Sun. Sep 25th, 2022
China launches Chang'e-4 lunar probe at the Xichang Satellite Launch Center in southwest China's Sichuan province, 8 December 2018.
enlarge / China launches Chang’e-4 lunar probe at the Xichang Satellite Launch Center in southwest China’s Sichuan province, 8 December 2018.

Xinhua/Jiang Hongjing via Getty Images

Late last week, China launched an ambitious mission that will send a lander and rover to the far side of the moon. This Chang’e-4 spacecraft is a major achievement for China, as no other country has ever landed a rover softly on the Earth’s remote side of the moon.

If successful, this mission will carry out several lines of important scientific research on the as-yet-unknown far side of the moon. However, Chang’e-4’s launch and landing also helps reveal the full scope of China’s spaceflight ambitions and how the space program advances the country’s ambitious geopolitical goals. In this post, we try to unravel some of the implications.

What happened?

On Saturday morning (China local time), a Long March 3B rocket sent a 4-ton lander and a 140 kg rover into space, and then this Chang’e-4 spacecraft performed a trans-lunar injection to send it to the send moon. The spacecraft should enter orbit around the moon on Wednesday.

China has not said when it will attempt to land on the far side of the moon, but observers speculate the attempt will likely take place in the first three days of January. Before this landing occurs, Chang’e-4 will need to connect to the Queqiao Relay spacecraft, which will have line-of-sight communications with both the lander, which is expected to land in the South Pole-Aitken Basin, as well as Earth.

Why the other side?

Tide locking means Earth is always facing one side of the moon, while the other side is facing away from our planet. (Pink Floyd despite albums, this side is not dark, as it receives about as much sunlight as the side facing our planet when the Earth-moon system orbits the sun). The Soviet Luna 3 mission took the first grainy photos of the far side of the moon in 1959, and in 1962 NASA’s Ranger spacecraft smashed into the surface.

The other side of the moon.  No robotic spacecraft has ever made a soft landing here.
enlarge / The other side of the moon. No robotic spacecraft has ever made a soft landing here.


But other than the flight past the Apollo mission and some recent lunar orbiters, the other side remains relatively unexplored. The other side has a much rougher, densely cratered appearance compared to the large, smoother maria that dominate the moon-to-Earth side. The exact reasons for this remain a mystery to scientists eager to make in situ measurements on the far side of the moon.

What will the lander and the rover do?

The lander will settle in the oldest and deepest impact basin on the Moon, the South Pole-Aitken Basin, and will focus on lunar geology. Scientists believe that rocks here will have a different composition than the lunar samples collected by the Apollo missions on the near side of the moon.

“It’s possible that this basin is so deep that it contains material from the moon’s inner mantle,” says space scientist Tamela Maciel. noticed on Twitter. “By landing on the other side for the first time, the Chang’e-4 lander and rover will help us understand so much more about the moon’s formation and history.”

The mission will provide China (and other countries) with information on best practices for piloting a rover on a surface that is never pointed directly at Earth and therefore needs to communicate via a relay satellite. It should also provide data for astronomers who one day want to set up a radio astronomical observatory on the far side of the moon, shielded from Earth’s abundant radio and satellite communications.

Is China planning to succeed the people?

China has an increasingly ambitious space program, which it sees as crucial to establishing itself as a global superpower. China has both military ambitions in space (where some of its technologies compete with the United States), and a desire for international prestige by doing new and interesting things in space. Sure, NASA has done a lot of amazing things, but it hasn’t done a mission like the one China is trying to do. This is one of the reasons why an unprecedented soft landing on the far side of the moon is a major problem for the country.

China is also developing the hardware needed to eventually send taikonauts to the moon. Earlier this year, the country indicated it plans to accelerate development of the large Long March 9 rocket, similar to the Saturn V booster, to around 2028. Chinese officials have previously said their long-term goal is a series of lunar surface missions. start in the time frame of 2030, and this rocket would make that possible.

Could they do it faster?

If it participates in a “race” back to the moon, China may be able to beat the United States. Under current plans, NASA is unlikely to return humans to the lunar surface before 2030. Already now, with its existing Long March 5 rocket, China could be on the moon “quite easily” in six to eight years, said former NASA administrator Mike Griffin, who is currently Secretary of Defense for Research and Engineering.

At a recent meeting of the National Space Council’s user advisory group, Griffin said, “They never seem to be in a rush. They seem to be playing the long game. So I’m not saying they’ll be on the moon in six hours. to eight years, but if they wanted to, they could. And to be back on the moon when the United States can no longer go on the moon is a travesty.”

The problem, Griffin said, is that this would be a devastating blow to the United States on the international stage. “I think such an event would trigger a realignment of geopolitical thinking, which would be extremely damaging to the United States,” he said. “Non-aligned nations want to make deals, they want to partner with the nations they believe to be leaders in the world. When very great and visible feats are delivered by people who see themselves as our adversaries, there is no way you could can look and say it’s good for the United States and our Western allies.”

How does NASA respond?

NASA has plans for both robotic exploration of the moon and eventual human landings. The space agency opts for an approach that stimulates commercial activity near and on the moon. Earlier this year, NASA scrapped plans for a single mission to explore one of the lunar poles for water, known as Resource Prospector, in favor of a partnership with nine companies to enable the delivery of small scientific payloads to the lunar surface.

“Some of the designs for the nine companies have the capability to provide rovers, and some have the capability to search for water,” NASA administrator Jim Bridenstine told Ars in an interview. “A lot of these companies are also planning a return to the moon. It’s a big development that could benefit NASA a lot. If we turn it over to the commercial companies, they’ll come up with the best ideas and the most cost-effective ways.”

NASA is also developing plans for a Lunar “Gateway” in orbit near the Moon, a small human space station that could serve as a platform for scientific study of the Moon and as a waypoint for vehicles to go up and down to the lunar surface. Critics have said the Gateway will only delay and make a human return to the moon more expensive; NASA says the Gateway is useful for using reusable lunar landers and making important breakthroughs needed for missions to Mars in the 2040s.

As a new race to the moon unfolds before us, China is taking a crucial first step.

By akfire1

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