Xi hails success of lunar mission

The capsule separated from the orbiter about 5,000 kilometers above the southern Atlantic Ocean and began to descend toward Earth.

It entered the atmosphere at around 1:41 pm at a speed of 10.9 kilometers per second, close to the second cosmic velocity, and then bounced out of the atmosphere in a maneuver to reduce its ultrafast speed.

The second cosmic velocity, also known as the escape velocity, refers to the ultrafast speed required to escape the gravitational field of a celestial body.

After a short while, the capsule reentered the atmosphere and kept gliding down. When the craft was about 10 km above ground, it released its parachutes and landed smoothly on the sandy grassland. The entire landing process was operated by the capsule itself with the help of its sensors and computers.

Shortly after touchdown, recovery personnel sent from the Jiuquan Satellite Launch Center arrived at the landing site in helicopters and off-road vehicles. The capsule is scheduled to be transported by an airplane to Beijing on Wednesday, where it will be opened by experts at the China Academy of Space Technology.

The samples will be taken out of the capsule and weighed before being delivered, in due course, to the National Astronomical Observatories, a subsidiary of the Chinese Academy of Sciences, according to the China National Space Administration.

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

The 8.35-ton spacecraft was designed and built by the China Academy of Space Technology, a subsidiary of China Aerospace Science and Technology Corp, and consisted of four components — an orbiter, a lander, an ascender and a reentry capsule.

After a host of sophisticated steps, the lander touched down at the South Pole-Aitken Basin, one of the largest-known impact craters in the solar system, on the morning of June 2. The landing marked the second time a spacecraft ever arrived on the lunar far side.

The vast region had never been reached by any spacecraft until January 2019, when the Chang'e 4 probe landed in the South Pole-Aitken Basin. The Chang'e 4 surveyed areas surrounding its landing site, but did not collect and send back lunar samples.

The Chang'e 6 lander worked for 49 hours on the moon's far side, using a mechanical arm and a drill to collect surface and underground materials. Meanwhile, several items of scientific equipment were activated to conduct survey and analysis assignments. After the tasks were completed, the sample-loaded ascender lifted off from the lunar surface and reached lunar orbit to dock with the reentry capsule and transfer the samples. In the final leg of the mission, the orbiter-reentry capsule combination flew back to the Earth's orbit, before separating on Tuesday.

The landscapes and physical characteristics of the lunar far side, which permanently faces away from Earth, are very different from those of the near side, which is visible from Earth, according to scientists. The new samples are expected to offer researchers around the globe useful clues to answer questions related to the moon, and will likely bring a range of invaluable scientific payoffs, they said.