However, something unexpected happened. 200110/0 In October, when most people in China were still enjoying the relaxation and comfort brought by the "Eleventh" holiday, the phone calls from the leaders of China Aerospace Science and Technology Corporation came one after another with nervousness in their voices.
It turned out that on June 3rd, 65438 10, Shanghai Institute of Aerospace Technology found that one point of the pressure sensor was not conductive when conducting cable continuity test on the spacecraft. Previously, the single cabin of the spacecraft had been tested for conductivity, which proved that it was in good condition. However, when the two sides were connected, one point was not conductive, and it was tested many times. This is the result.
In fact, this problem once appeared before the spacecraft entered the launch site. According to Yang Hong, the general technical director of shenzhou spaceship, at that time, it was considered that a socket was not quite matched. The operator first removed it and replaced it with another one, and found that there was no problem, so it did not attract attention. The faulty socket is just locked in the cabinet and not sent to the fault center for fault analysis.
To everyone's surprise, this problem appeared at the launch site again. Under the psychological pressure of "only success, not failure", sensitive astronauts become suspicious. There are more than 70 such sockets on the spacecraft. Could it be a batch problem?
The so-called batch problem refers to the problem of similar sockets, not a single socket. If it is a batch problem, it means that dozens of similar sockets on the spacecraft are suspicious objects and must be replaced again.
Replacing all sockets is not a small problem, and the spacecraft will have to disassemble the outsole again. Although we already have the experience of opening the outsole for Shenzhou-1 spacecraft, it is still a very risky thing to open the outsole. Experts from China Academy of Space Technology are very worried about the spacecraft.
At that time, experts put forward two opinions on how to solve this problem. One view is that these products "Shenzhou I" and "Shenzhou II" have been used and passed the actual test of launch. In addition, only one pin of the socket cannot be opened, but the spare pin is opened, which can completely guarantee the path of each signal, and the task can be carried out as planned without replacing the socket.
If you want to replace the socket, you have to wait for three months at the earliest before the manufacturer has launched a new product, which means that the launch of the long-prepared Shenzhou III spacecraft will be completely suspended and the huge team will be evacuated from the launch site. In the case of insufficient reasons, there is no need to make a big fight based on an insufficient assumption. Besides, there is no real person on Shenzhou III, only a "simulated person" for experiments. There is no need to "make a big fight" to delay a boat for one point.
Another view is that backup can only be used in the sky, and "Shenzhou III" should be consistent with the manned state. If the ground test is used, what should I do after last day? It is still uncertain whether the socket is a batch problem. If it is a batch problem, maybe "Shenzhou I" and "Shenzhou II" will go to heaven with problems.
"Shenzhou III" is an important technical state, and "Shenzhou 5" needs to be manned. If the changes are postponed to Shenzhou IV, the number of samples to be evaluated before launch will be reduced, so the reliability of manned flight cannot be guaranteed. Therefore, this problem must be investigated clearly, and it is necessary to change it.
In the history of world space, there has been a similar situation, and because the launch was not postponed, there was a tragedy.
1960101on October 22nd, the famous space expert korolev decided to postpone the launch when he was preparing to launch the Venus probe.
However, Marshal Niejelin, commander of the Soviet missile force who personally inspected the launch site, ordered with great displeasure: "In any case, we must troubleshoot today and ensure the launch on time tomorrow!"
However, korolev simply didn't have enough time for inspection and troubleshooting, so it had to launch again in the morning of 654381October 23rd. As a result, the rocket exploded, and more than 100 soldiers and scientists, including Marshal Nie Jielin, were killed, which was the largest casualty in the history of space flight in the world.
Yuan Jiajun, commander-in-chief of the spacecraft system, realized the seriousness of this problem. He discussed with Qi Faren and others: if it is not changed, the spacecraft will go to heaven with problems; If it is changed, the spacecraft may be shipped back to Beijing and the test team will have to evacuate the site. This is the time that the staff spent more than half a year racing against time! Being or not being, Yuan Jiajun is in a dilemma.
Can replacing more than 70 sockets in the cabin ensure the safety of the spacecraft? The spacecraft must open the outsole, and the sealing plate will be scrapped, which is more difficult than copying ... Qi Faren also stayed up all night for this.
The members of the on-site test team hope that this is only an individual accident, so that the big team will not quit the site and the Shenzhou III spacecraft can be launched as scheduled.
After receiving the report, China Aerospace Science and Technology Corporation immediately dispatched an expert group headed by Zhu Mingrang, the chief expert of components, to fly to Jiuquan base urgently. Before he left, Wang Liheng, general manager of China Aerospace Science and Technology Corporation and deputy commander of manned spaceflight project, said to Zhu Ming:
You have a great responsibility to go this time, and your opinions will determine whether the Shenzhou III spacecraft can be launched as scheduled.
The newly docked spacecraft must be unplugged. After all unplugged, the staff began to carefully check the "nerve" lines of these spacecraft.
There are more than 70 hatch sockets, exceeding 1000 nodes. The staff checked for a whole afternoon and found that only one point of so many nodes was not conductive, which was really difficult to check. Some staff believe that the signal lines are all double-point and double-line backups, which is totally unreasonable and should not be a big problem.
Later, the faulty socket was sent to the expert group. The expert group opened the faulty socket and found that the non-conduction was caused by poor contact between some circuits and copper pins.
After receiving the report, Zhang, deputy commander-in-chief of China Aerospace Science and Technology Corporation's manned spaceflight project, quickly asked the laboratory staff to make an analysis first to lay the foundation for decision-making. He is a chief designer and understands the influence of product quality on the success or failure of the project.
Connector is the most basic thing and the earliest installed component in spacecraft production. As the saying goes, the foundation is not firm, and the ground shakes. Zhang has spent a lot of time on the quality of aerospace products. Now the connector is not conductive. He deeply felt that the work was far from enough, and everyone's quality awareness was not fully in place.
Before coming to Jiuquan Satellite Launch Base, Hu, deputy commander-in-chief of manned spaceflight project, first consulted Wang Liheng, general manager of China Aerospace Science and Technology Corporation and deputy commander-in-chief of manned spaceflight project.
Wang Liheng thinks:
If you want to change "Shenzhou IV", it is better to change "Shenzhou III" this time.
A week passed, and when everyone was still discussing the issue of replacing the socket, Hu called Zhang, who was meeting in Shenzhen, and asked him to hurry back to the launch site.
Zhang Weiqing was also worried when he heard the problem of the direct socket. He left early in the middle of the meeting and flew to Lanzhou on the same day. It's already 10 months. It's raining in Lanzhou, and it's much colder than in Shenzhen. He added a sweater in Lanzhou and drove to the launch site overnight.
Because of the road construction, there are piles of earth dug everywhere, and it is too muddy to see clearly at night, which is quite dangerous. However, Zhang has been unable to take care of these things. It is better to think about how to deal with this matter while he is on his way. After arriving at the launch site the next day, he went directly to Hu's room.
Nonsense: "One side will change and the other side will not change. You are the deputy general manager of Aerospace Science and Technology Group in charge of this work. What do you say? "
Zhang also knows the situation by phone every day these days. Now Hu asked for his advice, and Zhang carefully said:
After listening to their meaning, double-point backup can ensure the smooth signal, which is just a retreat to ensure the progress. From the requirements of manned space flight, the spacecraft can't go to heaven with problems. Now that the problem has been found in the field, it must be solved. Besides, we haven't started yet. If the headquarters decides to change it, I agree with it. We can also take the opportunity to rectify product quality, and more importantly, improve everyone's quality awareness.
In the following discussion, the spacecraft system is still worried that replacing the socket will cause damage to the spacecraft. They suggested that if it is a batch problem, it should be changed. If not, it should not be changed. As long as we can ensure the success of the spacecraft flight, there will be no problem. 1000 points, only one point is not feasible, so it should not be a problem of mass production.
The focus of the debate shifted to whether it was a batch problem. Hu Shixiang asked the expert group whether this was a batch problem. Because there is no conclusive evidence, it is difficult for the expert group to draw a conclusion, but everyone tends to think that the design of the product itself is flawed, and it is possible to take the hidden danger to the sky by replacing a single component that shows problems.
Finally, Jean Zhu Ming said: "Before the product is analyzed, it is difficult to rule out the problem that it is not a batch. Because it is impossible to screen out faults now, and the probability of occurrence is unacceptable in manned space engineering, it is not good to draw an absolute conclusion. I can only say that this problem is difficult to rule out as a batch problem. "
Qi Faren is very dissatisfied with the opinion of the component expert group: "The conclusion you gave me is very vague, and it is difficult to rule out the batch problem. So what should we do? We must act according to the facts! This is not a batch problem, so I just need to deal with this one; If it is a batch problem, then the spacecraft will have to be dismantled. "
In order to find out whether it is a batch problem, Hu led the chief commander and chief designer of several major systems to the factory overnight. Find a similar plug directly from the production unit to see if it is a batch problem.
Eight plugs were found at that time. When the plug was dissected, it was found that the design scheme was unreasonable, the production process was problematic and the acceptance itself was not strict. This must be a batch problem.
I also learned from the socket designer that the original intention of this design was to reduce the resistance problem, but I didn't expect that this design might have poor contact in the production process. This is a batch product problem with both production and design problems.
There is no need to argue now. The only way is to change it, no matter how long it is delayed!
How long does it take to replace the socket, change the design scheme and reproduce after the change! What about Shenzhou III?
Qi Faren, the chief designer of the spacecraft, was full of tears and thoughts: in order to launch Shenzhou III at the end of 200 1, the developers worked overtime, and I don't know how much effort they paid. But now ... it can't be launched this year!
At the end of 10, all system personnel gathered in Beijing to hold a meeting and decided to postpone the launch of Shenzhou III spacecraft.
The meeting decided:
More than 70 sockets on the ship have been improved, reproduced and all replaced.
After the old socket, battery, computer and other equipment were removed from the Shenzhou III spacecraft, the base was sealed, and the test team did the installation and state recovery work after the production of the new socket was completed.
As the replacement of sockets involves the withdrawal of all launching teams, the schedules of Shenzhou IV and Shenzhou 5 have been arranged. Replacing the socket will delay the launch of Shenzhou III spacecraft for three months, which will inevitably affect the whole process of China's manned spaceflight project. It is of great significance, and the manned spaceflight project headquarters will submit a report to the central leadership. The central government approved the expert's report.
The spacecraft launch leading group decided that the progress should obey the quality, all the plugs on the spacecraft were replaced, the launch date was postponed, and the scientists and staff returned to their original units for standby.
Later practice proved that this was a correct decision, which not only ensured the successful launch of Shenzhou III spacecraft several months later, but also ensured that all the data of the spacecraft in the round-trip process between heaven and earth were true, conclusive and reliable, and accumulated valuable experience for China to truly realize manned space flight in the near future.
On the evening of March 25th, 2002, the moon was bright at Jiuquan manned space launch site in China. Next to the launch tower of the spacecraft whose height exceeds 100 meters, there stands the "Long March II F" bundled high-thrust launch vehicle. The top of the rocket is equipped with Shenzhou III spacecraft. Under the illumination of the light, the five-star red flag printed on the rocket is particularly bright.
At 22: 00 15, the Long March rocket ignited and lifted off. A long red flame spewed from the tail of the rocket, and there was a deafening roar over the launch site. Shenzhou-3 spacecraft flew rapidly into space, leaving a gorgeous trajectory in the dark.
10 minutes later, the spacecraft successfully entered the scheduled orbit.
The launch site rang with cheers and firecrackers from space workers.
The success of this launch marks new and important progress in China's manned spaceflight project and lays a solid foundation for sending Chinese astronauts into space in the near future.
In fact, the successful launch of China Shenzhou III was not smooth sailing. It was not only delayed for three months because of the socket problem, but also delayed for five minutes before the launch because of the Yogyakarta problem.
At the end of 200 1, the socket problem of Shenzhou III spacecraft was effectively solved, and all the preparations before entering the site were completed, but the Spring Festival in 2002 is not far away.
The Spring Festival is a time for family reunion. Astronauts have been busy for so many days, and most of them are looking forward to the spacecraft and rockets entering the venue after the Spring Festival. You can also take the opportunity to spend the Spring Festival at home and have a rest.
On February 2, 2002, just a few days before the Spring Festival, a rocket train entered the Jiuquan launch site. Due to the full preparation, various problems were solved before entering the site, and the re-inspection work was done in detail, so the test of the spacecraft and rocket launch site was also very smooth. The unit test of the rocket system was completed before the Spring Festival.
Three joint simulation tests of ship, arrow and tower were carried out, all of which passed smoothly. On March 18, 2002, the spacecraft and the rocket docked, waiting to be transferred to the launch tower.
According to the plan of the manned space engineering headquarters, the ship, arrow and tower assembly were transported to the launch tower on the 20th and launched on time on the 25th. At that time, the "Shenzhou III" spacecraft was postponed before launch, and when the launch window was fixed, it just happened to catch up with the "Riling" time.
The so-called "Riling" means that the satellite is between the sun and the earth around the vernal equinox and autumnal equinox every year, and the ground communication station aims at the satellite as well as the sun. The strong electromagnetic field generated by the sun may make satellite communication unable to work normally, which is the phenomenon of "solar eclipse" interruption.
The interruption of Yogyakarta generally does not last for a long time, only about 5 minutes. As long as it is not within the coverage of the monitoring station, it will not affect the measurement and control of the Shenzhou III spacecraft. However, according to the confirmed launch time, the survey ship "Wangyuan III" just passed by the "Riling".
Yu Zhijian, chief designer of TT&C transportation system, is no stranger to the problem of "Riling". As early as when determining the launch time of Shenzhou III spacecraft, he organized technicians to calculate the influence of solar eclipse on TT&C communication. At that time, it was calculated that the working time of Roy No.3 survey ship was half an hour different from that of Riling, so even if the communication signal was interrupted by Riling, there was enough time to re-establish.
Because of his full understanding of TT&C communication, chief designer Yu Zhijian did not raise this issue in manned spaceflight project.
However, the night before the launch, Hu, deputy commander-in-chief of the manned spaceflight project, suddenly received a phone call from Cao Gangchuan, commander-in-chief of the manned spaceflight project, asking whether "Riling" would bring difficulties to the measurement and control of the No.3 survey ship.
Wangyuan No.3 survey ship is responsible for the measurement and control of the return section of the spacecraft. Injecting the returned data into the spacecraft is not a small problem. If the "Riling" is interrupted when the spacecraft returns, it may lose control.
Cao Gangchuan asked the launch site to make a good calculation, and if not, it would postpone the launch for one day.
The wind in Gobi desert is very strong, especially in spring, and the launch window will also be affected by the strong wind. Hu was very nervous after receiving the phone call.
Hu Shixiang immediately found Yu Zhijian, the chief designer of TT&C communication system, to verify what impact the "Riling" problem would have on the launch test of Shenzhou III spacecraft. Can the measurement time of Roy III coverage area be staggered? If communication is interrupted, is there enough time to re-establish communication?
In order to provide detailed evidence for the manned space engineering headquarters, Yu Zhijian immediately organized personnel to recalculate at the launch site, and at the same time asked the research institute to recalculate, and both sides reported the calculation results to the manned space engineering headquarters.
Experts at the base have been arguing about Yogyakarta for several days. Counting it down, several experts have their own concerns. Some people are afraid that in the case of communication interruption, if there is an accident or signal interference during reconstruction, it will bring great variables to the launch test of Shenzhou III spacecraft.
In the face of everyone's worries and doubts, Yu Zhijian promised that there would be no problems after repeated calculations. If you are not at ease, you can postpone the launch for five minutes. Anyway, there is enough time.
With Yu Zhijian's statement, the chief designer of Wang Yongzhi and several experts at the scene nodded in succession. Finally, everyone unanimously decided:
Launch on 25th, delayed for 5 minutes.
The "Shenzhou III" launched this time is an unmanned spacecraft prototype, and the technical state of the spacecraft is completely consistent with the manned state. This launch test further improved the launch vehicle, spacecraft and TT&C launch system, and improved the safety and reliability of manned space flight.
The spacecraft is equipped with human metabolism simulator, anthropomorphic physiological signal equipment and human dummy, which can quantitatively simulate the important physiological activity parameters of astronauts in space.
Launch, escape and life-saving systems also played a role. This system is the main measure to ensure the safety of astronauts in an emergency.
Shenzhou III spacecraft consists of orbital module, return module, propulsion module and additional module. After the spacecraft enters space, it will continue to fly around the earth for several days and conduct a series of scientific experiments. China Academy of Sciences will conduct various space application experiments on the spacecraft. After that, the spacecraft return module will return to the ground, and the orbital module will continue to fly in space until the scheduled follow-up scientific test mission is completed.
During the on-orbit operation of the spacecraft, under the unified planning and dispatching of Beijing Aerospace Control Center, TT&C Center of Xi 'an Satellite, relevant TT&C stations and Roy Ocean Space Survey Ship will continuously track, measure and control the Shenzhou III spacecraft.
Shenzhou III spacecraft is mainly developed by China Academy of Space Technology and Shanghai Academy of Space Technology under China Aerospace Science and Technology Corporation, and Long March II F carrier rocket is mainly developed by China Academy of Launch Vehicle Technology. This launch is the sixty-sixth flight of the Long March series of launch vehicles.
Since 1996 and 10, China's launch vehicle has been successfully launched for 24 consecutive times. China Academy of Sciences, Ministry of Information Industry and other relevant units have developed ship-borne instruments and ground measurement and control equipment for this launch.
At 22: 00 15 on March 25th, Shenzhou III was successfully launched. In the accusation hall of Beijing Aerospace Command and Control Center, the most nervous and busy person is the chief dispatcher Shen Jinsong. Since the flight test of Shenzhou-1, he is 28 years old and has been sitting in this seat for the third time.
Beijing Aerospace Command and Control Center is the nerve center of China manned space system. As the chief dispatcher, Shen Jinsong has a great responsibility. From the launch site of the spacecraft to the monitoring stations and measuring ships around the world, from the ignition of the spacecraft to the return landing, thousands of dispatching orders were issued by him.
Every launch is as nervous as a war, and thousands of pairs of eyes stare at him. At this time, there can be no mistakes or hesitation.
More than two years ago, when the "Shenzhou-1" spacecraft was recycled, there was an emergency in measurement and control. At that time, he was only 25 years old, as cool as a cucumber, and issued a series of dispatching orders in a few seconds to ensure the smooth return of the spacecraft.
In fact, 80% of the technicians involved in this command and control task are young people under the age of 30. They have made great contributions to China's space flight and become the leading force in China's future space flight.
At 22: 23, the "Shenzhou III" spacecraft entered the scheduled orbit accurately, and the accusation hall of Beijing Aerospace Command and Control Center sounded warm applause.
Among these cheering and clapping scientists and technicians, there are actually many pregnant female scientists and technicians.
When the launch was successful, Chen Ye, a female engineer in labor, patted the fetus and said happily, "Little guy, we succeeded."
Cao, who works in the main computer room, is an engineer in the simulation group. She also took part in the launch mission with a big belly. For this task, she insisted on fighting side by side with her colleagues, and successively developed multi-task simulation platform, multi-task simulation system and simulation system emergency plan, which provided a strong guarantee for the center to carry out task drills.
After the "Shenzhou III" was ignited and lifted off, the Beijing Aerospace Command and Control Center reported the orbit parameters to the whole system in only 8 minutes. In the first two spacecraft tests, they also accurately calculated the trajectory of the ship and arrow after 8 minutes of separation, and the calculation accuracy was better than 100 meters.
The speed and accuracy of this orbit determination are also world-class.
China Aerospace TT&C Company started with a blank sheet of paper to calculate and determine the flight orbit of the spacecraft.
At the beginning of the establishment of Beijing Aerospace Command and Control Center, faced with the current situation of new tasks, new equipment, new systems and new personnel, scientific and technical personnel closely focused on the needs of China's manned space engineering construction, worked together to develop the external measurement support software with hundreds of processes, thousands of modules and tens of thousands of programs, and established a numerical legal orbit determination system, which made great efforts in measurement data processing, error correction and altitude.
In the three spacecraft tests, Beijing Aerospace Command and Control Center can calculate and determine the real-time orbit of the spacecraft through these automatic external measurement support software, and can intuitively reflect the trajectory and attitude of the spacecraft in the form of "three-dimensional animation", which provides a reliable basis for making flight control decisions.
For the successful launch of China Shenzhou III, the astronauts were really meticulous, which laid a solid foundation for the success of China's space flight. Although space launch is full of risks, in order to pursue a higher success rate, from the day when China's manned space project was officially launched, the vast number of scientific and technological workers have always strived for a success with a hundredfold effort.
For this successful launch, the astronauts have formulated millions of words of technical documents, stipulated strict operating procedures for each technical post and technical link, formulated emergency plans for every possible accident, and conducted repeated drills to ensure that the problem "returns to zero".
In order to realize China people's dream of flying as soon as possible, the vast number of scientific and technical personnel of Beijing Aerospace Command and Control Center aim at the forefront of world aerospace science and technology, innovate and tackle key problems, and have successively broken through a series of key technologies such as high-precision orbit determination, automatic generation of flight control plan, return control and landing forecast, high-speed data processing, visual measurement and control, and achieved more than 60 major scientific research achievements.
Three spacecraft tests show that TT&C technology of manned space flight in China is becoming more and more mature, and it ranks among the advanced countries in the world.