You can now admire the takeoff of a space rocket on TV and in the movies. The rocket stands vertically on a concrete launch pad. At a command from the control center, the engines turn on, we see a flame igniting below, we hear a growing roar. And so the rocket, in a puff of smoke, takes off from the Earth and, at first slowly, and then faster and faster, rushes upward. A minute later she is already at such a height that planes cannot reach, and in another minute she is in Space, in the near-Earth airless space.
Rocket engines are called jet engines. Why? Because in such engines the traction force is the reaction force (counteraction) to the force that throws the opposite side a stream of hot gases obtained from the combustion of fuel in a special chamber. As you know, according to Newton's third law, the force of this reaction is equal to the force of action. That is, the force that lifts the rocket to space equal to the force developed by hot gases escaping from the rocket nozzle. If it seems incredible to you that gas, which is supposed to be ethereal, throws a heavy rocket into space orbit, remember that air compressed in rubber cylinders successfully supports not only a cyclist, but also heavy dump trucks. The white-hot gas escaping from the rocket nozzle is also full of strength and energy. So much so that after each rocket launch, the launch pad is repaired by adding concrete knocked out by the fire whirlwind.
Newton's third law can be formulated differently as the law of conservation of momentum. Momentum is the product of mass and velocity. In terms of the law of conservation of momentum, the launch of a rocket can be described as follows.
Initially, the momentum of the space rocket at rest on the launch pad was zero (the large mass of the rocket multiplied by its zero velocity). But now the engine is on. The fuel burns to form great amount gaseous combustion products. They have high temperature and at high speed the rockets flow out of the nozzle in one direction, down. This creates a downward momentum vector whose magnitude is equal to the mass of the escaping gas multiplied by the velocity of that gas. However, due to the law of conservation of momentum, the total momentum of the space rocket relative to the launch pad should still be zero. Therefore, an upward impulse vector immediately arises, balancing the “rocket - ejected gases” system. How will this vector arise? Due to the fact that the rocket, which has been standing motionless until then, will begin to move upward. The upward momentum will be equal to the mass of the rocket multiplied by its speed.
If the rocket engines are powerful, the rocket very quickly gains speed, sufficient to launch spaceship into low-Earth orbit. This speed is called first escape velocity and is equal to approximately 8 kilometers per second.
The power of a rocket engine is determined primarily by what fuel is burned in the rocket engines. The higher the combustion temperature of the fuel, the more powerful the engine. In the earliest Soviet rocket engines The fuel was kerosene and the oxidizing agent was nitric acid. Now rockets use more active (and more poisonous) mixtures. The fuel in modern American rocket engines is a mixture of oxygen and hydrogen. The oxygen-hydrogen mixture is very explosive, but when burned it releases a huge amount of energy.
we examined the most important component of deep space flight - gravity maneuver. But due to its complexity, a project such as space flight can always be broken down into a large number of technologies and inventions that make it possible. The periodic table, linear algebra, Tsiolkovsky’s calculations, strength of materials and other entire fields of science contributed to the first, and all subsequent human space flights. In today’s article we will tell you how and who came up with the idea of a space rocket, what it consists of, and how, from drawings and calculations, the rocket turned into a means of delivering people and cargo into space.A Brief History of Rockets
General principle jet flight, which formed the basis of all rockets, is simple - some part is separated from the body, setting everything else in motion.
It is unknown who was the first to implement this principle, but various guesses and conjectures bring the genealogy of rocket science right back to Archimedes. What is known for certain about the first such inventions is that they were actively used by the Chinese, who loaded them with gunpowder and launched them into the sky due to the explosion. Thus they created the first solid fuel rockets. European governments showed great interest in missiles early
Second rocket boom
Rockets waited in the wings and waited: in the 1920s, the second rocket boom began, and it is associated primarily with two names.
Konstantin Eduardovich Tsiolkovsky, a self-taught scientist from the Ryazan province, despite difficulties and obstacles, himself reached many discoveries, without which it would have been impossible to even talk about space. The idea of using liquid fuel, Tsiolkovsky’s formula, which calculates the speed required for flight based on the ratio of the final and initial masses, a multi-stage rocket - all this is his merit. Largely under the influence of his works, domestic rocket science was created and formalized. In the Soviet Union, societies and circles for the study of jet propulsion began to spontaneously arise, including GIRD - a group for the study of jet propulsion, and in 1933, under the patronage of the authorities, the Jet Institute appeared.
Konstantin Eduardovich Tsiolkovsky.
Source: Wikimedia.org
The second hero of the rocket race is the German physicist Wernher von Braun. Brown had an excellent education and a lively mind, and after meeting another luminary of world rocket science, Heinrich Oberth, he decided to put all his efforts into creating and improving rockets. During World War II, von Braun actually became the father of the Reich's “weapon of retaliation” - the V-2 rocket, which the Germans began using on the battlefield in 1944. The “winged horror,” as it was called in the press, brought destruction to many English cities, but, fortunately, at that time the collapse of Nazism was already a matter of time. Wernher von Braun, together with his brother, decided to surrender to the Americans, and, as history has shown, it was happy ticket not only and not so much for scientists, but for the Americans themselves. Since 1955, Brown has been working for American government, and his inventions form the basis of the US space program.
But let's go back to the 1930s. Soviet government appreciated the zeal of enthusiasts on the path to space and decided to use it to their advantage. During the war years, the “Katyusha” system showed itself to be excellent volley fire who shot rockets. It was in many ways an innovative weapon: the Katyusha, based on a Studebaker light truck, arrived, turned around, fired at the sector and left, not allowing the Germans to come to their senses.
The end of the war presented our leadership with a new task: the Americans showed the world all their power nuclear bomb, and it became quite obvious that only those who have something similar can claim the status of a superpower. But there was a problem. The fact is that, in addition to the bomb itself, we needed delivery vehicles that could bypass US air defense. Airplanes were not suitable for this. And the USSR decided to rely on missiles.
Konstantin Eduardovich Tsiolkovsky died in 1935, but he was replaced by a whole generation of young scientists who sent man into space. Among these scientists was Sergei Pavlovich Korolev, who was destined to become the Soviets' "trump card" in the space race.
The USSR began to create its own intercontinental missile with all diligence: institutes were organized, the best scientists were gathered, a research institute for missile weapons, and work is in full swing.
Only a colossal effort of effort, resources and minds made it possible Soviet Union V as soon as possible build your own rocket, which they called R-7. It was its modifications that launched Sputnik and Yuri Gagarin into space, and it was Sergei Korolev and his associates who launched the space age of mankind. But what does a space rocket consist of?
Rocket design
Diagram of a two-stage rocket.
Even among people who have studied physics, one often hears a completely wrong explanation for the flight of a rocket: it flies because it is repelled from the air by its gases formed when gunpowder burns in it. This is what they thought in the old days (rockets are an old invention). However, if you were to launch a rocket in airless space, it would fly no worse, or even better, than in the air. The real reason The rocket's movement is completely different. It was very clearly and simply stated by the First March revolutionary Kibalchich in his suicide note about the flying machine he invented. Explaining the design of combat missiles, he wrote:
“Into a tin cylinder, closed at one base and open at the other, a cylinder of pressed gunpowder is tightly inserted, having a void in the form of a channel along its axis. The combustion of gunpowder begins from the surface of this channel and spreads over a certain period of time to the outer surface of the pressed gunpowder; the gases formed during combustion produce pressure in all directions; but the lateral pressures of the gases are mutually balanced, while the pressure on the bottom of the tin shell of gunpowder, not balanced by the opposite pressure (since the gases have a free outlet in this direction), pushes the rocket forward.”
The same thing happens here as when a cannon is fired: the projectile flies forward, and the cannon itself is pushed back. Remember the “recoil” of a gun and everything in general? firearms! If a cannon were hanging in the air, not supported by anything, after firing it would move backwards with a certain speed, which is the same number of times less than the speed of the projectile, how many times the projectile is lighter than the cannon itself. In Jules Verne’s science fiction novel “Upside Down,” the Americans even decided to use the recoil force of a gigantic cannon to accomplish a grandiose undertaking—“straighten the earth’s axis.”
A rocket is the same cannon, only it spews not shells, but powder gases. For the same reason, the so-called “Chinese wheel” rotates, which you probably happened to admire when setting up fireworks: when gunpowder burns in tubes attached to the wheel, gases flow out in one direction, and the tubes themselves (and with them the wheel) get the opposite movement. In essence, this is just a modification of a well-known physical device - the Segner wheel.
It is interesting to note that before the invention of the steamboat there was a design for a mechanical vessel based on the same beginning; the supply of water on the ship was supposed to be released using a strong pressure pump in the stern; as a result, the ship had to move forward, like those floating tins that are available to prove the principle in question in school physical offices. This project (proposed by Remsey) was not implemented, but it played a well-known role in the invention of the steamboat, as it gave Fulton his idea.
We also know that the most ancient steam engine, invented by Heron of Alexandria back in the 2nd century BC, was designed on the same principle: steam from the boiler flowed through a tube into a ball mounted on a horizontal axis; then flowing out of the cranked tubes, the steam pushed these tubes in the opposite direction, and the ball began to rotate.
The oldest steam engine (turbine), attributed to Heron of Alexandria
(2nd century BC).
Unfortunately, Heron's steam turbine in ancient times remained only a curious toy, since the cheapness of slave labor did not encourage anyone to practical use cars But the principle itself has not been abandoned by technology: in our time it is used in the construction of jet turbines.
Newton, the author of the law of action and reaction, is credited with one of the earliest designs for a steam car, based on the same principle: steam from a boiler placed on wheels rushes out in one direction, and the boiler itself, due to recoil, rolls in the opposite direction.
Steam car attributed to Newton.
Rocket cars, experiments with which were widely written about in 1928 in newspapers and magazines, are a modern modification of Newton's carriage.
For those who like to craft, here is a drawing of a paper steamer, also very similar to Newton’s carriage: in a steam boiler, steam is generated from an emptied egg, heated with cotton wool soaked in alcohol in a thimble; escaping as a stream in one direction, it forces the entire steamer to move in the opposite direction. However, the construction of this instructive toy requires very skillful hands.
Toy steamboat made of paper and eggshells. The fuel is alcohol poured into a thimble.
The steam escaping from the hole in the “steam boiler” (a blown egg) causes the steamboat to sail in the opposite direction.
Even among people who have studied physics, one often hears a completely wrong explanation for the flight of a rocket: it flies because it is repelled from the air by its gases formed when gunpowder burns in it. This is what they thought in the old days (rockets are an old invention). However, if you were to launch a rocket in airless space, it would fly no worse, or even better, than in the air. The true reason for the rocket's movement is completely different. It was very clearly and simply stated by the First March revolutionary Kibalchich in his suicide note about the flying machine he had invented. Explaining the design of combat missiles, he wrote:
“Into a tin cylinder, closed at one base and open at the other, a cylinder of pressed gunpowder is tightly inserted, having a void in the form of a channel along its axis. The combustion of gunpowder begins from the surface of this channel and spreads over a certain period of time to the outer surface of the pressed gunpowder; the gases formed during combustion produce pressure in all directions; but the lateral pressures of the gases are mutually balanced, while the pressure on the bottom of the tin shell of gunpowder, not balanced by the opposite pressure (since the gases have a free outlet in this direction), pushes the rocket forward.”
The same thing happens here as when a cannon is fired: the projectile flies forward, and the cannon itself is pushed back. Remember the “recoil” of a gun and any firearm in general! If a cannon were hanging in the air, not supported by anything, after firing it would move backwards with a certain speed, which is the same number of times less than the speed of the projectile, how many times the projectile is lighter than the cannon itself. In Jules Verne’s science fiction novel “Upside Down,” the Americans even decided to use the recoil force of a gigantic cannon to accomplish a grandiose undertaking—“straighten the earth’s axis.”
A rocket is the same cannon, only it spews not shells, but powder gases. For the same reason, the so-called “Chinese wheel” rotates, which you probably happened to admire when setting up fireworks: when gunpowder burns in tubes attached to the wheel, gases flow out in one direction, and the tubes themselves (and with them the wheel) get the opposite movement. In essence, this is just a modification of a well-known physical device - the Segner wheel.
It is interesting to note that before the invention of the steamboat there was a design for a mechanical vessel based on the same beginning; the supply of water on the ship was supposed to be released using a strong pressure pump in the stern; as a result, the ship had to move forward, like those floating tins that are available to prove the principle in question in school physics classrooms. This project (proposed by Remsey) was not implemented, but it played a well-known role in the invention of the steamboat, as it gave Fulton his idea.
Figure 7. The oldest steam engine (turbine), attributed to Heron of Alexandria (2nd century BC).
Figure 8. Steam car attributed to Newton.
Figure 9. Toy steamer made of paper and eggshells. The fuel is alcohol poured into a thimble. The steam escaping from the hole in the “steam boiler” (a blown egg) causes the steamboat to sail in the opposite direction.
We also know that the most ancient steam engine, invented by Heron of Alexandria back in the 2nd century BC, was designed on the same principle: steam from the boiler (Fig. 7) flowed through a tube into a ball mounted on a horizontal axis; then flowing out of the cranked tubes, the steam pushed these tubes in the opposite direction, and the ball began to rotate. Unfortunately, the Heron steam turbine in ancient times remained only a curious toy, since the cheapness of slave labor did not encourage anyone to put the machines into practical use. But the principle itself has not been abandoned by technology: in our time it is used in the construction of jet turbines.
Newton, the author of the law of action and reaction, is credited with one of the earliest designs of a steam car, based on the same principle: steam from a boiler placed on wheels rushes out in one direction, and the boiler itself rolls in the opposite direction due to recoil (Fig. 8) .
Rocket cars, experiments with which were widely written about in 1928 in newspapers and magazines, are a modern modification of Newton's carriage.
For those who like to craft, here is a drawing of a paper steamboat, also very similar to Newton’s carriage: in a steam boiler, steam is formed from an emptied egg, heated with cotton wool soaked in alcohol in a thimble; escaping as a stream in one direction, it forces the entire steamer to move in the opposite direction. However, the construction of this instructive toy requires very skillful hands.
Rockets rise into outer space by burning liquid or solid fuels. Once ignited in high-strength combustion chambers, these fuels, usually consisting of a fuel and an oxidizer, release enormous amounts of heat, creating very high pressure, under the influence of which combustion products move towards earth's surface through expanding nozzles.
Since combustion products flow down from the nozzles, the rocket rises upward. This phenomenon is explained by Newton's third law, according to which for every action there is an equal and opposite reaction. Since the engines are liquid fuel easier to control than solid fuels, they are usually used in space rockets, in particular, in the Saturn 5 rocket shown in the picture on the left. This three-stage rocket burns thousands of tons of liquid hydrogen and oxygen to propel the spacecraft into orbit.
To rise quickly, the rocket's thrust must exceed its weight by about 30 percent. Moreover, if a spacecraft is to enter low-Earth orbit, it must reach a speed of about 8 kilometers per second. The thrust of rockets can reach several thousand tons.
- Five engines of the first stage lift the rocket to a height of 50-80 kilometers. After the first stage fuel is consumed, it will separate and the second stage engines will turn on.
- Approximately 12 minutes after launch, the second stage delivers the rocket to an altitude of more than 160 kilometers, after which it separates with empty tanks. The escape flare also detaches.
- Accelerated by a single third-stage engine, the rocket propels the Apollo spacecraft into a temporary low-Earth orbit at an altitude of about 320 kilometers. After a short break, the engines turn on again, increasing the spacecraft's speed to about 11 kilometers per second and pointing it towards the Moon.
The F-1 engine of the first stage burns fuel and discharges combustion products into environment.
After launching into orbit, the Apollo spacecraft receives an accelerating impulse towards the Moon. The third stage then separates and the spacecraft, consisting of the command and lunar modules, enters a 100-kilometer orbit around the Moon, after which the lunar module lands. Having delivered the astronauts who have visited the Moon to the command module, the lunar module separates and stops functioning.
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