China's icebreaker Xuelong, or "Snow Dragon", returned to its Shanghai base after completing the country's 28th Antarctic expedition. Xuelong, an A-2 class icebreaker capable of breaking ice 1.2 meters thick, left the port of Tianjin on Nov. 3, 2011, and covered an estimated 28,000 nautical miles over the 163-day mission. During the expedition, Xuelong delivered supplies to the country's Antarctic stations, and scientists aboard conducted various scientific research tasks, including polar environmental survey and the installation of an Antarctica survey telescope.