Deep freeze
Technical support team works around the clock to make sure Chinese submersible can make it home
On June 27, 2012, Tang Jialing sealed himself inside a 2.1-meter steel tube and descended into the depths of the Mariana Trench. The Jiaolong reached 7,062 meters, the deepest dive ever recorded by the submersible and, at the time, a world record for crewed dives by a working deep-sea submersible of its class.
Now, as the technical lead of the Jiaolong, Tang's focus has shifted from the thrill of reaching the deep to the painstaking work of keeping the submersible operational. Last summer, that meant preparing the vehicle for a place far stranger than the Pacific seafloor: the Arctic ice pack.
In 2025, the Jiaolong completed more than 10 crewed dives beneath the Arctic ice, marking China's first manned dives in polar ice regions. Rather than piloting those dives, Tang spent months preparing for problems that a pilot cannot see from inside — batteries that struggle in the cold, hydraulic lines that stiffen, compasses that lose their sense of north and ice holes that can drift away before the submersible resurfaces.
