The moon is kind of shy. It only faces us with one side, hiding the other half of the sphere in the dark.

But what lies on the other side? Though we humans have reached much deeper into the space, the far side of the moon really is a virgin land.

For the first time in human history, China has launched a lunar mission to land a robotic craft on the far side of the moon.

As China's "Chang'e-4" paces toward the dark side of the moon, let's check out some interesting details of this unprecedented mission. 

The bridge of birds

Preparing for this mission was no easy job. China has been working for this moment for years.

Communicating with the robotic lander was one of the major challenges, as the far side of the moon always points away from the earth. So, there was no direct link for signals.

Therefore, as a solution, China in May launched the Queqiao satellite into the moon's orbit, positioning it so that it can relay data and commands between the lander and the earth.

(We at CGTN have covered a lot about Queqiao, and here's a summary if you are interested.)