The picture shows the Israeli Predator hydrogen powered drone. In February of this year, at the 17th Abu Dhabi International Defense Exhibition (IDEX) and the 8th Abu Dhabi International Maritime Defense Exhibition, Israeli drone manufacturer Heven Drones showcased its newly developed hydrogen powered drone, the "Raider". According to foreign media, the appearance of the "Predator" drone means that hydrogen powered drones are one step closer to flying into the battlefield. What is a hydrogen powered drone? Let's first take a look at the power source of the drone. There are currently two main driving methods for drones: fuel engines and electric motors. The former is usually fueled by kerosene, gasoline, etc., while the latter is powered by a battery pack. Both of these driving methods can be used for hydrogen powered drones, but their power source has been changed to hydrogen, using liquid hydrogen as fuel or hydrogen fuel cells instead of lithium batteries. The use of environmentally friendly hydrogen as the energy source for drones is the origin of the name hydrogen powered drones. The "Global Observer" completed its maiden flight in 2011 by AeroVirond and the "Phantom Eye" developed by another American company are both unmanned aerial vehicles powered by "liquid hydrogen+internal combustion engine". The "Predator" developed and showcased by Heven Drones is a drone powered by hydrogen fuel cells. Currently, using hydrogen fuel cells to drive hydrogen powered drones has become the main development direction. Its obvious advantages include the following two aspects: firstly, compared with hydrogen fuel engines, driving with hydrogen fuel cells is more convenient and produces less noise; Secondly, compared with lithium batteries, hydrogen fuel cells have higher energy storage efficiency, higher energy density, and stronger adaptability to high and low temperature environments. Due to its low noise, high energy density, strong environmental adaptability, and long battery life, hydrogen fuel cells have received attention from many countries and have accelerated their research and development process in recent years. However, there are also some technological bottlenecks in the development of hydrogen powered drones, including those driven by hydrogen fuel cells. For example, how to efficiently store hydrogen and improve its energy conversion ratio, how to increase hydrogen carrying capacity and reduce fuel cell manufacturing costs, how to optimize layout and reduce the impact of hydrogen storage tanks on aerodynamic shape and center of gravity distribution, etc. The existence of these problems has delayed the process of hydrogen powered drones flying into the vast sky. Heven Drones has explored this area and achieved certain results. It is reported that the "Predator" hydrogen powered drone has a wingspan of 5.5 meters or 7 meters and adopts a dual body structure to achieve a reasonable layout of hydrogen energy and power systems. It has four vertical takeoff and landing rotors and a streamlined tail, which to some extent balances deployment flexibility and good aerodynamic shape. Driven by a new type of hydrogen fuel cell, the drone can carry a payload of over 20 kilograms and fly continuously for more than 10 hours. On this basis, the company has adopted modular design to enable the "Predator" hydrogen powered unmanned aerial vehicle to carry different payloads for diverse missions. It is reported that the drone is expected to enter service in 2026. If this news is true, it means that in the future battlefield sky, there will be another multi-functional drone with hidden movements. (New Society)