By 
November 30th, 2020
Chang’e-5 lander departs orbiter. Credit: CCTV
China’s Chang’e-5 lunar mission — the country’s first attempt to retrieve samples automatically from an extraterrestrial body – is ready for a landing.
Credit: CCTV
The Chang’e-5 probe’s lander and ascender separated from its orbiter and returner at 4:40 a.m. Beijing time on Monday, according to the China National Space Administration (CNSA) on the same day.
Credit: CCTV/Inside Outer Space screengrab
Sealed deal
Getting down and dirty on the lunar surface, then collect Moon samples for return to Earth, is a complex affair.
Credit: New China TV/Inside Outer Space screengrab
“We have never done a whole process of taking and sealing samples,” said Peng Jing, deputy chief designer of the Chang’e-5 probe system of China Academy of Space Technology, also a scientist with China Aerospace Science and Technology Corporation (CASC).
China’s Chang’e-5 lunar mission will attempt to haul back to Earth samples of the Moon.
Credit: CNSA/CLEP
Peng told China Central Television (CCTV) this aspect of the work mainly depends on several complicated structures including drilling, robotically scooping up rocks and regolith on the lunar surface, and then place specimens in a high vacuum sealing device.
Ascender departs the Moon with lunar collectibles.
Credit: CCTV/Inside Outer Space screengrab
“If the air enters the sealed device during this process or during the samples’ transportation, it might pollute the samples,” Peng said.
Lunar liftoff
Another tricky part of the Chang’e-5 mission is the liftoff from the Moon of the ascender.
Ascender liftoff from lunar surface.
Credit: CCTV/Inside Outer Space screengrab
“The main difficulty is that when we first land on the Moon, we would not know how the lander performs beforehand. Besides, the most crucial part during the launch is the fact that the targeted direction needs to be really precise. Only when we have especially designed such a direction and the ascender has entered the target orbit, can it be able to rendezvous with the orbiter-returner combination and conduct further flying processes,” Peng said.
Autonomous rendezvous and docking between ascender and orbiter.
Credit: CCTV/Inside Outer Space screengrab
Autonomous operations
The ascender will autonomously dock with the orbiter-returner combination and poses another tough challenge.
Bringing the lunar goods back to Earth.
Credit: CCTV/Inside Outer Space screengrab
“We need to precisely anticipate the location and speed of the two spacecraft flying at the lunar orbit. Because the probes don’t match in size, our ascender weighs just around 300 to 400 kilograms during docking, while the combination weighs nearly 2,000 kilograms. Any error could knock off the smaller spacecraft, and that would make the docking job much more difficult than before,” Peng said. He added that the docking has a rather high requirement on accuracy, with an error range less than five centimeters.
If all goes according to plan, a successful Chang’e-5 mission would parachute back to Earth roughly 4 pounds (2 kilograms) of lunar collectibles, landing in Siziwang Banner in Inner Mongolia, north China.
Go to this CCTV video detailing the Chang’e-5 mission at:
Posted in Space News
