Weekly Technology Awards｜Driving into the Deep Blue to Explore the Unknown

In recent years, with the development of aerospace technology, human beings have been exploring space further and further, but there are still many difficulties and challenges in reaching the deepest places on earth. The deep sea is not as quiet and beautiful as humans imagine. As the penetration of sunlight gradually weakens, the deeper you dive, the darker the surrounding environment becomes. When you dive to a depth of 200 meters, the surroundings are already pitch black. Facing the unknown and changeable deep sea, every dive of human beings is a challenge.

Advanced equipment is the greatest reliance of mankind in understanding, developing and protecting the ocean. The seabed terrain is complex, and manned submersibles can meet the requirements of precise positioning, fine survey sampling and close observation under complex terrain, and can well complete seabed exploration tasks and deep-sea scientific research, which is of great significance to my country's deep-sea scientific research. The "Jiaolong" manned submersible research and development and application project also won the first prize of the National Science and Technology Progress Award in 2017. At that time, the "Jiaolong" operation mode and a complete set of safety assurance system promoted the rapid development of China's manned deep-sea diving business, realizing the strategic ambition of "entering the deep sea, exploring the deep sea, and developing the deep sea", and also marked that China's manned deep-sea diving has entered the ranks of international leaders.

In June 2002, the Ministry of Science and Technology formally approved the establishment of the "7,000-meter manned submersible" major project of the National 863 Plan during the 10th Five-Year Plan. In 2012, the Jiaolong set a Chinese manned deep-sea diving record of 7,062 meters, setting the world record for the maximum diving depth of similar operational submersibles at that time. The Jiaolong manned submersible is my country's first independently designed, integrated and developed operational deep-sea manned submersible.

The reason why the "Jiaolong" manned submersible has achieved leapfrog development in my country's deep-diving technology is inseparable from its technological innovation. Among them, there are 4 major technological breakthroughs that are the magic weapon for success. First, it has broken through the core technology of the safety of personnel, structures and equipment of manned submersibles under ultra-high water pressure of 7,000 meters; created a technical system for the safety design of submersible systems; and through overall optimization and integrated innovation, it has created the maximum diving depth record of manned submersibles at that time, and achieved an ultra-high coverage rate of 99.8% of the global ocean area in terms of operational capacity. Second, the technical difficulties of multipath, frequency shift and high noise in deep-sea information transmission have been perfectly solved. The "Jiaolong" can achieve deep, long-distance and high-speed underwater acoustic communication under complex underwater acoustic channel conditions, and at the same time has pioneered the development of an underwater acoustic communication system that can transmit images, data, text and voice information. Third, it has conquered the key technologies of "three precisions", namely deep-sea precise control, precise positioning and fine operation, and has effectively solved the control and operation problems of large submersibles in complex deep-sea terrain and flow field environments. Fourth, we have established full-process manned deep-sea diving operation procedures, created a deep-sea diving operation, testing and application system for China's manned submersibles, including land testing and sea trials, to ensure more than 150 continuous, safe and efficient diving operations.

The Jiaolong has not only achieved a breakthrough in the realization of manned deep-sea diving technology, but also played a great role in promoting the comprehensive development of deep-sea technology. With the successful development of the Jiaolong, the application and development of new materials and new equipment in the field of domestic deep-sea equipment has been successfully driven. For example, the high-strength titanium alloy hull used by the Jiaolong can withstand the huge water pressure in the deep sea. Based on the development and application of the Jiaolong, the Deep Sea Warrior and the Striver are also pushing China's new records in manned deep-sea diving to be constantly refreshed.

(Text by Zhu Yehua, Ph.D., Tsinghua University. Review expert: Zou Zhen, associate researcher at the China Science Popularization Research Institute)

China Association for Science and Technology Department of Science Popularization

Xinhuanet

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