Chang'e-6 Moon Mission

On May 3, 2024, the China National Space Administration (CNSA) launched a robotic spacecraft that aims to achieve a feat no nation has accomplished before. The Chang’e-6 mission is designed to land on the far side of the Moon, collect soil and rock samples, and return them safely to Earth. This mission targets a massive impact crater known as the South Pole-Aitken basin to unlock secrets about the early history of the solar system.

The Historic Launch Details

The mission began at the Wenchang Space Launch Center in Hainan province. A Long March-5 Y8 rocket, China’s most powerful launch vehicle, carried the 8.3-metric ton spacecraft into orbit. This launch initiated a complex 53-day mission profile.

Unlike previous sample return missions that targeted the near side of the Moon, Chang’e-6 faces unique orbital dynamics. The spacecraft had to perform a braking maneuver to enter lunar orbit before descending to its target site. The complexity of this mission highlights the rapid advancement of China’s lunar exploration program, following the successful Chang’e-5 mission in 2020 which returned samples from the near side.

Why the "Far Side" is Different

The Moon is tidally locked to Earth, meaning we only ever see one face. The “far side” is not necessarily dark, but it is permanently turned away from Earth. Scientists are particularly interested in this region because it is geologically distinct from the near side.

  • Crust Thickness: The crust on the far side is significantly thicker than the near side.
  • Volcanic Activity: The near side is covered in “maria” (large, dark basaltic plains formed by ancient volcanic eruptions). The far side is heavily cratered and lacks these extensive lava flows.
  • The South Pole-Aitken (SPA) Basin: Chang’e-6 targeted the Apollo crater located within the SPA basin. This is the largest, deepest, and oldest impact structure on the Moon. It spans roughly 2,500 kilometers (1,550 miles) in diameter.

By collecting samples here, scientists hope to retrieve materials from deep within the lunar crust or potentially the lunar mantle. This material could explain why the two sides of the Moon are so different.

Overcoming the Communication Barrier

Landing on the far side of the Moon presents a major technical hurdle: direct radio communication with Earth is impossible because the Moon’s mass blocks the signals. To solve this, China launched the Queqiao-2 relay satellite in March 2024, two months prior to the Chang’e-6 launch.

Queqiao-2 orbits the Moon in a highly elliptical frozen orbit. It acts as a bridge, receiving data from the Chang’e-6 lander and beaming it back to ground stations in China. Without this relay satellite, the lander would be completely isolated and unable to receive commands or transmit data during its descent and sampling operations.

International Instruments and Collaboration

While led by China, the Chang’e-6 mission carries scientific payloads from four other nations. This international cooperation allows scientists from Europe and Asia to study the lunar environment simultaneously.

  1. France: The DORN (Detection of Outgassing RadoN) instrument studies the transport of lunar dust and other volatiles.
  2. Italy: The INRRI (Instrument for Landing-Roving Laser Retroreflector Investigations) is a passive laser reflector used for precise distance measurement and positioning.
  3. Sweden: The NILS (Negative Ions at the Lunar Surface) payload, developed with the European Space Agency, detects negative ions emitted from the lunar surface due to solar wind interaction.
  4. Pakistan: The ICUBE-Q is a CubeSat that separated from the orbiter to capture images of the Moon and the spacecraft.

The Sampling and Return Process

The core objective of the mission is to retrieve approximately 2 kilograms (4.4 pounds) of lunar material. The lander utilizes two distinct methods to ensure a diverse sample collection:

  • Drilling: A drill bores into the surface to collect subsurface samples, preserving the stratigraphy (layers) of the soil.
  • Scooping: A robotic arm scoops regolith (loose soil) and rocks from the surface.

Once collected, the samples are sealed in a container on the ascent vehicle. This vehicle blasts off from the lunar surface and docks with the orbiter module waiting in space. This autonomous docking procedure in lunar orbit is highly technical. The samples are then transferred to a re-entry capsule.

The final leg involves the orbiter returning to Earth and releasing the capsule. It is scheduled to land in the Siziwang Banner landing site in Inner Mongolia.

Frequently Asked Questions

When did Chang’e-6 land on the Moon? The lander successfully touched down on the far side of the Moon on June 2, 2024.

How does this differ from the US Apollo missions? The NASA Apollo missions (1969–1972) were crewed missions that landed on the near side of the Moon. Chang’e-6 is a robotic mission targeting the far side. The geology of the two regions is vastly different.

What will happen to the samples once they return? The samples will be transported to specialized laboratories in Beijing. They will be curated and analyzed by Chinese scientists first, but CNSA has indicated that proposals from international researchers to study the samples will be welcomed later, similar to the policy for Chang’e-5 samples.

Is there water on the far side of the Moon? While Chang’e-6 is primarily looking at geological formation, the South Pole region is of high interest for water ice. The data regarding hydrogen content in the soil will help scientists understand the distribution of water resources on the Moon.