China will launch its third manned spacecraft Shenzhou-7 from Jiuquan Satellite Launch Center in Gansu province in the northwest on Thursday, a spokesperson with China's manned space program said on Wednesday.

One of the major tasks of the mission would be extravehicular activity (EVA), or known as space walk, the first of its kind attempted by Chinese taikonauts (astronauts), said Wang Zhaoyao.

Other tasks included the release of a small monitoring satellite and trials of satellite data relay, said Wang, also deputy director of China's manned space program office.

The Shenzhou-7, carrying three taikonauts, will be launched on a Long-March II-F carrier rocket and then moved into orbit at an altitude of 343 kilometers.

Two taikonauts would enter the orbital module, where they would put on EVA spacesuits and prepare for the extravehicular activities. One taikonaut would be donned with Chinese-made Feitian EVA suit and the other with a Russian Orlan suit.

"One taikonaut will get out of the cabin and take back the test samples loaded outside the module," Wang said.

"After the EVA is completed, the spacecraft will release a small monitoring satellite. A trial of the data relay of satellite Tianlian I will also be carried out," Wang said.

The Shenzhou-7 is scheduled to land in the central area of Inner Mongolia Autonomous Region in northern China after its mission is completed, Wang said.

Wang said compared with the previous two manned space missions, the Shenzhou-7 faced unprecedented technical difficulties.

"EVA is a big leap for the manned space program," he said. China had made a series of technical breakthroughs, including the research and development of an airlock module and EVA suit.

It would also be more demanding and risky than previous missions, he said.

"The process of extravehicular activities cannot be simulated completely on the ground and some of the newly developed products are to be tested in flight for the first time," Wang said.

During the mission, taikonauts would need to assemble and test the EVA suits, depressurize and repressurize the cabin, exit and re-enter the orbital module.

"The capability and skills of the taikonauts and the quality of their operations directly determine the result of the mission," Wang said.

The Shenzhou-7 crew had finished their last rehearsal and a final check of the spacecraft, rocket and ground observation and control system had been completed.

The crew is scheduled to meet the press at Jiuquan launch center 5:30 p.m. on Wednesday.

In 2003, China became the third country after the United States and Russia to send a human into orbit. It was followed up by a two-man mission in 2005.

(Xinhua News Agency September 24, 2008)