Half a century ago, there were two major Aerospace powers in the world, namely the United States and the Soviet Union. The Soviet Union realized the successful launch of the first human satellite and the first human mission into space. At that time, when the Soviet Union was competing, the United States saw that the Soviet Union had successively completed its pace of progress in space, and naturally was not willing to lag behind. In order not to lag behind the Soviet Union, the United States carried out a more adventurous space exploration activity, that is, manned lunar landing.
We should know that with the space technology more than half a century ago, even if human beings launch satellites into space, there are great risks, let alone send astronauts to other planets. This is a very dangerous space exploration. However, in order to attract the world’s attention and consolidate its strong position, after years of preparation, the United States finally realized the manned landing on the moon in 1969. At that time, American astronaut Neil Armstrong walked out of the “Apollo 11” spacecraft’s lunar module and left the first footprint of human landing on the surface of the moon, realizing the goal of human landing on the moon Like the dream of landing on the moon.
At that time, the successful manned landing of the United States on the moon was a major event that caused a sensation in the world. It immediately attracted the attention of the world. People had to sigh: the United States is really powerful. Even now, we still feel bold and incredible about the American landing on the moon half a century ago. In the past half century, although human exploration of the moon has been going on, there has never been a manned landing on the moon.
Can’t human beings land on the moon with modern technology? At this time, many people began to suspect that the U.S. landing on the moon might have been a hoax. They also raised many questions, such as why the national flag was flying? You know, there’s no atmosphere on the moon, but there’s no wind. Another example is that there is no launch platform on the moon. How did the astronauts successfully return to earth?
Although people have many doubts about the landing on the moon in the United States in those years, after scientists’ explanation, people understand it. Moreover, through the observation of the moon, the probe has indeed found the traces left by the U.S. landing on the moon. There is no doubt about the authenticity of Apollo’s landing on the moon.
Most people have no doubt about Apollo landing on the moon, but there is still a big question that many people don’t understand, that is, how did the astronauts return to the moon without a launch platform? The reason why many people have this question is that many people understand the situation of the earth.
In people’s cognition, whether launching satellites or probes on earth, as long as we want to put things into space, we need a powerful launch platform, which can complete the task of sending objects into space through the powerful thrust of rockets. Many people see satellites or probes launched through the Internet, so naturally they don’t feel the power of rockets.
But if you can take a look at the scene, you will see the tall and domineering style of the rocket, as well as the earth shaking vibration and huge hum generated during the launch. This is a process that makes many people nervous. It is possible that a small error will lead to the failure of the rocket launch.
To launch an object into space on earth, we need powerful booster rocket support and launch platform. But after the Apollo 11 spacecraft completed the exploration of the moon, the astronauts returned to earth without the help of the launch platform. What’s the matter? Is it easier to get into space on the moon? In fact, when we have a certain understanding of the moon, this question is easy to find the answer.
First of all, we need to understand that to enter space, an object needs a speed that can break away from the planet’s gravity. That is the so-called escape speed. The escape speed depends on the gravity of the star, and the gravity of the star is determined by its mass. The larger the mass is, the stronger the gravity is. Secondly, the escape velocity is also affected by the resistance of the atmosphere.
The earth’s atmosphere is relatively thick, so the escape speed is about 11.2km/s. To achieve this speed, more fuel is needed to provide boost. The fuel that the spacecraft can carry is extremely limited. Therefore, if the spacecraft wants to enter space, it must have a rocket full of fuel to boost it.
However, the moon is totally different from the earth. First, the moon has no atmosphere, and the spacecraft will not be affected by the resistance of the atmosphere. Second, the mass of the moon is only one 80th of that of the earth, so the escape speed of the moon is only 1.6 km / s. The escape speed is only about one tenth of that of the earth, so the auxiliary thrust required is very small.
Secondly, Apollo is not a whole spacecraft, it is composed of multiple parts, mainly composed of three function modules, namely service module, command module and lunar module. Different modules have different functions. Apollo spacecraft from the earth through rocket boost into space, after rest will start to the moon.
After reaching the lunar orbit, only the lunar module will carry astronauts to land on the moon. The lunar module is divided into upper and lower layers. The lower layer is very important. It shoulders the mission of landing on the moon and subsequent launching. When the astronauts complete the exploration of the moon and need to return, they will enter the upper layer of the lunar module. At this time, the lower layer becomes the launcher.
Due to the small gravity of the moon and no atmospheric barrier, the lunar module can be successfully pushed into the lunar orbit with only a little boost. After the lunar module enters the lunar orbit, the command module waiting there is fully integrated with the lunar module, and then the astronauts return to earth in the command module.
One of the reasons why man was able to land on the moon half a century ago is that the moon is very close to us, and the spacecraft can reach the lunar orbit in only a week or so. Another reason is that the moon has no atmosphere and its gravity is very small, so it is easy for the spacecraft to return to space after landing on the moon. If it’s a planet like Mars with a large mass and an atmosphere, then after landing, if the spacecraft wants to return to space again, it needs more powerful thrust.
Of course, our current space technology is still very backward. There is a limit to the energy of fossil fuels. Before a major breakthrough in energy is made, a spacecraft still needs to consume a lot of fuel to boost its entry into space. The energy constraints also restrict our exploration of the outer planet. The main reason why we can’t realize the manned exploration of Mars now is that we don’t have strong energy support.
The success rate of manned spacecraft landing on Mars is relatively high, but after landing, it is very difficult to return to earth. We need to build a launch platform on Mars and need more boost fuel. Mars is far away from the earth and only has a launch window every two years to send spacecraft to Mars. In this case, astronauts need at least two years to return from Mars.
However, with the development of human science and technology, these problems will be solved in the future. Once the controllable nuclear fusion technology that scientists have been studying and exploring is realized, human beings will get rid of the shackles of fossil fuels and enter the era of nuclear fusion. At that time, there was no need for rockets to boost the spacecraft into space. Relying on the powerful energy of nuclear fusion, it was easy to enter space. At the same time, the speed of the spacecraft will also be improved qualitatively. You can go to Mars at any time without waiting for any launch window. At that time, human civilization was considered to have initially become an interstellar civilization.
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