Photo taken on March 2 shows the huge expedition ship Zhang Qian, a Chinese diplomat who served as an imperial envoy to the world outside of China in the 2nd century BC, during the time of the Han dynasty. It will be served as the mothership of the deep-sea manned submersible — "Rainbow Fish" and go to the oceans around the world for scientific investigation.

The ship was built by Tianshi Shipbuilding Company in east China's Zhejiang province, with a total investment of 200 million yuan. According to plan, it will be launched in late march and be delivered for operation in June.

The ship is 97 meters long and 17.8 meters wide, with designed displacement of about 4,800 tons and designed draft of 5.65 meters. It's cruising speed reaches 12 knots with an endurance of 15,000 nautical miles. It can accommodate 60 people, with the self-sustaining capacity of 60 days.

In the period prior to delivery, the Zhang Qian will conduct trial operation for about 10 days to further test the related equipment and instruments. Then it will conduct its inaugural mission in the Mariana Trench. (Photo/Xinhua)