Long March No. 5, Long March No. 6, Long March No. 7, Long March No. 8 and Long March No. 11 are here
The Long March 8 transition scene. Sudong/Photo
The perfect “first show” of the Long March 8 has once again brought the Chinese Rocket family into the public eye.
At 12:37 on December 22, 2020, our country’s new-generation carrier rocket, Long March 8, made its first flight successfully at the Wenchang Space Launch Site in China in the manner of “one arrow and five stars”.
Prior to this, the Long March 5, Long March 6, Long March 7, and Long March 11 4 new-generation rockets have also completed their first flights. Now, with the successful maiden flight of Long March 8, our country’s new-generation carrier rockets have all made their debut during the “13th Five-Year Plan” period.
“In just a few years, the new Type 5 rocket successfully flew for the first time, which greatly improved China’s ability to enter space and further enriched and improved the basic structure of the new generation of carrier rocket series.” Wang Xiaojun, Dean of the First Academy of China Aerospace Science and Technology Corporation, told Reporter, during the “13th Five-Year Plan” period, a new generation of carrier rockets such as Long March 5, Long March 7, and Long March 8 made their collective debut and successfully made their first flight. They have gradually taken on an important role in intensive and complex space missions. It can be said that China’s carrier rockets The development has entered a new stage of green and pollution-free, and the carrying capacity has reached world-class.
Rockets in active service will gradually withdraw from the stage of history and achieve a full replacement of new and old in the future
According to Wang Xiaojun, the new generation of carrier rocket adopts non-toxic and pollution-free propellant. Based on the inheritance of the current carrier rocket technology, it has overcome the design and manufacture of 120 tons of liquid oxygen/kerosene engines, 50 tons of hydrogen and oxygen engines, and 5 meters in diameter. Wait for dozens of key technical difficulties.
On May 5, 2020, the Long March 5B carrier rocket developed for our country’s manned space station project successfully flew in Wenchang, officially kicking off the “third step” mission of China’s manned space project. Now, after more than half a year, the Long March 8 has successfully made its first flight, which has increased the carrying capacity of our country’s carrier rocket from 3 tons to 4.5 tons.
Wang Xiaojun told reporters that compared with the current carrier rockets, the new generation of carrier rockets not only uses non-toxic and pollution-free propellants, but also doubles their carrying capacity, greatly increasing China’s ability to enter space. With the development and improvement of the new generation of Long March series of carrier rockets, the carrier rockets currently in service will gradually withdraw from the stage of history and achieve a full replacement of new and old rockets.
He took the first flight of the Long March 8 as an example. This is a new type of rocket that takes into account both low-Earth orbit and geosynchronous transfer orbit launch capabilities. It effectively fills the capability gap of China’s new generation of launch vehicles.
Xiao Yun, commander-in-chief of the Long March 8 carrier rocket of the First Academy of China Aerospace Science and Technology Corporation, told reporters that with the development of China’s aerospace, the demand for low- and medium-orbit satellite launches has become more and more prosperous. 3 tons to 4.5 tons sun-synchronous orbit launch requirements. The Long March No. 8 came into being.
Xiao Yun said that the Long March 8 rocket will strongly promote the upgrading of our country’s medium-sized launch vehicles, and will drive and traction the development of our country’s low- and medium-orbit satellites to meet the needs of future low- and medium-orbit high-density launch missions.
According to him, since the 1980s, our country has developed plans for a new generation of carrier rockets, and has gradually formed a spectrum development plan for the new generation of small, medium and large carrier rockets.
After decades of pre-research and engineering development, our country has successfully developed a new generation of carrier rockets such as the Long March 5 and Long March 7, forming a common module of 2.25 meters, 3.35 meters and 5 meters in diameter, which is the next-generation carrier rocket “module” The foundation has been laid for the development of “integration, serialization and combination”.
Xiao Yun said that the development of the Long March 8 follows the established development thinking, fully inherits the products and technologies of the in-service models, learns from the existing test verification results, and realizes the rapid integrated development of the models.
According to Song Zhengyu, chief designer of the Long March 8 launch vehicle of the First Academy of China Aerospace Science and Technology Corporation, the Long March 8 is a new configuration rocket based on the Long March 7 rocket and combined with the three sub-stages of the Long March 3A series rocket. It uses a core-level bundled configuration with 2 boosters, with a total length of about 50.3 meters, a take-off mass of about 356 tons, a take-off thrust of about 480 tons, and a 700-kilometer sun-synchronous orbit with a carrying capacity of not less than 4.5 tons.
Song Zhengyu said that our country’s main carrier rocket with low-medium orbit launch capability can only send 3 tons of payload to sun-synchronous orbit, and Long March 8 has increased this capability to 4.5 tons. This is not only an improvement in the carrying capacity of the Long March series of rockets, but also an “upgrade” of the platform for payloads such as satellites.
“In the future, Long March 8 will form a more optimized and reasonable capacity layout with the new generation of carrier rockets such as Long March 5, Long March 6, Long March 7, and Long March 11. This will greatly enhance China’s space access capabilities. It is of great significance to promote the construction of low- and medium-orbit satellite networking.” Xiao Yun said.
Will Chinese rockets be reused and smarter in the future?
What will China’s rockets look like in the future, reusable or highly intelligent?
Among them, the former is full of expectations because of the attempts of American “Iron Man” Elon Musk. In the past few years, Elon Musk’s Falcon rockets have completed land and sea recovery. They are considered to be typical successful cases in the commercial aerospace field and once again ignited the dream of human migration to Mars.
From this perspective, the first flight of the Long March 8 seems to be of even greater significance. In the words of experts, “the shadow of the future Chinese rocket can be seen from it.” In the near future, the Long March 8 is expected to turn the technologies related to future rockets envisioned by researchers into reality one by one.
For example, in order to realize the “reusable” of rockets, engine thrust adjustment is an important technical means. In this launch, the Long March 8 launch vehicle has applied engine thrust adjustment technology, which is the first engineering application in our country’s launch vehicle.
According to Duan Baocheng, deputy commander-in-chief of the Long March 8 launch vehicle of the First Academy of China Aerospace Science and Technology Corporation, this technology can greatly improve the overall design optimization capability and mission adaptability of the rocket. Its first application has also carried out preliminary technical verification for subsequent related technologies. The development of reusable launch vehicles has laid the foundation.
He told reporters that at the beginning of the project, the Long March 8 rocket established a market demand-oriented development, and made efforts to achieve “double success” in rocket development and market tapping from comprehensive considerations such as capability indicators and economic reliability.
Duan Baocheng said that the development of the Long March 8 adopts the modal analysis technology combining virtual and real. The full-arrow dynamic characteristic data is obtained through the whole-arrow dynamic model assembly and numerical simulation calculation based on the existing module test data and dynamic model. The development and exploration of the Long March 8 has laid the foundation for the subsequent modal synthesis technology of large and heavy rockets, which will help greatly shorten its development cycle and reduce development costs.
He also specifically mentioned that, in order to occupy a favorable position in the commercial market, the research and development team carried out low-cost designs on the Long March 8’s electrical and structural aspects, and also carried out “vertical take-off and landing” research to adopt the rocket. With a recyclable design, we strive to achieve reusability.
In recent years, the high-density launch of our country’s carrier rockets has become normal, but occasional flight failures and even flight failures have occurred.
Some people imagine that if the rocket has the capability of fault diagnosis and autonomous flight, in the event of a failure, the rocket can adjust itself, and the flight results can be greatly improved?
The Long March 8 has also tried to solve this problem.
Song Zhengyu told reporters that on the Long March 8, researchers have studied and analyzed various load shedding stability control methods, and used auto-disturbance rejection technology for real-time compensation control to improve the effect of active load shedding and solve the problem caused by the large fairing. “Static instability” is a big problem.
He said that the nozzle polarity identification and control reconstruction algorithm based on the control effect can make the launch vehicle “smarter.” Through the application of this technology, the Long March 8 has the ability to recognize the flight faults in the taxiing segment on-line, and can automatically reconstruct the attitude control under specific fault conditions, which improves the adaptability and intelligence of flight control.
Change from customization to universal, and the future launch mission cycle will be shorter
According to data from the First Academy of China Aerospace Science and Technology Corporation, the Long March 8 rocket has been transferred to the engineering development stage since April 2018, and the factory review has been completed in October 2020.
Song Zhengyu said that it only took more than two years from the model demonstration to the first flight of the rocket to have the factory conditions. This is rare in the history of the development of a new generation of launch vehicles.
He told reporters that in response to the current long test period of our country’s launch vehicles and long space-occupying time in the launch area, the scientific research team actively explored the rocket’s fast launch path and designed the “two flats and one vertical” launch mode for the Long March 8, that is, horizontal assembly, Overall transportation in a horizontal state and vertical transition and docking of the star cover assembly.
According to him, it is estimated that around 2022, the Long March 8 will be launched with “two levels and one vertical”. By then, the launch area will no longer require large-scale and complex towers, which can reduce construction costs.
Wang Xiaojun told reporters that during the “Thirteenth Five-Year Plan” period, the ever-increasing capabilities and number of launches of the Long March series of carrier rockets allowed the Chinese to explore the universe further.
During the “13th Five-Year Plan” period, in the face of high-density launches, the First Academy of China Aerospace Science and Technology Corporation proposed to change the design of “custom rockets” to “universal rockets”-rockets can be applied to other missions with minimal adaptation. The adjustment period of the rocket launch mission has been reduced from the original 18 months to 4 to 5 months.
Wang Xiaojun revealed that the new generation of rockets can achieve the final assembly and launch capability of 5-8 rounds per year, and complete the group batch production. It is worth mentioning that the launch site process of the normal temperature liquid rocket has also been reduced from the original 35 days to 15 days.
He took the Long March 11 as an example. The rocket is an all weather one, capable of being launched within a few hours, greatly enhancing our country’s ability to quickly enter space.