On 4th June 2024, China’s uncrewed Chang’e-6 spacecraft lifted off from the far side of the Moon carrying a precious cargo of samples, marking an exciting moment in lunar exploration. This ascent followed the successful and historic landing of Chang’e-6 on the dark side of the Moon just two days prior.
The Chang’e-6 mission represents a significant leap for the Chinese Lunar Exploration Program (CLEP), administered by the China National Space Administration (CNSA). The far side of the Moon, also known as the “dark side,” is permanently hidden from Earth’s view. This unexplored territory holds scientific potential due to its unique geological history and potentially pristine environment, shielded from Earth’s radiation belts.
Mission Made Possible?
Named after the Chinese Moon goddess, Chang’e-6 was launched on China’s most powerful rocket, the Long March 5, from Wenchang Satellite Launch Center on 3rd May. The spacecraft reached the vicinity of the Moon roughly a week later and orbited for 20 days to find an appropriate landing site.
On 30th May, Chang’e-6’s lander-ascender combination separated from its orbiter-returner combination and the former descended to the lunar surface. It performed a fully autonomous soft landing on 1st June, in the southern part of the Apollo crater within the vast South Pole-Aitken (SPA) Basin. SPA is a colossal impact crater believed to be the oldest and largest crater on the Moon. Scientists theorise that the SPA Basin may contain unique materials ejected from deep within the lunar mantle during the impact event that formed it. By analysing these materials, researchers hope to gain a deeper understanding of the Moon’s internal composition and evolution.
Landing on the far side of the Moon is significantly more complex than landing on its near side due to the phenomenon of tidal locking, which means that the far side of the Moon never faces Earth. This makes direct communication with ground stations impossible, as there is no line of sight for data transfers. Automation on the far side is also challenging, especially at high latitudes, where long shadows can confuse landers. To overcome these obstacles, a complex relay satellite network is necessary to facilitate communication between the lander and Earth. For this mission, the Queqiao-2 relay satellite, launched in April, played a crucial role in maintaining a continuous communication link during the landing and sample collection phases.
Sample Collected, Returning to Earth
On June 3, 2024, the ascender successfully took off from the lander portion of the Chang’e-6 probe and entered a predetermined circumlunar orbit. There, it will rendezvous with the orbiting service module, where the samples will be robotically transferred into a re-entry capsule for their return to Earth. The landing is expected to occur in China’s Inner Mongolia region around June 25.
If all goes as planned, the mission will provide China and the astronautic community with a pristine record of the Moon’s 4.5-billion-year history and yield new clues on the solar system’s formation. It will also allow for an unprecedented comparison between the dark, unexplored region and the Moon’s better understood Earth-facing side.
More about the Chang’e-6:
Chang’e-6 consists of four modules:
The Chang’e-6 probe also carries four international scientific payloads.
