By Liu Shiyao, In recent years, China has made remarkable strides in marine technology, propelling the deep-sea industry to new heights.
Jiaolong, China’s first independently designed and integrated 7,000-meter-class manned deep-sea submersible, has completed 317 dives since its maiden mission in 2009. It has enabled a total of 900 trips down to the deep sea, providing strong support for deep-sea exploration in China and around the world.
On Nov. 10, 2020, China’s independently developed deep-sea manned submersible Fendouzhe, or Striver, set a Chinese diving record of over 10,000 meters in the Challenger Deep, an 11,000-meter chasm located at the bottom of the Mariana Trench in the western Pacific Ocean. This made China the second country in the world to achieve manned dives to 10,000 meters.
As of now, Fendouzhe has completed a total of 329 dives, 25 of which were deeper than 10,000 meters, ranking first in the world in terms of the number of dives and individuals involved in 10,000-meter deep-sea exploration. This achievement signifies that China has reached the world’s leading level in deep-sea manned submersible exploration.
At a depth of 10,000 meters in the Mariana Trench, the water pressure is close to 1,100 atmospheres, equivalent to the weight of 2,000 African elephants on the back of a person. What enables Fendouzhe to navigate this extreme condition and roam freely at the depths of the ocean floor? The answer lies in the manned capsule.
The manned capsule technology was developed by a research team from the Institute of Metal Research, Chinese Academy of Sciences (CAS). Based on thorough investigation, logical reasoning, research and practical tests, they have overcome technological challenges related to materials, forming, welding, and other aspects of manned capsules.
“For example, we have produced a novel titanium alloy material that can meet our requirements for strength, toughness, and weldability,” said Yang Rui, a member of the research team.
Chinese researchers have also made breakthroughs in fiber optic cable control technology, anti-low-temperature design, and the development of solid buoyancy materials, which encompass a wide range of technological domains such as material science, high-precision manufacturing, navigation positioning, and data transmission.
These advancements have not only enhanced China’s capacity for deep-sea exploration, but also laid a solid foundation for its deep-sea scientific research, resource development, and international cooperation.
The transmission of electromagnetic waves is impeded by the immense depth of the ocean, which can reach thousands of meters. How is it possible to maintain long-distance communication and data transmission underwater?
To tackle this challenge, Chinese scientists have dedicated almost a decade to developing the hydroacoustic communication system. By refining signal modulation and anti-interference algorithms, the system can ensure stable data transmission in a deep-sea environment, with the communication range exceeding 10 kilometers.
In the pitch-black depths of the ocean, where the terrain is highly complex, precise control systems play a crucial role.
Researchers from the Shenyang Institute of Automation of the CAS, have overcome the challenge by enabling Fendouzhe’s control system to perform functions such as online intelligent fault diagnosis based on data and model prediction, fault-tolerant control based on online control allocation, and autonomous collision avoidance on the seabed.
In the future, with the help of artificial intelligence, high-performance computing and other emerging technologies, deep-sea scientific exploration is poised to achieve more targeted terrain exploration and collection of biological and mineral samples.
Expanding “circle of friends” in deep-sea exploration
China has been expanding international cooperation while delving deeper into deep-sea exploration.
From October 2022 to March 2023, the Institute of Deep-sea Science and Engineering of the CAS organized the first international manned deep-sea research mission in the waters around Oceania.
The Fendouzhe submersible, aboard the scientific research ship Tansuo-1, traveled for 157 days and sailed more than 22,000 nautical miles, collecting rich samples of deep-sea macroorganisms, rocks, nodules, sediments, and seawater.
“In the deep sea, there were many glowing bioluminescent plankton, which looked like shooting stars in the night sky. Though their appearance was fleeting, they were colorful and breathtaking,” said Chuar Cheah Hoay, a marine scientist with National University of Singapore, who was unable to contain her excitement.
In August this year, Hoay joined an international scientific mission in the Western Pacific Ocean organized by the Chinese Ministry of Natural Resources, diving into the seabed with China’s manned submersible Jiaolong.
“The biodiversity in seamounts on the seabed is incredibly rich. This time, I finally had the chance to observe deep-sea sponge communities and coral reefs underwater, and the impact far exceeded reading literature or watching documentaries,” Hoay remarked.
The scientific mission marked the first time that foreign scientists carried out deep-sea scientific research on Jiaolong. Eight foreign scientists and three scientists from China’s Hong Kong Special Administrative Region dived into the depths on Jiaolong for sampling.
