Solving the three major problems of Mount Everest: What black technologies did DJI drones use to set the highest transportation record?

Tuchong Creative

Mount Everest was once a forbidden zone for humans, and it was also a forbidden zone for many technological products. After all, extremely high altitudes, bad weather, and complex terrain are not friendly to people and objects. However, just recently, another thing broke through this forbidden zone - it is a drone, or a civilian drone that has not been specially modified at all. What does this show? It shows that it is born strong. It is no surprise that the one who created this feat is China again. DJI announced that it recently completed the high-altitude transportation test of drones in the southern slope of Mount Everest for the first time, and successfully completed the round-trip transportation mission on the route at an altitude of 5,300 to 6,000 meters, setting the highest altitude transportation record for civilian drones. During this period, the drone completed the verification of hovering, empty flight and cargo flight, laying a solid foundation for subsequent practical applications.

DJI's drone is testing the transport of materials on the Nepal side of Mount Everest (Source: Video screenshot)

I believe you have probably heard of this name - Green Boots. It may be the most famous landmark on Mount Everest. But in fact, "it" is a climber who died in the process of climbing. There are many such landmarks on Mount Everest. The reason why they did not receive timely rescue after their death and could not return to their hometown after their death is because of the harsh environment of Mount Everest, which makes rescue, transfer and transportation of materials extremely difficult and costly. With the further improvement of the performance of domestic drones, can they also provide climbers with more reliable and cheaper material transportation guarantees, make more contributions to garbage removal, reduce the damage to the environment caused by mountaineering activities, and protect Mount Everest and the natural environment? The answer is definitely!

However, it is very difficult to fly a drone to Mount Everest. There are three main reasons: the challenge of thin air, the test of extreme climate, and the requirement of high-precision navigation and control.

As the roof of the world, the Everest region has an extremely high altitude and low air density, with the atmospheric content being only one-third of that at sea level. The flight of drones requires the lift provided by airflow. Like the wings of airplanes, the rotors of drones also have a special design - the shape of the rotors is usually curved on the upper surface and flat on the lower surface. When the air flows over the wings, the airflow on the upper surface is faster and the pressure is lower; the airflow on the lower surface is slower and the pressure is higher. This pressure difference generates lift. Although the cross-sectional shape and angle of attack of the rotor blades determine the magnitude of the lift, the rotor speed, the wind speed flowing through the rotor, and the air density around the rotor when it is working will also affect the magnitude of the lift. Dense air contains more air molecules and can provide more support, while sparse air is just the opposite. There are not so many air molecules to provide support, and the lift becomes smaller. This means that the propeller needs to rotate at a higher speed to generate enough lift. Only by designing more efficient motors and optimized propellers can we ensure that drones can still maintain stable flight in low-density air. At the same time, the fuselage must be light and strong enough. The use of lightweight composite materials effectively reduces the weight of the entire aircraft, allowing it to carry more supplies and fly longer distances.

The test of extremely low temperature is also fatal to drones. It will affect battery performance, reduce the chemical reaction rate of lithium batteries, reduce battery capacity, and shorten the flight time of the aircraft. It will also increase the internal resistance of the battery, resulting in a voltage drop, which may not provide enough power to the motor and electronic equipment of the drone, affecting flight performance. Low temperature will also affect the mechanical properties of the drone. For example, it will make the lubricating oil viscous or even solidify, affecting the normal operation of its moving parts. It will also make some materials fragile and more likely to break or damage. In addition, low temperature poses great challenges to the accuracy and speed of sensors, and the stability and sensitivity of flight control systems. The temperature on Mount Everest can be as low as minus 40 degrees Celsius. Drones must have multiple properties such as cold resistance and waterproofness. This is the main battlefield of lightweight composite materials, and well-designed insulation measures have completed this key task together. There are also strong winds and blizzards. Strong winds will interfere with the stability of drones, increase mechanical stress on the drone fuselage and rotors, and may also affect the accuracy and image quality of sensors. Blizzards will also bring additional effects of increased load and obstructed vision. Therefore, drones need to have excellent wind resistance to ensure stable flight in adverse weather conditions. Those of us who have played with drones a little bit know how difficult this is. DJI has really achieved this by being able to fly steadily in a force 7 wind.

Finally, there is navigation. The terrain in the Everest region is complex, and traditional GPS signals may be interfered with, which requires drones to be equipped with a multi-modal combined navigation system that integrates multiple technologies such as GPS, Beidou and inertial navigation to ensure high-precision positioning and stable flight.

From this perspective, it is no exaggeration to say that it is far ahead in the world. Although there are some similar products in the world, such as Zipline's Zips, Amazon and UPS drones, and Elroy Air's Chaparral, etc., they each have different characteristics and advantages. But DJI's FlyCart 30's outstanding performance in high altitudes and complex environments is unmatched by other drones.

Now some of you must be wondering, what about the Ingenuity rover launched by NASA to Mars? The atmosphere of Mars is thin enough, the climate of Mars is special enough, and the terrain of Mars is complex enough, right? Is our model comparable to it?

This is a good question, let's expand on it briefly. The atmosphere of Mars is indeed thinner, with a density of only 1% of that of the Earth, so if you want to fly, you need a higher rotor speed and a lighter fuselage design to generate enough lift. The Ingenuity UAV uses an ultra-long and high-speed rotating double rotor design, and the fuselage weighs only 1.8 kg. The temperature difference on the surface of Mars can reach 100 degrees Celsius, which has an impact on materials, battery performance, electronic equipment, mechanical lubrication and flight performance. UAVs must have strong temperature resistance. The Ingenuity UAV uses high-strength lightweight materials, and its design focuses on heat preservation and temperature resistance. Furthermore, due to the communication delay between Mars and the Earth, the Ingenuity UAV must have a high degree of automation and autonomous flight capabilities. It is equipped with a variety of sensors and advanced flight control algorithms, and can independently complete flight missions under communication delays. So in essence, the technical level and innovation of the Ingenuity are also very powerful-it not only optimizes the fuselage and rotors, but also has a powerful intelligent control and energy supply system. It can be said that these two drones have each demonstrated excellent technical levels in their specific environments. The drones on Mount Everest are mainly used to cope with the extreme environment of high altitude on Earth, focusing on efficient power systems, cold and wind resistance, and navigation in complex terrain; the Ingenuity drone flies in the thin atmosphere of Mars, highlighting the rotor design, lightweight structure, and autonomous flight capabilities. Both have their own unique advantages, representing human technological innovation and breakthroughs in different fields and extreme environments, and demonstrating the diversity and advancement of drone technology in different application scenarios, and both are worthy of the praise of being far ahead.

Back to ourselves, this breakthrough not only helps to improve the efficiency and safety of the low-altitude economy, but also promotes the development of drone technology and strengthens our scientific and technological strength. In the future, we look forward to drone technology shining in more fields and creating more miracles.

This article is a work supported by the Science Popularization China Creation Cultivation Program

Author: Science Rocket Uncle Popular Science Video Creator

Reviewer: Dai Yuting, Professor of Beijing University of Aeronautics and Astronautics

Produced by: China Association for Science and Technology Department of Science Popularization Produced by: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.