BEIJING, 0ct. 14 (Xinhuanet) -- Four Chinese monitoring ships in charge of tracking and measuring the Shenzhou-6 manned space flight encountered bad sea conditions Friday night.

　　The No.3 ship, one of the four "Yuanwang"-series surveying ships stationed in the Pacific Ocean, the Indian Ocean and the Atlantic Ocean, was suffering a particularly stern situation with 4-meter-high sea waves driven up by fresh gale.

　　All of the four ships have prepared emergency schemes in case of worse sea situations.

　　China has set up a space telemetry network consisting of some 20 surveying stations on land and four tracking ships to monitor the flight of its second manned spacecraft Shenzhou-6 and collect data it transmits from space, according to Jian Shilong, an official in charge of the network.

　　Since the vessel carried two astronauts into space Wednesday morning, the four monitoring ships have accomplished about 50 tasks including receiving sound and images from and sending orders to the orbiting spacecraft.

　　The No. 3 ship conducted an orbit maintenance early Friday morning to restore the spacecraft, which had slightly deviated from the orbit due to gravity, to its original trajectory.

　　The four ships, all were involved in China's past five Shenzhouflights during 1999-2003, boast advanced technologies in terms of the functions and precision of measuring and controlling, automatization and reliability, said Jian.