The Chang'e-6 mission collected 1935.3 grams of lunar samples, which is more than Chang'e-5, because when Chang'e-6 dug up the lunar soil and put it in the container, when it dug up the seventh shovel, the container monitor prompted that the target capacity had been reached, which means that it had dug enough, and it was basically full! But at this time, the eighth shovel has been excavated, so is this eighth shovel of lunar soil still installed? The operators of the Chang 6 sampling deliberated for a long time, probably thinking that there was still room in the container, so they finally unanimously decided to put the eighth shovel of lunar soil into it.
At present, lunar samples have been handed over to the Chinese Academy of Sciences. This marks the official transition of the Chang'e-6 mission from the project implementation stage to a new stage of scientific research.
The China National Space Administration (CNSA) has published detailed information on the application process for lunar sample research and the international cooperation on lunar samples.
Unlike the landing area of the young geological body in the Chang'e-5 landing area, the South Pole-Aiken Basin is the oldest known impact basin structure on the lunar surface and the largest identified and confirmed impact basin in the solar system. The South Pole of the Moon-Aiken Basin reaches the South Pole of the Moon in the south and the Aiken Crater in the north. The Von Kármán impact crater in the Chang'e-4 landing area and the southern part of the Apollo Basin in the Chang'e-6 landing area are both located in the north-central position of the South Pole-Aiken Basin (not the south pole of the Moon). As early as 2020-2023, in a series of discussions, the Chang'e-6 pre-selected landing area was tentatively designated as the South Pole-Aitken Basin (also known as the South Pole-Aitken Basin9) and further refined to the southern margin of the Apollo Basin.
And China has also made it clear that the lunar soil on the back of the moon brought back by Chang'e-6 is significantly different from the front of the moon, Hu Hao, the chief designer of the Chang'e-6 mission, said that during the sampling process, it feels that the lunar soil on the back side of the moon is not the same as the lunar soil on the front, the lunar soil on the front is more delicate and loose, and the state on the back seems to be different, and Li Chunlai, deputy chief designer of the Chang'e-6 mission and a researcher at the National Astronomical Observatories of the Chinese Academy of Sciences, revealed that the samples collected by Chang'e-6 on the back of the moon may be very different from the positive samples in terms of mineral chemical composition. We'll see it soon.
Through remote sensing and Chang'e-4 in-situ exploration, the main rock type in the Antarctica-Aiken Basin is monzonite, which is a mafic rock (mafic-rich, silicon-poor magmatic rock) with perilla pyroxene and calcium-rich plagioclase as the main mineral components. In the past, only sporadic monzonite breccia or glass with similar composition to monzonite were found in the lunar rocks and lunar soil specimens brought back by the United States and the Soviet Union, and typical large-scale monzonite bodies were not directly found. However, the lunar soil and lunar rock have vertical heterogeneity and regional heterogeneity, that is, the material composition of the lunar surface is not the same everywhere, so if the colonite is quarried from the sampling point in the Chang'e-6 landing area, it will be a strong verification of remote sensing and Chang'e-4 in-situ detection, and will help supplement the genesis and magmatic evolution information of the lunar monzonite geological body.
It can be expected that the lunar samples collected by Chang'e-6 will be different from those of Chang'e-5, Apollo and Luna, especially the differences in element occurrence status, mineral assemblage, rock type, chronology, grain order, mechanical properties, electromagnetic properties, spectral curves, lunar soil maturity, and secondary minerals.
Scientific problems that Chang'e-6 can solve (Source: Hui Pu)
(1) The origin of lunar dichotomy. By comparing the differences between the crust source and mantle source rocks on the front and back of the Moon, we provide a key constraint for the origin of the lunar dichotomy.
(2) Composed of deep lunar crust or mantle. Petrological and geochemical signatures of deep lunar crust or mantle materials were obtained by searching for possible impact excavations in the Chang'e-6 lunar soil.
and (3) the formation time of the Antarctica-Aitken Basin. By studying the possible presence of impact lava in the Chang'e-6 lunar soil, the formation time of the Antarctic-Aitken Basin and the Apollo impact crater was determined, as well as the depth and extent of the impact melt pools caused by the impact.
(4) History of volcanic activity on the far side of the Moon. By studying the basalt cuttings in the lunar soil of Chang'e-6, the stages and properties of volcanic activity on the far side of the moon were obtained, and the chemical evolution and thermal evolution history of the lunar mantle were revealed.
(5) Volatiles in lunar soil at mid-latitudes. By studying the volatile content of the main materials (basalt cuttings, impact glass, etc.) in the lunar soil of Chang'e-6, the volatile composition of the lunar mantle on the far side of the moon and the injection and retention mechanism of water caused by solar wind were revealed.
(6) Update of the impact crater chronological model. The consistency between the Chang'e-6 landing site and the existing crater chronological models was compared, and the heavy bombardment hypothesis of late 3.9 billion years ago was tested.
(7) Discoveries of new minerals and/or rocks. Discover new minerals or rocks and reveal the mechanisms and conditions under which they formed.
This has also made NASA extremely interested, and the United States has openly and secretly hoped that China can share these precious samples. The Americans have even publicly stated that they do not prohibit China from donating lunar soil to them.
However, Bian Zhigang, deputy director of the China National Space Administration, said that the root cause of the obstacle to China-US space cooperation is that domestic laws such as the "Wolf Clause" of the United States hinder China-US space cooperation.
"If the U.S. really wants to have normal space exchanges with China, they should take concrete steps to remove the obstacles," he said. ”
US space sanctions against China began back in the 90s
In August 1987, China used the Long March-2 carrier rocket to launch a test satellite equipped with two microgravity test devices of the French company Matra, and successfully recovered, which was the first time that China provided satellite carrying services for a foreign company, and this was the first time that China entered the international commercial space market.
At the same time, China faces a serious challenge from the United States, which opposes the use of Chinese launch vehicles to launch satellites containing American components. As a demonstration of our sincerity, we have signed a Memorandum of Agreement on Satellite Technology Security with the United States.
In this case, there are almost strict regulations on protecting the technical safety of US-made satellites when they are launched in China: "The US government must supervise the implementation of the technology control plan. Access to all equipment and technical data is to be controlled 24-hour by U.S. personnel trained in U.S. government security procedures. Such personnel should control contact throughout the entire process of preparation for launch, satellite launch, and return of equipment to the United States. ”
At the same time that China's Long March rockets have achieved a series of commercial launches, the United States, as the world's largest satellite manufacturer, has imposed increasingly strict export control policies on China, and the US government has repeatedly imposed sanctions on China's commercial launch services under various pretexts.
Even so, in the continuous international commercial launches carried out in 1990~1999, China occupied 7%~9% of the market share, but on May 25, 1999, just when the smoke of the US-led NATO's brazen attack on the Chinese Embassy in the Federal Republic of Yugoslavia had not yet dissipated, the US Congress threw out another so-called investigation report -- the "Cox Report", which claimed that China had unscrupulously "stolen" or "illegally obtained" US satellite technology through commercial launches, especially through fault investigations. missile technology, U.S. launch vehicle fairing technology, and intelligent distributor technology to enhance China's military space capabilities, thereby threatening U.S. national security.
To this end, the U.S. government prohibits satellites manufactured in the U.S. and containing components controlled by the U.S. International Traffic in Arms Regulations (ITAR), which refers to the International Traffic in Arms Regulations, a set of regulations by the U.S. government that controls the import and export of defense-related goods and services that appear on the U.S. Arms List.
That is, the United States prohibits any satellite that uses American components from being launched on Chinese rockets. This is a fatal blow to China's competition for commercial space launches around the world.
On June 12, 1999, the Long March-2C/SD carrier rocket successfully launched a pair of Iridium satellites, which was also the last time that the mainland provided launch services to the United States. Since then, cooperation between China and the United States has been severed, and this is the behavior of the United States, and it has nothing to do with China.
In 2011, the "Wolf Clause" was passed, which legally prohibits cooperation with China
And in 2011, the U.S. Congress passed the "Wolf Clause," which limits U.S.-China cooperation in the space field. Drafted and promoted by former U.S. Congressman Frank Wolfe, this clause is one of the biggest barriers to Sino-US space science and technology cooperation. On the issue of China-US space cooperation, the Wolf Clause can be summarized into two points: (1) non-cooperation; (2) We do not accept it. "Non-cooperation" means that NASA and the White House Office of Science and Technology Policy are not allowed to cooperate with China or Chinese state-owned companies in the space field. "Not hosting" means not allowing official Chinese visitors to be hosted in facilities owned or used by NASA.
In 2012, NASA issued detailed guidance for its subordinate companies, saying that the decree applies not only to the primary institutions of these companies, but also to their subsidiaries. From the state to the company, all individuals have been cut off, and even Chinese scholars and researchers have been subjected to strict scrutiny.
Space cooperation between China and the United States is completely impossible, because US law stipulates that China cannot engage in space cooperation with the United States, otherwise it will be a violation of US law.
China has embarked on its own aerospace path
In fact, it was after the release of the "Cox Report" that the astronauts were filled with great anger along with the smoke of the US bombing of the Chinese Embassy in the Federal Republic of Yugoslavia.
This pen is engraved in the flesh and blood of the Chinese astronauts, making the Chinese astronauts realize that only by self-improvement can we show our swords. "In this world, in the end, you still have to fight for strength. We have to lie down and taste the guts, we must fight for this breath! These are the words engraved in the hearts of every astronaut.
Three days after the Chinese Embassy in the Federal Republic of Yugoslavia was attacked, the Long March-4B carrier rocket successfully made its maiden flight, sending the Fengyun-1C satellite and the Shijian-5 satellite into space.
The success of this launch greatly encouraged the confidence of Chinese astronauts, and a 20-meter-long banner with the words "Strongly condemn the barbaric atrocities of the United States, unite to forge the Chinese sword" and signed by tens of thousands of astronauts was included in the collection of the Museum of the Chinese Revolution (now the National Museum) as a cultural relic.
China is constantly developing along its own space path, and through the implementation of the strategies of "Long March rocket + European satellite", "Long March rocket + domestic satellite", and "whole satellite export in orbit", China has successfully played a set of "combination punches" in the process of restraint and containment, breaking the restrictions of the United States to a certain extent, but due to the obstruction of the United States, China's share of the commercial launch market is still small.
For example, in order to obstruct the development of China's Beidou satellite, the United States proposed to delete certain frequencies, including the frequency of the Beidou generation system used for position reporting services.
However, no matter how obstructed by the United States, Chinese astronauts have always moved forward, which is an important reason why China's Chang'e-6 was able to successfully return from the back of the moon.
China became the third country in the world to return from the moon after the United States and the Soviet Union, the first country in the world to land on the back of the moon, and the first country in the world to return from the back of the moon.
No one knows how difficult it will be to embark on such a great manned space project, which is strategically important, and China will not be helped by anyone, so it can only rely on its own strength, and how difficult it will be to achieve such great results.