Mine is originally a PPT. After converting it into word, you can then paste it into the PPT. "I know the earth is round because I saw a circle; then, I saw that it is still three-dimensional. When I go

When looking down,... we saw ships dragging their wakes in the Indian Ocean, bush fires in some parts of Africa, and a storm with thunder and lightning sweeping across 1,000 miles of Australia, presenting a three-dimensional landscape of nature.

” This is a description by astronauts when talking about the scene of looking at the earth from the space shuttle.

The development of aerospace technology is one of the most eye-catching undertakings in the world today. It promotes the progress of human science and technology and expands the field of human activities from the atmosphere to the outer space.

Aerospace technology is the crystallization of modern science and technology and an integration of basic science and technical science. Aerospace technology is an important symbol of a country's scientific and technological level.

Aerospace technology is a comprehensive engineering technology, mainly including: guidance and control technology, thermal control technology, jet propulsion technology, energy technology, space communication technology, telemetry and remote control technology, life support technology, aerospace environmental engineering technology, rocket and aerospace

The design, manufacturing and testing technology of spacecraft, the launch, return and on-orbit technology of spacecraft, etc.

The aerospace system that integrates multiple technologies is a modern high-tech complex system. It is not only large-scale, high-tech and cutting-edge, but also consumes huge manpower and material resources and has a long engineering cycle.

Today, aerospace technology has been widely used in political, military, economic, scientific exploration and other fields, and has become a symbol of a country's comprehensive national strength.

Human beings have long had the ideal of traveling into space and conquering the universe.

The planets in the universe have always been full of attraction and mystery to humans. Many beautiful myths and legends reflect humans' yearning for the universe and their mood to explore the mysteries of space.

"Chang'e Flying to the Moon", "The Cowherd and the Weaver Girl", as well as Sun Wukong soaring in the clouds and mists, a somersault thousands of miles, etc.

The history of space flight begins with the history of rocket technology. Without rockets, there would be no space flight.

Tracing back to the source, China is the first country to invent rockets.

The word "rocket" appeared in the Three Kingdoms Period (220-280 AD).

However, the rockets at that time only had flammable materials tied to the front end of the arrow shaft, which were fired from the crossbow after being ignited, so they were also called "burning arrows."

With the emergence of gunpowder, one of the four great inventions of ancient China, gunpowder replaced flammable substances, allowing rockets to be rapidly used in the military.

In the late Tang and early Song dynasties in the 10th century AD, there were written records of gunpowder being used in rockets. Although the rockets at this time used gunpowder, they still had to be shot by crossbows.

The appearance of a rocket that is actually propelled by gunpowder jets rather than fired from a crossbow is recorded in the "Wu Bei Zhi" compiled by Mao Yuanyi of the Ming Dynasty, as shown in Figure 1.1.

Although this primitive rocket is not as complex as modern rockets, it already has a warhead (arrow), a propulsion system (powder cartridge), a stabilizing system (tail feathers) and an arrow body structure (arrow shaft). It can be considered a modern rocket.

prototype.

The Chinese nation not only invented the rocket, but also was the first to apply series (multi-stage) and parallel (bundling) technologies to improve the rocket's carrying capacity.

The "Godly Fire Flying Crow" recorded in the historical records of the Ming Dynasty is the embodiment of parallel technology; the "Fire Dragon Out of Water" is the specific application of series and parallel comprehensive technology, as shown in Figure 1.2.

The world's first "astronaut" who tried to fly to space on a rocket also appeared in China.

According to legend, at the end of the 14th century, there was a man in China called "Wan Hu" who held a large kite in each hand and asked others to tie him to a special seat. Behind the seat were 47 of the largest rockets at that time.

(also known as "fire").

He tried to achieve the ideal of "lifting off" by using the thrust of rockets and the aerodynamic lift of kites.

Although "Wanhu"'s brave attempt failed and he sacrificed his life, he was still the first person in the world to use the power of rockets to fly.

At the end of the 19th century and the beginning of the 20th century, rockets developed vigorously again.

The development of modern rocket technology and space flight has led to the emergence of many aerospace pioneers who have the courage to explore, among whom K.

3．

Tsiolkovsky (~OHCTaHTHH3ayapandoBHq UHOaKOBCKHfi), R.

Robert Goddard, H.

Hermann Oberth.

Former Soviet scientist Tsiolkovsky devoted his life to the research of using rocket technology for space flight.

In his classic works, he made a profound demonstration of the idea of ??rocket flight, and was the first to theoretically prove the argument that multi-stage rockets can overcome gravity and enter space.

1. Established the basic mathematical equations of rocket motion and laid the foundation of aerospace science.

2. First of all, it was affirmed that liquid rocket engines are the most suitable power devices for spacecrafts, discussed the possibility of liquid hydrogen and liquid oxygen being used as propellants in rockets, and pointed out the direction for the development of launch vehicles. These views only lasted for several decades.

It became a reality.