Bengaluru: A sample return capsule from China’s Chang’e-5 Moon mission carrying the lunar regolith or soil, made of Moon rocks and dust, safely touched down in North China’s Inner Mongolia Autonomous Region at approximately 2 am local time Thursday (11.30pm IST Wednesday).
This is the first lunar sample return since 1976, when the former Soviet Union’s Luna 24 returned with lunar material.
The material weighing approximately 2 kg was collected by digging and scooping on the Moon by the mission’s lander, before being loaded onto an ascent vehicle that subsequently docked with an Earth-return module. The service module of the mission’s orbiter then released the return capsule, which eventually landed on Earth with the samples.
The mission gathered samples for just two days on the Moon before landing at Siziwang Banner in Inner Mongolia, where Chinese astronauts land home. The China’s National Space Administration (CNSA) said in a statement that the re-entry capsule will be airlifted to Beijing before being opened.
Nature of the Moon samples
Unlike the previous lunar samples from the US’s Apollo missions and the Soviet Luna missions, Chang’e-5’s samples are taken from newer lunar rock. The mission landed on a high volcanic region called Mons Rümker in the northwestern part of the near side of the Moon.
While the rest of the lunar regolith is thought to be as old as the Moon itself — over 3 billion years in age — volcanic rock is much younger as volcanic activity continued for billions of years and formed layers of new rock. Chang’e-5’s samples are thought to be no more than 1.3 billion years old.
Studying such young rocks gives more insight into the formation and evolution of the Earth-Moon system, and by extension, the solar system. It also helps planetary scientists recalibrate how they date surfaces on rocky bodies in the inner solar system.
The Apollo and Luna missions together had collected a total of 400kg worth of lunar samples.
Technical feats and future objectives
The Chang’e-5 return mission used a skipping re-entry method to mitigate the extreme speeds at which the capsule sped towards Earth. This method was tried out during the experimental test flight for the mission earlier.
Returning satellites typically fly at around a speed of 7.8 km per second, but Chang’e-5 return module was flying at over 11.2 km per second, at the speed of Earth’s escape velocity.
The capsule first skipped over the upper layers of the atmosphere to lower speed, before dipping in and plunging safely. The skip re-entry process took approximately 15 minutes.
The capsule’s parachutes opened about 10 kilometres above the ground.
China used advanced radar as well as newly developed powered exoskeletons for two members of the search crew, equipped with communication transponders, searchlights, and power, for search and recovery.
The European Space Agency (ESA) helped China track the spacecraft as it entered the Earth’s atmosphere.
The China National Space Administration has found #ChangE5!!!
— ESA Operations (@esaoperations) December 16, 2020
The Chang’e-5 has successfully completed 11 stages of its lunar mission, concluding one of China’s most sophisticated space missions. It is a part of the eight-mission Chang’e programme, which also saw the first ever successful landing of a craft on the far side of the moon.
The upcoming three missions will include more sample collection, but also the establishment of a “research base” on the lunar surface to explore natural resources available on the Moon.