China’s Chang’e-6 to Bring Back Key Lunar Samples from Far Side
China’s Chang’e-6 lunar probe is poised to make its historic return journey from the moon’s far side, carrying samples that scientists hope will shed light on the early evolution of the solar system.
Launched on May 3 from Hainan province, Chang’e-6 is named after the mythical Chinese moon goddess. The fully robotic probe landed in the South-Pole Aitken Basin, a gigantic impact crater on the moon’s far side, which permanently faces away from Earth. This region has never been explored before.
In December 2020, China’s Chang’e-5 mission collected samples from the moon’s near side, marking the first lunar material retrieval in 44 years. Previously, the uncrewed Luna 24 mission by the former Soviet Union in 1976 collected 170.1 grams of samples from Mare Crisium on the moon’s near side. Between 1969 and 1972, six Apollo missions collected 2,200 samples weighing a total of 382 kilogrammes, also from the moon’s near side.
James Carpenter, head of the European Space Agency’s lunar science office, highlighted that samples collected by the Apollo missions suggest the South-Pole Aitken Basin on the far side was formed during an epoch of heavy bombardment of the solar system, Earth, and moon. However, this theory remains controversial. To understand these events, samples from the South-Pole Aitken Basin are crucial.
A Tight Window for Collection
Upon landing, Chang’e-6 had a 14-hour window to drill, excavate, and seal 2 kg of material, aiming to be the first probe to bring back samples from the moon’s far side. This is in contrast to the 21-hour window of Chang’e-5 in 2020. The mission had to be completed quickly before the sun set, as the mission would end once it got dark.
While China has improved the efficiency of its digging and drilling machines compared with 2020, challenges could still arise during the sampling phase. Chang’e-5 returned 1.73 kg of lunar samples instead of the planned 2 kg because the drill could only create a hole 1 metre deep, encountering impenetrable layers beneath the surface.
Return and Collaboration
The Chang’e-6 samples will be sealed on a rocket booster atop the lander, which will launch back into space, dock with another spacecraft in lunar orbit, and transfer the samples. The expected landing in China’s Inner Mongolia is around June 25.
Throughout the mission, payloads from Italian, French, and Pakistani research institutes, as well as the European Space Agency, will collect data on space and lunar questions. This highlights the growing international collaboration and the significant role of China’s space programme, which is competing with the United States to build a lunar outpost in the next decade.
Carpenter noted the “extremely strong” collaboration between European and Chinese scientists in analysing the lunar samples brought back by Chang’e-5 and expressed hope for similar cooperation with Chang’e-6.