About aviation!

Humans have long wanted to swim in space. 1903, mankind opened up the first moon park on earth. You can board a winged car in the shape of a cigar for 50 cents, then the car body shakes violently, and finally board a moon model.

In the same year, the Wright brothers flew in the air for 59 seconds, and one was Constantine? Ziolkowski, a self-taught Russian, published an article entitled "Space Exploration with Reaction Instruments". In his article, he calculated that the missile must fly at a speed of10.8 million miles per hour to overcome the gravity of the earth. He also suggested building a liquid-driven multistage rocket.

◇ 19 1 1 year-19 19 years

Robert, a withdrawn man from Massachusetts, USA? Goddard proved with complicated calculations that the rocket to the moon can be made.

The name "Goddard" quickly became the laughing stock of American continent. Goddard lived in seclusion on the farm during menstruation, and successfully ignited the first liquid-driven rocket in history on March 1926.

◇ 192 1 year-1930

1923, Hailmann, an expert and physicist on Verne? Oberth published a 92-page booklet full of formulas. He wants to use this booklet called "Rocket Flying into Space" as a primary textbook for aerospace.

Oberth pointed out that rockets can also fly in a vacuum, and the speed is faster than the escaping driving gas. "Under certain conditions, there will be a particularly efficient aircraft that can easily fly to another strange celestial body." . He drew a sketch of the space station, including space missiles. It seems natural that space visionaries also consider building a space mirror. Oberth's article aroused people's great interest in aerospace. At that time, mankind seemed to have only one wish-to leave the earth.

◇ 193 1 year-1940

1932, the young Soviet Union established its first space organization. The organization soon became a branch of the Red Army, because before communism was established on Mars, engineers had to develop military missiles to maintain order on the earth.

1929- 1930 is a very successful film in Germany, called "Mrs. Moon". Oberth participated in the filming of this film as a scientific consultant. In the audience sat a senior named Braun and Nebel, Willie? Lai and Klaus? Mr. riddle. Together, they formed the "Aerospace Association" and lived a life of strict self-discipline like monks. Soon after, they tested the jet rocket at the "Rocket Launch Site" in Rein Kendoff, Berlin, and calculated the parabola to Mars. Walter, two engineers from the Army Weapons Bureau? Dornberg and Carl? Becker joined the association under the guise of a citizen. Since 1934, rocket research has been a secret in Germany.

1937, Wernher? Feng? Braun became the technical director of the newly-built Penemende Army Research Institute. The Institute is a comprehensive building, located on the island of Uterdom in the Baltic Sea. It consists of an assembly workshop, an experimental platform and a transmitter. Its sole purpose is to develop missiles that can be used in actual combat as soon as possible. In the autumn of 1939, these engineers successfully sent "aggregat 5" (A5) (A5) with control instruments to an altitude of 8km. It is said that it is equipped with a control device that can strike ground targets.

◇ 194 1 year-1950

1942 10 year13 October, the missile A4 was successfully launched for the first time. Later, the legendary "Moon Goddess" was painted on the V2 missile. It flew to an altitude of 90 kilometers. The missile "Aggregat 4" is a "primitive cell", from which the missile and space programs of the two superpowers grew up. These plans have branded the rest of this century and provided the possibility of human self-destruction.

Penemende base shows that this highly integrated missile technology needs certain management and financial support, which can only be provided by the state, that is, the military. Braun later explained that in order to continue developing the missile program, he joined the Nazi Party and became the captain of the SS emergency unit at 1940.

Penemende is a paradise for craftsmen. The best engineers gather here and can turn their drawings into finished products at once. There are wind tunnels and laboratories here, the first cruise missile and the first electronic analog calculator have been developed, and the gyro control technology, wireless communication and precision water pump have been improved.

1On September 8th, 944, when the first "retaliatory weapon" V2 missile hit London, Penemende people clinked glasses with champagne. At the end of the war, about half of the total 6,000 V2 missiles were launched to Antwerp, London, Maastricht and other cities. It is estimated that V2 missiles killed 65,438+02,685 people, two thirds of whom were civilians. Two days after Hitler's death, these engineers decided to surrender to the Americans.

◇ 195 1 year-1960

In the 1950s, there was an accepted basic view that which country successfully established the permanent space station first would control the whole earth sooner or later. Feng? Braun described intercontinental missiles, submarine missiles, space mirrors and possible trips to the moon to Americans. He once envisaged the establishment of a space station with frequent manned and capable of launching nuclear missiles. He said: "If we consider that the space station flies over all inhabited areas on the earth, then people can realize that this nuclear war technology will give satellite manufacturers an absolute advantage in the war.

Experts at the Rand Military Research Institute in California believe that the first country to launch a satellite will "become a leading country in both military and scientific aspects". This is why the Tass news agency reported on June 4th 1957 that the Soviet Union successfully launched Sputnik 1, the first satellite orbiting the Earth, which shocked the United States. At that time, the United States was still busy transforming the "Redstone short-range tactical missile" in order to launch nuclear warheads from Turkey to the Soviet Union. The US satellite program is still being worked out. Now, the first artificial earth satellite is serving the world capitalism. Edward, the father of hydrogen bombs? Taylor said that the United States lost this "more important battle than Pearl Harbor". It was not until President Reagan appointed him as an adviser to the "Star Wars Project" that his mood was restored.

The competition for space superiority has entered an important juncture. The technicians of Baikonur Space Center, located on the grassland of Kazakhstan, did their best to make their American counterparts disheartened. 1957, they sent a bitch named "Leika" into orbit around the earth; In the United States, Pioneer at Cape Canaveral fell from a height of one and a half meters to the launch pad and exploded.

◇ 196 1 year-1970

196 1 year, Gagarin became the first man to go into space. Russians use him to show that it is not angels or God flying around in the sky.

American John? The slogan of Kennedy's campaign was "New Frontier". He explained: "We are once again living in an era full of discovery. Space is our inestimable new frontier. " For Kennedy, the Soviet Union's first entry into space was "the most painful failure that the United States has experienced for many years". The only way out is attack and defense. 1958, the United States established the National Aeronautics and Space Administration, and launched the first satellite "Explorer" in the same year. 1962 John? Glen became the first American to enter Earth orbit.

On April 20th, the day after the failed invasion of Cuba, President Kennedy ordered the drafting of a report. The report sounds rather desperate: "Is there another dramatic turning point full of hope-the space program will let us win?"

1961On May 25th, Kennedy said, "We should send a man to the moon and return him to the earth safely before the end of 1960s". The plan to plant the Stars and Stripes on this lifeless stone planet will cost 25 billion dollars. Congress approved the plan, and at the same time approved the deployment of 1 000 "militia-to-ground intercontinental strategic missiles" and 656 "Polaris medium-and long-range strategic submarine nuclear missiles". The race to the moon has begun. When the Apollo program reached its climax, * * * 500,000 people participated in this action. In order to save time, NASA limited the number of take-off tests to a minimum. Test docking technology and control technology of Gemini manned spacecraft; The rover and the lunar orbiter searched for a suitable place to land on the surface of the moon. Apollo 8 successfully flew around the moon. Astronauts dedicated the poems in Genesis to mankind on Christmas Day in 1968.

1On July 20th, 969, "Apollo 1 1" landed on the moon, becoming the first event broadcast to the world by TV in this century.

Space historian William? When writing the Apollo program, bruns said: "The motivation of the greatest discovery of mankind so far is completely wrong. But this is still the greatest adventure of mankind and the legend of this Millennium Odyssey. " Feng? Braun said cheerfully: "We know that gaining leadership in space means gaining leadership on earth."

Six successful Apollo landings brought back 400 kilograms of moon rocks, but the scientific community still doesn't know how the moon was formed. Man roamed the moon in a spaceship that landed on the moon and realized that there was really nothing to find and dream about on the moon. Why spend money to travel to the moon? The Vietnam War and Apollo 13, which almost caused disaster, made NASA worry about failing again. As a result, the last three Apollo missions were cut, and the budget of NASA was gradually reduced to one third.

Many scientists are skeptical about the dangerous manned space flight, and they prefer to explore the solar system by plane.

The top secret document of the Central Committee of the Soviet Union * * *196365438+February 3rd formulated the manned moon landing plan. However, the development of spacecraft is very slow. The Soviet Union quickly lost its leading position in the space competition with the United States. After Brezhnev succeeded Khrushchev as the national leader, the Americans realized their moon landing plan, but the take-off of Soyuz was delayed.

1April 23, 967 Vladimir? Komarov sent the unfinished Soyuz into space. Twenty-four hours later, the astronauts were killed because the main parachute didn't pop up when they landed on Earth. 1968 5438+00 in June, unmanned Soyuz 2 was launched, Georgi? Beregovoy was supposed to dock with Soyuz 3, which was launched the next day, but Beregovoy failed to dock manually. ...

At that time, Americans achieved a breakthrough: three astronauts flew around the moon in the Apollo spacecraft. In this context, the first docking of two manned spacecraft scheduled for June 1969+ 10 is of special significance.

Shatarov's first spaceship Soyuz-4 took off on an unlucky day-1969 65438+10/3. Near takeoff, the transmitter suddenly showed a system failure and the flight was forced to cancel.

65438+1October14th, Soyuz 4 took off smoothly. On June 5438+05, the "Soyuz 5" that yeliseyev, Khrunov and Vorinov took broke down again. The take-off of this second spacecraft is closely related to the flight time of Soyuz-4 over Baikonur, and delaying the launch is tantamount to declaring the whole plan a failure. Several military experts at the launch site proposed to replace the damaged parts and promised to complete them before launch. Baikonur launch site is in severe winter. In this environment, they completed the replacement work in record time ... the spacecraft approached each other through automatic devices. 100 meters, astronauts need to approach and dock manually. Everything is going well. Astronaut Khrunov was the first to carefully drill out the narrow hatch, looked around, grabbed the handle outside the spacecraft and slowly walked towards the docking Soyuz 4. He is floating horizontally, and his feet can't touch the objects outside the spacecraft. A long rope tied him to Soyuz 5.

Yeliseyev then entered "Alliance -4". The space work lasted for 37 minutes. The spaceship docked for four and a half hours. 65438+1October 17, Soyuz 4 returned to the ground.

Vorinov should fly Soyuz 5 and return the next day. However, something unexpected happened. The first problem occurred before the brake engine was turned on. He should see the floating earth and find out whether the spaceship is spinning and in the right position. Otherwise, if the engine is not in the opposite direction, it will not brake, but will accelerate, so the astronauts will stay in space forever. At that time, it was found that due to ballistic error, the spacecraft entered the night ahead of schedule. Vorinov can't see the earth, and can't determine whether the position and direction of the spacecraft are correct with the naked eye. He had to give up landing.

The flight command center suggested that the direction of the spacecraft should be adjusted manually in the next flight. Vorinov did this easily, the engine started at the right time, and Soyuz 5 finally flew to the earth. After six minutes, the landing equipment will be separated from the daily life cabin and the equipment cabin. But the astronauts suddenly heard a loud noise on their heads, and the beam above the hatch was bent, and there was a gap in the hatch, which was enough to reduce the pressure in the cabin 100 mm Hg. But the most terrible thing is yet to come: Vorinov saw the towering antenna from the observation hole. This means that there is no separation from the huge equipment cabin. In this case, you will die if you enter the atmosphere.

When entering the atmosphere, Vorinov saw the fire from the observation hole. The black smoke from the engine room is full of burning smell. The spaceship is spinning. He watched the sun for a while, the earth for a while ... suddenly exploded. The spaceship spun faster and was surrounded by flames.

The explosion finally let the landing gear leave the equipment cabin. At this time, it is still 90 kilometers away from the earth.

The landing was carried out in severe overload and crazy rotation. The doctor was surprised later: how can the human body bear all this and why there is no cerebral hemorrhage? Then bang, it's time to open the umbrella. But Vorinov knew that the rope would get tangled when rotating, the top of the umbrella would not open, and the spacecraft would fall to the ground like a stone. This time he was very lucky: although the parachute rope was broken, the spacecraft paused and began to turn in the other direction, and the parachute finally opened. Vorinov returned to the ground.

◇ 197 1 year-1980

After the failure of the race to the moon, Soviet engineers concentrated on assembling the manned space station. The first generation space station in the Soviet Union was a salute, and it was the earliest orbiting space station in the world. 197 1 year, the first space station "Salute 1" was put into orbit, and the pressure valve was opened in advance on the way back, resulting in the death of three astronauts. After that, there were five Soviet space stations, Salute -2, Salute -3, Salute -4 and Salute -5. Each ship weighs about 19 tons and is 16 meters long. There is only one docking port for docking with Soyuz manned spacecraft. On this space station, the longest continuous stay of astronauts is 63 days.

◇ 198 1 year-1990

The second generation space stations are Salute -6 and Salute -7. Their docking ports have been increased to two, which can separate manned and cargo ships at the same time. Soyuz is used for manned and Progress is used for cargo ships.

Salute -7 orbital science station was launched on April 1982, with no manned crew. Astronauts and supplies are provided by manned aircraft and cargo spacecraft respectively. The longest continuous stay on Salute -7 is 2 1 1 day. Salute -7 is about 15 meters long and weighs about 20 tons. There are two doors that dock with the spacecraft in front and back, which can dock with two spacecraft at the same time. Equipped with a variable orbit engine, the track height can be increased to ensure long-term operation. There are three sealed cabins and two unsealed cabins. The maximum diameter of the capsule is more than 4 meters. The cabin is bright, comfortable and full of water supply, which ensures the astronauts' long stay in the space station. Salute -7 flew for more than four years, and 10 crew members at home and abroad worked on the station for more than 800 days, and obtained a large number of scientific data and pictures, producing the first batch of high-quality single crystals made in space, the longest of which was 1984. At that time, a three-person crew composed of Chizim, Solovy and Diekoff flew 237 times continuously. 1in August, 1986, the manned flight of Salute -7 orbital station stopped, and it was transferred to a higher orbit together with the connected Cosmos-1686 satellite complex.

In 1980s, the third generation space station "Peace" of the Soviet Union reached the peak of its space activities, which made Americans jealous. The "Peace", known as the "Artificial Tiangong", was launched on1February 20th, 986. It is the only manned space orbital station that can run in near-earth space for a long time. The cabins corresponding to quantum 1, quantum 2, crystal, spectrum and nature form a huge space orbit complex with a weight of 140 tons and a working volume of 400 cubic meters. There are 106 Russian and foreign astronauts who have been inspected in this "small space factory", with as many as 22,000 scientific research projects and 600 key projects.

The most attractive experiment carried out on the "Peace" is to prolong people's stay in space. Prolonging people's stay in space is the most crucial step for people to fly out of the cradle earth and March into Mars and other celestial bodies. To solve this problem, we need to overcome weightlessness, cosmic radiation and psychological obstacles caused by people in space. Russian astronauts have made great progress in this respect, among which astronaut poliakov created a record of 438 days of continuous flight of "Peace", which cannot but be regarded as an important achievement in the history of space flight in the 20th century. A large number of life science experiments such as cultivating quail, salamander and planting wheat were carried out on the orbital station.

However, after the disintegration of the Soviet Union, Russia, which was independent from the disintegration, has been in a "reliable state" because of its political turmoil, poor production mechanism and extremely difficult economy for many years. The "Peace" orbital station is the pride of Russians. In order to support its operation, Russia set up a people's fund-raising foundation to maintain "peace" and held a car rally from Moscow to St. Petersburg last month, with the aim of raising funds, but the proceeds were very small. The ultimate fate of "peace" is forced to be laid off.

198 1 April, the first space shuttle "Columbia" was launched, and the whole country was proud of it. When NASA promoted the plan to Congress, it said that it was a reusable "space shuttle" and could save money, but the actual cost of the plan reached astronomical figures-654.38+000 billion US dollars. Since then, the American space shuttle has taken off frequently and completed many space missions, such as satellite launch and space experiments. The Soviet Union successfully launched the first space shuttle "Bran" at Baikonur Space Center on June 5438+0988+065438+1October 5438+05, and the space shuttle was launched unmanned.

However, the American space shuttle suffered a major setback at 1986. 654381On the morning of October 28th, the American space shuttle Challenger blasted off from the launch pad of Kennedy Space Center in Cape Canaveral, Florida, and suddenly exploded 73 seconds later. The space shuttle worth $6,543.802 billion was blown to pieces and crashed into the Atlantic Ocean, killing all seven crew members, including Captain Scobie and Japanese-American Oni Tsuka. Mcauliffe, a 37-year-old female middle school teacher, is one of them. She is the first ordinary American citizen to participate in space flight from 1 1465438. This is the 10 flight of Challenger and the 25th flight of the American Space Shuttle. On June 365438+1October 3 1, 15000 astronauts braved the cold wind and held a memorial service for the seven crew members who crashed at the Johnson Space Center in Houston. President Reagan attended the memorial service and expressed condolences to the families of the victims. On February 3, President Reagan ordered the establishment of a presidential commission of inquiry composed of 13 people to investigate the cause of the space shuttle crash. During the four-month investigation, the investigation committee headed by former Secretary of State Rogers visited 160 people, held 35 investigation meetings and collected 63,000 documents and hundreds of photos. On June 9th, the investigation committee formally submitted a 256-page investigation report to President Reagan. According to the investigation, the explosion of Challenger was caused by the problem of the right booster rocket. When launching, the temperature is too low, which affects the rocket gasket and leads to explosion.

◇ 199 1 year -2000

If the Mir space station is regarded as the third generation space station, the International Space Station belongs to the fourth generation space station. The International Space Station (ISS) project costs more than 60 billion US dollars, and it is the largest manned spaceflight project of mankind to date. From the initial conception to the final implementation, it is not only the product of the competition between the United States and the Soviet Union, but also the result of the current cooperation between the United States and Russia, which reflects a historical process from the side.

1993, the Clinton administration proposed to change the plan of "Freedom" space station from the United States alone to international cooperation, bringing in America's rival in the space field, Russia, and then jointly building it with Japan, the European Space Agency and Canada as partners. It can be said that the United States is far-sighted in attracting Russia to participate in the construction of the International Space Station. It can not only reduce the cost of the space station by using Russia's ready-made hardware and manned space technology and experience, but also prevent the spread of Russian space technology, which can be described as "killing two birds with one stone".

Russia, which inherited the achievements of Soviet space science and technology, is unable to carry out large-scale space activities alone due to domestic political turmoil and economic difficulties, so it is also willing to join hands with the United States to build a space station. In this way, two old enemies during the Cold War decided to jointly build the International Space Station. After five years of preparation, the space station was officially "started" at the end of 1998.

The implementation of the International Space Station program is divided into three stages. The first phase from 1994 has been completed. During this period, the United States and Russia mainly carried out a series of joint manned space activities. The American space shuttle docked with the Russian "Peace" orbital station eight times and flew together, which exercised the ability of American astronauts to live and work in the space station. The second stage started from June1998+065438+1October: Russia put the main cabin of the space station, the functional cargo cabin, into orbit with a proton -K rocket. It also undertakes some military experiments, so the cabin is only allowed to be used by American astronauts. The launch and docking of the experimental module will mark the end of the second phase, when the space station has begun to take shape and can accommodate three astronauts for a long time; The third stage is to send the living module of the United States, the experimental module made by the European Space Agency and Japan, and the mobile service system of Canada into space. When these modules are docked with the space station, it marks the final completion of the assembly of the International Space Station. At this time, the number of astronauts on the space station can be increased to seven.

The International Space Station is expected to be completed in 2004. Upon completion, it consists of six experimental modules (one from the United States, one from the European Space Agency and three from Russia), one living module, two connecting modules, service system and transportation system. It is a monster with a length of 88 meters and a weight of about 430 tons. On-site living module volume1.200m2.

The United States, Russia and other 15 countries jointly built the International Space Station, which indicates that an era of joint exploration and peaceful development of space is coming. However, the achievements of manned space activities for decades are far from satisfying their desire for space. "The road is long and Xiu Yuan is awkward, and I will search up and down." Humans have always had the desire to conquer space and the determination to use space resources peacefully. 1998165438+10 In October, Glenn, the 77-year-old American astronaut who entered Earth orbit, once again set foot on a trip to space with his unswerving ambition, as if to tell mankind that conquering space at such a speed is not a dream.

One of the most important inventions of the twentieth century was the birth of the airplane. Since ancient times, human beings have dreamed of flying in space like birds. The kite invented by China people more than 2,000 years ago, although it can't take people into space, can be called the originator of the plane.

At the beginning of this century, there were two brothers in America, who made great contributions to the history of aircraft development in the world. They are the Wright brothers. At that time, most people thought it was impossible for an airplane to fly by its own power, but the Wright brothers didn't believe this conclusion. From 1900 to 1902, the two brothers made more than 1000 gliding test flights.

Finally, in 1903, the first manned aircraft "Voyager" 1 was built and the test flight was successful. Therefore, they won the honorary award of 1909 from the US Congress. In the same year, they established Wright Aircraft Company. This is a great success in the history of aircraft development.

1903 12 17 The Wright brothers flew their unit for the first time.

Maneuvering flight

19101210, at the Paris exhibition, an airplane crashed while performing. The pilot was thrown out of the burning cabin. However, this plane has aroused great concern. Because it uses a new engine. The designer is the pilot himself. He is Romanian and his name is Henry. Koanda, graduated from French higher technical school. The engine he designed is a 50-horsepower engine, in which the fan pushes the air backward, and at the same time, an afterburner is added to make the gas fully expand in the tail nozzle, thus increasing the reverse thrust. This is the earliest jet engine.

In the late 1930s, the maximum horizontal flight speed of piston-driven propeller aircraft reached 700 kilometers per hour, and it was close to the sound speed when diving. The problem of sound barrier is increasingly prominent. The former Soviet Union, Britain, the United States, Germany, Italy and other countries have vigorously carried out the research work of jet engines. Aoan, a German designer, was the first person to successfully develop a new engine. 1934 Aoan obtained the patent of centrifugal turbojet engine. 1939 On August 27th, Aoan made a He- 178 jet with his engine.

After the jet engine was developed, scientists further made the plane fly over the sound barrier. 10 years later, this work was finally completed by Americans.

194710 June 14, in Sangerfield, California, USA, Bell Company tested a plane that could break through the sound barrier. In the morning 10, a huge B-29 bomber took off, and a small plane with a strange shape hung under the cabin. This small plane was named X- 1 rocket plane. The X- 1 aircraft is equipped with four rocket engines with a total thrust of 2,700kg, and the fuel used is dangerous liquid hydrogen and alcohol. When the B-29 bomber descended from the air, its four rocket engines ignited one after another, and the sound was like thunder. 28 seconds after the aircraft engine starts 1 min, Mach number reaches 1? 0, the plane reached the speed of sound. At this time, the fuel of X- 1 aircraft is running out, and the speed becomes faster, reaching Mach number 1? 06, the height at this time is 13000m. Although the test flight was successful, this record was not recognized because the X- 1 aircraft did not take off by its own power.

The invention of the airplane has brought people new dissatisfaction with the benefit of the whole people. The plane needs to run when it takes off, and it needs to build a corresponding runway and airport. This has brought a lot of inconvenience, so some people began to explore aircraft that can take off and land vertically, commonly known as helicopters.

1939 On September 4th, the world's first practical helicopter was born. That is the VS-300 helicopter successfully developed by Sikorsky Company, an American engineer. Sikorsky was originally from Russia and moved to the United States on 1930. The VS-300 helicopter he made has 1 main rotor and 3 tail rotors. Later, after many test flights, the 3-tail rotor was changed to 1, and this practical helicopter became the originator of modern helicopters.

The world's first combat helicopter

After the birth of VS-300 helicopter, it had a great influence, especially since 1950s, the manufacturing technology of helicopter developed rapidly. Before the mid-1950s, the power plant of helicopter was in the period of piston engine, and then it entered the period of jet turbine shaft. The rotor material structure technology has also gone through several stages; In the 1940s-1950s, it was a metal-wood wing mixed structure, in the 1950s-1960s, it was a metal structure, in the 1960s-1970s, it was a glass fiber structure, and it developed into a new composite structure after the 1970s.

In the 1920s, airplanes began to carry passengers. At the beginning of World War II, the United States began to convert a large number of transport planes into passenger planes. Since the 1960s, some large transport planes and supersonic transport planes have appeared in the world, and turbofan engines have gradually become popular. The famous ones are An -22 and Il-76 produced by the former Soviet Union; American C- 14 1, C-5A, Boeing-747; Airbus in France and so on. Supersonic transport aircraft include Concorde jointly developed by Britain and France and Tu-144 of the former Soviet Union. However, the development of supersonic passenger aircraft is not optimistic. The price of Concorde was too high, which affected the benefit, so it was discontinued in the 1980s. Tu- 144 in the former Soviet Union was grounded in the 1980s for the same reason.

The first civil aircraft

Since the invention of the airplane, it has become an indispensable means of transportation for modern civilization. It profoundly changes and affects people's lives. Due to the invention of the airplane, the time for human beings to travel around the world has been greatly shortened. The first round-the-world trip was completed in16th century. At that time, the Portuguese Magellan led a fleet from Spain, which took three years to cross the Atlantic and Pacific oceans, circle the earth and return to Spain. /kloc-At the end of 0/9, it took a Frenchman 43 days to travel around the world by train. After the invention of the airplane, people made another round-the-world trip at 1949. A B-50 bomber flew 37,700 kilometers around the earth in just 94 hours after four beautiful aerial refueling. It's better to be strong than not. After the supersonic plane appeared, people flew higher and faster. 1979, spector, an Englishman, flew 36,900 kilometers and circled the earth in only 14 hours and 6 minutes. In less than a day, you can fly to every corner of the earth. Isn't this a miracle for people who lived before the 20th century?

Airbus A330-200

The intricate air routes connect countries all over the world, providing people with convenient and fast passenger transportation. As early as the 1920s, air transport started regular flights to transport passengers and mail. Nowadays, air routes extend in all directions, and people will see a silver plane at any time, like a big bird, passing by in the blue sky. For modern people, it is common to be in Beijing in the morning and in another city thousands of miles away in the afternoon without being tired. Before the 20th century, this was unthinkable. From then on, steep mountains and endless oceans will no longer be daunting. Yin Yan closely links people of different races and colors in different regions. Through constant communication, people sow friendship and transmit information, so as to achieve mutual communication, mutual understanding and mutual promotion and jointly promote human civilization.

The invention of aircraft also made the air transport industry develop unprecedentedly, and many raw materials needed for industrial development had new sources and channels, greatly reducing people's dependence on local natural resources. Especially after the birth of supersonic aircraft, air transportation has become more prosperous. Those livestock that are not suitable for long-term transportation and delicious food that are difficult to preserve for a long time can also fly to all corners of the country and give them to people all over the world.