China's new deep-sea manned submersible Fendouzhe (Striver) set a national record by diving to a depth of 10,909 meters in the Mariana Trench on Tuesday. The record dive was enabled by several deep-sea technologies involving materials, energy supply and communications.
The submersible embodies China's progress in deep-sea technologies and its increasing capabilities in ocean detection and research.
It carried three experts to conduct scientific research for about six hours on the bed of the Mariana Trench. Ye Cong, chief designer of the submersible, told the Science and Technology Daily that the first challenge is dealing with the extreme water pressure, which is equivalent to 2,000 elephants stepping on a person's back.
That places a high demand on materials and structural design. In addition to withstanding the huge water pressure, the submersible has to carry personnel and a number of scientific equipment, which further increases the challenge during manufacturing, Ye said.
The submersible uses titanium alloy to build the shell of the manned cabin, which not only withstands water pressure but also reduces the weight as it is light, and provides more space inside the cabin.
The ball-shaped manned cabin was constructed with an innovative welding method that reduced the number of seams and increased reliability.
The deep-sea area below 6,000 meters is key to solving major scientific problems such as the origin of life and the evolution of the earth. The submersible can take images of seabed topography and marine organisms, and can use its robotic arms to take samples of ocean life and seabed sediments.
According to state broadcaster CCTV, the robotic arm can rotate 360 degrees and can operate at an accuracy of one centimeter.
The submersible is powered by a specially-designed lithium battery that can ensure stable power supply in the deep sea.
It was supported by two mother ships Tansuo-1 and Tansuo-2, on which the key equipment such as the submersible deployment and retrieval systems are domestically produced.
The submersible is equipped with an advanced acoustic communication system that allows it to receive instructions from the mother ship, transmit data, navigate, and measure the depth of the ocean floor.
Bao Gengsheng, a researcher from the Institute of Deep-sea Science and Engineering under the Chinese Academy of Sciences, said although China has 10,000-meter deep-sea unmanned submersibles, the development of manned submersibles is necessary.
Manned submersibles have better maneuverability and can carry more scientific equipment for conducting underwater research. The development of manned submersibles will also contribute to breakthroughs in key technologies for deep-sea exploration, Bao said.