On November 23, the Long March 5 rocket launched from the Wenchang spaceport, lifting off the Chinese Chang’e 5 lunar probe. The mission aims to bring back two kilograms of lunar surface samples. This is the first lunar sample return attempt since the Soviet Luna 24 mission in 1976.
Rocket failure delayed the mission by three years
Chang’e 5 is China’s most difficult lunar mission to date. It was originally supposed to launch in 2017. However, the ambitious schedule was thwarted due to the failure of the Long March 5 launcher, resulting in the loss of the Shijian 18 telecommunications satellite. It was caused by a serious malfunction in the YF-77 engines powering the rocket’s second stage. The resulting engine redesign turned out to be quite problematic for the engineers. The Long March 5 rocket could not launch again before the end of 2019. Due to the large mass of the Chang’s 5 mission (8,200 kg), the switch to another rocket was not an option.
|2.07.2017||Shijian 18 (rocket malfunction)|
|5.05.2020||New crewed spacecraft prototype|
|23.06.2020||Tianwen-1 Mars mission|
|23.11.2020||Chang’e 5 lunar mission|
After several changes to the flight schedule, Chang’e 5 only flew on the sixth launch of the Long March 5 rocket. Lift off occured on November 23 at 21:30 CET. After 34 minutes of flight, the Chang’e 5 mission was injected into a trajectory leading towards the Moon. The flight towards the Silver Globe will take as long as five days. The mission’s objective is to collect samples from a volcanic formation called Mons Rümker. It lies in the Oceanus Procellarum region on the western edge of the visible side of the Moon.
It is one of the geologically younger areas on the Moon’s surface. Thus, the soil samples will be the youngest to be ever returned to Earth. The landing is scheduled for November 29. The entire mission will take place in a very short time – just one lunar day.
Chang’e 5 will bring back the first lunar samples in over 40 years
The previous time lunar soil samples were brought back to Earth in 1976. Luna 24 ultimately turned out to be the Soviet Union’s final lunar mission. It’s return capsule delivered only 170 grams of samples.
The Chinese intend to retrieve much more. Chang’e 5 is to deliver as much as 2 kilograms of samples. A special drill will be used for probing. It is supposed to dig up to two meters deep. Then the samples will be transferred to the probe’s ascent section. This part of the spacecraft is to launch from the lunar surface on December 1. Then it will dock to the Moon circling orbiter, and transfer the samples into the return capsule. This is the part of the spacecraft that will actually come back to Earth.
On December 10, the five-day return flight from the Moon will begin. Between December 15 and 16, the return capsule will deploy from the Chang’e 5 spacecraft five thousand kilometers above the Earth. To slow down it’s speed, a so-called skip reentry maneuver will be used. In practice it is very similar to stone skipping in a pond. Before the fast flying capsule will enter the Earth’s atmosphere with a speed of 11 kilometers per second, it will first bounce off it to lose some of the speed.
A similar maneuver was already carried out in 2014 during the Chang’e 5-T1 mission testing Moon return technologies. As with that mission, the Chang’e 5 landing is planned in the Siziwang area of the Inner Mongolia province. Following return to Earth the samples will be sent to Chinese laboratories.
Previous Chinese lunar missions
The Chinese Chang’e lunar program (嫦娥 工程, Cháng’é Gōngchéng) has been in development since 2003. It was named after Princess Chang’e, a Chinese mythological goddess who ruled the moon. The program includes three main stages: 1) entering orbit around the moon, 2) landing on its surface and 3) bringing back samples.
In the first stage, two orbiters headed towards the Moon: Chang’e 1 and Chang’e 2. They were followed by the Chang’e 3 and Chang’e 4 lander and rover missions. It is worth noting that Chang’e 4 landed on the “dark side of the Moon”, which is not visible from Earth. A feat that neither the United States nor the Soviet Union had done before.
To communicate with Chang’e 4, it was necessary to previously send a dedicated telecommunications satellite. Queqiao was placed at the L2 libration point located behind the Moon. Thus, establishing a communication link with the lander and rover was possible from the Earth.
Chang’e 5 will inaugurate the third phase of the program. Followed by it, in 2023, China intends to bring back more samples as part of the Chang’e 6 mission. On the long term Beijing focuses on preparations to land Chinese astronauts on the lunar surface.
The international context of lunar exploration
Overall, the Chang’e 5 mission should be seen in the context of a new lunar space race. With the new wave of lunar probes, China has taken the lead. The United States does not plan to launch a few uncrewed landers until the next year. In the coming years, Americans will be the first to return back to the Moon, or at least its orbit. The first crewed flight of the Orion capsule will take place in 2023. At first, the astronauts will only fly around the Moon (similar as in the Apollo 13 mission). Later, the construction of the small Gateway space station will begin.
The return of the Americans the the Moon’s surface was announced for 2024, but it was only a political declaration made by the Trump administration. Landing in 2024 was to mark Trump’s second term in office, although analysts did not believe this very optimistic date. The Biden administration will probably postpone the return to the lunar surface by a few years, and Chinese missions towards the Moon will probably not start earlier than in the 2030s. But the launch (and eventual success) of the Chang’e 5 should be a refreshing warning that the US China race for space domination is still ongoing.
Gunter’s Space Page
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