China's upgraded Jiaolong submersible shatters deep-sea mission records

China's manned deep-sea submersible, Jiaolong, has achieved operational milestones following a major technological overhaul. From ​February 27 to March 25, the upgraded submersible completed its first sea trials, setting new records in diving frequency and efficiency.

During a ​10-day operational window, Jiaolong executed ​14 dives, including a historic ​four "two-dives-per-day" missions and ​nine consecutive "one-pilot-two-scientists" operations, according to the country's Ministry of Natural Resources.

This latest upgrade, which began in November last year, focused on critical components like the propulsion system and battery packs that are domestically produced. The components include the 7000m-rated oil-immersed lithium batteries with higher energy density, the low-noise direct-drive direct current thrusters for improved propulsion efficiency, a deep-sea hydraulic buoyancy control system, and expanded emergency hydraulic interfaces. 

The trials at 3000-meter depth confirmed the reliability of these upgrades, marking significant progress in Jiaolong's energy efficiency and localization of core technologies.

Following its upgrade, Jiaolong is scheduled to conduct over 80 dives in 2025, the ministry said.