On May 3, 2024, China's lunar exploration program ushered in a historic moment - Chang'e-6 was successfully launched and entered the Earth-Moon transfer orbit. This feat not only marks the steady progress of the fourth phase of China's lunar exploration program, but also marks the beginning of the first human return journey of sampling from the far side of the moon, which is planned to last 53 days, with the goal of collecting samples from the south pole of the far side of the moon - the Aitken Basin, and trying to bring back 2 kilograms of lunar soil.
The mission and challenges of Chang'e-6
As a backup to Chang'e-5, Chang'e-6 was given a unique mission: to conduct lunar surface surveys and collect samples from the Apollo crater region of the South Pole of the Moon-Aitken Basin. Due to its geographical features and age structure, this area has become an important site for the study of the formation and evolution of the Moon, and is considered a treasure trove of scientific research.
Over the past few decades, humans have returned 10 lunar samples, but all of them are located on the front side of the moon. The mission of Chang'e-6 is complex and of great scientific significance. It will collect lunar samples in two ways: "surface extraction", which is to grab part of the lunar soil from the lunar surface through a robotic arm and claw, and "drilling", which is to drill two meters below the lunar surface with a special drill bit to collect deep lunar soil. Subsequently, these samples will be returned to Earth through lunar take-off, lunar orbit rendezvous and docking, moon-to-ground transfer, and re-entry recovery.
This process involves a number of technical challenges. The research team has achieved a series of key technological breakthroughs, including the design and control of the lunar retrograde orbit, lunar sample collection, precise hovering and landing on the far side of the moon, take-off and ascent on the far side of the moon, and the launch and return of the return capsule. On the far side of the Moon, the probe cannot communicate directly with the ground tracking and control station, and needs the support of a relay satellite. As a result, China launched the Queqiao-2 relay satellite in March 2024 to provide relay communications support for Chang'e-6 and future missions.
The value of the far side of the Moon and international cooperation
Wang Qiong, deputy chief designer of Chang'e-6, pointed out that the far side of the moon is basically an ancient lunar crust and highlands, with more potholes, which may hide the secrets of the moon's formation and evolution. The Antarctica-Aitken Basin is not only one of the oldest and largest impact craters on the Moon, but also one of the largest known impact craters in the solar system. Therefore, the Chang'e-6 mission is of great scientific value.
It is worth mentioning that the Chang'e-6 mission also demonstrates the openness and inclusiveness of China's aerospace industry. In 2019, the China National Space Administration (CNSA) announced international cooperation opportunities, planning to use a 20kg payload space for international scientific payloads. The ICUBE-Q CubeSat from Pakistan, the Radon Detector from France, the ESA/Sweden Negative Ion Analyzer and the Laser Corner Reflector from Italy were finalized. Through these international collaborations, Chang'e-6 has not only brought about a major breakthrough in science, but also demonstrated to the world China's confidence and openness in space.
From missing out to leading
The history of China's lunar exploration program can be traced back to the late 80s of the 20th century, although it was not officially launched due to financial constraints at that time. However, in 2004, the first phase of the lunar exploration project, the lunar exploration project, was officially approved, which opened the three-step strategy of "orbiting, landing, and returning" of China's lunar exploration project. Since then, China's lunar exploration program has gradually been on the right track, and so far it has achieved "eight victories in eight battles".
Among them, the success of Chang'e-4 is a milestone - this is the first time that a human spacecraft has made a soft landing on the far side of the moon, truly realizing China's leadership in lunar exploration projects. The successful launch of Chang'e-6 has further consolidated China's leading position in lunar exploration programs.
Despite the many breakthroughs, the road ahead of lunar exploration is still full of challenges. In addition to technical difficulties, the rugged terrain on the far side of the moon, complex landforms, and problems of communication between the Earth and the Moon are all difficulties that need to be overcome. As Wu Weiren, chief designer of the lunar exploration project, said, "We have too little to lead, and we have to continue to work hard." ”
The successful launch of Chang'e-6 has laid the foundation for China's future lunar exploration program and manned lunar landing. At the same time, this feat also provides new perspectives and opportunities for all mankind to explore the moon and the solar system, and takes a solid step towards a deeper and farther cosmic path.