Indian Defence Review

Advanced Tactical Laser, attached to C130-Hercules

All at Sea

The US Navy is making great strides in the development of DEW with its Laser Weapon System (LaWS) now in the final stages. After installation on an operational warship, the USS Ponce, LaWS is slated to undergo field trials or what the Navy calls an “at-sea demonstration” in the Persian Gulf in early 2014. A solid-state laser weapon, it is claimed to be effective against targets such as Unmanned Aerial Vehicles (UAV) and speedboats and has reportedly destroyed at least one test UAV. Since the weapon needs neither propellant nor explosives, it can continue firing so long as power is available. As compared with hundreds of thousands of dollars expended by a single missile launch, a laser shot might cost just a dollar. With unmanned devices proliferating across the globe, a device like LaWS that could destroy enemy UAVs cheaply would be a huge advantage.

LaWS is designed to be plug-and-play. It can be retrofitted on warships with minimal modification, using existing targeting systems and power. To begin with, it is envisaged that LaWS would be employed only against small boats and slow-flying UAVs. The intruder might first be illuminated by an intense beam of light to warn it to turn away. If that doesn’t work, high power can be selected to destroy the offending craft. A significant advantage would be the system’s reduced logistics trail since refuelling would also serve to replenish laser power, thus ‘rearming’ it.

Most laser weapons are flexible. At the flick of a switch they can be used for less-lethal applications such as weapon targeting or to heat objects so as to make them easier for infra-red trackers to acquire or merely to dazzle pilots. Electronic systems, electro-optical sensors and infrared systems on enemy aircraft, surface vehicles, ships and submarines can all be degraded.

However, the system may be easily overwhelmed because the rate of ‘fire’ is restricted by the time needed to illuminate one target before turning to the next. The environment at sea may also be unfavourable. Heaving seas, saltwater, sea spray, fog and rain – all impede a laser weapon’s accuracy and effectiveness. Most current lasers are inadequate against a variety of threats because they are not powerful enough. That is why laser weapons are intended to supplement rather than replace conventional weapons onboard a ship. Lasers also need to become much more efficient. They currently waste about 70 per cent of the energy they consume as useless heat, heat that needs more power to dissipate. These enormous quantities of power can only come at the cost of the engine and other onboard systems unless the ship is redesigned from scratch.

Beamed Terror

A top terrorist is out on an evening walk. The area is remote and there are no potential threats in sight, so the heavily-armed bodyguards maintain a discreet distance from their leader, allowing him a few moments of privacy – perhaps to mentally plan his next attack. Suddenly the guards hear a scream and see their chief writhing on the ground in flames. While some run to his assistance, the rest quickly scour the surrounding area and scan the clear sky. They see nothing, hear nothing. Then it is all over. Their leader appears to have been felled literally by a bolt from the blue. The only clues on the body are smouldering clothing and intense burn marks akin to a lightning strike. High up in the sky, a distant plane turns away and relays a ‘mission successful’ message to its command post thousands of miles away.

Such a fictional attack using a directed-energy beam may not be possible today. But the US Air Force has long been exploring laser weapons. In 2008, the Advanced Tactical Laser (ATL) that generated infra-red light of lethal intensity was fitted on a C-130 Hercules transport plane. It was succeeded by a larger version, inside a modified Boeing 747-400F, that was intended against missile launches. The Boeing YAL-1 Airborne Laser Testbed (earlier known as Airborne Laser) was meant to destroy Tactical Ballistic Missiles (TBMs) while in boost phase. It was claimed to have destroyed at least two test missiles in 2010. However, the US financial crisis took its toll and the programme was cancelled in December 2011. According to experts, to be operationally effective against a missile being launched, the laser would need to be 20 or 30 times more powerful than the tested which clocked in at about 100 Kilowatts. Although the YAL-1 was abandoned as financially unviable, the possibility of mounting the same laser on high-flying Unmanned Combat Air Vehicles (UCAV) is being considered.

An attacker with an airborne laser weapon has several advantages. To begin with, although the beam is silent and invisible, it enables a terrifyingly precise attack that can leave a deep impression on eye witnesses. The spectacular effects on a human target include instantaneous burst-combustion of clothing and rapid death through violent trauma. Whenever a shock attack happens, especially such a mysterious one, quick evaluation and decisions are demanded. For instance, after the alleged chemical attack in Syria in August, investigators were expected to deliver a swift verdict on whether the attack was indeed chemical and who the perpetrator might be. However, a doctor or investigator arriving at the scene of a directed-energy strike would be unlikely to have any previous experience of ‘death by laser attack’. There would be no bullet or weapon fragments to identify the originator of the attack. The investigators might not even categorically conclude that a laser was involved. This would give the attacker the added benefit of plausibly denying involvement in the attack.

Focus on the Future

Although laser weapons are becoming increasingly possible, practical military devices may still be some years into the future. Significant issues remain to be addressed. For instance, the strength of the beam is greatly reduced by clouding, rain, haze or even dust. Lasers also waste most of the energy they consume as heat. To avoid damage due to overheating, they must be supported by bulky and heavy cooling equipment. A possible way to make a laser weapon more thermally efficient might be to use cheap, high-temperature superconductors. But the device would still need a convenient source of plentiful electricity storage or generation.

According to directed-energy technologists, laser power is increasing, system weight is decreasing and the quality of the beams is improving. Importantly, the aim is getting better. Since overheating needs to be prevented, it may currently be more practicable to deploy laser weapons to defend fixed assets where water and power availability need not be major problems perhaps for the defence of a nuclear plant. At sea, too, a large nuclear-powered carrier would have abundant power and unlimited water for effective cooling.

However, to mount an effective laser device on a combat aircraft, it must be lightweight, compact, not too thirsty for power and easily cooled. This is currently a tall order. And if fitting a sufficiently powerful laser on a plane is still a tough proposition, present techniques are totally inadequate to produce a practical handheld laser weapon – a classic ray gun that can instantaneously beam death and destruction.