China has developed a new cooling system that allows high-energy lasers to operate infinitely without overheating, an innovation that could point a laser-sharp threat at US space dominance.
South China Morning Post (SCMP) reported that scientists from China’s National University of Defense Technology at Changsha, Hunan province, developed a new cooling system that eliminates the harmful heat generated by high-powered lasers, reportedly solving the overheating problem that has limited their operating time and performance.
SCMP notes that a laser weapon generates a high-energy beam using stimulated emission, which involves exciting atoms or molecules in a crystal or gas gain medium to a higher energy state.
When those excited atoms or molecules return to their ground state, they emit photons amplified by optical feedback to create a high-power laser beam, with a highly-precise beam control system directing and controlling the laser typically using mirrors and lenses.
As the beam passes through the air, it heats the gas in its path, causing it to expand and create a turbulent flow, making the beam scatter and distort, reducing its effectiveness and accuracy.
The heated gas can contaminate the mirrors and lenses in the system, degrading its performance and lifespan. In addition, larger pollutant particles burning on the mirrors can result in cracking or damage, reducing the practicability of high-energy laser weapons.
The Chinese science team claimed to have developed an internal beam conditioner that cools down the weapon and improves gas cleanliness.
According to the SCMP report, the system utilizes an air source to provide cool, dry air that flows through a heat exchanger, with gas at the optimum temperature regulated by a gas flow control system and injected into the laser beam path before being removed.
SCMP also noted some design challenges the research team encountered, such as ensuring that the gas flow achieved the desired cooling and cleaning effects, making the device compact and efficient enough for practical applications, and properly building the device to prevent turbulence and vibration from affecting beam quality.
Beijing Times noted the invention has several implications for the battlefield, which include extended engagement durations, amplified range and damage, and reduced maintenance and repair costs. The report also touts other advantages of laser weapons, such as instantaneous hits, negligible cost per shot and possible anti-satellite applications.
The Beijing Times report claims that previous US attempts to make high-power lasers into practical weapons, such as the Mid-Infrared Advanced Chemical Laser (MIRACL), Tactical High Energy Laser (THEL) and Airborne Laser (ABL), were eventually scrapped due to their unwieldy size and weight, unsatisfactory destructive power and relatively short range.
China’s internal beam conditioner may be a game-changer for its laser weapons program, especially for ground-based anti-satellite weaponry. For one, ground-based lasers have size, coverage and power advantages over airborne and satellite-mounted weapons.
They can destroy satellites with scalability and plausible deniability, as it is difficult to attribute a blinding laser attack on a satellite orbiting hundreds of kilometers above Earth at thousands of meters per second, as the temporary outage of a satellite could be accidental or the result of hard-to-detect aggression.
In May 2023, Asia Times reported that China may have built ground-based anti-satellite weaponry at its secretive Korla facility in Western Xinjiang, with such weapons intended to conceal sensitive military areas from spy satellites.
Satellite imagery of the Korla facility by US geospatial company BlackSky shows two laser gimbals mounted in hangars with retractable roofs that open around solar noon when foreign imaging satellites are most active.
The satellite imagery also shows huge anti-satellite lasers close to the size of ship-mounted weapons alongside domed structures, likely containing tanks for the gas required to operate the lasers.
Apart from the Korla site, China may have another such facility at Bohu in Xinjiang, with satellite imagery of the Bohu site showing fixed lasers for satellite ranging and mobile truck-mounted lasers for dazzling.
Apart from ground-based weapons, China may already have developed space-based laser weapons. Space-based weapons have several advantages over ground-based systems, such as the shorter distances between orbiting satellites and the lack of atmospheric distortion that degrades laser range and power.
Asia Times reported in March 2022 that China had developed a satellite-mountable solid-state pulse laser capable of generating a megawatt laser light and firing 100 times per second for half an hour without overheating in space.
It is reportedly capable of blinding satellite cameras or permanently blinding satellites. Upon testing, the device reportedly generated a five-nanosecond beam, but it was powerful enough to blind human beings or vaporize target surfaces permanently.
Recent advances in laser cooling technology, including a new cooling device made of copper and indium to absorb excess heat, reportedly made the weapon possible.
Despite those developments, China may still lag the US in other laser weapon areas. Asia Times noted in April 2023 that while China is adept at making smaller laser weapons, such as one possibly used in a February 2023 blinding laser attack against a Philippine Coast Guard (PCG) ship in the South China Sea, it lacks larger models that can intercept bigger targets such as missiles.
Both ground- and space-based laser weapons have drawbacks. Ground-based lasers require vast amounts of power to affect targets high in orbit and have atmospheric beam distortion and accuracy issues at great distances.
Space-based laser weapons face the challenge of developing a power source that is compact and powerful enough to be mounted on a satellite.
As such, China’s laser weapons program may be an asymmetric response to US space dominance, wherein the US exploits the space domain for strategic-level missile defense, intelligence and command and control, with its military and commercial satellites acting as early warning systems, eyes in the sky, or nerve centers for modern military operations.
The ongoing Ukraine war has vividly shown the decisive edge the US maintains in space dominance, with China possibly taking note for its Taiwan contingency plans.