According to Zhang, the mission differs from previous ones in three ways.

It will carry out extra-vehicular activities, which will put the airlock module and space suits to test in space for the first time.

The three astronauts will stay in Shenzhou 7 for up to five days, testing its rated capacity. Experiments will also be conducted using new satellite communications technology.

There are two kinds of space walk. One is when the astronaut is tied to the spaceship and the other is a free walk, where they are unattached, according to Pang Zhihao, a researcher with the China Academy of Space Technology.

During the Shenzhou 7 mission, a space walker will conduct a free walk, said Pang, adding that the early space walks conducted by Russia and the United States were not free walks.

To ensure that the mission is a success, experts have prepared plans to deal with more than 30 emergency situations to guarantee the astronauts' safety, Zhang said.

China has initiated a step-by-step approach for its astronauts. This began with the single-person Shenzhou 5 flight in 2003 of 14 orbits, followed by the two-person voyage of Shenzhou 6 in 2005 lasting 5 days, and now the coming mission.

The exact day that the three-person crew will take off in October is yet to be announced, but there has been talk about broadcasting the space walk live on television when it happens.

Yuanwang 6, an ocean-going tracking ship, has been delivered for service in Shanghai to participate in the Shenzhou 7 flight and to assist with the space walk. It joins sister ship, Yuanwang 5, in maritime space surveying and mission control operations.

Plans are already underway for Shenzhou 8 and Shenzhou 9, said Qi Faren, an academician at the Chinese Academy of Engineering and researcher of the China Spaceflight Technology Research Institute, who is credited as chief designer of China's first five Shenzhou spaceships and chief consultant for Shenzhou 6 and Shenzhou 7. He added that, "the intervals between each launch will become shorter."