ON BOARD SHIP XIANGYANGHONG 09, May 23 (Xinhua) -- Jiaolong, China's manned submersible, began a dive in "Challenger Deep" in the Mariana Trench, the world's deepest known trench, Tuesday, with a Xinhua News Agency journalist on board.
The dive began at around 7 a.m. local time, and nearly three hours later, the submersible reached the planned depth of 4,811 meters.
Jiaolong is expected to stay under water for around nine hours and to return to the surface at about 4 p.m.
The main tasks for this dive include testing the submersible's technical equipment, including its mechanical arms.
Jiaolong will also collect samples of sea water, sediment, deep-sea life and rocks.
On May 16, the Xiangyanghong 09 set sail for the Yap and Mariana trenches in the western Pacific Ocean with the submersible and 96 scientists onboard, beginning the third stage of China's 38th oceanic expedition.
Ten dives are planned for this stage.