China is scheduled to launch the Shenzhou VII manned spacecraft and conduct the maiden spacewalk later this year. An umbilical cord may play an important role in this spacewalk.
The Shenzhou VII manned spacecraft is due to be launched later in 2008. The craft will carry three astronauts, one of whom is expected to conduct "extra-vehicular activities".
Yang Liwei, the nation's first cosmonaut, along with Fei Junlong and Nie Haisheng, the second batch of cosmonauts, are now receiving training together with 11 others. They all hope to be one of the three cosmonauts aboard the Shenzhou VII, the third manned space mission expected to launch in October this year. China may broadcast live each move of its first ever spacewalk for the upcoming space mission, Pang Zhihao, a research fellow with the China Academy of Space Technology (CAST), told the Shanghai Morning Post.
In fact, walking in space is totally different from walking on the earth. Instead of using their feet astronauts move in space with the support of their hands, mechanical arms and/or motor-driven devices. Handrails are often installed inside and outside spacecrafts, to assist the astronauts in moving their bodies through space.
Spacewalk activities are complicated and involve complex technologies. China's future spacewalk is designed primarily to aid in creating a space station and preparing the astronauts for space assembly and repair work.
China's first spacewalk maybe realized via an umbilical cord. Cosmonauts have two ways to move in space: one uses an umbilical cord and the other is called "free style", Pang explained.
The umbilical cord connects the cosmonaut to the spacecraft. It guarantees the life support system for the cosmonaut, including all necessary oxygen, pressure, power supply and communications. The cord would also prevent him from moving too far away from the spacecraft, as the length of the cord should not exceed 5 meters to avoid getting twisted.
A manned motor-driven device with more than 20 nozzles is necessary for a "free-style space walk". The device is just like a small rocket, and astronauts can move in space by controlling the directions and thrust of the rocket. The space walkers can extend as far as 100 meters in this way.
Compared with the "free style", the "umbilical cord" mode is less complicated and safer. All the maiden spacewalks done by foreign countries have been conducted using an umbilical cord, according to Pang.
(China.org.cn by Yang Xi, February 1, 2008)
