China's science ship Tansuo-1 loaded with the manned submersible Shenhai Yongshi (Deep Sea Warrior) returns to its home harbor in Sanya, south China's Hainan Province, on March 10, 2019, after finishing its first expedition in the Indian Ocean. The 121-day expedition trip organized by the Chinese Academy of Sciences began on Nov. 10, 2018. The ship traveled 17,000 nautical miles on the expedition during which scientists surveyed five deep-sea hydrothermal areas and collected a trove of samples for ecological environment research. (Xinhua/Guo Cheng)