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)