I believe everyone still remembers that in December 2020, the Chang'e-5 probe successfully brought back precious lunar samples from the moon, which is the first unmanned lunar sample return mission to Earth in the history of the mainland, and it is also the first time in more than 40 years that human beings have gone to the moon to retrieve precious lunar samples. When the Chang'e-5 probe went to the moon to collect samples, the United States expressed the hope that we could share the results of Chang'e-5, and later the United States repeatedly asked us to share the samples brought back by the Chang'e-5 probe.
At that time, this situation also sparked heated discussions among major netizens. Because the United States passed the so-called "Wolf Clause" back in 2011, NASA scientists can only cooperate with us if it is approved by the US Congress. The United States unilaterally legislated to prohibit them from cooperating with us in space spaceflight, but NASA later had to take the lead in "breaking the law" and asking us for samples of Chang'e-5.
Although the United States has unilaterally enacted legislation prohibiting cooperation with us, we still adhere to the principle of openness in lunar exploration and other aspects, and we are open to the international community whether it is the International Space Station or the Chang'e-5 sample. In October 2023, we said that we would soon open the application for Chang'e-5 samples to the international community.
An internal NASA email also mentioned that NASA has asked the U.S. Congress to "give the green light" for NASA scientists to apply to us for samples brought back by the Chang'e-5 probe, because they believe that the samples brought back by the Chang'e-5 probe have "unique value".
On the 26th of this month, the first international loan review meeting of lunar samples for the Chang'e-5 mission will be held, and 10 scientists from the United States, Japan and other countries will present their research plans on lunar samples. Each applicant will have 15 minutes to present their presentations and will be asked questions by the judges.
Chang'e-6 is poised to launch
The Chang'e-5 probe successfully retrieved precious lunar samples, like several previous lunar sampling missions in human history, were taken from the front side of the moon, and humans have never been to the far side of the moon before to bring back samples from the far side of the moon, so scientists believe that the samples on the far side of the moon may have unique scientific value.
In order to learn more about the far side of the moon, we have already launched the Chang'e-4 probe to land on the far side of the moon, and in the first half of this year, we will also launch the Chang'e-6 probe to land on the far side of the moon, go to the far side of the moon to retrieve samples, and then return to Earth. It's mid-April, and we're getting closer to the launch of the Chang'e-6 probe, and new developments on the Chang'e-6 probe should be announced soon.
The official public account of "Wenchang Aerospace Cultural Tourism" issued a recruitment document to recruit "[May Day Holiday] Chang'e-6 Rocket Launch Ceremony One-day Tour", which may imply that the Chang'e-6 probe will be launched around May Day. Of course, this is just for your reference, and the actual launch time is subject to the official announcement.
The Queqiao-2 relay satellite related to the Chang'e-6 probe's mission to take samples from the far side of the moon and return to the earth has been launched as early as March 20, and has entered the 24-hour circumlunar large elliptical orbit on April 2, and on April 6, it successfully completed the communication test with the Chang'e-4 probe, and from April 8 to April 9, the Queqiao-2 relay satellite also carried out a communication test with the ground state of the Chang'e-6 probe. It can be said that the Queqiao-2 relay satellite is ready, just waiting for the arrival of the Chang'e-6 probe.
The Chang'e-6 probe, which will be launched in the first half of this year, is a backup to the Chang'e-5 probe, after the Chang'e-5 probe successfully completed the mission of landing on the moon for sampling and returning to the earth, which shows that the mainland has mastered the technology of probes to go to the moon for sampling, and from a technical point of view, the Chang'e-6 probe can theoretically complete the lunar landing and bring back lunar samples.
However, compared to the Chang'e-5 probe, the Chang'e-6 probe will be much more difficult. Because the moon is tidally locked, the far side of the moon is always facing away from the earth, and we cannot directly see the far side of the moon, and the landing site of the Chang'e-6 probe is located in the south pole of the far side of the moon-Aitken Basin, that is, we cannot directly grasp the actual situation of the Chang'e-6 probe's flight, landing, sampling, take-off and other processes on the far side of the moon. If you land blindly on the surface of the moon, the risk is high.
In order to solve this problem, the Queqiao-2 relay satellite set off in advance, and after arriving at the predetermined orbit, the Queqiao-2 relay satellite will fly around the moon, and in this process, the Queqiao-2 relay satellite will provide relay communication services for the lunar landing mission, sampling mission, and lunar take-off on the far side of the moon.
The instructions issued by our researchers were first transmitted to the Queqiao-2 relay satellite, and then the Queqiao-2 relay satellite was relayed to the Chang'e-6 probe, and the information of the Chang'e-6 probe was also transmitted to the Queqiao-2 relay satellite, and then relayed back to Earth by the Queqiao-2 relay satellite. In this way, the problem of the moon occluding the signal is solved.
It is also necessary to provide relay communication services through the Queqiao-2 relay satellite, which also puts forward higher requirements for the launch window of the probe. The reason is very simple, when the probe arrives at the moon, it needs to choose the opportunity to carry out module separation, and then land on the moon, and after completing the lunar surface sampling task, it also needs to take off from the lunar surface into the lunar orbit, and then realize rendezvous and docking in the lunar orbit, and finally the probe returns to the earth with lunar samples.
Due to the need for relay satellites to provide relay communication services, when the probe is operating on the far side of the Moon, the Queqiao-2 relay satellite is needed just on the far side of the Moon to provide communication services. Therefore, this mission needs to integrate the operation of the Queqiao-2 relay satellite and the Chang'e-6 probe.