The Chinese-made unmanned submersible "Haima" can dive to a depth of 4,500 meters via remote control.
After 219 days and 53,000 km on the sea, the 130 specialists on board the Chinese marine research vessel "Hai Yang Liu Hao" (Ocean 6) have completed their voyage across the western Pacific Ocean.
The vessel of the Guangzhou Marine Geological Survey (GMGS) returned to Dongguan City in Guangdong Province, south China on Tuesday.
The scientists conducted a wide range of research. They collected geological data and samples from the deep sea by using China's unmanned submersible "Haima", capable of diving to a depth of 4,500 meters via remote control.
The largest sample collected by Haima at this mission is a "cobalt-rich crust" that weighs 62 kilograms.
The cobalt is a kind of metal that can be used to make batteries for new energy vehicles and special materials used in aviation and aerospace projects.