Early on 24 June, China's crewed deep-sea submersible, the Jiaolong, set a new Chinese record by diving more than 7000 meters near the Mariana Trench. The sub will now be put to use for undisclosed research and exploration trips in the next 3 to 5 years.
The plunge is remarkable in part because China began deep-sea exploration only a decade ago. (This dive did not match that of National Geographic explorer James Cameron, however, who reported reaching a depth of 10,898 meters in a privately financed sub in March). Although researchers at the No.702 Institute of China Shipbuilding Industry Corporation in Wuxi first proposed building a deep-diving sub in 1992, the project did not get the green light until 2002. To speed its development, about 40% of the vehicle's parts, including the robotic arms, underwater lighting equipment, and imaging system, were imported or made abroad, project chief designer Xu Qinan told Chinese media. The heart of the vehicle, the pressure compartment, was designed in China, but construction was outsourced to a Russian company because China lacked the expertise to weld titanium alloy plates together in a way to withstand the crushing pressures so deep below the ocean's surface.
On 13 June, Jiaolong and its three-member diving team arrived at the Mariana Trench for six dives to test two distinct functions: cruising at a given depth to explore or staying on the ocean floor to collect samples. On its fourth dive on Sunday morning, Jiaolong touched bottom at 7020 meters after a 3-hour descent. The successful plunge concludes Jiaolong's R&D phase, and the submersible will be "turned over from its research team to its operating team" at the National Deep Sea Base currently under construction in Qingdao, according to Zhu Min, deputy designer of Jiaolong at the Chinese Academy of Sciences' Institute of Acoustics.