What difficulties did Chang'e 5 encounter during the moon landing? How was it solved?

Chang'e-2 was successfully launched as a pilot mission of the second phase of the project. After conducting high-resolution imaging of the Hongwan area where Chang'e-3 will land, Yu began to expand the mission, completed technical tests to enter an orbit around Japan's Lagrangian point 12, and then flew by the Toutatis asteroid and sent back photo. Chang'e-2 has become my country's farthest detector from the earth, and has also set a precedent for my country's multi-target deep space exploration. The Chang'e-3 probe consists of a lander and a patrol aircraft. All landed in the Hongwan area on the front side of the moon. After landing, the patrol team and the lander separated and completed their scheduled lunar surface exploration missions respectively. The Chang'e-5 flight tester is mainly used to verify semi-ballistic jump re-entry and return technology. After passing through the Earth-moon rotation, perilunar rotation, and Earth-lunar rotation, the return module breaks away from the service module and re-enters the return flight. Finally, it successfully landed in the predetermined area of ??Siziwang Banner in Inner Mongolia.

Chang'e-4 made adaptive improvements on the basis of Chang'e-3, choosing the far side of the moon for landing and patrol detection missions, and launching the relay star Queqiao to solve communication problems. It successfully landed in the South Pole-Aitken Basin on the far side of the moon, becoming the world's first spacecraft to achieve soft landing patrol detection on the far side of the moon. It is still working normally. The Chang'e-5 probe consists of an orbiter, returner, lander and elevator. According to the latest news, it was launched by the Long March 5 carrier rocket at around 4:30 and has successfully entered the Earth-moon transfer orbit. First of all, there must be a ship with sufficient transportation capacity, and then there must be the support of sampling methods. Just like long-distance freight, you need trucks with strong load capacity and enough porters. What is the most difficult thing to do on the lunar surface of Chang'e-5? Sampling was secondary, a problem Apollo didn't solve.

The goal of collecting about 2 kilograms of lunar soil during the rocket separation test of the Chang'e 5 orbiter is the starting point for all designs. The overall launch mass of Chang'e-5 reaches 8.25 tons, which not only exceeds the 5.8-ton Lunar 24 (the Soviet Union's most advanced unmanned spacecraft on the lunar surface) in shape, but is also more than an era ahead in configuration design. Because Lunar 24 did not master the automatic rendezvous and docking technology in lunar orbit, it had to choose the option of taking off directly from the lunar surface and returning to the earth. During the lunar take-off phase, the return capsule, fuel and larger cabin structure need to be carried, which greatly limits the amount of sampling. In the end, only 0.17 kilograms of lunar soil was obtained, less than one-eleventh of the Chang'e-5 mission goal. Lunar 24 Chang'e-5 is the first spacecraft to apply automatic rendezvous and docking technology in deep space orbit. The riser does not need to return directly to the earth, and only needs to use less fuel to enter the lunar docking orbit, so more weight can be distributed to the capacity needs. This is why the amount of lunar soil collected by Chang'e 5 is higher than that of Lunar 24. Ten times the root cause.

It should be pointed out that the maximum lunar soil collection volume of Chang'e-5 is far more than 2kg, but 4kg. The lunar orbit will automatically rendezvous and dock. Having a powerful spacecraft system is only the first step. How to collect and capture lunar soil is the second difficulty. To this end, Chang'e-5 is equipped with two lunar soil collection systems for drilling and surface sampling. The corresponding actuators are core drilling rigs and sampling robotic arms. Throughout the history of human spaceflight, Chang'e 5 is still the only one in the world that uses two sets of sampling mechanisms on an extraterrestrial planet at the same time. If you want to control these two sampling systems, the upper components need to provide sufficient power. This is why you chose to land on the moon at noon on the lunar calendar. Since the incident angle of the sun is the largest, the power generation of the solar wing of the landing assembly can reach the maximum, thereby supporting the sampling mechanism to collect lunar soil. In order to improve the power supply capacity, the lander's solar wings have been doubled compared to Chang'e-3 and Chang'e-4.