By Zhu
Zengquan
On Oct. 15, the Shenzhou
V, China's first manned spacecraft, was launched into space
using a Long March-II-F carrier rocket from the Jiuquan Satellite
Launch Center in northwest China's Gansu Province. Both the
spacecraft and the carrier rocket were designed and built by China
independently.
After a landmark 21-hour
and 23-minute expedition around the globe 14 times, on Oct. 16 the
spacecraft touched down almost precisely at the primary landing
site in the grasslands of north China's Inner Mongolia.
The successful Shenzhou
mission made China the third country in the world to send a man
into space, following the former Soviet Union and United
States.
Wang Yongzhi, 71, is the
chief designer of China's manned space project and a world-famous
rocket technology specialist. He gave an interview
recently.
Starting with
spaceship
Q: The
success of China's first manned spaceflight has attracted worldwide
attention. Some foreign media said that basically the Chinese
manned spacecraft was modeled on the designs of Russia and the
United States. Can you talk about the distinguishing features of
China's manned space project?
A: I
want to make two points clear. First of all, manned spaceflight is
a massive, systematic project. It has been developed by China
independently. Second of all, hundreds of people have been engaged
in this project. Everyone has contributed to its success, and I
cannot claim all the credit for myself.
On January 8, 1992, the
central government made definite that China's manned spaceflight
should start with a spaceship instead of shuttle. The manned
spaceship program was put under an authorized plan on September 21
of that year, and four people were appointed in charge: Gen. Ding
Henggao as general director, Gen. Shen Rongjun and Liu Jiyuan as
deputy general directors, and I was appointed chief
designer.
The decision of starting
with a spaceship was based on China's actual conditions. However,
because of this, we had to face a gap of at least 40 years. When
evaluating the program in 1992, we expected our spaceship would be
launched in ten years time. By 2002, 41 years had passed since Yuri
Gagarin, the first cosmonaut of the former Soviet Union, was hurled
into space. If we designed a spaceship similar to that one launched
by the Russians 41 years ago, where would the significance of our
project lie?
After repeated
discussion, we finally set out the goal of China's manned space
program: on condition that safety must be ensured, manifesting the
Chinese characteristics of the spaceship. In the final design, we
were to realize an all-round technological innovation, since it was
easy to make partial improvements with computer
technology.
The central government
decided on September 21, 1992 to push the manned space program
ahead in three steps: first, to launch two unmanned spacecraft and
one manned spaceship; second, to develop technologies ensuring the
precise docking between the spaceship and orbit module, and to set
up a space lab; third, to develop more efficient and reliable
vehicles able to launch a space station.
In the first step, which
was called the "921 Project," four tasks were expected to be
accomplished, i.e., mastering basic technologies for manned
spaceflight, developing scientific space research, providing a
primary carrier rocket and retrieving device for the spacecraft,
and gaining experience for the planned eventual space station
project.
As the chief designer,
I've been under tremendous strain. Since we started late, we had to
try hard to catch up with those countries that had already led a
manned spaceflight. Actually, we held the ambition that once our
spaceship came out, it would rival the best in the
world.
Surpassing the
Soyuz
Q: So
far, which country boasts the best manned spacecraft in the
world?
A:
Since the time of the former Soviet Union, Russia has launched 92
manned space flights. The United States, the other big power in the
field of spaceflight, gave up its spaceship after several initial
trials, and turned to shuttlecraft development. So as far as
spaceship design is concerned, beyond all doubt, Russia has held
the lead.
Following Gagarin's
Vostok and Alexei Leonov's Voskhod, at the beginning of the 1960s,
the former Soviet Union conceived the Soyuz in the competitive
atmosphere of the then Moon race. The Soyuz has ever since been the
longest serving manned spacecraft in the world.
Q: What
are the main features of the Soyuz?
A:
Unlike the one-man Vostok craft, the three-seat Soyuz is composed
of the reentry, orbital and service modules, and is able to conduct
active maneuvering, orbital rendezvous and docking.
The Soyuz T version of
the spacecraft flew its first manned mission in 1980, and since
1986 the Soyuz TM modification of the craft has been delivering
crews to the Mir space station for over 10 years. The modifications
feature multiple improvements in design, including the introduction
of the new weight-saving computerized flight-control system and
most important, the improved emergency escape system.
In addition, another
version of the spacecraft, known as the Soyuz TMA, has been
developed. The Soyuz TMA upgrades allow the TMA version to be used
as a "lifeboat" for the International Space Station
(ISS).
Our goal is to catch up
with and surpass the Russian Soyuz. From the very beginning, we put
forward a three-module plan. I was in charge of making an appraisal
report on the three-module program, and the design was finally
passed by an expert group in a vote of 3:2. The panel, set up by
the then Ministry of Aero-Space Industry, comprised five
authorities in China's space industry.
Q: As
you mentioned before, the three-module design is an advanced
feature of the Russian Soyuz TM. Then, where do the technical
improvements and Chinese characteristics lie in terms of your
three-module plan?
A:
Dissimilar to the Soyuz TM, Shenzhou V has the orbital module in
front. This multifunction orbital module, which has been enlarged
by an additional section, gives expression to the superiority of
our new technology.
The reason why we
proposed the three-module plan was to design China's first manned
spacecraft into an efficient and reliable vehicle, so that with
little improvement in the future, it could be used to directly
launch space stations, as planned in the third step of our space
program. If adopting a conservative double-module program
initially, additional docking experiments would be necessary to
transform the double-module into three-module
combination.
Jump over the
monkey experiment
Q: From
the launch of the unmanned Shenzhou I to Shenzhou IV, people kept
on asking if experimental monkeys were put inside the spacecraft.
Have you conducted such experiments in the past?
A: As a
matter of fact, we jumped over it. Let me give you some statistical
figures. By the end of 2001, as many as 426 astronauts throughout
the world had been sent to outer space. By August, 2002, flights
into space had reached 906. Now the record for the longest stay in
space is two years, 17 days and 15 hours. So there has been a
generally accepted opinion about whether or not astronauts can deal
with weightlessness and adapt to space life. Definitely we don't
have to test it with animals any more.
What really counts is if
we can provide a reliable living environment for astronauts inside
the module. All living conditions in the module must be 100 percent
guaranteed, including oxygen supply, temperature, moisture, air
composition, and atmospheric pressure.
Traditionally, all of
the above conditions had to be tested with animals. Some people
once suggested buying monkeys from south China's Yunnan for
"aero-training". However, monkey experiments have many
disadvantages. First, the experiment is expensive. It takes no less
than 30 million yuan (roughly US$3.75 million) to set up a monkey
feed experiment. Second, our spacecraft was designed to be able to
fly in space for 7 days and nights in a row. If a monkey aboard
didn't know how to eat and drink during that time and died, who
could convincingly claim that it was not the craft's problem? Such
cases can do nothing but create unnecessarily increases in an
astronaut's mental strain. Third, since the maximum metabolic rate
of the monkey is only one-sixth of that of man, at least 18 monkeys
would have to be put in the three-seated spacecraft, otherwise
human life in the module could not be simulated accurately and
completely.
Q: Your
description reminds me of the story of the Monkey King wreaking
havoc in a Heavenly Palace, an episode from a popular ancient
Chinese novel entitled Pilgrimage to the West. But, how
did you test the living environment in the module?
A:
Instead, we used a metabolic simulation device to test all the
living conditions in the module. Several trial launches of an
unmanned spaceship demonstrated that in the module, everything
including oxygen supply was fine. Until last year, some people
still kept on warning me that it was too risky to hurl an astronaut
into space without experimenting on animals. Indeed, before their
manned spaceflight, both the United States and the former Soviet
Union conducted animal experiments. In this regard, they gained
enough experience for us to draw on, so we really didn't have to do
it all over again.
Multifunction
orbital module
Q: Can
you give more details on the orbital module?
A: In
fact, space application has been the most important purpose of
China's manned space project. In this respect, the design of
Shenzhou V's orbital module is a good illustration. Honestly
speaking, it's a multifunction module. To take the Russian Soyuz TM
as an example, when it returned after five days in outer space,
both the orbital module in the middle and the service module in the
rear burned up in the atmosphere; only the reentry module in front,
protected by heat-proof layer, was eventually recovered.
The Soyuz TM's orbital
module was discarded in five days, while the Shenzhou V's will
orbit for at least half a year for further scientific experiment.
Launching a spacecraft is terribly expensive, so we must take the
ultimate responsibility for our work. Therefore, keeping the
orbital module in orbit can serve multiple purposes.
First, like an
experimental satellite, the orbital module in orbit can continue to
send back precious scientific data in the future.
Second, benefiting from
materials collected by the orbital module in orbit, both
theoretical space science and practical space application
researches can be developed simultaneously. In this way,
technically, the Chinese
Academy of Sciences will be able to make necessary preparations
for large-scale space application afterwards.
Third, the orbital
module in orbit can be used for docking experiments. Strictly
speaking, the planned space station project cannot get started
until the docking technology has been well mastered.
The former Soviet Union
and the United States each made five docking trials before
launching their space stations. They placed a spacecraft into orbit
at first, and then launched a second one into the same orbit. Since
their spaceships could stay in space for 5 days at most, the
link-up operation between the two crafts needed to be completed
within 5 days.
We have planned to do
the docking experiment differently. One way is to keep the orbital
module in orbit for two years. So all spacecraft launched in the
next two years will be able to dock with the orbital module.
Another way is to keep the orbital module in orbit for half a year.
Then we will launch a spacecraft at half-a-year intervals to dock
with the orbital module. Each time we leave the new craft's orbital
module in orbit to replace the previous one. Therefore, every
docking experiment only needs one launch instead of two. In other
words, both the former Soviet Union and the US had to launch ten
crafts to do five docking trials. If we want to do the same number
of trials, we only need to make six launches. All in all and either
way we can save tremendous amounts of money.
Putting safety
first
Q: On
February 1 this year, the US space shuttle Columbia blew up,
killing all seven astronauts aboard. That disaster stunned the
whole world. What safety measures have been adopted in your manned
spacecraft?
A: In
our overall program, astronaut's safety has been a matter of prime
importance. Actually, we've designed four escape schemes at the
firing stage and 11 escape schemes at the lift-off stage to
guarantee astronaut's safety.
We've also taken many
lifesaving measures to protect against possible dangers once the
spaceship enters orbit. For instance, in our final plan, after its
fifth rather than tenth circuit, the spaceship would in advance
change its orbit from elliptical to circular to increase the
craft's chance to return to the earth's surface in case of
emergency.
In the 1990s, we fired a
retrievable satellite, but due to a program error, it did not
return on time until several years later. This accident has sounded
an alarm. If similar things happened to our spacecraft with a food
load that can sustain the astronauts no more than ten days, it's
not hard to imagine what will follow.
So we thought of
installing a manual control device on the craft. For this, some
people specifically consulted a Russian cosmonaut. The latter
answered, "Without manual control of the spaceship, I have the
right not to go aboard." Therefore, we hardened our resolve to
install manual control.
There is a distance of
2,200 kilometers between the launch site and the seacoast. In case
of any possible accident, we set up four rescue stations in
Dongfeng, Yinchuan, Yulin and Handan respectively. However, if the
carrier rocket fell into the Pacific Ocean, rescue work would meet
a tremendous challenge. Definitely, it's beyond our ability to draw
on aircraft carriers and hundreds of planes for reconnoiter and
rescue at sea, as the United States used to do. Instead, in a wide
expanse of water, we delineated three relatively small areas in
which rescue forces were disposed. At the same time, an additional
engine in the service module would be started in case of emergency
to send the spacecraft to the closest sea area following a
pre-designed program. This method has made assistance and salvage
at sea much easier and more efficient.
Over the past 11 years,
we've taken great pains with complicated escape schemes. It's not
an overstatement to say that within our power, we've employed
whatever means to guarantee the safety of both the astronaut and
the spaceship.
'Shenzhou is
Chinese spacecraft'
Q:
What's your reaction to the rumor that Shenzhou was modeled on
Russian design?
A: In
2001, I was invited to Moscow to attend a conference to mark the
40th anniversary of Gagarin's spaceflight. Meanwhile, the Moscow
State Aviation Institute, my Alma Mater, conferred an honorary
Ph.D. on me. At the conferring ceremony, I gave an account of
China's manned spaceflight developments. Vasiliy Pavlovich Mishin,
chief designer of the Soyuz and also my adviser at Moscow State
Aviation Institute, was sitting right beside me then. After my
speech, Mishin said in a loud voice, "Shenzhou is not the Russian
Soyuz. Shenzhou is a Chinese spacecraft!"
(The author is vice
commissar from General Armament Department of the
PLA)
(China.org.cn,
translated by Shao Da, November 4, 2003)