Chang'e 6 reaches historic moment in its mission

China's Chang'e 6 robotic mission has reached a crucial moment in its historic lunar odyssey — its landing craft successfully touched down on Sunday morning on the moon's far side, the little-known hemisphere of our celestial neighbor.

With the assistance of the Queqiao 2 relay satellite, the Chang'e 6 landing craft softly settled on the lunar surface at 6:23 am in a designated site inside the South Pole-Aitken Basin, the largest, oldest and deepest basin recognized on the moon.

The landing marked the arrival of China's, and also the world's, second-ever spacecraft on the far side, which is believed by scientists to hold clues to many mysteries surrounding the moon and the solar system.

In the next two days, the Chinese craft is set to use a robotic arm and a drill to collect surface and underground substances and then put them into a sealed container before elevating the precious materials into lunar orbit for a return journey.

If the unprecedented adventure goes according to plan, it will be the first time that dust and rocks from the lunar far side have been retrieved, in contrast to all of the previous samples that were obtained from the near side. And the new samples will probably offer researchers around the globe useful keys to solving their questions about the moon and will likely bring a diversity of invaluable science payoffs.

According to the China National Space Administration, Chang'e 6's complex landing operation began on Thursday as the landing craft separated from the orbiting combination, which consists of an orbiter and a reentry capsule, on the day to prepare for the crucial landing operation.

When everything was ready early on Sunday morning, the landing craft began to conduct orbital descent at 6:09 am, lowering itself from the previous position.

The craft kept adjusting its attitude during the descent process as its 7,500-newton-thrust main engine worked to reduce its fast-flying speed. Its special cameras took pictures of the selected destination and transmitted them to computers to determine the final landing point and also to identify possible hazards on the surface, such as large rocks, so the craft could maneuver to avoid them.

When reaching an altitude of about 100 meters above the moon, the landing vessel suspended its descent and hovered for a very short time to carry out accurate laser scanning of obstacles before continuing to descend at a slower, steady speed.

At the last moment of the challenging operation, when the craft was several meters above the surface, its main engine stopped and the craft activated a buffer system and touched down smoothly on the lunar surface, becoming the second spacecraft to arrive on the lunar far side after China's Chang'e 4 which achieved this feat in January 2019.

The Chang'e 6 mission, the world's first attempt to bring samples from the far side of the moon back to Earth, was launched by a Long March 5 heavy-lift carrier rocket on May 3 from the Wenchang Space Launch Center in Hainan province, the nation's southernmost spaceport.

It entered lunar orbit on May 8 and started to fly around the silver sphere.

Like all previous Chinese lunar probes, the 8.35-metric-ton Chang'e 6 spacecraft was designed and built by the Beijing-based China Academy of Space Technology, a subsidiary of China Aerospace Science and Technology Corp, and also consists of four major components — an orbiter, a lander, an ascender and a reentry capsule.

Before the latest mission, China fulfilled a lunar sample-return mission — the Chang'e 5 in the winter of 2020, which landed on the moon's near side and finally recovered 1,731 grams of samples.