On the morning of June 23, the long march 3B carrier rocket lifted the last global networking satellite of beidou-3 from Xichang Satellite Launch Center. The satellite successfully entered the scheduled orbit and the launch was a complete success. After a 7-day emergency response, the long Sany rocket completed its global networking launch with perfect performance.
People concerned about the space launch mission must have noticed that the last geostationary orbit satellite of beidou-3 was originally scheduled to launch on the morning of June 16, and that more than 6 a.m. on that day, Xinhua news agency released the delayed launch mission. A week later, on the 23rd, the launch was carried out successfully.
So, why was the final mission of beidou-3 global networking stopped before the planned launch window? What efforts did the astronauts make to ensure the smooth launch on June 23?
Abnormal pressure data!
On the evening of June 15, changsany rocket has completed the conventional propellant filling according to the process and started the pre launch function inspection. Everything is going on step by step.
In the launch and test hall, the two presidents of rockets and satellites and the test team members sat at their respective stations to watch the technical data. In the hall, only the loud command sound of commander 01 sounded from time to time.
Just after 20 oclock, Luo Qiaojun, the deputy chief designer of the rocket cryomotor from the sixth Academy of Aerospace Science and technology group, and Chen Minghang, the test team member, frowned. They found that the pressure data of the pressure reducing valve in the I extension of the rocket three-stage engine was abnormal. Its not a small matter that the value is a little bit different from the normal value, because its state directly relates to the normal operation of the three-stage engine and the success or failure of the task. Luo Qiaojun said.
The third stage of changsany rocket (Photo by Gao Nan)
Chen Minghang joined in 2012 and has participated in more than ten long 3A series rocket launching missions. His post is engine system post, and his main work is data interpretation and parameter monitoring of three-stage engine. First, eliminate the extreme situation of abnormal data caused by the failure of measuring equipment, and then further check the valve. After running quickly to the test room to verify the accuracy of the data, the fact threw a basin of cold water on Chen Minghang: the measuring equipment worked normally.
A few minutes later, a rush of footsteps came. The leader in charge of the mission command of the launch center summoned the rocket two presidents and technical personnel to leave the hall and study countermeasures in the conference room on the third floor.
After discussion, the experts opinions were quickly concentrated: if the test equipment problem is eliminated, the valve product needs to be checked as soon as possible to see if there is a problem; if the problem is located in the valve product, the similar product needs to be replaced quickly so as to continue the follow-up launch process. According to this operation, the launch window of the 16th will still be able to catch up.
u25b2 at 20:43 on June 15, the two presidents of the rocket and the technicians held an emergency meeting to discuss the technical problems (photographed by Liu Huaiyu)
The leader of the launch center confirmed the experts opinions, immediately clarified the specific division of labor, and required to promote the disposal work under the fully anticipated conditions. At last, the on-site leaders pointed out that the space launch should not be sloppy. If the conditions are not met, the mission can be postponed, and we must ensure that there is no hidden danger.
Under the leadership of Cen Zheng, commander in chief of the first Academy of Aerospace Science and technology, and Jiang Jie, chief designer, technicians quickly sorted out the troubleshooting steps and the backup products to be prepared for disposal.
On the launch tower, the operator entered the rocket cabin according to the process to check the pressure reducing valve, and a chicken claw shaped small crack on the shell came into view. The news came that all the people present were in a cold sweat.
The personnel in the launch site quickly contacted the comrades in Beijing of the first Academy of Sciences to check the whole process of the same batch of products from design to production and inspection. At the same time, emergency replacement of backup products, and check whether their working conditions meet the requirements.
Near 12 oclock, the newly replaced products of the same batch are in normal working condition after testing, and have the conditions for implementation. However, the astronauts who have always insisted on strict and careful work did not make the decision to restart the launch soon.
At 1:00 a.m. on the 16th, the results of material analysis on samples of products from Beijing came, and the problems were repeated. At this time, the group company is in the process of holding a seminar at the launch site overnight for the participation of the two presidents of rockets and satellites. After discussion, we believe that although the troubleshooting indicators are normal, we should be cautious and safe, and we should firmly make sure that there is no doubt and no hidden danger.
Wu Yansheng, party secretary and chairman of the group company, and Yang Baohua, Party member and deputy general manager, carefully studied and decided to postpone the launch mission after listening to the reports on rockets, satellites and other aspects, thoroughly eliminate the hidden dangers, and promptly report their opinions to the leaders of the mission headquarters.
Subsequently, the Mission Command formally made a decision: the launch mission was postponed and the launch time was to be determined.
At 6 oclock in the morning, relevant parties announced the news to the society in time through the media.
Prepare for the best from the worst
Knowing that the task was postponed, some netizens expressed their concern and understanding rationally after regretting: come on, make sure there is no mistake! Im waiting for you in the future.
u25b2 June 16, Xichang Satellite Launch Center (photographed by Liu Huaiyu)
More than 4 a.m., reporters in the test team live to see that the rocket launch test team dragged their tired body back in twos and threes. Longwei and Chen Minghang, who are working with the operators to replace the backup products on the launch tower, have not slept all night. Their faces are haggard and they are still discussing the work of returning to zero with their colleagues.
At 9:30, aerospace science and Technology Group held a meeting at the launch site to convey the spirit of learning instructions from superior leaders, and to study and deploy the next phase of work. Yang Changfeng, chief designer of Beidou satellite navigation system engineering, arrived at the meeting to convey the spirit of instructions from the superior leaders and pointed out that according to the requirements of the superior leaders, put down the burden, do a good job actively and steadily, and ensure that there is no risk. At last, he said with great emphasis that he believed that our team could overcome difficulties and solve problems.
We should prepare for the worst and strive for the best results. The more severe the situation is, the more sober we need to be. We should find weak links in the quality review and improvement work to ensure the successful implementation of the task, Wu stressed at the meeting
u25b2 meeting site (photographed by Liu Huaiyu)
Yang Baohua put forward clear requirements again for detailed analysis and sound response to the problem through multi-party coordination.
here was no parallel in history! Maximum fuel release
On the morning of 18th, aerospace science and Technology Group held video conferences in Beijing, Xichang, Sichuan and Xian, Shaanxi, inviting rocket satellite development experts, superior leaders and material experts from China Steel Research Institute to analyze and locate the problems. After a morning of intense discussion, we reached a conclusion that we can return to zero and decided to continue the launch mission with qualified alternative products. In the afternoon of the same day, Xichang Satellite Launch Center held a headquarters meeting to discuss the follow-up work plan and make a decision to restart the launch mission.
On the evening of the 18th, the staff worked overtime to install the replacement products delivered from Beijing. After testing, the indicators met the task requirements. But there was still no time to let them breathe: due to the high temperature in summer, the fuel temperature and air pillow volume in the rocket tank filled with conventional propellants had changed, which did not meet the launch implementation conditions.
Its a tough decision. Its obviously not good if we dont let it out. If we let it out and refill it, will there be any new problems in the process?
Only when it is difficult can it show courage. After the decision, the long three armour series rocket is about to discharge and refill the largest propellant ever.
Most of the rocket propellant discharging operations are single point manual control. Sometimes, the control of switch size and flow velocity needs to be identified by hearing, which is very difficult. The opening and closing valves on the rocket also need to be opened many times. Whether they can bear these actions is also a practical test of product quality.
u25b2 on June 19, Yang Changfeng, chief designer of Beidou satellite navigation system engineering, and the two presidents of the chang-3a series rockets guided the rocket conventional propellant discharge operation in Xichang Satellite Launch Center (Photo by Liu Huaiyu)
From the 19th to the 20th, the oxidizer and combustor at the first stage, the second stage and above the four booster nozzles of the rocket respectively completed the discharge operation safely. Roughly, the amount of spillage accounts for about 3 / 4 of the total amount of refuelling, which is rare in the world.
One wave is not flat, another is rising. In the high temperature of summer, the delay of launch after refueling brings new problems to astronauts. During the inspection of the discharged booster oxygen tank, the staff found that the flange bolts connecting the sensor were slightly corroded and needed to be replaced as soon as possible.
This operation can only be carried out in the narrow body of the rocket. The operator should wear the shelter of chemical defense and obey the instrument cabin to drill into the interior of the rocket, and quickly and accurately complete the demolition and installation of new products in a prone position. In a few seconds between disassembly and assembly, it is necessary to keep a high level of vigilance and calm response to the dangerous substances that may be encountered at any time.
Finally, Yan Lei and Liu Yongning, two young people in their 30s, who are product assemblers in 211 plant of No. In the face of danger and precise operation, the comrades of plant 211 played an important role in this emergency response, and their professionalism and solid skills made me admire them. Said Jiang Jie, chief designer of the rocket.
On the morning of June 23, when the news of the successful launch mission came, the tense nerves of the rocket launch test team members finally relaxed
During the reporting period of beidou-3 global networking, the situation of epidemic prevention and control in Beijing changed. Compared with the distressing epidemic situation, the delayed launch and emergency disposal of the rocket in Xichang Satellite Launch Center can also be called ups and downs.
From the early stage of star and arrow test to the wide attention from all walks of life, from the emergency disposal of sudden problems on the eve of launch to the announcement of postponement before the arrival of launch window, to the zero problem and restart the implementation of launch task After sleepless nights, spacemen from both sides cooperated with the officers and soldiers of the launch site to actively and steadily complete a series of disposal, only for one common goal: never let the rocket bring any hidden danger to the sky.
As we all know, due to the high risk of space launch, it is a common phenomenon to delay the launch all over the world. This time, I witnessed the impact of continuous thunderstorms over the launch site after the mission was postponed, experienced the largest propellant discharge and refilling in the history of long 3A series rockets, and learned that the product assembly personnel risked a huge risk to replace the flange bolts of the booster oxygen tank We have a deeper understanding of the high-risk nature of Aerospace Launch, as well as a deeper understanding of the spirit and quality of aerospace, such as love the motherland, selfless dedication, self-reliance, hard work, strong coordination, courage to climb.
Space exploration is the cause of the brave. We firmly believe that, on the way to the summit of Aerospace Science and technology, the calm, resolute and determined Chinese astronauts will surely bear the heavy trust and make great achievements again, so that the Chinese peoples pace of exploring space will be greater and further.