China's research vessel Xuelong, or "Snow Dragon," leaves the port of Qingdao Olympic Sailing Center under the escort of China Coast Guard for its fifth Arctic expedition in Qingdao, east China's Shandong Province, July 2, 2012. Xuelong, an A-2 class icebreaker capable of breaking ice 1.2 meters thick, is estimated to travel over 17,000 nautical miles during its 90-day voyage. It is scheduled to return to Shanghai on Sept. 29. [Xinhua]