NANJING -- Chinese space tracking ship Yuanwang-7 started its maritime space monitoring and communication mission for Tianzhou-1, China's first cargo spacecraft, on Monday morning.

Yuanwang-7 is sailing into the Pacific Ocean, the first time for the ship to carry out a journey independently. During its maiden voyage in July 2016, the ship was accompanied by Yuanwang-6.

The vessel is also expected to perform emergency response and scientific tasks after reaching its destination in the Pacific Ocean on Thursday.

Designed by China, Yuanwang-7 is 220 meters long, 40 meters high and has a displacement of nearly 30,000 tons.

Yuanwang-7, part of the country's new generation of spacecraft tracking ships, entered service on July 12, 2016. It has performed scientific research and experiment-related tasks, including tracking missions for the maiden flight of the Long March-5, space rendezvous and docking of manned spacecraft Shenzhou-11 and the Tiangong-2 space lab.

The Yuanwang-1 and Yuanwang-2 ships, China's first-generation space tracking vessels, entered service in 1979, making China the fourth country to master space tracking technology after the United States, Russia and France.