The only satellite on the far side of the Moon: Who achieved this?

The far side of the Moon has always captivated the attention of scientists and researchers. This mysterious and unexplored area cannot be observed directly from Earth due to the Moon's tidal locking. The Chinese space program became the first to achieve significant success in studying the far side of the Moon, starting with the "Chang'e-4" mission. Furthermore, China has planned an even more ambitious mission — "Chang'e-6," which will continue lunar research and potentially bring samples of lunar soil from this unknown region back to Earth. Let's explore why the far side of the Moon is so important for science and how China intends to carry out the landing and exploration with "Chang'e-6."

What Makes the Far Side of the Moon Unique?

The far side of the Moon remains invisible from Earth due to gravitational tidal interactions that have synchronized the Moon's rotation on its axis with its orbit around Earth. As a result, Earth can only see one side of the Moon, while the opposite side is always hidden from us. This "dark side" (more accurately referred to as the "far side") is significantly different from the visible portion:

• Geological Features: The far side of the Moon has virtually no "seas" — large flat basalt plains that make up a significant part of the visible side. Instead, it is covered with craters and highlands.

• Electromagnetic Silence: The far side of the Moon is shielded from radio interference generated by Earth. This makes it an ideal location for deploying radio telescopes that can study deep space without disruptions.

Despite numerous missions, the far side of the Moon has long remained inaccessible for direct study and landings due to the lack of direct communication with Earth.

A Turning Point: "Chang'e-4" and the First Step on the Far Side

Before the "Chang'e-4" mission (2019), no country had successfully achieved a soft landing on the far side of the Moon. The China National Space Administration (CNSA) accomplished this by launching a relay satellite "Queqiao" (Magpie Bridge), which was placed in orbit beyond the L2 Lagrange point of the Earth-Moon system. This satellite provided communication between the "Chang'e-4" lander and Earth, making the successful operation of the mission possible.

"Chang'e-4" became the first spacecraft not only to land on the far side of the Moon but also to conduct scientific research. The success of this mission paved the way for the next phase — "Chang'e-6."

What is "Chang'e-6"?

"Chang'e-6" is a Chinese mission aimed at exploring the Moon and bringing back soil samples from the far side to Earth. This will mark an important milestone in lunar exploration and allow scientists to learn more about its composition, geological history, and evolution. The "Chang'e-6" mission is part of a larger "Chang'e" program that China has been implementing since the 2000s.

The main objectives of "Chang'e-6" include:

1. Landing on the far side of the Moon.

2. Collecting lunar soil samples.

3. Returning samples to Earth for detailed analysis.

4. Continuing research on the features of the far side of the Moon.

Operation of the "Chang'e-6" Lander

The "Chang'e-6" mission is a complex multi-stage operation that includes launching the spacecraft, performing a soft landing, collecting samples, and returning to Earth. Here are the key stages of the mission:

1. Launch

The spacecraft will be launched into orbit using the heavy-lift "Long March 5" rocket. This launcher has already proven its reliability in previous missions, including the launch of "Chang'e-5."

2. Relay Communication

As with "Chang'e-4," communication with Earth will be maintained by the "Queqiao" satellite, which continues to operate in orbit around the Moon. This satellite may be supplemented with an additional relay to ensure stable data transmission.

3. Landing

The "Chang'e-6" lander will be equipped with advanced navigation and autonomous control systems to safely execute a soft landing at a pre-selected site on the far side of the Moon. The landing area is expected to be of scientific interest, such as near the South Pole-Aitken basin, one of the largest and oldest impact craters in the solar system.

4. Sample Collection

After landing, the module will use robotic manipulators and drilling equipment to collect lunar soil samples. It is planned to collect up to 2 kg of material, including samples from the surface and deeper layers of soil.

5. Return to Earth

After completing the sample collection, the module will send a capsule with the soil to lunar orbit, where it will dock with the orbital module. The return module will then head back to Earth, where the sample capsule will land in China.

Scientific Significance of the Mission

"Chang'e-6" has immense significance for science. Here are the main research directions that will help unlock the mysteries of the Moon:

1. Lunar Soil Analysis: Studying the chemical composition and mineralogy of soil from the far side will help understand the history of the Moon's formation.

2. Geological Reconstruction: Data about rocks from the South Pole-Aitken basin will help clarify the timeline of impact events in the solar system.

3. Preparation for Moon Exploration: The results of the mission will aid in developing technologies for future missions, including the possible construction of lunar bases.

A Glimpse into the Future: China's Lunar Program

"Chang'e-6" is just one phase of China's ambitious program for lunar exploration. After this mission, China plans to:

• "Chang'e-7": Explore the lunar south pole, where water ice reserves may exist.

• "Chang'e-8": Test technologies for building a lunar base, including 3D printing structures from lunar regolith.

• International Collaboration: China is interested in establishing an International Lunar Scientific Station (ILRS) in partnership with Russia and other countries.

The "Chang'e-6" mission is an important step in lunar exploration and the expansion of human knowledge about our natural satellite. It will not only deliver unique soil samples from the far side to Earth but also serve as further evidence that space is a realm for international collaboration and scientific discoveries. The success of "Chang'e-6" could mark the beginning of a new era in lunar exploration and prepare humanity for the next phase — the establishment of permanent bases on its surface.