China is set to return the first-ever rocks from the Moon’s far side. Jean Deville and Blaine Curcio take a look at what the mission has in store
On 16 December 2020, the return capsule of the Chang’e 5 mission landed in China’s Inner Mongolia Autonomous Region. It had travelled hundreds of thousands of miles from the Moon, carrying 1,731g (61 oz) of precious lunar dust. Remarkably, this represented the first lunar sample return mission since the USSR’s Luna 24 brought back 170g (6 oz) in August 1976. There will be no 44-year wait this time though, as China is planning to launch its next lunar sample-return mission this year, with an expected May launch date.
Chang’e 6 is bound for the far side of the Moon and will be humanity’s first sample from the region, representing an important symbolic, scientific and possibly strategic win for the rising space power. The mission was originally a back-up for Chang’e 5 and is composed of four independent modules: the lander, the ascender, the orbiter and the return vehicle, with an estimated total mass of 8,200kg (18,077lb). It will launch from the Wenchang Space Launch Centre on China’s current most powerful rocket, the Long March 5.
Once Chang’e 6 enters lunar orbit, the lander will separate from the orbiter vehicle and descend to the lunar surface, performing a fully autonomous soft landing in the South Pole–Aitken (SPA) Basin, a 2,500km-diameter (1,550 mile) impact crater on the far side of the Moon. It is understood to be the largest, deepest and oldest crater on the Moon (4.2–4.3 billion years), with an unusual ▶ geochemical composition that is different from the rest of the lunar surface.
To date, China’s Chang’e 4 lander and rover are the only spacecraft to have touched down on the lunar far side. It’s been surveyed by several lunar orbiter missions, but as the Soviet and US missions of the ’60s and ’70s remained on the near side, no samples have ever been retrieved from the region.
The samples Chang’e 6 collects will enable further study of the region’s composition, giving scientists a much better understanding of the formation of the Moon. The impact that created the SPA is also believed to have excavated deep into the lunar crust, which could potentially provide insights
