China's fly-by-laser drones

China is developing a drone powered by high-energy laser beams which could keep it airborne for unlimited periods. Drones have become the de rigueur weapon of choice on the modern battlefield, especially in the war in Ukraine. But like combat aircraft, the range and operational endurance of drones are restricted by their power source. A drone that could effectively fly for ever would create a huge advantage in surveillance and intelligence-gathering missions. Researchers at the Northwestern Polytechnical University in Shaanxi province have succeeded in converting light energy from a laser into electricity, using a photoelectric conversion module that could be fitted to a drone. Lasers can be diverted by changing atmosphere and air turbulence. But the researchers led by Professor Li Xuelong of the university’s school of artificial intelligence, optics and electronics, have devised a way of adapting the shape and density of the laser beam so that it could be automatically adjusted to reduce the impact of weather patterns. Although there is no evidence that China is close to producing a drone with limitless endurance, the researchers have apparently demonstrated the technology to make this feasible. By contrast, the US Reaper drone which is America’s most deployed unmanned aerial vehicle has an operational endurance limit of about 40 hours and is powered by a turboprop engine. America’s longest-range drone, Global Hawk, can fly at high altitudes for more than 30 hours and is powered by a single Rolls-Royce turbofan engine. China’s current advanced drones, such as the Wing Loong models, are claimed to have an endurance capability of around 40 hours and are powered by a turbocharged engine. Until now, the focus of government-funded researchers in both western and Chinese defence industries and universities has been on developing lasers for use as anti-drone weapons. As the export of armed and surveillance drones has proliferated in recent years, so the need to counter the threat they pose has increased. Laser weapons are seen as one of the best options for the future. The US and China are engaged in developing such weapons. Like China, the Pentagon may also be looking into using lasers to power drones. Last year it emerged that the Pentagon’s research arm, DARPA, was examining ways of using lasers on fleets of drones to beam electricity to remote military theatres to save on the huge cost of flying in diesel to generate electrical power.