The Yuanwang V ship returned to a China port after a 117-day mission of remotely tracking the Shenzhou VII space space which blast off in late September.

The return signaled the completion of the tracking mission by five ships for support of China's first space walk.

The ships, Yuanwang I,II, III, V and VI, set sail Aug. 18 last year and traversed nearly 100,000 sea miles in the Pacific and Atlantic Oceans.

China successfully launched the Shenzhou VII manned spacecraft on Sept. 25. During the 68-hour flight, taikonaut Zhai Zhigang, wearing a domestically made Feitian space suit, conducted a 20-minute space walk. China became the third nation to conduct a space walk, after Russia and the United States.

The ships monitored the entire space walk and also kept tabs on the depressurization of the orbital module when the taikonaut left and re-entered the spaceship.

They also controlled the shuttle's solar panels, its orbit maneuvers and maintenance.

"In previous missions, including the Shenzhou V and Shenzhou VI missions, only four tracking ships were deployed," said Jian Shilong, director with the China Maritime Tracking and Control Department. "We added one more to the Shenzhou VII mission to monitor the taikonaut's extra-vehicular activities."

In all, China boasts a fleet of six Yuanwang space tracking ships which have carried out some 70 expeditions and traveled more than 1.5 million sea miles in the Pacific, Atlantic and Indian oceans.

The tracking ships constitute China's space telemetry network together with some 20 terrestrial surveying stations.