China's state-of-the-art manned submersible, Jiaolong, dived to a depth of 6,965 metres at the Mariana Trench in the western Pacific and returned safely to the surface late yesterday afternoon with samples of water and sea life.
The dive mission, which started at 5am and lasted about 10 hours, was aimed at testing Jiaolong's ability to reach 7,000 metres. The vessel, with three crew on board, stayed at a depth of 6,965 metres for several hours while they conducted research.
They sent their first picture, taken at a depth of 4,500 metres, to the submersible's mother ship, Xiangyanghong 09, showing part of Jiaolong's sample collection area.
The trip had been delayed by one day for repairs after engineers discovered during a regular check on Monday morning that sea water had seeped into an oil pipe in the submersible's hydraulic system and caused some corrosion.
Jiaolong left Jiangsu on board the Xiangyanghong 09 on June 3 and dove to a depth of 6,671 metres on Friday.
Xu Qinan, Jiaolong's chief designer, told the China.com.cn news portal yesterday that the successful dive meant that China could now search 99 per cent of the world's oceans, exploring for deep-sea resources and collecting biological samples around the globe.
Six dives at the Mariana trench have been scheduled for Jiaolong on this voyage, with an attempt at reaching 7,000 metres set for its fifth dive.
