Despite numerous human visits to the moon, the part never visible from Earth, known as the "far" or "dark" side, remains a subject of speculation. Initially thought to be similar to the near side, 60 years of robotic observations and Apollo missions have revealed distinct features, particularly in terms of geology. Surprisingly, the moon's far side has only about 1% of its surface covered by maria, the craters formed by lunar volcanic activity, contrasting sharply with the near side, where approximately 31% is maria-covered. In an effort to further explore this mysterious aspect of the moon, China is preparing to launch a significant mission to its dark side.
In the next few days, China will launch a robotic spacecraft on the first of three technically challenging missions to the moon's far side, which will prepare the way for the country's first crewed landing and the establishment of a station on the lunar South Pole.
Since the inaugural Chang'e mission in 2007, China has made significant strides in lunar exploration. Named after the legendary Chinese moon goddess, these missions have helped close the technology gap between Russia and the United States. In 2020, China successfully returned samples from the moon's near side to Earth, marking the first such mission in over four decades. Utilizing the backup spacecraft from this mission, China is scheduled to launch Chang'e-6 this week, with the goal of collecting soil and rocks from the moon's far side, which permanently faces away from Earth.
Chang’e-6 has no direct line of sight with Earth, so during its 53-day mission—which includes a previously untried ascent from the moon’s "hidden" side on its way home—it must rely on a freshly launched relay satellite orbiting the moon. When China begins to search for water at the south pole and establish a basic outpost with Russia in 2026 and 2028, respectively, the same relay satellite will support the unmanned Chang'e-7 and 8 missions. By 2030, China wants to send astronauts to the moon.
NASA's administrator, Bill Nelson, has expressed concerns about Beijing's intentions regarding the lunar poles, particularly regarding potential water resource claims by China. Despite China's stated commitment to collaborative efforts for a shared future, Nelson has consistently highlighted these concerns. China intends to transport payloads from countries such as Pakistan, France, Italy, and Sweden on Chang'e-6, and payloads from Russia, Switzerland, and Thailand on Chang'e-7. However, due to U.S. legal restrictions, NASA is prohibited from engaging in any form of cooperation with China.
In 2026, under NASA's independent Artemis program, the United States plans to send its first astronauts to the moon since 1972. The landing site is slated to be near the south pole, representing a significant milestone in American space exploration."
International cooperation is key (to lunar exploration)," Clive Neal, professor of planetary geology at the University of Notre Dame, told Reuters. "It's just that China and the U.S. aren't cooperating right now. I hope that will happen."
Chang’e-6 is scheduled to make a landing attempt on the northeastern side of the massive South Pole-Aitkin Basin, which is the solar system's oldest known impact crater.
In February, IM-1, a collaboration between NASA and Texas-based company Intuitive Machines, accomplished the southernmost lunar landing on record. However, upon landing at Malapert A near the south pole, the spacecraft experienced notable mechanical issues, including significant swaying. This incident underscores the inherent risks involved in lunar landings, even in areas presumed to have relatively flat terrain.
The South Pole is commonly referred to as the "golden belt" for lunar research, symbolizing an area of significant potential for fruitful scientific exploration.
Long-term research bases might be supported by polar ice without the need for costly resources to be carried from Earth. The 2008 launch of India's Chandrayaan-1 satellite verified that ice exists inside polar craters. The sample return from Chang'e-6 may also provide additional insight into the early development of the moon and the inner solar system.
The moon's far side exhibits a greater density of craters without old lava flows, attributed to the absence of volcanic activity, preserving essential components from the moon's early development. Previous lunar sample missions, including those by the US, the former USSR, and China in 2020, focused solely on the near side of the moon, where volcanic activity has been historically prominent. Chang'e-6's proposed mission involves using a drill and motorized scoop to gather around 2 kilograms (4.4 pounds) of samples, aiming to expand our knowledge of the lunar surface's geological composition."If successful, China's Chang'e-6 mission would be a milestone-making event," Leonard David, author of "Moon Rush: The New Space Race," told Reuters. "The robotic reach to the Moon's far side, and bringing specimens back to Earth, helps fill in the blanks about the still-murky origin of our Moon."
In summary, China's upcoming Chang'e-6 and Chang'e-7 missions to the moon's far side signify a notable progression in lunar exploration. This ambitious endeavor aims to collect samples from an area largely unexplored by previous missions, potentially enhancing our understanding of the moon's geology and early development. While fostering competition among nations and raising tensions, scientific cooperation and technological innovation are expected to yield valuable insights that could reshape our understanding of the moon and the wider solar system.