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)
