HELSINKI — Chang’e-6 is set to make its lunar landing attempt this weekend, a critical moment in China’s mission to collect the first samples from the far side of the moon.
Chang’e-6 launched on May 3 and entered lunar orbit a little more than four days later. Since then, he has been waiting for optimal conditions for his landing attempt. The far side of the Moon, never visible from Earth, holds the keys to scientific mysteries concerning the Moon’s history and composition.
The mission is targeting a landing in the southern part of Apollo Crater in the vast South Pole-Aitken Basin. The sun began to rise over the crater on the far side of the moon early on May 28.
Landing is now set for around 20:00 Eastern Saturday, June 1 (0000 UTC June 2), according to the European Space Agency (ESA), which is involved via a payload developed in Sweden.
The Chang’e-6 lander will separate from the orbiter mission in lunar orbit in preparation for descent. The landing is timed according to the appropriate level of illumination on the surface and orbit of the lander.
If successful, the lander will go through initial checks and setup. Then he starts drilling and collecting materials from the surface. These samples, expected to weigh up to 2,000 grams, will be loaded into the ascent vehicle. The Ascender will then launch the precious cargo back into lunar orbit, where it will rendezvous and connect with the orbiter. Surface operations will take about 48 hours.
All aspects of Chang’e-6 were brilliantly planned and timed to give the mission a chance to succeed. Chinese scientists are excited about the prospect of analyzing the samples if they are successfully delivered to Earth around June 25.
“I’ve analyzed science data from the Chang’e-4 mission that landed on the far side of the Moon, and I’m constantly excited about new insights from ongoing data from the rover. That’s why I’m particularly excited about the Chang’e-6 mission,” said Xu Yi, an assistant professor at Macau University of Science and Technology. SpaceNews.
“The reasons for the asymmetry in the scale of volcanic activity between the near and far sides of the Moon are still the subject of various hypotheses. Chang’e-6 will likely collect lunar samples from a variety of sources, including products of local volcanic activity. The dating and compositional analysis of these samples will provide more ground truth information about volcanic activity on the far side.”
Chang’e-6 spacecraft and payload
The Negative Ions on the Lunar Surface (NILS) payload developed by the Swedish Institute of Space Physics and the Detection of Outgassing RadoN (DORN) instrument from France will collect data during the lander’s operating time on the surface. On board the lander, which also carries the small rover, is an Italian passive laser reflector. The lander will then suffer damage during launch of the egress module, likely ending surface operations.
Chang’e-6 also carried a small, jointly developed Pakistan-China university satellite. Icube-Q took images of the Moon and the Sun that were launched into lunar orbit.
Since the far side of the Moon is permanently out of sight of Earth, direct communication is impossible. To overcome this, the mission is supported by the Queqiao-2 satellite. This spacecraft operates in a specialized lunar orbit. Its role is to reflect communications between Chang’e-6 on the far side and ground stations on Earth.
Based on Chang’e-5’s close return mission in 2020, the ascender and orbiter are likely to rendezvous and dock about two days after launch. The winch will be retired a few days later. The orbiter would then prepare to leave lunar orbit at the calculated time. It would then release the reentry capsule just before its return to Earth, around June 25.
Chang’e-5 collected 1,731 grams of samples, less than the expected 2,000 grams due to a drilling problem. The samples revealed a number of insights about the Moon, its composition and history. The samples were first made available to Chinese institutions, but access has been extended to international scientists. NASA researchers were also given permission to request samples, except for a congressional ban on bilateral activities between NASA and Chinese entities.
Chang’e-6 is part of China’s broader lunar goals. Earth will follow with two missions to the Moon’s south pole. These are Chang’e-7 in 2026 and Chang’e-8 around 2028. Earth aims to launch its first manned lunar mission by 2030.
Both sets of missions are part of the plan to establish a permanent lunar base. This project is known as the International Lunar Research Station (ILRS) program, planned for the 1930s. Several countries and organizations signed up for the project.