Yuanwang-7.(Photo/Xinhua)

China's new-generation spacecraft tracking ship Yuanwang-7 sailed into the ocean from the Yangtze River on Tuesday, beginning its maiden mission.

Yuanwang-7 was accompanied by Yuanwang-6. Yuanwang-5 also set out days before.

The three will carry out 10 missions in the Pacific and Indian oceans, including maritime tracking of the manned spaceflight Shenzhou-11, in the latter half of this year, according to the ship's officer.

Shenzhou-11 will carry two astronauts to dock with Tiangong-2, China's second orbiting space lab, set to launch in the fall, allowing two astronauts to live in space for up to 30 days.

China has seven Yuanwang space tracking ships, which have carried out some 70 expeditions and traveled more than 1.5 million nautical miles.

Construction on Yuanwang-7 started in 2014 and it was commissioned on July 12. It is 224.9 meters long, 27.2 meters wide and 44.2 meters high, and has a displacement of 27,000 tons. It is capable of resisting strong typhoons, and can carry 100 days of supplies.

Two rocket carrying ships, Yuanwang-21 and Yuanwang-22, will set out in mid August to transport Long March-5, China's largest carrier rocket scheduled to be launched later this year.