China’s Chang’e 5 mission is one step closer to returning a lunar sample to Earth.
The uncrewed probe recently landed on the moon in an area called Oceanus Procellarum, where it drilled down into the rock and scooped up a sample of lunar soil or regolith. This sample was then collected in a sample container and loaded into an ascent module which headed back to dock with the main spacecraft.
The docking between the ascent module and the main spacecraft was successful, and the sample has been transferred ready for its return journey to Earth. This tricky maneuver required the two components to meet exactly without the aid of navigation satellites, something that has not been done since an Apollo mission in 1972. Even then, there were astronauts to oversee the process. This time, the craft had to perform the docking without the aid of humans directly overseeing the procedure.
To achieve the docking, the craft used a pair of microwave radars: One on the main craft and one on the ascent module. These two radars communicated the distance between the two modules and allowed the two to adjust their positions and meet perfectly.
The spacecraft has four parts: The orbiter which orbits around the moon, the lander which is the part which descended to land on the moon and collect the sample, the ascender which carried the sample from the surface back into orbit, and the re-entry capsule which will bring the sample back from the moon to Earth.
The next step in the mission is for the ascent module to detach from the re-entry capsule. This capsule will then return from orbit around the moon to orbit around Earth. It will then re-enter the Earth’s atmosphere to land in a site in the Inner Mongolia region of China.
If successful, this will make China one of only three countries that has collected a sample from the moon, joining the U.S. and Russia. There has not been a lunar sample return mission since the 1970s, so these samples have tremendous scientific value.
Current interest in the moon is high, with NASA planning to send a crewed mission there soon and the recent discovery of water on the lunar surface.
