Progress For Laser Defenses

The U.S. Navy has a prototype grade 400 kW laser, which is a significant improvement on past efforts. Ideally, a laser can destroy incoming drones, shells, and missiles at a minimal cost per shot with an ammunition supply that never runs out. The more powerful the laser, the less time it needs to keep its beam on target to sufficiently damage to target to prevent it from striking. 

Public records about these weapons have been coy about just how much time on target is needed, how far away the target can be, and what countermeasures or atmospheric conditions can prevent it from working. So, it is hard to know if it is ready for prime time yet. And, 400kW still isn't really all that powerful. That's just the power of a fairly powerful commercial electric car or truck (it is equivalent to about 300 horsepower). But, there is little doubt that more power is better, even though scaling up the power of a military laser presents serious technical challenges. If we can get to a ready to deploy 400kW defensive laser by 2026, perhaps we can get a megawatt defensive laser on line by 2030.

When it is ready for prime time, this active defense could be revolutionary, and could (together with electronic warfare methods and electromagnetic pulses to disrupt guidance systems and kinetic interceptors and new lighter armor materials) end the one shot, one kill era of smart bombs, guided missiles, and one way armed drones that persisted for about thirty years, in a major victory for defense, after a sustained period of time in which offenses have largely overcome armor and maneuverability.

Ships and point defenses for forward operating bases are a natural place to start, because the size and weight of the system isn't too critical. This could be the difference between large surface warships being viable or not, a vulnerability that the Secretary of Defense is well-aware of himself (not that anything he says should be given too much credibility, particularly since his budget is driven to a great extent by fear of a Chinese military threat):

In a rare admission, US Defense Secretary Pete Hegseth has said that the Chinese hypersonic missiles can destroy all US aircraft carriers in just 20 minutes.

“So far our [US] whole power projection platform is aircraft carrier and the ability to project power that way strategically around the globe,” said Hegseth in a recent interview.

However, Hegseth added that China’s 15 hypersonic missiles “can take out 10 aircraft carriers in the first 20 minutes of the conflict,” added Hegseth. . . . 

According to a US Department of Defense (DoD) report published in December 2024, China’s hypersonic missile technologies have greatly advanced during the past 20 years. Many PRC missile programs are comparable to other international top-tier producers.

China’s deployment of the DF-17 hypersonic glide vehicle (HGV)-armed medium-range ballistic missile (MRBM) will continue to transform the People’s Liberation Army’s (PLA’s) missile force, the DoD added. The system, which was fielded in 2020, may replace some older short-range ballistic missiles (SRBM) units and be used to strike foreign military bases and fleets in the Western Pacific. The DF-27 may have an HGV payload option in addition to conventional land-attack, anti-ship, and nuclear payloads. Official Chinese military writings indicate this range class spans 5,000–8,000 km (3,107–4,971 miles), designating the DF-27 as an intercontinental ballistic missile (ICBM), and the local media indicates that it can potentially range as far as Alaska and Hawaii. On July 27, 2021, China tested an ICBM-range HGV that traveled 40,000 km (24,854 miles).

In April 2019, the PLA Navy revealed during its 70th-anniversary celebration that its new guided-missile cruiser can employ long-range, land-attack cruise missiles and, in 2022, launched the YJ-21 hypersonic missile designed to defeat aircraft carriers.

According to the DoD, China has the world’s leading hypersonic missile arsenal and has dramatically advanced its development of conventional and nuclear-armed hypersonic missile technologies.

But imagine a system like that retrofitted into a C-17 or a B-52, that would go from having no defense but flares, to being able to destroy multiple incoming anti-aircraft missiles in flight before they do any harm, or to a military satellite that could destroy missiles intended to destroy it before they hit.

According to the contract announcement, the goal is to design, integrate, and test a high-powered directed-energy subsystem suitable for deployment aboard naval vessels and potentially land-based platforms.

At the heart of the effort is creating a 400-kilowatt-class laser weapon. This will be achieved by combining multiple 50-kilowatt laser modules into a unified beam supported by a precision beam-control assembly. Such a design is key to scaling laser systems to higher powers without compromising beam quality or accuracy.

The technology is being pursued for defensive purposes, like shooting down drones, missiles, and potentially hypersonic weapons, as well as other military uses, including remote sensing and battlefield illumination.

While the Pentagon has disclosed few technical details, industry experts note that this level of directed-energy output would represent a major leap in laser weapon capabilities. By comparison, most current operational laser systems deployed by the Navy, such as the Laser Weapon System (LaWS), have outputs of around 30 to 100 kilowatts.

A 400-kilowatt system would potentially allow US forces to intercept faster and more robust targets at greater distances, burning through drone bodies or missile casings within seconds of contact.

From Interesting Engineering.

Less obviously, high powered lasers might provide naval ships with intermediate options between sinking an opponent's ship and doing nothing, a challenging task when, for example, the Chinese Coast Guard or paramilitary merchant marine ships harass Filipino fishing vessels, and a naval escort vessel would like them to stop without causing an international incident.

A 400kW laser isn't going to sink a seaworthy ship in most cases. But it could inflict controlled and measured damage, like destroying the offending ship's radar, or some of its communications equipment, or one of its hydraulic control lines, or it reconnaissance drones, or one of its weapons, that would encourage the offending ship to back off. And, it could do so with minimal risk of causing collateral or otherwise unintended damage.