The safe landing of China's Chang'e-5 returner on Earth carrying precious lunar samples was hailed as a success. But what ever happened to Chang'e-5's ascender, lander and orbiter?

In order to unveil more details and stories behind the Chang'e-5 mission, CGTN talked to Professor Yang Yuguang, vice chair of Space Transportation Committee of the International Astronautical Federation, during a live interview on Friday.

Click here to review the interview.

After transferring the lunar samples, the ascender used the rest propellants to lower its altitude and crashed on the lunar surface. 

"We deorbited the ascender to let it crash. This is to avoid making it space rubbish or influencing other missions in the future," the professor said. 

Similarly, after separating from the returner, the orbiter carried out an orbiter maneuver "to avoid collision with the returner," and "was deorbited into the atmosphere and burned out."

Different from the ascender and the orbiter, the lander, which finished its task after the ascender lifted off, "will remain permanently on its landing site" on the north of the Mons Rumker in Oceanus Procellarum, also known as the Ocean of Storms, on the near side of the moon, said Yang.

Interestingly, a U.S. robotic spacecraft orbiting the moon, known as Lunar Reconnaissance Orbiter (LRO), has taken a photo of the lander using its high-resolution cameras, he added.

Samples collected in two ways

The professor also shared more details on the two ways Chang'e-5 collected lunar samples – drilling from beneath the lunar surface and scooping on the surface.

As the lunar environment is harsh, drilling and scooping, two different measures armed with different technologies, serve as a backup for each other.

"If one failed, we still had a chance with the other," explained Yang.

In the terms of scientific research, samples collected in both ways are useful in helping scientists know the history of the moon.

"The soil is influenced by the solar wind and also by the extremely high and low temperatures of the moon. So much information is damaged. If we can drill deep under the surface, we can get some original examples," said Yang.

Beneath the lunar surface, there are different layers of soil, and "the sequence of the layers is very useful information" as different layers correspond to different eras.

Solar wind also has a significant influence on the surface soil. 

"Studying the influence of solar wind and the lunar surface environment is important for Earth, and useful for us to construct a lunar base in the future," Yang said.

When drilling for the samples, Chang'e-5 used a stick of two colors. The bottom of the stick is black and the rest is white.

"This kind of design isn't for good looks, but for dealing with various drilling situations," Yang explained. "We don't know the hardness of the soil, so we must make the stick hard enough. The black part is made of a very hard material."

However, "every gram is valuable," so a different material is used to reduce the weight, which is the white part.