NANJING -- Space-tracking ship Yuanwang 5 returned to its port Tuesday, after finishing the latest monitoring mission in the Pacific Ocean for the Long March 5B rocket launch.

The ship has operated 81 days at sea, sailing over 20,000 nautical miles. Due to the COVID-19 pandemic, no port calls were made during the voyage, and more than 80 percent of crew members did not disembark for over 100 days, said Chen Xiaohua, head of the ship.

After docking at the port, crew members will take rest, examine facilities and replenish supplies for upcoming missions including the Mars exploration and lunar exploration.