Indian Defence Review

F-35 Lightning II

Many believe that laser DEWs herald the dawn of a new era in military affairs. According to an October 2016 report by Washington-based analysts MarketsandMarkets, the global market for DEWs is projected to grow to $24.45 billion by 2021, at a compound annual growth rate of 28.9 per cent. The main factor driving this impressive growth is the increasing demand for effective defence against missiles and UAVs.

After the Chinese invented  gunpowder in the ninth century, warfare progressively came to be characterised almost exclusively by explosive weapons. Today, no forceful military action is even conceivable without guns, rockets, bombs, missiles, mines, torpedoes and the like. However, dramatic change may be around the corner in the shape of Directed Energy Weapons (DEW). These non-explosive devices use some of the commonest forms of energy such as light and microwaves to achieve destructive or lethal results. Unlike most kinetic energy weapons, these can be fired with pinpoint accuracy and can also be quickly scaled from the non-lethal to the lethal and achieve effects that vary from merely blinding a surveillance camera or incapacitating a person to disabling the engine of a truck or even blasting an aircraft or missile out of the sky.

DEWs are devices that emit highly focused energy such as laser, microwave, electromagnetic radiation, radio waves, sound or particle beams. However, particle-beam weapons are not true DEWs because they use micro-projectiles rather than pure energy. Of these, low-power lasers have been used for many years to guide kinetic weapons to their targets, but High-Power Lasers (HPL) have now emerged from the pages of science fiction to be employed as destructive weapons themselves. Together with high-power microwaves, HPLs have the greatest promise as weapons of war. And it is no coincidence that the United States (US), which has always depended on advanced technology to win war, is in the forefront of DEW research.

Military Edge

Every nation seeks to remain ahead of its adversaries by deploying numerically larger and technologically superior forces. If the US is the world’s dominant superpower, it is due in large measure to its relentless emphasis on research and development into weaponry. For the last few decades, it has reigned unchallenged thanks to its precision strike capability and its use of space based assets for military operations. If US forces needed to drop one thousand bombs to neutralise a certain type of target in the Second World War, they required perhaps a hundred in the Vietnam War and ten by the time of the 1991 Gulf War. Today, the job can be done by just one Air-Launched Cruise Missile (ALCM) or Precision Guided Munitions (PGM) with a high level of assurance of achieving the desired result.

But now the US is not alone as many other countries have such capability. Russia even claims to have developed a hypersonic missile, so fast that practically, it cannot be targeted or intercepted. That is why technologists are investigating new routes to military superiority, including hypersonic missiles, hypersonic rail guns and DEW. All three technologies improve the attacker’s ability to penetrate heavily defended areas and take on time-sensitive targets, by reducing the time of flight before the weapon strikes the target. All require difficult trade-offs regarding their size, weight, range, reliability and accuracy. All need large investments to reach maturity. While hypersonic missiles and rail guns are limited by the number of weapons a warship or aircraft can carry, a laser DEW is limited only by fuel capacity.

Advantage DEW

DEWs are technologically challenging, but their potential is immense. Laser-based DEWs could dramatically lower the cost of offensive and defensive weaponry and reduce collateral deaths and destruction by virtue of their incredible accuracy. Operating at the speed of light, DEWs can respond to fast-flying targets practically instantaneously, track them and then aim and strike. They can easily switch targets, merely by repointing and refocusing their beam-directing optical system. They also promise to be far more effective at countering Unmanned Aerial Vehicles (UAV) and ultimately cruise and ballistic missiles than the expensive interceptor aircraft and air defence missiles currently employed for the purpose. Since they function silently and almost invisibly, it is often hard for the victim to tell where the beam came from. This adds the advantage of plausible deniability – very useful in these times when military as well as law enforcement agencies are under ruthless media glare.

A major feature of laser-based DEWs is their practically unlimited magazines, unlike the restricted capacity of conventional weapons. For instance, a strike aircraft on a mission over hostile territory, becomes like a flying club aircraft after its munitions have been expended. It regains its lethality only after it lands and rearms. Similarly, a warship, a tank or an infantry soldier must be regularly rearmed to remain potent. In contrast, a laser DEW can store thousands of “shots” and continue to operate till the electricity that powers its electronics or the fuel that generates that electricity, runs out. So a combat aircraft equipped with laser weaponry would have much greater staying power than an adversary armed with kinetic armament. Munitions soon get expended, but if the fuel to fire an aircraft’s DEW runs low, the pilot needs only to link up with the nearest orbiting tanker to refuel as well as rearm before returning to the fray. And the same laser DEW can serve for self-defence, say against shoulder-fired missiles as well as for offensive action against a variety of targets.

HPL Jets

The US Air Force Research Laboratory (AFRL) is pinning its hopes on its recently launched five-year Self-Protect High Energy Laser Demonstrator (SHiELD) Advanced Technology Demonstrator (ATD) programme. SHiELD aims to equip a combat aircraft with a small, agile HPL system and so give it an advanced self-defence capability to counter missile threats and enhance its survivability. The programme will need to create adequate on-board power and optics while respecting the weight and size limitations of a combat aircraft.

In a year or so, the AFRL intends to equip legacy aircraft with 50-KiloWatt (kW) pod-based laser systems that can take out soft air and ground targets. To begin with, the launch platform would be the large Lockheed AC-130 Gunship and the Boeing C-17 Globemaster III transport aircraft, both of which have ample space, weight and power supply. The aim of laser DEW would be to shoot down or degrade incoming anti-aircraft missiles or throw them off course by zapping their radar systems or other electronics. This should not be difficult since the most advanced missiles may also be the most vulnerable due to their critical reliance on complex electronics. Depending on the success of miniaturisation, combat jets such as the Boeing B-52 Stratofortress, Boeing F-15 Eagle and even smaller ones like the General Dynamics F-16 Fighting Falcon, may be equipped with bolt-on defensive lasers. Ground testing of a weapon called the High Energy Laser (HEL) has already been completed and the first airborne tests are expected to take place by 2021.

By the early 2020s, laser-based DEWs may have increased power (over 150 kW), range and lethality. Stealth fighters such as the Lockheed Martin F-35 Lightning II would perhaps be equipped with an internally mounted HPL weapon so as not to degrade their low-observable characteristics. The same laser device may fire in a low-power mode for defence or boost power output to “fry” sensitive electronics, sensors or engines of airborne as well as ground targets. In the 2030s, the USAF’s sixth generation fighter which is now in the conceptual stage, will most probably have the capability to attack other aircraft and ground targets using laser weapons. If the power of the device can be boosted to around 300 kW, it could even achieve a “kill”.

LaWS of the Sea

One advantage of degrading or disabling the electronics of an aircraft, missile, vehicle or communication system as against destroying it, is that the adversary might suspect simple system failure and hence not respond forcefully as it would in the event of a conventional hostile act. That is one reason why even low-powered laser weapons may have a bright future. In December 2014, the US Navy fielded the world’s first operational Laser Weapon System (LaWS), a 33-kW device, aboard the USS Ponce deployed in the Persian Gulf. LaWS is a solid-state DEW consisting of six commercial lasers that pump energy into a material infused with certain chemical elements. These elements emit light which is amplified by mirrors and directed at the target. LaWS can only tackle soft-skinned boats and small UAVs, that too only at close range. It can also be used as a telescope or range finder.

Although its capability is none too impressive, LaWS and similar devices may be the best hope to counter the growing threat of UAV swarms. For that, they need to be upgraded to 100 kW or more so that they can burn a hole through the skin of their target more quickly. UAVs are becoming ridiculously cheap and even rudimentary ones can carry small munitions. Equipped with improved artificial intelligence, a large swarm of armed UAVs could mount a coordinated attack against a target. And a warship equipped with today’s guns and missiles would be powerless to defend itself against such an assault.

There is also the economic angle. Does it make sense to launch a highly expensive missile against a very cheap UAV? The current defensive systems would either quickly run out of ammunition or neutralise the UAV swarm only at a cost of thousands of dollars per missile. On the other hand, LaWS type of weapons could promptly take out several incoming UAVs at a cost of less than a dollar per shot. And warships would be only too happy to dispense with the explosive laden magazines that currently render them highly vulnerable to a direct hit by a PGM.

There is a vast difference between a lab laser and an operational weapon, so LaWS is a significant milestone. In battle, the laser DEW’s Size, Weight and Power consumption (SWaP) must all be low, yet it must be rugged and have enough power output to be effective. Laser weapons also produce copious amounts of waste heat as they fire repeatedly and to keep them cool is another formidable challenge. For instance, in the General Atomics High Energy Liquid Laser Area Defence (HELLADS), a coolant flows right through the solid lasing medium to extract waste heat. HELLADS has achieved 50 kW power output and weapons engineers believe it can be scaled up much further.

Gas-powered or Solid-state?

The older gas-powered and chemical-based lasers are high-powered, but do not meet the SWaP requirements to operate from an aircraft or tank. On the other hand, the latest electrically powered solid-state lasers are fairly light and compact, besides being robust and reliable. But since their power output is nowhere near the megawatt level of chemical lasers, they cannot engage distant targets. Hence efforts are on to develop a 100-kW solid-state laser device which would be suitable at least as a tactical weapon. With a range of approximately four kilometres, it could be employed for Counter Rocket, Artillery and Mortar (C-RAM) and counter-UAV tasks.

As a laser beam passes through the atmosphere, it is subject to diffraction, absorption and turbulence. To maintain its effective range and lethality, it must retain its focus and resist being degraded by the atmosphere – also known as good beam quality. Indeed, one of the biggest challenges of laser weapons design is to ensure good beam quality while boosting power output. A large aperture helps shrink the beam focus, but increases the size and weight of the assembly.

Fibre-based lasers that use optical fibres as the lasing medium, are a promising avenue for research; their advantage – superior beam quality and ease of cooling. Irrespective of the type of laser, the ultimate aim is to develop a powerful HPL weapon that falls within the SWaP limitations of a ship, aircraft, tank or other surface vehicle.

CHAMP – the Microwave Champion

High-Power Microwave (HPM) devices are second only to lasers as DEW candidates. These focus microwave energy to knock out power grids, disrupt electronics systems or prevent anti-aircraft missiles from locking on to the target. The USAF’s Counter-electronics High Power Microwave Advanced Missile Project (CHAMP) is a technology demonstrator intended to develop an air-launched HPM weapon that can degrade or damage hostile electronics systems. It is planned to be mounted on the Lockheed Martin JASSM-ER cruise missile. This is how it will work. The JASSM-ER will probably be launched from a stealth aircraft, manned or unmanned. Its CHAMP payload will then generate a concentrated beam of microwave energy, directing pulses of thousands of volts towards a target building or small area. This will trigger a deadly power surge in the victim computers, mobile phones, vehicles and even tanks. The damage will occur in seconds and may be permanent.

Another type of HPM weapon under development persuades unruly crowds to disperse without killing anyone by rapidly raising their body temperature. It could be a useful alternative to the reviled pellet guns.

India Lagging

India is far behind in the high stakes DEW race. But with the Defence Research and Development Organisation (DRDO) now prioritising DEW development in its technology perspective and capability roadmap, the situation may gradually improve. The DRDO has already built several basic laser systems to disarm mines and Improvised Explosive Devices (IEDs), vehicle-mounted dazzlers to disperse crowds and hand-held devices that can detect explosives or overpower armed intruders. It is currently developing a 10-kW vehicle-mounted DEW for possible use against UAVs at ranges of up to five km. DRDO’s Laser Science & Technology Centre (LASTEC) in Delhi, is responsible for the development of lasers for directed energy applications as one of its major missions. However, most DRDO projects are plagued by huge time and cost overruns so it is anyone’s guess when Indian combat aircraft, ships or tanks will be armed with indigenous laser DEWs. The budgetary allocation too is nowhere near what the military would like and it is inevitable that tanks, ships, aircraft and explosive weapons will take priority over DEW.

Space War

Apart from the US, several nations including Russia, China, India, UK, France and Israel are now overtly or covertly researching DEWs. Reports from Russia claim that military technologists have developed a DEW powerful enough to destroy or disable the electronic guidance and navigation systems of manned and unmanned aircraft as well as PGMs. China too is making rapid progress in DEW research. And space is an arena driving both nations’ quest for DEW weapons.

Russia and China are aware of the American military’s critical reliance on GPS navigation and tactical battlefield networking that is achieved through a large constellation of intelligence, communication and navigation satellites. Therefore, they are investigating DEW devices specifically designed to take out satellites and render the US “blind” and directionless. It is believed that Chinese military technologists have been trying for over a decade to develop DEWs against space assets in order to neutralise America’s formidable strategic advantage. Since China cannot hope to overtake the US in military hardware for years, if not decades, it is the obvious thing to do. And as China’s space programme is inherently dual use, it would not be difficult to orbit a laser Anti-Satellite (ASAT) weapon in the guise of a peaceful civilian satellite, only to bare its fangs as and when the need arises.

Wonder Weapon or Pie in the Sky?

Many believe that laser DEWs herald the dawn of a new era in military affairs. According to an October 2016 report by Washington-based analysts MarketsandMarkets, the global market for DEWs is projected to grow to $24.45 billion by 2021, at a compound annual growth rate of 28.9 per cent. The main factor driving this impressive growth is the increasing demand for effective defence against missiles and UAVs.

And yet the difficulties facing DEWs should not be underestimated. Apart from the high cost of development, insufficient funding and inadequate testing facilities, they face major technological challenges. Governments too cannot be faulted for being somewhat sceptical of claims of imminent breakthroughs because the billions of dollars already spent on DEW research, have largely failed to deliver. Indeed, laser DEWs may rank among the most over-hyped weapons of war ever. Shorn of the more optimistic claims, their practicality in war is still in doubt. It speaks volumes that the US Navy’s LaWS is still the only operational DEW in the world. Kinetic weapons also offer many capabilities that DEWs probably never will. Therefore, for the foreseeable future DEWs will complement rather than replace conventional munitions.

Finally, every new weapon system attracts a counter sooner or later. The US Office of Naval Research already has a Counter Directed Energy Weapons (CDEW) programme to find new ways of defending against hostile HPL, HPM and other DEW. Given the publicity surrounding US efforts to develop cutting-edge DEW capabilities, it is a safe bet that Russia and China are feverishly trying to develop their own countermeasures. And some may be fairly simple. For instance, since any type of airborne particle diffuses laser energy, heavily polluted air is itself a defence. China reportedly plans to generate copious amounts of black smoke around high-value targets to frustrate American laser weapons. Other measures being contemplated include special coating to reflect or redirect hostile lasers and special materials to dissipate the heat generated by the beam striking the target so as to avoid or delay destruction. Some types of electronic equipment can also be hardened to resist an HPM attack. And just as there are anti-missile missiles, defensive lasers may serve to track the laser emitter and then use a dazzler to disrupt its control system.

DEWs have the potential to be a game-changer as they transform current concepts of warfare and weaponry. But with a classic cat-and-mouse game starting between the developers of DEW weapons and the countermeasures enthusiasts, it is by no means certain who will win.