The first spacecraft to attempt a landing on the far side of the moon is due to the departure from a launch facility in China, a historic step in lunar exploration.
The mission Chang & # 39; and 4 of the Chinese space agency aims to bring down a robotic lander and a rover in the vast and unexplored basin of the South Pole-Aitken.
Named after the Chinese moon goddess, the spaceship Chang & # 4 should be launched around 6:30 pm GMT on Friday from the Xichang satellite launch center in Sichuan, southwest China. The dock for which it is intended is more than 15,000 miles (24,000 km) across and eight miles deep.
"Going to the far side of the moon is one of the main technological features of the hat for China," said Katherine Joy, a lunar scientist from the University of Manchester. "The Chinese lunar space program is extremely ambitious.
"It will go to a place that is truly special for lunar science." The impact crater dug a huge hole in the lunar crust and possibly in the lunar cloak, potentially unlocking rocks that we would not normally find on the moon's surface. "
If the shot of the moon goes smoothly, the probe will turn into a lunar orbit, descend on the engines and then drop the last few meters on the sterile surface in the first week of January. Once the dust has stabilized, the lander unfolds a ramp for the rover aboard to get off the ground. In all, the mission will deliver more than a ton of hardware on the lunar surface.
Chinese officials have revealed few details about the precise probe landing site, but a study conducted in May by researchers at the China University of Geosciences Planetary Science Institute described how Chang & 4 would explore the crater Von Kármán found at the time. interior of the huge basin of impact.
In looking at the side of the moon that constantly faces far from the Earth, mission controllers have to deal with the fact that they can not communicate directly with the spacecraft. Instead, messages from and to Chang & # 39; and 4 will be broadcast by the agency's Queqiao satellite, located in a "orbit around the sky" on the other side of the moon.
Chang & # 4 and 4 is the last giant leap in China's rapidly changing and ambitious lunar program. The first two Chang missions and in 2007 and 2010 sent the probes in orbit around the moon. They were followed by Chang & # 3; a lander and rover who landed on the Mare Imbrium lava plane on the near side of the moon. For the third phase of the program, the missions of Chang & # 39; and 5 and 6 will try to collect lunar samples and bring them back to Earth. The launch of Chang & # 5 and 5 is scheduled for December next year.
The tools on board the lander and the rover will allow them to study the local lunar geology, probe the inside of the moon and analyze the solar wind – the flow of high-energy particles that are coming out of the sun. An experiment on board will test the growth of plants in weak lunar gravity.
"Landing on the opposite side for the first time, the lander and the rover of Chang & # 39; and 4 will help us understand much more about the formation and history of the moon, but, just as important, it gives us the opportunity to play mission from the far side of the moon and to relay data on the Earth through a satellite that surrounds the farthest side, "said Tamela Maciel, of the British National Space Center in Leicester.
The moon always shows the same face on Earth because it is close enough to be locked in place by the gravitational field of the planet. One of the permanent mysteries of the moon is why the near side has a different chemical appearance on the other side. Landing on the opposite side and examining his geology, scientists can get some suggestions on how this happened.
The Chinese mission reflects a broader revival of interest in the moon by national space agencies. US, European, Russian, Japanese and Canadian agencies have set their sights on a "moon gate", a living station that will orbit around the moon and provide a stopping point for astronauts working on the lunar surface.
Beyond the science of understanding how the moon was born, scientists see other benefits of working on the surface. The moon is an excellent observation post for the Earth and the sun. And on the far side of the moon, the electromagnetic noise coming from terrestrial transmissions is almost completely blocked, making it a privileged point from which to perform radio astronomy.
"Astronomers have long dreamed of an array of radio telescopes built on the far side of the moon, said Maciel." Since the farthest side of the moon is not facing the Earth, it is protected from all our radio noise, and a radio telescope here would be like running away from the light pollution of the city and seeing the night sky from the top of a mountain.
"With a radio telescope on the far side of the moon, we would be able to explore the farthest and oldest objects in the universe like never before.But first we have to practice a mission from the far side, and that's what Chang & # 39; and 4 will help us to do ".