“This is my goal: If it’s in line of sight of a ship, the first solution that we’re using is directed energy.”
Adm. Daryl Caudle summed up the reason the U.S. Navy destroyer USS Preble is of interest to anyone following the process of modern ships being made smaller and cheaper to defend against small uncrewed threats. Preble has since been revealed to have deployed its 60-kilowatt-class High-Energy Laser with Integrated Optical Dazzler and Surveillance (HELIOS) to kill four uncrewed aerial vehicles as part of an at sea counter-UAS demonstration a very early indicator of shipboard lasers becoming operationally viable equipment.
The difference between HELIOS and the previous bolt-on experiments is the extent to which the systems are overlaid on the ship. The laser is known as Aegis combat system, which is to be used within the Aegis combat system, which is to detect, track, and fire on the target in the same decision-making loop as the guns and missiles already used by a destroyer. The fact that it integrates is as important as raw power: the time distance between sensor track and weapons-grade aimpoint is reduced, and lasers are either “repeatable” or a laboratory novelty.
A laser has always fascinated a ship, and the magazine depth is its attraction. In the traditional close-in defense, rounds are limited, missiles are limited and when a ship burns its inventory, it is not as simple as stopping at the gas pump. A laser switches the arithmetic and transforms fuel and electrical capacity into the number of shots to put commanders with a means to reserve the high-quality interceptors to the threats that do necessitate their usage. An analysis of Congress has a number of times pointed out that the marginal cost of the shot is generally pegged at the cost of electricity generation, which is usually estimated at approximately 1 to less than 10 per shot, and that this contrasts with the duration of stay of a ship in the battle before it “going Winchester.”
The four-drone engagement by Preble, however, also brings out the trap: the capacity is added by lasers but not limits. A shipboard laser is a line-of-sight weapon, and when one can see a target, the power of the beam becomes less effective over distance as the air steals power and turbulence blows the point. The tax of moisture and salt has its share, whether it be beam propagation or mere resistance of optics to a marine climate. A laser must also remain long enough on one object to cause disabling damage, and then move to the next object, and this limits the saturation of a single emitter.
The most mundane constraint is the one that is likely to determine the scalability of lasers on a fleet level: power. According to a Congressional Research Service report summary, even the latest Flight III Arleigh Burke destroyers are already stretched by massive electrical demands, and Navy officials have cautioned that installation of a system such as HELIOS may need equipment deletion, or very aggressive power management. It is that trade space which narrows as the ambitions increase to 60 kilowatts up to the 300-600 kilowatt range which the Navy has discussed as the ambition of future ships.
Then HELIOS can be taken as a supplementary layer, not substitution layer: a utility to drones, and other sorts of “minor aerial threats,” and a means of saving missile stocks subjected to reuse cycles. The demonstration made by Preble illustrates that the beam can be returned to the sea more than once and be shot against several targets in the air. The tougher engineering push the implementation of more power, cooling, and ruggedized optics in warship-sized packages, remains to be determined that far by the idea.
