The content of this article is written with authoritative information combined with personal opinions, and the source of the literature and screenshots have been marked at the end of the article, please be aware.
At 14:07 on June 25, 2024, the Chang'e-6 returner landed safely in the predetermined area of the Four Princes Banner in Inner Mongolia. The most remarkable thing about this landing is that Chang'e-6 also carried soil samples from the far side of the moon. So, what is the significance of this for the mainland's aerospace industry? And why did it poke at the pain point of the United States?
Needless to say, there is no need to say much about the difficulty of this mission. After the launch, Chang'e-6 went through 53 days and 11 flight stages, breaking through a number of key technologies, such as the design and control of the lunar retrograde orbit, intelligent rapid sampling on the back of the moon, take-off and ascent on the back of the moon, and other technologies, before finally successfully completing the mission.
Mach 30 orbit technology is one of the key technology crystallizations in this space mission. In fact, before overcoming the technical problem of Mach 30 into orbit, the real problem is how to solve its precursor problem, that is, to simulate a Mach 30 wind tunnel on Earth. If this problem is solved, then the follow-up problem will be solved.
A wind tunnel, or wind tunnel laboratory, is an experimental equipment that artificially generates and controls the airflow at a certain speed to observe the effect of the airflow on the entity.
In fact, the design and development of modern aircraft is basically inseparable from wind tunnels, and each aircraft needs to spend thousands of hours on wind tunnel experiments. For example, in the 50s of the 20th century, the development of the American B-52 bomber carried out more than 10,000 hours of wind tunnel experiments. If you can't even create such an experimental environment, then finding a solution is even more impossible.
Mach 30, which translates to 37,044 kilometers per hour. For comparison, the fastest manned aircraft in the world, the SR-71, is known to have a maximum speed of Mach 3.56, the final orbital speed of the shuttle after entering space is 28,000 kilometers per hour, and the crew of Apollo 10 returns to Earth at a speed of 39,705 kilometers per hour, the fastest speed achieved by mankind so far.
It can be said that the speed of Mach 30 is almost the same as the fastest speed ever recorded by man. To make matters more difficult, we didn't want to reach Mach 30, but to be able to maintain this speed consistently for a long time to ensure controllability.
And the completion of this incredible feat is the JF-22 hypersonic wind tunnel led by the Chinese Academy of Sciences. Construction of the hypersonic wind tunnel began in 2018 and was officially completed four years later. It is capable of simulating the state of a hypersonic vehicle at Mach 30 and a speed of 10 kilometers per second. Its arrival has made the mainland's achievements in this field directly ahead of the United States by at least 20 years.
On September 15, 2022, the Continental Academy of Launch Vehicle Technology officially released the "Suborbital Transportation New Technology Project!" In the future, it can be anywhere in the world within an hour! officially announced that the suborbital vehicle has entered the practical stage. The suborbital vehicle mentioned in the article can reach a speed of Mach 30 per hour, which is also one of the technical puzzles of Chang'e-6.
The mastery of Mach 30 orbit technology also proves that the gap between the mainland and the United States is widening little by little, and it is only a matter of time before the result is almost broken.
After all, although the United States built a Mach 30 wind tunnel early, it is a defective product that cannot be stabilized at this rate for a long time, and although the mainland started late, it has already achieved initial results, and the gap between this is self-evident.
In addition to the Mach 30 technology into orbit, the return process of Chang'e-6 is also worth mentioning. The return capsule of Chang'e-6 did not directly pass through the atmosphere and land like an ordinary aircraft, but re-entered the atmosphere twice and then executed the landing command.
After completing the lunar soil collection, the Chang'e-6 collector lifted off into orbit around the moon, and then docked with the orbiter and the re-entry capsule to hand over the lunar soil. After being transferred from orbit around the moon, the re-entry capsule disintegrated with the orbiter again and rushed to Earth alone.
Due to the distance, Chang'e-6 will accelerate to 11.2 kilometers per second during this period, compared to the first cosmic velocity of 7.92 kilometers per second when a typical low-Earth orbit spacecraft lands. This speed approaches the second cosmic velocity, exceeding 30 times the speed of sound. However, the disadvantage of this advantage is that the heat released and the impact force after landing can also be very exaggerated.
In order to reduce friction and heat release, the designers of the mainland proposed a roundabout plan, allowing the aircraft to use a semi-ballistic jump to return, first entering the atmosphere at high speed, then turning back under aerodynamic action, and then returning when the speed drops to the first cosmic velocity.
However, under this scenario, the return capsule will have a flight range of more than 6,000 kilometers, and no deviations will be allowed in it. What's more, this plan was proposed as early as 2004, but it will not be put into practice until 2024, which shows that the technical bottlenecks that need to be broken through are quite complex. This is also one of the key points that worries the United States.
When the good news of the successful completion of the Chang'e-6 lunar exploration mission came, many countries came to say goodbye and even applied for lunar soil samples. However, at this moment, the United States came to intervene.
On June 28, NASA spokesman Faith Marco claimed that the mainland had invited France, Italy, Pakistan and the European Space Agency to work together to collect samples from the far side of the moon, but did not invite NASA.
Such arguments of the United States are, of course, vexatious. After all, it was the United States that first promulgated the "Wolf Clause" in 2011, which prohibits the mainland from participating in any joint scientific research activities related to NASA, and even more explicitly prohibits NASA from cooperating with any agency with a Chinese background.
And Nelson, the current director of NASA, also firmly expressed his support when asked whether he supported the "Wolf Clause" when he applied for the congressional budget. It can be seen that this is the common attitude of the United States.
On July 1, 2024, the spokesperson of the Ministry of Foreign Affairs of the mainland held a press conference and clearly answered that the mainland government is open to China-US space exchanges and cooperation. The Chang'e-6 mission has made a global announcement of opportunities, and we welcome countries around the world to participate in the study of lunar samples. Lunar soil samples are scarce, and since the US has not taken the initiative to apply for participation, there is no reason why we must share them.
Even if Nielsen goes out and says that the delivery of lunar soil will not violate the Wolf Treaty, as the true leaders of the Chang'e-6 program, we have the right to freely distribute the ownership of lunar soil. After all. The United States does not respect us anymore, so why should we give the United States a piece of the pie when it is beneficial?
It can also be seen from the absurd statements of the United States that the technological breakthrough completed by Chang'e-6 really made them feel a sense of urgency, and even became a sword of Damocles hanging over their heads. Of course, we have no intention of competing in space, the continent has its own plans and will firmly follow its own path. Our moon landing project will remain open to the world, not like the United States.
Resources:
"Chang'e-6 Returner Safely Lands to Achieve World's First Sample Return to the Far Side of the Moon", Xinhua News Agency
"Sub-rail transportation new technology project project! In the future, it can be anywhere in the world within an hour! 》China Academy of Launch Vehicle Technology
"Innovative Technology Helps the Moon Back to "Dig Treasure"", Xinhua News Agency
#头条首发大赛#