Space engineering has a number of flaws when it comes to landing small planes on the moon. In late April, the Japanese HakutoR probe attempted to land on the lunar surface, but the module lost contact with Earth and crashed into the ground during the failed attempt.
Physics and astronomy professor Flavio Alarsa explains that the moon’s high speed and lack of an atmosphere make missions difficult.
“Ships always travel at around 2,000 kilometers per hour, that is 8 km per second. It’s like driving from the city of São Paulo to the coast in 9 seconds. On the moon you have to land at a speed of 1 meter per second, secondly, it shatters the probe,” explains the professor.
In order to land on celestial bodies with an atmosphere like Mars, spacecraft rely on three different braking systems. Are you:
To “park” on the moon, you can only rely on the retro rockets. Understand how each of these elements works below.
1 of 4 Why do small spacecraft so often fail trying to land on the moon? — Photo: Arte g1/Juan Silva Why do small spaceships so often fail when trying to land on the moon? — Photo: Arte g1/Juan Silva
1 heat shield
As the name suggests, the shield serves to protect against the high temperatures generated by friction with the atmosphere, turning the ship into a giant fireball. The shield houses the ship’s sensors, which measure altitude and collect other data. Outside the temperature can reach 2,000 °C and inside only 10 °C.
According to Alarsa, the friction caused by the shield can reduce speed by about 5 to 10 thousand kilometers. After that, he will be expelled from the ship and the other sensors will start to work.
2 parachute
In this second moment, a parachute is deployed to further dampen the speed of the fall. However, like the heat shield, it only works when there is an atmosphere (a layer of gases surrounding planets like Earth and Mars).
3 retro rockets
During the final phase, the sensors measure range and other variables to eventually fire the retrorockets and provide the final deceleration that leads to landing.
This is the most critical moment. Especially since these are retro rockets only type of braking possible to land on the moon, which requires huge amounts of fuel that is not easy to transport. If a mistake is made at this step, the ship will collide and break apart.
“This creates technical instability. Assuming there are four rockets at the base of the probe, used throughout the descent, they burn a lot of fuel. And if one of them stops working, the spacecraft becomes unstable,” says Alarsa.
vertical descent
The professor also explains that the modules on the moon must descend vertically, unlike, for example, airplanes, which descend tangentially and parallel to the runways.
“But it enters tangentially and has to make a turn to turn down, something very tricky. On the Apollo mission, this curve was called the ‘death curve’.
“And it could all work out and in the end the ship could hit a rock and ruin everything,” Alarsa points out.
Japanese probe takes picture of moon’s surface
Foot on the brake and right angle
Cassio Barbosa, an astronomer at the FEI University Center, explains that this happens because spaceflight landings are always delicate moments.
“Deceleration is the most critical phase because it comes very quickly and it’s not just about putting your foot on the brake, but at the right angle to brake enough for the moon’s gravitational orbit to catch it,” he says.
He goes on to say that this is not an exclusive feature of moon landings. “It’s like an airplane, the worst moments are takeoff and landing,” he says.
Before that, in 2019, two other missions were also unsuccessful. They are:
- BeresheetIn Israel, which fell to the moon after engine failures. It was the first private space mission to land on the moon organized under the supervision of the North American Space Agency (NASA).
2 of 4 The Beresheet spacecraft’s selfie was taken about 13 kilometers from the lunar surface. The Israeli flag reads “Small Country, Big Dreams”. — Photo: Disclosure / SpaceIL and Israel Aerospace Industries The selfie of the Beresheet spacecraft was taken about 13 kilometers from the lunar surface. The Israeli flag reads “Small Country, Big Dreams”. — Photo: Disclosure / SpaceIL and Israel Aerospace Industries
- Chandrayaan2of the India, lost contact with Earth shortly before landing. The aim of the mission was to get more information about the moon’s mineral composition and the possible presence of water there (confirmed in 2023 thanks to a Chinese mission that collected lunar glass spheres in 2020).
3 of 4 India sent a mission to the moon on July 22, 2019. — Photo: Indian Space Research Organization/Portal India sent a mission to the Moon on July 22, 2019. — Photo: Indian Space Research Organization/Portal
Cassio Barbosa also attributes the failed attempts to the fact that these private company initiatives were probably not based on a consistent spatial plan.
These are private initiatives that had no realistic landing tests and therefore failed.
— Cassio Barbosa, astronomer at FEI University Center
He also says that if the snow loses communications, the mission can only be kept on course with an autonomous navigation system. But when the problem involves engine failure, there is nothing that can be done.
China: successful mission
4 of 4 Yutu2 robot, part of the mission that arrived on the far side of the moon in January 2019, carried by the Chang’e 4 spacecraft. — Photo: Our Space/Disclosure Yutu2 robot, the Part is the mission that arrived on the far side of the moon in January 2019, captured by the Chang’e 4 spacecraft. — Photo: Our Space/Disclosure
In late 2018, China launched an exploration module to bring a robot to the “dark side” of the moon. You can only see one side of the moon because it revolves at the same speed as it revolves around the earth.
“China made the first landing, even on the other side of the moon,” emphasizes Cassio.
Also see:
- Unprecedented image of a black hole spewing out a powerful jet of matter released by scientists
- The innovations of the space suits used in the return to the moon