Officials prepare to recover the landing module of the Chang’e-6 moon probe after it landed in Inner Mongolia, in northern China on June 25, 2024.
| Photo Credit: AFP

On June 25, Chinese personnel picked up a 300-kg cannister from the Inner Mongolian Autonomous Region; it contained two fistfuls of soil and rocks. The event made international headlines because the cannister had started its journey on the moon’s far side — the side permanently facing away from the earth — and the soil and rocks it carried came from there, a place in the Solar System only Chinese robots have visited thus far.

The mission, called Chang’e 6 (named after a mythological moon goddess), was part of the Chinese lunar exploration programme and the country’s most important yet. A sample-return mission is more complicated than other types of robotic missions to the moon — including orbiters, landers, and rovers — because of the number of moving parts and stronger time constraints.

For Chang’e 6, the China National Space Administration (CNSA) sent a lander to the moon’s surface, like India did with the Vikram lander of Chandrayaan 3. There, a drill and scooper extracted some material samples from and just below the moon’s surface and deposited them in the cannister. The cannister was then placed in an ascender module that lifted off from the lander to orbit, where it rendezvoused with the orbiter. The cannister was here moved to a returner spacecraft. This spacecraft flew to within 5,000 km of the earth and ejected the cannister. The cannister finally made its way to the ground after a bounced atmospheric re-entry manoeuvre.

The lander landed on the moon’s far side, which doesn’t have line of sight from the earth, so no signal from the earth’s surface could reach it. The CNSA instead had ground stations communicate with the lander by sending signals to a satellite it had already installed in orbit around the moon. When this satellite came in view of the lander, it relayed the signals to the lander, collected the replies, and later beamed them to the earth. The mission lasted 53 days.

Once the capsule landed, officials flew it to the Chinese Academy of Space Technology in Beijing. There, experts of the Chinese Academy of Sciences would have taken the samples out and placed them in storage, in preparation for research and analysis. The world’s first mission to the moon’s far side was Chang’e 4, which in 2019 delivered a lander and a rover there. In Chang’e 5, the CNSA executed a sample-return mission from the near side, and followed it up with Chang’e 6.

Also read | China launches lunar probe mission to collect samples for first time from far side of moon

Two leaders

Various countries of the world have made ‘returning’ to the moon a priority of their respective national space programmes. Two vague leaders have emerged in this race: one led by the U.S. and the other by China. The U.S. is currently focusing on sending payloads built by private companies to the moon and on a major programme to regularly land humans on the moon from the early 2030s.

If the moon is to have room for everyone, we need to understand both its sides. The far side is little like the near side. It is more covered by rocky terrain, has had less volcanism and, not being shielded by the earth like the near side, receives more solar radiation on its surface. The far side is scientifically important for two reasons. One, it’s an important part of the spatial and temporal map of the Solar System scientists are piecing together to reveal its evolution and guide future exploration. Two, Yung Kai-leung, a Hong Kong Polytechnic University professor and member of a team that contributed to the moonstuff collection system, told the Chinese national broadcaster the far side suffers more meteor strikes, and which future moon bases must be protected against. The Chang’e 6 lander also descended in the Apollo Basin, an ancient crater where materials from the moon’s deep crust or mantle could have been pushed out.

Researchers will now study the 1.93 kg of moonstuff in the hopes of learning something about the moon and the early solar system. The CNSA has said China’s researchers will have first crack at the returned samples, followed by researchers from abroad who applied for access. We don’t yet know if any Indian groups did. The results of these studies will be more valuable than gold.

In this photo released by Xinhua News Agency, a replay screen shows Chang’e-6 probe collecting samples on the moon surface, at Beijing Aerospace Control Center (BACC) in Beijing, on June 4, 2024.
| Photo Credit: AP

China says a spacecraft carrying rock and soil samples from the far side of the moon has lifted off from the lunar surface to start its journey back to Earth.

The ascender of the Chang’e-6 probe lifted off on June 4 morning Beijing time and entered a preset orbit around the moon, the China National Space Administration said.

The Chang’e-6 probe was launched last month and its lander touched down on the far side of the moon on June 2.

Xinhua News Agency cited the space agency as saying the spacecraft stowed the samples it had gathered in a container inside the ascender of the probe as planned.

The container will be transferred to a reentry capsule that is due to return to Earth in the deserts of China’s Inner Mongolia region about June 25.

Missions to the moon’s far side are more difficult because it doesn’t face the Earth, requiring a relay satellite to maintain communications. The terrain is also more rugged, with fewer flat areas to land.

Xinhua said the probe’s landing site was the South Pole-Aitken Basin, an impact crater created more than 4 billion years ago that is 13 kilometers (8 miles) deep and has a diameter of 2,500 kilometers (1,500 miles).

It is the oldest and largest of such craters on the moon, so may provide the earliest information about it, Xinhua said, adding that the huge impact may have ejected materials from deep below the surface.

The mission is the sixth in the Chang’e moon exploration program, which is named after a Chinese moon goddess. It is the second designed to bring back samples, following the Chang’e 5, which did so from the near side in 2020.

The moon program is part of a growing rivalry with the U.S. — still the leader in space exploration — and others, including Japan and India. China has put its own space station in orbit and regularly sends crews there.

The emerging global power aims to put a person on the moon before 2030, which would make it the second nation after the United States to do so. America is planning to land astronauts on the moon again — for the first time in more than 50 years — though National Aeronautics and Space Administration(NASA) pushed the target date back to 2026 earlier this year.

File picture of the lunar lander of the Chang’e-4 probe in a photo taken in 2019.
| Photo Credit: AP

China on May 3 launched a lunar probe mission to collect samples for the first time from the far side of the moon and bring them to Earth for scientific studies.

The Chang’e-6 mission is tasked with collecting and then returning samples from the moon’s far side to Earth — the first endeavour of its kind in the history of human lunar exploration, China National Space Administration (CNSA) said.

The lunar probe was carried by a Long March-5 Y8 rocket which blasted off from the Wenchang Space Launch Site on the coast of China’s southern island province of Hainan.

Chang’e 6 consists of four components: an orbiter, a lander, an ascender and a re-entry module, according to a report by the state-run China Daily.

After collecting dust and rocks on the moon, the ascender will transport the samples to the lunar orbiter for transfer to the re-entry module, which will carry them back to Earth.

The CNSA said earlier that the mission is poised to make breakthroughs in key technologies, such as automatic sample collection, take-off and ascent from the far side of the moon. Meanwhile, the probe will carry out scientific exploration of the landing zone.

The CNSA has announced that scientific instruments from France, Italy and the European Space Agency/Sweden will be on board the lander of the Chang’e-6 mission and a Pakistani payload on the orbiter. A major space power, China in the past successfully launched unmanned missions to the moon which included landing a rover. China has also sent a rover to Mars.

Earlier, China announced plans for a manned lunar landing by 2030.

India became the first country to land near the little-explored lunar south pole region last year when its Chandrayaan-3’s lander, carrying the Pragyaan rover successfully landed there.