China's deep-sea sub resurfaces

China's deep-sea submersible, the Jiaolong, has completed its experimental exploration mission in the northeast Pacific Ocean.

The vessel resurfaced and returned to the mother ship. All three crew members left the cabin after the 5-hour-plus mission. During the process, crew members sent back photos to the control center. The Jiaolong's main missions include physical, chemical and biological research, as well as exploration and deep-sea salvage.

Thursday's dive reached a depth of 4,027 meters. The Jiaolong is designed to reach depths of 7,000 meters. The crew has a future target of 5,000 meters, which, if successful, would set a world record. The Jiaolong completed 17 dives in the South China Sea between May and July last year, reaching depths of over 3,700 meters.

Cui Weicheng, a crew member of Jiaolong, said, "This experiment has achieved our expectations. It's the first test dive, and our goal of testing the new improved technologies was realized. We reached even deeper than we planned. I'm happy about that."