Can Lasers Be Used To Intercept Hypersonic Weapons? In the past three decades, significant advancements have been made in intercepting and destroying incoming ballistic missiles, cruise missiles, and high-value high-speed uncrewed aircraft.
This shift has transpired with the advancements made with major air and missile defense (AMD) batteries.
Qingtian Hypersonic Cruise Missile. Screenshot.
Platforms first introduced during 1991 Operation Desert Storm, like the US-made Patriot system, have seen dramatic improvements in their range and engagement envelope by introducing more modern interceptor missiles and much more effective radars.
Despite the recent experience of a Patriot battery operated by the Ukrainians intercepting a Russian Kh-72 Kinzhal hypersonic missile, this is an act far more challenging than one might imagine. A good deal of the probability of success depends on the speed of the incoming missile.
Numerous and varying reports have been made as to the Kinzhal’s maximum speed, ranging from Mach 4 to a top velocity of Mach 10. That creates a challenging scenario for intercepting the Kinzhal based on the missile’s actual speed.
The time that a Patriot battery would have to be able to identify, track, and then destroy a hypersonic Kinzhal target would be 109.3 seconds if traveling at Mach 4 to only 43.7 seconds if moving at its maximum Mach 10 speed.
Additionally, this intercept timeline assumes the missile was at a distance of 150 kilometers out when first detected. This would mean that a Patriot crew would have only two minutes from the moment that the missile was first detected, then would have to launch a counter missile to intercept the Kinzhal, which does not fly at hypersonic speeds, to the actual hit-to-kill impact on the incoming target.
Options Other Than Missile Interceptors
Given these very narrow intercept windows, there has been a search for more advanced technology that could better defend against hypersonic weapons. Again, one of the main complications is that hypersonic weapons of any kind—this includes cruise missiles, glide, and boost-glide vehicles—travel at Mach 5 or higher speeds.
Then, there is the factor that most of these systems have some level of in-flight maneuverability. All the while, they tend to fly at lower altitudes and travel on very difficult-to-track trajectories. This makes intercepting these weapons far more complicated than taking out a traditional ballistic missile in the terminal phase.
Lockheed Martin demo video of laser system. Image Credit: Lockheed Martin video screenshot.
Options being researched to develop countermeasures to hypersonic weapons include high-power lasers, microwave weapons, railguns, and hypersonic interceptors. Another possibility is using what are sometimes described as “soft-kill” options like cyberattacks.
Cyberattacks can disable or otherwise compromise a hypersonic vehicle’s flight or navigation module. This option of looking for a single point of failure can confuse, overload, or otherwise shut down a guidance system while the weapon is en route to its target.
A cyber weapon can be equally effective at shutting down land- sea- or airborne-based launch platforms instead of the weapon itself. Critical subsystems, such as receivers for satellite navigation signals or the computer-operated control surfaces on the vehicle, can also be spoofed.
Use Of Lasers For Missile Defense
Since the 1990s, “blue-sky” research projects have examined the possibility of using lasers for missile defense. This is an ideal option in theory and better than all the other methodologies for several reasons.
One is that—as detailed above—using a kinetic-kill missile defense system is problematic. It requires detecting the hypersonic vehicle at a long distance, and even then, the crew of a ground-based system like a Patriot batter has only seconds to respond.
Using soft-kill options is effective, but there needs to be a high level of confidence that a cyberattack can get past firewalls and other onboard protection protocols. There is also the reality that the exploited vulnerability will eventually be identified, the “back door” into the hypersonic weapon system will be remedied, and this option will be closed off.
In comparison, lasers have the virtue of being a countermeasure system that literally sends a burst at the speed of light. It can also be used to neutralize a hypersonic weapon in more than one manner.
One is to score a direct hit on a hypersonic weapon. The hit might not destroy the missile completely, but a high-power laser strike could disrupt the high-speed airflows—the boundary layer around the missile—which would disable or take it off course.
The other possibility would be for a laser to target the seeker’s head or whatever guidance package is navigating the weapon to its target. Blinding that part of the hypersonic weapon with a laser would render it useless.
However, the limitations of laser technology have not changed in this same 30-plus-year period. Current lasers might not produce a burst with enough power to damage or destroy a hypersonic missile. This problem is especially true for a missile’s nose cone, which is typically made of ablative material that can survive high temperatures.
Could Lasers Work?
Lasers can also only engage a weapon within visual range. If the weapon is moving at a high Mach regime, this may not be possible unless the laser is linked to a sophisticated target acquisition and fire control system. That targeting system would also have to maintain a positive target lock while the incoming hypersonic weapon is moving at such high speeds.
The short version is that a laser seems like an ideal defense against a hypersonic weapon, but the technology is still unavailable for this to be a viable solution.
About the Author: Reuben F. Johnson
Reuben F. Johnson is a survivor of the February 2022 Russian invasion of Ukraine and is now an Expert on Foreign Military Affairs with the Fundacja im. Kazimierza Pułaskiego in Warsaw. He has been a consultant to the Pentagon, several NATO governments and the Australian government in the fields of defense technology and weapon systems design. Over the past 30 years he has resided in and reported from Russia, Ukraine, Poland, Brazil, the People’s Republic of China and Australia.
