From ancient China to Mars and Gaza

A brief history of rockets and missiles

The Greek scholar Archytas was a mathematician, philosopher, astronomer and military man. But he was also a magician. A Roman historian says that Archites used to amaze the inhabitants of his city of Tarentum (now Taranto in southern Italy), with a flying display of a bird made of wood. The bird moved quickly along the wire on which it was hanging, as a jet of steam was emitted behind it. The stunt devised by the wise Greek about 2,400 years ago was probably the first use of the propulsion power of gases. In this case it was water vapor - that is, steam - that was emitted through a thin tube, pushing the bird along the wire. In fact, the bird acted according to the physical law of action and reaction: the gases release pressure in a certain direction, so the bird is pushed with equal force in the opposite direction. But more than two thousand years passed before Isaac Newton formulated this law as part of his laws of motion.

instead of eternal life

Many years have passed since Archites astonished the inhabitants of Tarentum, and until the next development in the harnessing of the propulsion power of gases. It is not clear exactly when it was made, and when the first rockets appeared, but apparently the breakthrough came from China in the 12th or 13th century. A few hundred years earlier, Chinese alchemists were looking for a way to produce the elixir of eternal life. Although they did not succeed in the original task, they instead developed the black powder, known today as gunpowder. There is indeed documentation of the use of flammable materials with special properties in earlier periods in other regions, but the material developed by the Chinese alchemists in the ninth century (AD) was stable and safe, and was also composed of available materials: saltpeter, sulfur and coal dust. Saltpeter (rock salt, in Latin) is a mineral consisting mainly of potassium nitrate. When it is heated in the presence of the sulfur and carbon in the coal powder, the mixture ignites and releases a relatively large amount of gases (mainly carbon dioxide, nitrogen gas and hydrogen sulfide). When the heating is done inside a closed vessel, the pressure of the gases increases more and more, until the vessel...explodes.
Apparently, this was exactly the historical use of gunpowder. The Chinese used to fill a bamboo reed with the black powder, seal it and throw it into the fire during festivals and holidays, to create an explosion effect. But not all the reeds were completely sealed, and sometimes, such a reed with an opening of the appropriate size, would suddenly rise from the fire into the sky, with the tremendous force of the gases released from the hole. Some scholars realized the potential inherent in the discovery and began to experiment with the new technology. The first documentation of the use of such rockets tells of a battle between the Chinese and the Mongols in 1232, in which the Chinese used "fire arrows" - long sticks to which a short bamboo reed is attached, pierced at the end and filled with gunpowder. The operator ignited the gunpowder, and the fire arrow came at breakneck speed to a distance of hundreds of meters, making a terrifying hiss and spitting fire behind it. It is not clear if these arrows caused any real damage to the Mongol enemy, but their psychological effect was enormous, and resulted in the defeat of the Mongols. But the Mongols came out of their downfall: they adopted the new technology, and soon began to perfect it themselves. They are probably also responsible for the fact that the rockets spread to the Arab world and from there to Europe in a relatively short time. The term "rocket" was probably coined by the Italians, and is derived from "racchetta" - "short fuse".

Cannons instead of missiles

At that time, the rockets were mainly used for pyrotechnics (D-Nor fireworks), and as a means of starting fires at the enemy. The French writer and historian Jean Froissart is the one who apparently came up with the idea of ​​launching the rocket through a tube, which improved its accuracy, and created a first prototype for some of today's rocket uses. However, historically, the rocket has lagged far behind its parent, the gunpowder. Instead of fielding all the weapons, the Europeans warmly embraced another Chinese invention: the cannon. Gunpowder is compressed in a thick metal tube, one end of which is sealed, a heavy ball is rolled into the tube, and a fuse is lit with its end inside the gunpowder. When the powder ignites, the pressure of the gases flings the heavy bullet at tremendous speed towards the enemy, and with a little skill you can achieve impressive accuracy. The invention of the cannon changed the face of warfare, allowing an attacking army to easily batter the walls of any fortress, or sink ships from a great distance. It didn't take long and light cannons designed to be carried by hand also appeared on the battlefield, and their bullets were not intended to collapse walls, but to crush internal organs of humans and animals. Thanks to the rifles and pistols, gun powder earned its familiar foreign name, gun powder.

From India to England

At the end of the 18th century, the British army advanced in its efforts to conquer India. However, in the battles for the conquest of the principality of Mysore, in the south of the subcontinent, the local fighters surprised them with sophisticated rocket attacks. The Indians also used metal pipes to make the rockets, not just bamboo canes. Although they did not cause much destruction, the rockets caused panic mainly among the horses of the British cavalry, forcing the English to retreat. Some of the rockets were also attached to a sharp front blade, which caused them to go off balance near the end of their trajectory, and thus, what landed on the British soldiers was a flying sword swinging wildly and destroying everything in its path. After the British managed to conquer Mysore, they sent home samples of the rockets, to develop a similar weapon. The task was assigned to Colonel William Congreve, and he studied the Indian rockets and perfected them. Congreve developed, among other things, an exploding or flaming warhead, and his rockets helped the English defeat Napoleon in the famous Battle of Waterloo (1815). Congreve also invented a lighting rocket equipped with a parachute, a principle used in lighting bombs to this day. The rockets developed by Congreb were a metal tube several tens of centimeters long, equipped with a very long wooden stick (sometimes up to two meters), as a tail that allows them to maintain balance. After studies showed that the rocket would be more stable and would roll around itself during flight (like a rifle bullet), another English engineer, William Hale (Hale), developed a more sophisticated model of a rocket, with small tail fins and several curved tubes to expel some of the gases. These rockets - more similar to contemporary rockets - were more stable in flight, and above all they were exempt from the long and cumbersome tail. Despite these improvements, the use of rockets as a military weapon gradually declined due to rapid improvements in battle cannons, which were the weapon of choice. In the First World War, for example, almost no rockets were used, except for a little use of light bombs.

Along with the development of rockets as weapons and pyrotechnics, from time to time crazy people appeared who dreamed of rockets as means of transportation. A Chinese legend from the 16th century tells of a government official named Wan Hu who wanted to fly with the help of rockets. He attached a seat above a battery that included no less than 47 rockets, and ordered his men to ignite together. When the smoke cleared, it became clear that Wan Ho and the rocket train were gone. It seems that he fulfilled the biblical story about Elijah the prophet, and ascended in the heavenly storm. It is not clear if Van Ho's story actually happened in reality, but over the years several inventors tried to develop a rocket vehicle on wheels - a kind of locomotive or a car - developments that did not really succeed. At the beginning of the 20th century, the vision appeared that changed the world of rockets forever.
Konstantin Tsiolkovsky was born in 1867 in a small village in western Russia. He became partially deaf due to a childhood illness, and this prevented him from completing his studies in elementary school. What the education system did not give him, he made up for on his own with obsessive reading, mainly of science books. He taught himself mathematics, physics and chemistry, and got a teaching position. Inspired by the books of Jules Verne, Tsiolkovsky discovered a growing interest in space exploration. He published many ideas regarding the establishment of manned colonies in space, space stations and even the idea of ​​the elevator to space, which he conceived inspired by the construction of the Eiffel Tower. However, in contrast to science fiction books, Tsiolkovsky offered practical solutions to many problems related to human activity in space: he designed biological systems for supplying food and oxygen, and even systems of double doors that would allow exiting a spaceship into the vacuum of space, or entering it. Until his death in 1935, he published about 400 articles, many of them dealing with rockets. He studied in depth the air resistance to rocket motion, formulated it mathematically, and calculated that it is possible to develop a multi-stage rocket that would overcome the Earth's gravity, if powered by liquid oxygen and liquid hydrogen. He also came up with ideas on how to build such a rocket, and how to develop a steering system for the rocket. Although he never built a rocket himself, he is today considered one of the fathers of the field and one of the pioneers of the idea of ​​manned space flight.

Liquid state

While Tsiolkovsky was publishing his articles in Russian, on the other side of the planet, a young American from Massachusetts began to show great interest in the development of rockets for space exploration. Already in high school, Robert Goddard published an article about the theoretical possibility of space flight. Without apparently knowing the works of his Russian colleague, Goddard developed the idea of ​​propelling rockets with liquid fuel at the same time, with the idea of ​​reaching space. When he completed his doctorate in physics, in 1911, he began to devote himself to developing such rockets in practice. Goddard's efforts were delayed by the outbreak of World War I. He joined the army's request to develop a portable rocket weapon, and led the efforts to develop the bazooka - an anti-tank rocket that a soldier can carry himself. The development was completed by others, and years later the bazooka was one of the most important weapons in World War II. Goddard returned to liquid fuel, and in December 1926 successfully launched the first rocket powered by liquid oxygen and gasoline. He himself developed a system of tanks and pumps that injected the two fuels into a combustion tank, from which the gases were ejected under pressure and launched the El Al rocket. The small rocket (about 30 cm long) flew for a total of 2.5 seconds, reached a height of about 12 m, and fell in a cabbage patch, less than 60 m from the launch site, on a farm belonging to Goddard's aunt. However, the small experiment broke the ground and proved the feasibility of propelling rockets with liquid fuel. Goddard began perfecting his rockets, and within a decade he was already launching rockets 4-5 meters long to a height of several kilometers. He developed a gyroscopic navigation system, which made it possible to change the direction of the rocket, and go from a vertical mirror to a horizontal flight, parallel to the ground. In 1941, Goddard stopped the experiments, and joined the American military effort shortly before its official entry into World War II. To his disappointment, the forces did not show much interest in his proposals for the development of long-range rockets, and instead the Navy required him to help develop sophisticated rockets for rapidly accelerating aircraft, to optimize their launch from aircraft carriers. Goddard was engaged in the development of this system until his death from throat cancer in 1945, a few days before the surrender of Japan and the end of World War II.
Mark and

Although the American forces did not show much interest in Goddard's rockets, on the other side of the Atlantic there were actually those who showed great interest in them. Even before the start of World War II, the Nazi regime decided to invest in a missile program. Doctor Werner von Braun (von Braun), a young physicist and engineer, a space enthusiast, who had already experimented with launching rockets powered by liquid fuel, was recruited for the mission. Von Braun was wholeheartedly tied to the Nazi war effort, and was involved in the development of V2 rockets (they were intended to replace the V1, which was not a rocket but actually an unmanned jet plane, loaded with explosives, which the Nazis sent at the end of the war mainly towards London and Antwerp). The V2 was a very large rocket - about 14 m - that was fueled by alcohol and liquid oxygen, and carried 1,000 kg of explosive material to a distance of 300 km. In September 1944, the first V2 rocket was launched towards Britain, and by the end of the war, the Nazis had managed to launch about 3,000 such rockets and cause the death of more than 7,000 people. However, on the German side, at least 20,000 forced laborers who were employed in the production of the rockets died in harsh conditions in underground bunkers. Von Braun never protested the working conditions of the prisoners, but after the first launch he commented that the rocket worked well, but landed on the wrong planet. Due to these and other comments that he would rather launch rockets to the moon than against humans, von Braun was arrested by the Gestapo on suspicion of crimes against the state. He was released only under the pressure of his colleagues, who claimed that without him it would not be possible to continue the production of the rockets. Towards the end of the war, a V2 rocket captured by the Americans arrived in the hands of Robert Goddard, as we know. He was convinced that this was a copy of his work, and later von Braun admitted that the technologies developed by Goddard saved the Nazi missile developers many years of toil.

discovered America

At the end of World War II, it was already clear to all parties that the weapon of the future would be a combination of the newly developed nuclear weapons with long-range launch capabilities. Von-Braun, who probably understood better than anyone where the wind was blowing, quickly organized himself with a group of his men, and surrendered himself to the American army before the Nazis could eliminate them to protect the secrets of the missiles. Von Braun and a group of more than 100 German engineers were transferred in a secret operation to the USA, and instead of being prosecuted for war crimes, they were engaged in the development of intercontinental missiles for the Americans, and especially in the development of guided missiles - such that it would be possible to aim them at the target and correct the direction even while in flight. The position of the German engineers was ambiguous. They were not prisoners of war, but they were forbidden to move around without a military escort. In 1955, the restrictions were lifted, and von Braun received American citizenship. At the same time as his work in the development of military missiles, von Braun began to publicize his ideas about space exploration, including a plan to establish a manned space station and launch astronauts. He also produced with Disney Studios several television series about space exploration, hoping to stimulate public interest in his ideas.

From the Gulag to space

As von Braun and his colleagues made their way to the US, an even larger group of workers in the German missile system made their way to the other side of the Iron Curtain. The Soviet army captured no less than 5,000 of the people involved in the development, production and launch of V2 missiles, along with missiles and missile parts, and all of them were placed at the disposal of the head of the Soviet Union's missile system, Sergei Korolyov. Korolev's path to this status was not easy: he started as a glider developer, and gradually moved to aircraft design and was exposed to the field of rocket propulsion. In the 30s he was already developing rockets, but in 1938 he was banned during Stalin's purges, and was imprisoned in the Gulag after one of his colleagues informed him that he was investing too much of the country's resources in developing rockets powered by liquid fuel, instead of the solid fuel rockets on which the Soviet regime preferred to focus. During his imprisonment, he was held in a special camp for scientists, and continued to engage in rocket development, under close supervision of the regime. In 1944 he was finally released and his conviction was overturned. He returned to the development of missiles and received the rank of colonel in the Red Army. At the end of the war, he did a lot of research on the V2 and its refinement, and within a few years he already had missiles capable of carrying a nuclear warhead to a distance of thousands of kilometers, similar to the missiles that Von Braun developed at the same time in the USA. Like von Braun, Korolev also showed a growing interest in launching rockets into space, and submitted to the authorities plans to fly animals and women into orbit around the Earth. On October 4.10.1957, 7, the USSR launched the first satellite, Sputnik, on top of an RXNUMX missile - a ballistic missile developed by Korolev, and successfully returned it. The space age has begun.

Big Ben to the moon

The Soviet success stunned the Americans. About four months later, they also succeeded in launching the first satellite, Explorer, on a ballistic missile that had been converted to launch into space. At the same time, the Americans separated the civilian missile program from the military, and established NASA, the National Space and Aeronautics Agency. However, Korolev and his men continued to rush forward and overtake the Americans in space exploration: they launched a dog in a satellite and soon began to launch probes to the moon, on improved R7 rockets. After several failures, in 1959 the probe "Luna-2" landed on the moon, becoming the first man-made object to land on another celestial body. On April 12.4.1961, 1, the USSR celebrated its greatest victory: the first manned flight into space. The Vostok-7 spacecraft, carrying cosmonaut Yuri Gagarin, was also launched on an improved R120,000 rocket, and completed a full circle of the Earth. The Soviets were the masters of space and the kings of missiles. The Americans managed to respond by sending the first astronaut - Alan Shepard - only to the edge of space, without circling Earth. The sense of failure reached the White House, and President Kennedy hurried to set the ambitious goal: landing a man on the moon by the end of the decade. From then on, Washington invested huge capital in the space program, an investment that the Soviets were unable to compete with. Von Braun and his team, who were now working at NASA, worked hard on the development of the most formidable rockets - the Saturn rockets. These rockets were required to generate tremendous power not because of the large space to the moon, but because of the need to carry a huge weight to an orbit around the Earth, from there, in the absence of gravity and atmosphere, it is possible to launch a spacecraft to the moon using a relatively weak rocket engine. The largest rocket built in the series, Saturn V, was supposed to carry a payload of 2,000 kg to an altitude of about XNUMX km. For comparison, a ballistic missile carrying an atomic bomb needs to reach a tenth of this height, with a payload a hundred times smaller.
Saturn Five was not fundamentally different from the V2 rockets, or even from the simple rocket that Goddard had launched on his aunt's farm some 40 years earlier. It contained tanks of two liquid fuels, which ignite in a special section and emit gas under pressure, which propels the rocket. Unlike the simpler rockets, Saturn was a multi-stage rocket: actually several rockets mounted one above the other. The lower one is activated first, providing the first impulse. When it runs out of fuel (liquid oxygen and rocket fuel on a basis similar to jet fuel), it disconnects and falls, and the second stage comes into operation, until its fuel runs out, and then the third stage is activated (both were powered by a mixture of liquid oxygen and liquid hydrogen). This method allows the advanced stages to propel a smaller and lighter missile, and also to adjust the engine to the stage where the missile is supposed to be (a different power is needed to propel from zero speed, than to upgrade the speed at high altitude). The complete rocket, with the spacecraft on top, was a huge tower almost 112 m high (taller than the Statue of Liberty and the London "Big Ben"), more than 10 m in diameter and weighing about 3,000 tons. After five launches in the Apollo program, the rocket successfully carried the Apollo 11 spacecraft on its way to the moon. The three astronauts, Neil Armstrong, Edwin Aldrin and Michael Collins were national heroes, but the rocket's developer, Werner von Braun, was also not absent, and in 1975, two years before his death, he was awarded the National Medal of Science. The principle model he developed for space rockets is still used today. When the Americans decided to launch the biggest payload of all, a space shuttle (weighing about 2000 tons, ten times more than the Apollo spaceships), a special launch system was developed. The huge, orange, rocket-like structure is nothing more than a 47-meter-high fuel tank, which supplies about 760 tons of liquid hydrogen and liquid oxygen to the engines installed in the shuttle itself. The two rockets adjacent to it provide most of the acceleration for the start of the launch: they are powered by solid nitrogen fuel (ammonium perchlorate) and operate in the first two minutes after launch, detach and fall into the sea, and are usually collected for reuse. This system brought the shuttles to a relatively low orbit (about 400 km). For launches to more distant destinations, such as Mars, multi-stage rockets are still used, which successfully carry a heavy payload to a higher orbit around Earth, and launch it from there to the destination.

going back

The missile capabilities of the two powers have been further refined over the years, and have also spread to other countries. Today, many countries possess intercontinental missiles capable of flying into space, with nuclear and other warheads, returning to the atmosphere and hitting with great precision small targets thousands of kilometers from the launch point. Eleven countries currently possess launch capabilities that allow them to place a satellite in space on their own. Various missiles are also adapted for launching from submarines, ships, planes or ground vehicles. Certain models are also equipped with the housing systems such as heat sensors, which allow them to locate a certain target (for example an airplane engine) and pursue it. At the same time, with the spread of knowledge and technology, less advanced countries also acquired the tools to manufacture simple missiles. In recent years, terrorist organizations have also been equipping themselves with rockets - bought or self-made. One of the simplest rockets is the "Qassam", which the terrorist organizations in the Gaza Strip have been producing since the beginning of the last decade. The rocket's fuel consists mainly of potassium nitrate (the same saltpeter remembered from the Chinese black powder) - a substance used as an agricultural fertilizer, and it is very easy to obtain. Compress a mixture of it and sugar into a metal tube (e.g. a sign post), add some explosive (which can also be easily made from agricultural fertilizer), light it and set it off. Gradually and with the help of knowledge from different countries, the terrorist organizations included the rockets, increased the range and the amount of explosive material. However, the rocket itself operates on the same simple principle: solid fuel that burns and releases gases, plus a stabilization mechanism and a warhead. Most of these rockets do not have a guidance mechanism, and what determines the place of impact are the launch angle, the speed of the rocket, and its range.

Missiles and words

Wars abound
And there is no shortage of trouble here
So between a missile and a rocket
Let catch relax in the shade
From "Let a thrash be put on a dune" from the movie "Givat Halfon does not answer". Words: Assi Dayan, Music: Naftali Alter).

From a lexical point of view, there is no distinct difference between "missile" and "rocket". In fact, in the dry definition, a missile is any object that is thrown with great force, usually with the help of a barrel or a launch mechanism. According to this broad definition, a rifle bullet or a mortar shell are also missiles. Among the professionals, the currently accepted distinction is that a "missile" is a rocket with a steering or direction system, which can be controlled even after launch. In contrast, a simple rocket lacks such mechanisms, and once it leaves the launch facility, there is no control over it. The terms "ballistic missile" or "intercontinental missile" are used today mainly to describe missiles whose trajectory is mostly outside the atmosphere.

Missiles vs. Missiles

With the improvement of the missile systems, the USA and the USSR began to develop systems to intercept ballistic missiles from the 70s. These systems are based on radar, which is supposed to detect the launch of ballistic missiles and track them. At the same time, they launch relatively small and extremely fast missiles, which are supposed to collide with the target missile or explode next to it and destroy it. Both countries have developed some such systems, but they have hardly been tested in real operational conditions.
In the first Gulf War (1991), the US converted Patriot anti-aircraft missiles to intercept Iraqi Scud missiles, but with very limited success. The system was refined over the years and showed better results in the Second Gulf War (2003). One of the leading countries in the field is Israel, which in cooperation with the US developed the "Arrow" missiles designed to destroy ballistic missiles or long-range missiles. At the same time, Israel developed in recent years (with American funding) the "Iron Dome" system, designed to intercept short-range rockets. The development of the system faces huge challenges due to the speed of the reaction needed to intercept a rocket that has a flight time of a minute and even less. During this time, the interception system is required to calculate the rocket's trajectory, decide whether to launch a missile against it (according to the expected impact location), and release the missile so that it hits in time. "Iron Dome" has already been tested in many operational scenarios, and the defense establishment says that its success rates are higher than 80% and even 90%. We must attribute the successful interception capabilities not only to the system developers and their initiatives, but also to the credit of Tsiolkovsky, Goddard, von Braun, Korolev and other inventors who dreamed of flying to the stars, but the technologies they developed contributed greatly to our daily lives - from watching TV via satellite to improved personal security Thanks to the fast missiles.

The same topic on the science website and across the web:

• Devotion, Zionism and some parts of "Toys R Us" - an interview with the leading team of "Iron Dome", all of whose members are graduates of the Technion, about the secret of the system's success
• The robotics that will save us from missiles
• After the Second Lebanon War, we realized that it is impossible to agree to a threat without having a response to it, and within a year we were already in the first test of an Iron Dome
• The latest technologies in rocket production

• Von Braun's legacy - the small light
• A history of rocketry in six chapters, Spaceline website
  A brief history of rockets on the NASA website