China's third manned space mission Shenzhou-7 on Friday entered a stable circular orbit where the taikonauts assembled the 4.4-million-dollar space suit for extra-vehicular activity (EVA) and trained themselves for the country's maiden spacewalk after spending their first day in space.

The spacecraft is circling at 343 km above the earth, orbiting every 90 minutes. It blasted off in northwest China at 9:10 p.m. on Thursday.

In this video grab on Friday, astronaut Jing Haipeng talks to the command and control center of Shenzhou VII. [Xinhua]

Starting from 10:20 a.m. Friday, two taikonauts Zhai Zhigang and Liu Boming spent more than 11 hours unpacking and assembling the EVA suits in the orbital module, while Jing Haipeng stayed in the re-entry module to keep an eye on the vessel operation.

One of the suits is China-made Feitian while the other is a Russian Orlan.

Tests by the two astronauts showed the two suits were normal, according to the ground command in Beijing. The two men were also in normal physical condition, the ground command said.

Zhai and Liu began adaptive training after finishing assembling the suits. The training, which was to make sure the taikonauts could adapt to the low-gravity environment in space, lasted about 100 minutes.

The spacewalk, expected to last about 30 minutes, is scheduled to take place at 4:30 p.m. Saturday.

One taikonaut will conduct the spacewalk assisted by another who will stay in the orbital module during the process. The other one will stay in the re-entry module.

The spacewalker will fetch a piece of experimental material fixed on the exterior surface of the orbital module.

The exact duration of the spacewalk, however, might be adjusted according to the physical condition of the taikonaut, according to Wang Zhaoyao, spokesperson with the manned space program.

Wang said the whole process would be broadcast live on television.

"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 EVA suit and an airlock module.

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. Thus, The capability and skills of the taikonauts and the quality of their operations would directly determine the result of the mission, he said.

Yang Liwei, who piloted China's maiden space flight in 2003, has said the intensive psychological shock would be unavoidable for the astronaut when he moved out of the capsule.

Since the operation was highly automatic, it was the psychological factor other than the manual operation that decided the success of the mission, Yang said.