destroying the target, while a “soft kill” usually confounds or neutralizes the target without permanent damage. Jamming an attacking aircraft’s radar so it has to turn back would be a soft kill.)
Another kind of laser is the chemical laser, like the system on the Airborne Laser Test Bed, a modified 747, where chemical reactions produce the energy. But when the chemicals are expended, the ship must be resupplied.
Research continues to develop lasers that have higher power levels and improved beam quality, as well as managing the large amounts of power required. The temperatures involved will require special cooling. For the weapon to be practical, it will need to be fully integrated into the combat management system and the battleforce network.
All naval weapons must operate in a harsh environment, and that presents challenges for lasers, too. Using lasers in a marine environment must take into consideration the waves, sand, smoke, dust, water, and salt and other atmospheric effects in the air that can diffuse, scatter, absorb, or defocus a beam of light. Surface targets are harder to hit because of these factors.
BAE System’s John Perry said his company is teaming up with Boeing to offer a 10-kilowatt SSL that can be mounted onto the Mk. 38 machine gun currently used for surface ship force protection. For that reason, there is very low impact on the ship for power, weight, or space, Perry said. “You get speed-of-light delivery and a bottomless magazine, and whatever you point at you’re going to hit.”
For example, Perry said the laser can be aimed at a belt of 50-caliber ammunition on the deck of an attacking craft and cause the rounds to detonate on board.
The laser can be used to “burn the eyes out” of an anti-radiation missile, or burn out the engine control unit of an attacking vessel. The lethality can be increased by increasing power as needed.
“This is basically a COTS [commercial off-the-shelf] system, used in manufacturing. The automotive industry uses these lasers cutting steel 24/7,” Perry said.
In addition to lasers, other types of directed energy weapons (DEWs) include microwave weapons and millimeter-wave weapons. The Active Denial System (ADS) is a millimeter-wave electromagnetic energy transmitter that can be used for force protection. The millimeter waves heat up the surface of the skin. An individual who tries to get too close to a ship or structure protected by ADS will experience an incapacitating burning sensation that can only be reduced by turning around and moving away. ADS is non-lethal, and leaves no ill effects.
EMRGs are also disruptive technology in nature.
These weapons seem simple in principal. Grid power replaces gun powder. Electricity travels down a rail, passes through an aluminum armature and back down the other rail, creating an electromagnetic field pushing the projectile that propels it out the barrel.
“It uses electricity instead of gun propellant to fire a projectile from a naval gun,” said Roger Ellis, railgun program manager for the ONR. “Energy stored in a capacitor bank is released into a railgun in a matter of milliseconds, creating an electromagnetic field behind the projectile that pushes out at Mach 7, or 2½ kilometers per second.”
The Navy recently conducted a demonstration at the Naval Surface Warfare Center (NSWC) at Dahlgren. The 33-megajoule test firing on Dec. 10 was a world record. An ambitious campaign is under way using the laboratory gun at Dahlgren to test different combinations of rails, projectiles, and other materials at that power level to learn what works best.
“Pulse power” allows the weapon system to store energy and then release it quickly enough to create the powerful force to propel the projectile.
The gun can be used as an offensive weapon to strike positions hundreds of miles away, and because the warhead is inert – meaning it doesn’t carry an explosive charge – collateral damage at the target can be minimized. But the lack of high-energy explosives in the warhead doesn’t mean the target will not be damaged. The kinetic energy of the projectile traveling at such high speeds is destructive on impact.
“The rounds can be guided and dispense fragmentation munitions just before hitting a target, such as ground forces, ships, or radar installations,” said Charles Garnett, the project manager at NSWC Dahlgren.
The railgun eliminates the gun propellant used to fire the projectile out of the barrel, and the high-explosive warheads as found on conventional guns. The rounds take up less space and do not require the same special handling or storage as explosives do.
There is still much to learn about railguns.
“The performance capabilities of a future railgun weapon system can be significantly improved through advanced material innovations and breakthroughs,” said Ellis.
“The same force ‘pushing’ the round down the barrel also wants to push the rails apart,” said Ellis.
Because launching projectiles from railguns involves such enormous amounts of electricity, the materials used for the power systems, rails, barrels, and projectiles are critical. For example, the ability to store power generated by the ship requires new battery technology, and the ability to discharge large amounts of power instantaneously requires sophisticated capacitors, all of which require new system interfaces between high-power loads and platform power distribution, and it all has to fit onto a ship.
“The launcher and pulsed power EM railgun system elements require high-conductivity, high-strength, low-density conductors, as they are subject to high heat and damage phenomena resulting from current concentrations,” said Ellis.
The Navy is studying extended service life for materials and components; high-strength, dielectric, structural materials; high-speed, high-current, metal-on-metal, sliding electrical contacts; compact pulsed power systems and power electronics; high-conductivity, high-strength, low-density conductors; and repetitive rate switches and control technologies.
Nanomaterials, composites, surface treatments, tailored alloys, and phase-change materials are example areas where recent technological advances may enable new methods of meeting these railgun challenges.
The test round looks different from a real railgun bullet. The “warshot” will have an aerodynamically shaped bullet surrounded by a sabot and an armature pushing from behind. The sabot falls away outside of the barrel as the bullet continues to the target.
“The projectile requires high thermal resistance, a low coefficient of thermal expansion, and erosion/ablation-resistant materials to deal with in-flight temperatures and heat flux experienced while traversing the atmosphere,” said Ellis.
ONR is studying aerothermal protection systems for the bullets – or flight vehicles – and high-acceleration tolerant electronic components and structural materials so they will survive the extremely high g-force.
Right now, each firing must be managed individually. ONR’s goal is to demonstrate the thermal and power management that will produce an auto-loading gun capable of a repetitive “firing rate of military significance,” which means the power system can charge the capacitors then discharge them quickly to fire the gun in a repetitive manner for multiple firings in a short period of time.
The high-power long-range railguns require a ship capable of generating, storing, and making available large amounts of power. The Zumwalt-class DDG 1000 guided-missile destroyer is such a ship, built from the keel up with the power for energy weapons, and the sophisticated power electronics needed to move power around where it is needed. Alternatively, an energy storage module can be used on ships with smaller amounts of prime power.
While an EMRG can be used as a long-range strike weapon from larger platforms like the DDG 1000, the concept can also be applied to smaller guns, and therefore smaller combatants. The goal is to test the laboratory EMRG at the 64- to 80-MJ power level, which will have the muzzle energy to achieve the desired 200-plus nautical mile range for naval surface fire support (NSFS) missions. The Navy is also looking for potential early transition of a smaller multi-mission system that could support missile defense, long-range strike, and surface warfare. ONR has funded both General Atomics (GA) and BAE systems to develop 32-MJ advanced composite railgun prototypes to be delivered to the government for testing and evaluation. Unlike the laboratory launcher, which is designed to facilitate testing, these guns look very similar to the gun mounts on combatants today.
The General Atomics “Blitzer” is a multimission EMRG system suitable for smaller platforms. “Initial studies by GA indicate that a railgun system with a muzzle energy of 20 MJ can fit into the space presently occupied by the 5-inch gun on DDG 51-class of guided-missile destroyers,” said Thomas Hurn, director of advanced weapon launcher systems for General Atomics. “A 20-MJ EMRG is a very capable weapon system that can engage supersonic, sea skimming, anti-ship cruise missiles [ASCM] at the horizon as well as defend against ballistic missiles. In addition, this system can support offensive indirect fire missions such as anti-surface warfare and NSFS at ranges significantly farther than today’s gun systems – up to around 100 nautical miles.”
Hurn says GA has collaborated with General Dynamics Armament and Technical Products (GD-ATP) in Burlington, Vt., experts in magazine and auto-loader systems. “We have determined that approximately 1,000 rounds can be stored for the EMRG we envision. “That’s about twice the number of rounds carried in the 5-inch gun magazine today.”
Blitzer can be integrated with the existing combat management system to provide target queuing and tracking, Hurn said. “For direct-fire ship defense missions, the high muzzle velocity of an EMRG provides the rounds with fast times-to-target and longer ranges compared with conventional guns. These longer ranges require the use of guided projectiles in order to be accurate enough to defeat the threat.”
Hurn said GA and Boeing are collaborating on a system that uses command guided projectiles for ship defense missions. “The ship’s onboard sensors track the target and the outgoing EMRG projectile, and command the projectile to intercept the incoming threat. The per-round cost is kept lower, and the per-round reliability is kept higher using command guidance. The projectile would be an airburst round and deploy tungsten penetrators near the target to enhance the probability of kill. The command guidance required for this mission could be integrated into existing fire control systems.”
For precision strike missions over the horizon, the Blitzer round would be guided using GPS and Inertial Navigation System (INS), Hurn said.
Some tried-and-true weapons continue to evolve, as do ways to employ them. The Standard Missile family of missiles, which joined the fleet in the 1960s, now has new versions with range and capabilities far beyond anything its designers anticipated. Today, the Standard Missile-3 (SM-3) can shoot down a ballistic missile in space. In fact, this weapon was used successfully to hit an errant satellite that posed a potential threat upon reentry. This remarkable ability was derived from the Aegis Combat System and the SM-3.
Another version of the Standard family, the SM-6, has range that exceeds the sensor range of the Aegis SPY-1 radar on the launching ship. The SM-6 carries an active seeker head and can acquire and home in on targets without guidance from the ship in flight. In fact, the Navy’s Navy Integrated Fire Control-Counter Air (NIFC-CA) combines the capabilities of Aegis and the SM-6 with Cooperative Engagement Capability and the new carrier-based E-2D Hawkeye Airborne Early Warning (AEW) aircraft, which can tell the SM-6 where to go to find its target, far beyond the ship that fired the missile.
The DDG 1000 has an entirely new gun, called the Advanced Gun System (AGS), that is planned to fire the 155 mm rocket-assisted Long-Range Land Attack Projectile (LRLAP). The GPS-guided LRLAP can fly 63 miles and more and hit targets with precise accuracy. This Navy system benefited from technology leveraged from the U.S. Army’s 155 mm Excalibur round.
Chief of Naval Operations Adm. Gary Roughead, speaking at ASNE Day 2011, sponsored by the American Society of Naval Engineers, mentioned the Navy’s centennial of Naval Aviation and pointed at some new technologies and systems that will be joining the fleet. He cited the recent first flight of the unmanned combat air system carrier unmanned attack aircraft and successful launch of a tactical aircraft from an electromagnetic launch system, which will replace steam catapults at sea. Roughead pointed to new aircraft like the P-8 Poseidon maritime surveillance aircraft and the EA-18G Growler, which will replace the EA-6B Prowler in the electronic attack role, and the E-2D Hawkeye. New unmanned aircraft such as Broad Area Maritime Surveillance (BAMS), the Navy’s version of the Global Hawk, and the MQ-8 Fire Scout are also becoming operational.
The U.S. Navy: More Than 50 Years of Laser Technology
From scalpels to corrective eye surgery to weapons, laser technology has advanced from scientific curiosity to scientific fact since the first successful laser demonstration on May 16, 1960, by Theodore Maiman at Hughes Research Laboratory, Malibu, Calif. The Office of Naval Research (ONR) sponsored the Shawanga Lodge Quantum Electronics Conference that brought laser physicist-inventors together to brainstorm the technology in 1959.
ONR also invested in the maser, the precursor technology to the laser, in the late 1940s-1950s. Researchers sought a means of using short-wavelength radiation to investigate molecular structure. The result was the maser, or “microwave amplification by stimulated emission of radiation.” Once developed, researchers soon began work on the idea of replacing microwaves with light. The laser and its numerous commercial applications soon followed.
Researchers at ONR are applying laser technology in naval maritime defense. The Navy and Marine Corps’ science and technology provider is developing a laser that promises to change warfighting at sea.
This article first appeared in the Defense, Spring 2011 Edition.