Chang'e returns from the far side of moon, full explanation of Queqiao relay satellite

The Chang'e-6 mission is the first human mission to return to the far side of the moon. The difficulty is self-evident. Due to the obstruction of the moon itself, the probe landing on the far side of the moon cannot directly achieve telemetry, communication and data transmission with the earth. The "Queqiao" relay satellite becomes a "communication station" between the Chang'e probe and the earth, building a "bridge" for information connection between the earth and the moon. In addition to sampling on the far side of the moon, for the fourth phase of the lunar exploration project, which includes the exploration of the lunar south pole and the basic construction of the lunar scientific research station, "Queqiao-2" is the "master switch" of the entire project.