How to prioritize power?, A Question to the End | Manned Lunar Landing for Space Development | China | Lunar Landing

The moon is a close neighbor of our blue planet and a transit station for humanity to move further into deep space. At present, China is carrying out the fourth phase of lunar exploration project. Not long ago, China also had a schedule for manned lunar landing. The new generation of manned rockets in China is expected to make its first flight in 2027, and it will also achieve the first Chinese landing on the moon before 2030.

Aerospace development prioritizes power. Recently, the main engine of China's manned lunar landing rocket, the 130 ton pump rear swing liquid oxygen kerosene engine, developed by the Sixth Academy of Aerospace Science and Technology Group, completed its sixth test on the test bench. The cumulative test time of the engine reached 3300 seconds, and the working time exceeded 10 times the task time. This verified the reliability of the engine's operation and once again set a new record for single test of China's 100 ton engine.

How difficult is the development of rocket high thrust engines? Why do we need to repeatedly test drive? Can there be over a thousand tons of thrust engines in the future that can help China's aerospace industry move towards deeper space?

What is "rocket engine ignition test"?

Firstly, let's focus on the main engine of the lunar rocket. The engine is the core component and the "heart" of a rocket. The greater the kinetic energy and strength of the heart, the more it can lead heavy rockets to explore higher orbits in space. This time, the single test time of the main engine of China's manned lunar landing rocket has set a new record, which is another leap for China's aerospace power industry to verify the technology of "high thrust" engines.

What exactly is "rocket engine ignition test"? Engine testing, in simple terms, is the process of igniting the engine and verifying the rationality of its design scheme and process reliability. This is an indispensable and important part of the development and delivery of any type of engine. The so-called "test drive" actually has dozens of types, which will run through various stages of engine development before and after. Each stage of test drive has different meanings, and the ignition time varies from a few seconds to hundreds of seconds.

Experts say that in the development stage of a certain type of engine, the engine will complete a complex process from single component testing to full system testing, from a small valve to a complete engine, all of which need to go through countless trials and tribulations. After the development phase, engine testing will enter the identification phase. After completing the testing phase, this type of engine can be delivered for rocket use, but this does not mean the end of the testing. Each engine needs to be "warmed up" on the test bench to meet the standards. With the continuous progress of China's aerospace industry, the test bench is becoming increasingly busy.

What are the characteristics of solid rocket engines and liquid rocket engines?

The engine is the core component of rockets, and currently the mainstream launch vehicle engines are mainly divided into liquid rocket engines and solid rocket engines. So, what are the characteristics of both engines?

Solid rocket engines, as the name suggests, are rocket engines that use solid fuel as propellant. In contrast, liquid rocket engines work on the same principle, both of which generate enormous thrust by igniting the propellant, sending spacecraft into a predetermined orbit of several hundred or even tens of thousands of kilometers.

The difference is that solid engines mainly use solid fuel such as hydroxybutylene, which is a high-energy gunpowder. The Long March 11 carrier rocket uses solid fuel. The liquid engine mainly uses liquid propellants such as liquid hydrogen and liquid oxygen, and the well-known Long March 5 rocket uses liquid hydrogen and liquid oxygen.

Due to the use of different fuels, their respective characteristics are also different. Liquid engines have the characteristics of strong controllability and long ignition time, while solid engines have the advantages of simple structure, flexible maneuverability, and large instantaneous thrust. In the future, the engine combination mode based on the combination of the two advantages will also become a new design concept, which is also the direction that the world's aerospace powers are committed to developing.

How much thrust does a manned lunar rocket engine require?

A few days ago, at 9:31 am on May 30th, the Long March 2F Y16 carrier rocket carrying the Shenzhou-16 manned spacecraft ignited and successfully launched at the Jiuquan Satellite Launch Center. This time, the Shenzhou-16 astronaut crew headed to the Space House, which is the most well-known "divine arrow" of China's manned spaceflight - the Long March 2F series, is undoubtedly a "space special train".

The Long March 2F carrier rocket has a total length of approximately 58.3 meters, is equipped with four boosters, and has a takeoff weight of approximately 500 tons. Approximately 90% of the rocket's weight comes from the fuel it carries, which can accelerate it to a first cosmic speed of 7.9 kilometers per second in approximately 580 seconds.

Orderly Promotion of the Development of New Generation Manned Rocket and Heavy Rocket

At this moment, the Chinese space station is operating in an orbit 400 kilometers away from Earth, but the average distance between the Earth and the Moon is 384400 kilometers, which requires the assistance of a new generation of manned rockets with a stronger "heart". China is currently debating a manned lunar landing plan, and the new generation of manned launch vehicles is expected to have the conditions for their maiden flight in 2027. In the near future, Chinese astronauts are expected to land on the moon, and an international lunar research station will be built in the future. How much thrust does a rocket need to complete these tasks? What new requirements are needed?

It is reported that the diameter of the arrow body of the new generation of manned rockets is equivalent to that of the Long March 5 carrier rocket. By comprehensively applying mature rocket technology, it will meet the requirements of China's manned moon landing mission.

Long Lehao, an academician of the CAE Member and consultant to the chief rocket engineer of the Long March series of the First Academy of Aerospace Science and Technology Group: equivalent to three core stages of the Long March V, bind it together. Each core stage is connected in parallel with three assemblies. Each assembly has seven engines, and each engine has a thrust of nearly 120 tons, which is such a giant. Of course, there is also a second stage, which will divide the three Chinese people into two launches. The carrying capacity of the low Earth orbit can reach about 70 tons, and the carrying capacity of the Earth Moon transfer orbit, which is the transfer orbit from Earth to the Moon, is about 27 tons. This may be divided into two launches, which will enable three Chinese people to land on the Moon before 2030.

At the same time, Academician Long Lehao introduced that China's heavy-duty carrier rocket is also under development. Its rocket body diameter reaches 10.6 meters, height is about 110 meters, low orbit carrying capacity can reach more than 150 tons, and Earth Moon transfer orbit carrying capacity can reach more than 50 tons. This will be the rocket with the strongest carrying capacity in the future.

Long Lehao, academician of the CAE Member and chief engineer consultant of the Long March series rockets of the First Academy of Aerospace Science and Technology Group, said that such a rocket has exceeded the carrying capacity of all rockets in history. In the future, in addition to achieving our more distant goals, such as manned Mars exploration, the establishment of a moon base, and even in the future, direct civilian use, we will let it build a space solar power station for transportation. Now the progress is good. The specific appearance has been done, produced, and the first, second, and third level engines have been correspondingly subjected to the short-range hot commissioning assessment of the whole system, that is to say, the specific plan has been determined.

What progress has been made in the development of higher thrust rockets?

In fact, China's independently developed rocket engines have been frequently reporting good news.

Last November, the first complete test of China's maximum thrust liquid rocket engine, independently developed by the Sixth Academy of Aerospace Science and Technology Group, was successfully completed. This type of engine is designed with a thrust of 500 tons and is also the world's largest dual thrust chamber high-pressure supplementary combustion liquid oxygen kerosene engine. It is reported that the thrust of a 500 ton liquid oxygen kerosene engine is four times that of an active 120 ton liquid oxygen kerosene engine. The success of the first complete test drive marks a significant breakthrough in the development of this type of engine.

At the end of last year, the first complete hot test of China's largest thrust 80 ton level liquid oxygen methane engine independently developed by the Sixth Academy of Aerospace Science and Technology Group was successfully completed, providing the driving force for China's commercial space launch vehicles and laying an important technical foundation for the development of reusable launch vehicles. The thrust of an engine determines the size of the aerospace stage. With the tremendous development of power technology, we believe that China's aerospace industry will achieve even greater leaps.

At what stage has China's preparations for manned lunar landing progressed?

In less than 7 years until 2030, at what stage has China's preparations for manned lunar landing reached? How many steps are needed to achieve the moon landing next? Let's listen to the introduction of Ji Qiming, the assistant director of the China Manned Space Engineering Office.

Ji Qiming, Assistant Director of the China Manned Space Engineering Office: To achieve the landing of Chinese astronauts on the moon before 2030, we have completed the key technical research and development of the relevant spacecraft for the moon landing mission. Of course, we have also completed the demonstration and compilation of the overall lunar landing plan, which is the current progress.

As for the next 7 years, I think it should be divided into three major stages: the first stage is to complete various research and construction tasks, including the completion of the new generation of manned launch vehicles, the new generation of manned spacecraft, the lunar lander for landing, as well as the development of flight products such as lunar suits and manned lunar rovers, as well as the supplementary construction of ground equipment and facilities such as the Wenchang Space Launch Site and the measurement and control communication landing site. The second stage is about to enter the verification phase of unmanned flight. If the mission goes smoothly in this stage, we will enter the third stage, which is the flight phase of manned lunar landing.