Long March 3B (CZ-3B) is a large three-stage liquid-limited rocket developed by China Academy of Launch Vehicle Technology on the basis of Long March 3A and Long March II bundled launch vehicles. The total length of the rocket is 54.838m, the first and second stage diameters are 3.35m, the booster diameter is 2.25m, the third stage diameter is 3.0m, the fairing diameter is 4.0m, the takeoff mass is 425.8t, and the standard GTO carrying capacity is 5.
It has been 24 years since the launch of 1996 Long March 3b. On this basis, China introduced several improved models. The Long March 3B is mainly used to launch geosynchronous orbit satellites, and it is the main rocket for commercial satellite launch service in China.
The Long March 3b has achieved very good results in recent years, all of which are continuous, and dozens of high-intensity launches have been successful. A large number of famous payloads such as Chang 'e III/IV, various Beidou satellites, Zhongxing, Asia Pacific and Fengyun IV were put into orbit, and the penultimate Beidou III networking satellite was put into GEO on March 9. It is a high-orbit launch vehicle with the largest launch volume and relatively high maturity in China.
In 20 17, China and Indonesia signed the Nepal Parapa -N 1 communication satellite project, which was developed by the Fifth Academy of China Aerospace Science and Technology Corporation. The enhanced communication satellite platform Dongfanghong -4 is used to cover Indonesia and other regions. After three years of development, Parapa -N 1 communication satellite was delivered to customers in orbit on April 9, 2020, but the launch failed.
During the rocket launch, the first and second stages of the rocket fly normally, while the third stage works abnormally. The monitoring data shows that the third stage of the rocket and the satellite wreckage have fallen, and the satellite launch failed. At present, the possible problems are: the second and third stage separation failed; The third stage of the rocket failed to ignite once; The third stage auxiliary ignition failed.
As early as August 3, 20091day 17: 28, China launched the Indonesian "Parapa -D" communication satellite in xichang satellite launch center with the "Long March 3B" carrier rocket. The first and second stages of the rocket flew normally, but after the second ignition of the third stage, there was an abnormal situation, which made it impossible to send the satellite into the scheduled orbit.
The cause of the accident is that the primary ignition of the rocket's third-stage engine works normally. After the secondary ignition of the three-stage engine, the thrust of one of the hydrogen-oxygen engines is low, resulting in the apogee of the satellite being lower than the predetermined value.
After a lapse of 1 1 year, Long March 3 B made a similar mistake, but it was also a communication satellite of Indonesia. Such a mistake should not have happened, at least the satellite was successfully put into orbit. This time, the third stage of the direct rocket and the satellite fragments were dropped.
PALAPA-N 1 satellite is used to replace Palapa-D commercial communication satellite currently in orbit.
These two space accidents can be avoided. Take the Long March 7th last month as an example. As early as 20 16, Long March 7 was successfully launched at Wenchang Space Launch Site in China, and this time Long March 7 was converted into a medium-sized launch vehicle on the basis of Long March 7' s new generation of medium-sized high-orbit three-stage liquid-limited launch vehicle, all using mature technology.
There were only two major failures in the Long March 3B in 24 years, both of which were related to the third stage of the rocket. In addition to this one in 2009, there is 1 1 on June 9, 2007. In xichang satellite launch center, China launched the "Zhongxing 9A" radio and television broadcasting satellite with the Long March 3 B 28 carrier rocket, and the third stage of the rocket was also abnormal. The satellite failed to enter the scheduled orbit, but on that occasion, Zhongxing 9A "walked" alone in space with its own fuel, climbed more than 20,000 kilometers, and completed a "space self-rescue" in 16 days to reach the scheduled orbit.
The reason why the third-level problem appears again this time should be related to the promotion of Changsanyi. Although Chang Sanyi has always been called Chang Sanyi, it has been upgraded with the development of space technology in China over the years. As I said just now, there are many types of branches, and there may be some problems in the process of improvement.
Although it is a commercial launch, it will be compensated if there is space insurance. Aerospace insurance refers to insurance that provides risk protection for aerospace products, including satellites, space shuttles and launch vehicles. For example, 19951the "Asia-Pacific II" satellite launched in xichang satellite launch center on October 26th caused a total loss of the stars and arrows, and the economic compensation paid by the insurer was as high as $654.38+62 million.
The Parapa -N 1 project is the first time that a domestic communication satellite has made a breakthrough in the Indonesian space market, which is of great significance for promoting China's space products to further explore the international market. PALAPA-N 1 project will improve Indonesian communication and broadcasting, promote social progress and economic development, and it is also another achievement of China Aerospace in the "Belt and Road" construction.
The failure of this launch is bound to make other countries question China's space launch capability and affect China's space products to expand overseas markets.
If Chang Sanyi affects China's development of overseas markets, the failure of the last Long March 7A rocket launch will have a great impact on China's next space mission, because it will include the completion of major projects such as Beidou navigation and the third phase of lunar exploration, the completion of major tasks such as Mars exploration, the first flight of Long March 5B, Long March 7A and Long March 8A carrier rockets, and the launch of commercial satellites such as Asia-Pacific 6D satellite and satellite Internet convergence test star of the group company.
After these two space missions, according to the plan, the Long March 5 B- 1 carrier rocket will carry a new generation of manned spacecraft test ship to perform its first flight mission in the middle and late April.
I have to say that China's space mission schedule is too tight, and every mission node is very tight. Compared with Europe and America, there are insufficient funds and talents.
China Aerospace should set aside time, draw inferences from others, sum up its failures and lessons, and make better preparations for going to the distant sea of stars.
For decades, Chinese astronauts have advanced in success and failure. In the task again and again, people have understood the meaning of the "Long March". I hope you can give astronauts more understanding. Xiu Yuan still has a long way to go, and we are still trying to explore.
We will succeed in the end, we will succeed!