A rocket is a missile, aircraft or other vehicle that obtains thrust from a rocket engine. Rocket engine exhaust is formed from propellant carried within the rocket before use. Rocket engines work by action and reaction and push rockets forward by expelling their exhaust in the opposite direction at high speed, can therefore work in the vacuum of space. In fact, rockets work more efficiently in space than in an atmosphere. Multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Compared with airbreathing engines, rockets are lightweight and powerful and capable of generating large accelerations. To control their flight, rockets rely on momentum, auxiliary reaction engines, gimballed thrust, momentum wheels, deflection of the exhaust stream, propellant flow, spin, or gravity. Rockets for military and recreational uses date back to at least 13th-century China. Significant scientific and industrial use did not occur until the 20th century, when rocketry was the enabling technology for the Space Age, including setting foot on the Earth's moon.
Rockets are now used for fireworks, ejection seats, launch vehicles for artificial satellites, human spaceflight, space exploration. Chemical rockets are the most common type of high power rocket creating a high speed exhaust by the combustion of fuel with an oxidizer; the stored propellant can be a simple pressurized gas or a single liquid fuel that disassociates in the presence of a catalyst, two liquids that spontaneously react on contact, two liquids that must be ignited to react, a solid combination of fuel with oxidizer, or solid fuel with liquid oxidizer. Chemical rockets store a large amount of energy in an released form, can be dangerous. However, careful design, testing and use minimizes risks; the first gunpowder-powered rockets evolved in medieval China under the Song dynasty by the 13th century. The Mongols adopted Chinese rocket technology and the invention spread via the Mongol invasions to the Middle East and to Europe in the mid-13th century. Rockets are recorded in use by the Song navy in a military exercise dated to 1245.
Internal-combustion rocket propulsion is mentioned in a reference to 1264, recording that the "ground-rat", a type of firework, had frightened the Empress-Mother Gongsheng at a feast held in her honor by her son the Emperor Lizong. Subsequently, rockets are included in the military treatise Huolongjing known as the Fire Drake Manual, written by the Chinese artillery officer Jiao Yu in the mid-14th century; this text mentions the first known multistage rocket, the'fire-dragon issuing from the water', thought to have been used by the Chinese navy. Medieval and early modern rockets were used militarily as incendiary weapons in sieges. Between 1270 and 1280, Hasan al-Rammah wrote al-furusiyyah wa al-manasib al-harbiyya, which included 107 gunpowder recipes, 22 of them for rockets. In Europe, Konrad Kyeser described rockets in his military treatise Bellifortis around 1405; the name "rocket" comes from the Italian rocchetta, meaning "bobbin" or "little spindle", given due to the similarity in shape to the bobbin or spool used to hold the thread to be fed to a spinning wheel.
Leonhard Fronsperger and Conrad Haas adopted the Italian term into German in the mid-16th century. Artis Magnae Artilleriae pars prima, an important early modern work on rocket artillery, by Kazimierz Siemienowicz, was first printed in Amsterdam in 1650; the Mysorean rockets were the first successful iron-cased rockets, developed in the late 18th century in the Kingdom of Mysore by Tipu Sultan. The Congreve rocket was a British weapon designed and developed by Sir William Congreve in 1804; this rocket was based directly on the Mysorean rockets, used compressed powder and was fielded in the Napoleonic Wars. It was Congreve rockets that Francis Scott Key was referring to when he wrote of the "rockets' red glare" while held captive on a British ship, laying siege to Fort McHenry in 1814. Together, the Mysorean and British innovations increased the effective range of military rockets from 100 to 2,000 yards; the first mathematical treatment of the dynamics of rocket propulsion is due to William Moore.
In 1815 Alexander Dmitrievich Zasyadko constructed rocket-launching platforms, which allowed rockets to be fired in salvos, gun-laying devices. William Hale in 1844 increased the accuracy of rocket artillery. Edward Mounier Boxer further improved the Congreve rocket in 1865. William Leitch first proposed the concept of using rockets to enable human spaceflight in 1861. Konstantin Tsiolkovsky also conceived this idea, extensively developed a body of theory that has provided the foundation for subsequent spaceflight development. Robert Goddard in 1920 published proposed improvements to rocket technology in A Method of Reaching Extreme Altitudes. In 1923, Hermann Oberth published Die Rakete zu den Planetenräumen Modern rockets originated in 1926 when Goddard attached a supersonic nozzle to the combustion chamber of a liquid-propellant rocket; these nozzles turn the hot gas from the combustion chamber into a cooler, hypersonic directed jet of gas, more than doubling the thrust and raising the engine efficiency from 2% to 64%.
Use of liquid propellants instead of gunpowder improved the effectiveness of rocket artillery in World War II, opened up the p
An attack helicopter is an armed helicopter with the primary role of an attack aircraft, with the capability of engaging targets on the ground, such as enemy infantry and armored fighting vehicles. Due to their heavy armament they are sometimes called helicopter gunships. Weapons used on attack helicopters can include autocannons, machine guns and guided anti-tank missiles such as the Hellfire. Many attack helicopters are capable of carrying air-to-air missiles, though for purposes of self-defense. Today's attack helicopter has two main roles: first, to provide direct and accurate close air support for ground troops, second, the anti-tank role to destroy enemy armor concentrations. Attack helicopters are used to supplement lighter helicopters in the armed scout role. In combat, an attack helicopter is projected to destroy around 17 times its own production cost before it is destroyed. Low-speed, fixed wing Allied aircraft like the Soviet Polikarpov Po-2 training and utility biplane had been used as early as 1942 to provide night harassment attack capability against the Wehrmacht Heer on the Eastern Front, most in the Battle of the Caucasus as exemplified by the Night Witches all-female Soviet air unit.
Following Operation Overlord in 1944, the military version of the slow-flying Piper J-3 Cub high-wing civilian monoplane, the L-4 Grasshopper, begun to be used in a light anti-armor role by a few U. S. Army artillery spotter units over France. During the summer of 1944, U. S. Army Major Charles Carpenter managed to take on an anti-armor role with his rocket-armed Piper L-4, his L-4, bearing US Army serial number 43-30426 and named Rosie the Rocketer, armed with six bazookas, had a notable anti-armor success during an engagement during the Battle of Arracourt on September 20, 1944, employing top attack tactics in knocking out at least four German armored vehicles, as a pioneering example of taking on heavy enemy armor from a slow-flying aircraft. The Germans themselves were engaged in such ad-hoc, low-speed "light aircraft" platforms for ground attack late in the war, with one subtype of the Bücker Bestmann trainer—the Bü 181C-3—armed with four Panzerfaust 100 anti-tank grenade launchers, two under each of the low-winged monoplane's wing panels, for the concluding two months of the war in Europe.
This sort of role, being undertaken by low-speed fixed-wing light aircraft was something, likely to be achievable after World War II, from the increasing numbers of post-war military helicopter designs. The only American helicopter in use during the war years, the Sikorsky R-4, was only being used for rescue and were still much experimental in nature. In the early 1950s, various countries around the world started to make increased use of helicopters in their operations in transport and liaison roles. On it was realised that these helicopters, successors to the World War II-era Sikorsky R-4, could be armed with weapons in order to provide them with limited combat capability. Early examples include armed Sikorsky H-34s in service with the US Air Force and armed Mil Mi-4 in service with the Soviet Air Forces. In the opening months of the Korean War era, in August 1950 a joint US Navy and Marine Corps test used a newly acquired Bell HTL-4 helicopter to test if a bazooka could be fired from a helicopter in flight.
One of the larger 3.5 inch models of the bazooka was chosen, was mounted ahead and to the right of the helicopter to allow the door to remain clear. The bazooka was tested, although it was discovered that it would require shielding for the engine compartment, exposed in the model 47 and other early helicopters; the helicopter itself belonged to a Marine experimental helicopter squadron. This "experimental" trend towards the development of dedicated attack helicopters continued into the 1960s with the deployment of armed Bell UH-1s and Mil Mi-8s during the Vietnam War, to this day the pair of most produced helicopter designs in aviation history; these helicopters proved to be moderately successful in these configurations, but due to a lack of armor protection and speed, they were ineffective platforms for mounting weapons in higher-threat ground combat environments. Since the 1960s, various countries around the world started to design and develop various types of helicopters with the purpose of providing a armed and protected aerial vehicle that can perform a variety of combat roles, from reconnaissance to aerial assault missions.
By the 1990s, the missile-armed attack helicopter evolved into a primary anti-tank weapon. Able to move about the battlefield and launch fleeting "pop-up attacks", helicopters presented a major threat with the presence of organic air defenses; the helicopter gunship became a major tool against tank warfare, most attack helicopters became more and more optimized for the antitank mission. In the mid-1960s, the U. S. Army concluded that a purpose-built attack helicopter with more speed and firepower than current armed helicopters was required in the face of intense ground fire from Viet Cong and NVA troops. Based on this realization, with the growing involvement in Vietnam, the U. S. Army developed the requirements for a dedicated attack helicopter, the Advanced Aerial Fire Support System; the aircraft design selected for this program in 1965, was Lockheed's AH-56 Cheyenne. As the Army began its acquisition of a dedicated attack helicopter, it sought options to improve performance over the continued use of improvised interim aircraft.
Douglas A-26 Invader
The Douglas A-26 Invader is an American twin-engined light bomber and ground attack aircraft. Built by Douglas Aircraft Company during World War II, the Invader saw service during several major Cold War conflicts. A limited number of modified United States Air Force aircraft served in Southeast Asia until 1969, it was a fast aircraft capable of carrying a large bomb load. A range of guns could be fitted to produce a formidable ground-attack aircraft. A re-designation of the type from A-26 to B-26 led to confusion with the Martin B-26 Marauder, which first flew in November 1940, some 20 months before the Douglas design's maiden flight. Although both types were powered by the used Pratt & Whitney R-2800 Double Wasp eighteen-cylinder, double-row radial engine, they were different and separate designs — the Martin bomber originated in 1939, with more than twice as many Marauders produced in comparison to the Douglas design; the A-26 was Douglas Aircraft's successor to the A-20 Havoc known as Douglas Boston, one of the most successful and operated types flown by Allied air forces in World War II.
Designed by Ed Heinemann, Robert Donovan, Ted R. Smith, the innovative NACA 65-215 laminar flow airfoil wing of the A-26 was the work of project aerodynamicist A. M. O. Smith; the Douglas XA-26 prototype first flew on 10 July 1942 at Mines Field, El Segundo, with test pilot Benny Howard at the controls. Flight tests revealed excellent performance and handling, but engine cooling problems led to cowling changes and elimination of the propeller spinners on production aircraft. Repeated collapses during testing led to reinforcement of the nose landing gear; the A-26 was built in two different configurations. The A-26B had a gun nose, which could be equipped with a combination of armament including.50 caliber machine guns, 20mm or 37mm auto cannon, or a 75mm pack howitzer. The gun nose version housed six.50 caliber machine guns termed the "all-purpose nose" commonly known as the "six-gun nose" or "eight-gun nose". The A-26C's "glass" nose termed the "Bombardier nose", contained a Norden bombsight for medium altitude precision bombing.
The A-26C nose section included two fixed M-2 guns replaced by underwing gun packs or internal guns in the wings. After about 1,570 production aircraft, three guns were installed in each wing, coinciding with the introduction of the "eight-gun nose" for A-26Bs, giving some configurations as many as 14.50 in machine guns in fixed forward mounts. An A-26C nose section could be replaced with an A-26B nose section, or vice versa, in a few man-hours, thus physically changing the designation and operational role; the "flat-topped" canopy was changed in late 1944 after about 820 production aircraft, to a clamshell style with improved visibility. Alongside the pilot in an A-26B, a crew member served as navigator and gun loader for the pilot-operated nose guns. In an A-26C, that crew member served as navigator and bombardier, relocated to the nose section for the bombing phase of an operation. A small number of A-26Cs were fitted with dual flight controls, some parts of which could be disabled in flight to allow limited access to the nose section.
Access was through the lower section of the right-hand instrument panel, open to allow access to the nose for the bombardier, who would sit next to the pilot. This was similar to British designs like the Lancaster, Blenheim/Beaufort, etc. A tractor-style "jump seat" was located behind the "navigator's seat." In most missions, a third crew member in the rear gunner's compartment operated the remotely controlled dorsal and ventral gun turrets, with access to and from the cockpit possible via the bomb bay only when, empty. The gunner operated both dorsal and ventral turrets via a novel and complex dual-ended periscope sight, a vertical column running through the center of the rear compartment, with traversing and elevating/depressing periscope sights on each end; the gunner sat on a seat facing rearward, looked into a binocular periscope sight mounted on the column, controlling the guns with a pair of handles on either side of the column. When aiming above the centerline of the aircraft, the mirror in the center of the column would flip, showing the gunner what the upper periscope was seeing.
When he pressed the handles downward, as the bead passed the centerline the mirror would automatically flip, transferring the sight "seamlessly" to the lower periscope. The guns would aim wherever the periscope was aimed, automatically transferring between upper and lower turrets as required, computing for parallax and other factors. While novel and theoretically effective, a great deal of time and trouble was spent trying to get the system to work which delayed production, it was difficult to keep maintained in the field once production started; the Douglas company began delivering the production model A-26B to the United States Army Air Forces on 10 September 1943, with the new bomber first seeing action with the Fifth Air Force in the Southwest Pacific theater on 23 June 1944, when Japanese-held islands near Manokwari were attacked. The pilots in the 3rd Bomb Group's 13th Squadron, "The Grim Reapers", who received the first four A-26s for evaluation, found the view from the cockpit to be restricted by the engines and thus inadequate for low-level attack.
General George Kenney, commander of the Far East Air Forces stated that, "We do not want the A-26 under any circumstances as a replacement for anything."Until changes could be made, the 3d Bomb G
A cannon is a type of gun classified as artillery that launches a projectile using propellant. In the past, gunpowder was the primary propellant before the invention of smokeless powder in the 19th century. Cannon vary in caliber, mobility, rate of fire, angle of fire, firepower; the word cannon is derived from several languages, in which the original definition can be translated as tube, cane, or reed. In the modern era, the term cannon has fallen into decline, replaced by guns or artillery if not a more specific term such as mortar or howitzer, except for high calibre automatic weapons firing bigger rounds than machine guns, called autocannons; the earliest known depiction of cannon appeared in Song dynasty China as early as the 12th century, however solid archaeological and documentary evidence of cannon do not appear until the 13th century. In 1288 Yuan dynasty troops are recorded to have used hand cannons in combat, the earliest extant cannon bearing a date of production comes from the same period.
By 1326 depictions of cannon had appeared in Europe and immediately recorded usage of cannon began appearing. By the end of the 14th century cannon were widespread throughout Eurasia. Cannon were used as anti-infantry weapons until around 1374 when cannon were recorded to have breached walls for the first time in Europe. Cannon featured prominently as siege weapons and larger pieces appeared. In 1464 a 16,000 kg cannon known as the Great Turkish Bombard was created in the Ottoman Empire. Cannon as field artillery became more important after 1453 with the introduction of limber, which improved cannon maneuverability and mobility. European cannon reached their longer, more accurate, more efficient "classic form" around 1480; this classic European cannon design stayed consistent in form with minor changes until the 1750s. Cannon is derived from the Old Italian word cannone, meaning "large tube", which came from Latin canna, in turn originating from the Greek κάννα, "reed", generalised to mean any hollow tube-like object.
The word has been used to refer to a gun since 1326 in Italy, 1418 in England. Both Cannons and Cannon are correct and in common usage, with one or the other having preference in different parts of the English-speaking world. Cannons is more common in North America and Australia, while cannon as plural is more common in the United Kingdom; the cannon may have appeared as early as the 12th century in China, was a parallel development or evolution of the fire-lance, a short ranged anti-personnel weapon combining a gunpowder-filled tube and a polearm of some sort. Co-viative projectiles such as iron scraps or porcelain shards were placed in fire lance barrels at some point, the paper and bamboo materials of fire lance barrels were replaced by metal; the earliest known depiction of a cannon is a sculpture from the Dazu Rock Carvings in Sichuan dated to 1128, however the earliest archaeological samples and textual accounts do not appear until the 13th century. The primary extant specimens of cannon from the 13th century are the Wuwei Bronze Cannon dated to 1227, the Heilongjiang hand cannon dated to 1288, the Xanadu Gun dated to 1298.
However, only the Xanadu gun contains an inscription bearing a date of production, so it is considered the earliest confirmed extant cannon. The Xanadu Gun weighs 6.2 kg. The other cannon are dated using contextual evidence; the Heilongjiang hand cannon is often considered by some to be the oldest firearm since it was unearthed near the area where the History of Yuan reports a battle took place involving hand cannon. According to the History of Yuan, in 1288, a Jurchen commander by the name of Li Ting led troops armed with hand cannon into battle against the rebel prince Nayan. Chen Bingying argues there were no guns before 1259 while Dang Shoushan believes the Wuwei gun and other Western Xia era samples point to the appearance of guns by 1220, Stephen Haw goes further by stating that guns were developed as early as 1200. Sinologist Joseph Needham and renaissance siege expert Thomas Arnold provide a more conservative estimate of around 1280 for the appearance of the "true" cannon. Whether or not any of these are correct, it seems that the gun was born sometime during the 13th century.
References to cannon proliferated throughout China in the following centuries. Cannon featured in literary pieces. In 1341 Xian Zhang wrote a poem called The Iron Cannon Affair describing a cannonball fired from an eruptor which could "pierce the heart or belly when striking a man or horse, transfix several persons at once."By the 1350s the cannon was used extensively in Chinese warfare. In 1358 the Ming army failed to take a city due to its garrisons' usage of cannon, however they themselves would use cannon, in the thousands on during the siege of Suzhou in 1366; the Korean kingdom of Joseon started producing gunpowder in 1374 and cannon by 1377. Cannon appeared in Đại Việt by 1390 at the latest. During the Ming dynasty cannon were used in riverine warfare at the Battle of Lake Poyang. One shipwreck in Shandong had a cannon dated to 1377 and an anchor dated to 1372. From the 13th to 15th centuries cannon-armed Chinese ships travelled throughout Southeast Asia; the first of the western cannon to be introduced were breach-loaders in the early 16th century which the Chinese began producing themselves by 1523 and began improving on.
Japan did not acquire a cannon until 1510 when a monk brought one back from China, did not produce a
The United Kingdom the United Kingdom of Great Britain and Northern Ireland, sometimes referred to as Britain, is a sovereign country located off the north-western coast of the European mainland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, many smaller islands. Northern Ireland is the only part of the United Kingdom that shares a land border with another sovereign state, the Republic of Ireland. Apart from this land border, the United Kingdom is surrounded by the Atlantic Ocean, with the North Sea to the east, the English Channel to the south and the Celtic Sea to the south-west, giving it the 12th-longest coastline in the world; the Irish Sea lies between Great Ireland. With an area of 242,500 square kilometres, the United Kingdom is the 78th-largest sovereign state in the world, it is the 22nd-most populous country, with an estimated 66.0 million inhabitants in 2017. The UK is constitutional monarchy; the current monarch is Queen Elizabeth II, who has reigned since 1952, making her the longest-serving current head of state.
The United Kingdom's capital and largest city is London, a global city and financial centre with an urban area population of 10.3 million. Other major urban areas in the UK include Greater Manchester, the West Midlands and West Yorkshire conurbations, Greater Glasgow and the Liverpool Built-up Area; the United Kingdom consists of four constituent countries: England, Scotland and Northern Ireland. Their capitals are London, Edinburgh and Belfast, respectively. Apart from England, the countries have their own devolved governments, each with varying powers, but such power is delegated by the Parliament of the United Kingdom, which may enact laws unilaterally altering or abolishing devolution; the nearby Isle of Man, Bailiwick of Guernsey and Bailiwick of Jersey are not part of the UK, being Crown dependencies with the British Government responsible for defence and international representation. The medieval conquest and subsequent annexation of Wales by the Kingdom of England, followed by the union between England and Scotland in 1707 to form the Kingdom of Great Britain, the union in 1801 of Great Britain with the Kingdom of Ireland created the United Kingdom of Great Britain and Ireland.
Five-sixths of Ireland seceded from the UK in 1922, leaving the present formulation of the United Kingdom of Great Britain and Northern Ireland. There are fourteen British Overseas Territories, the remnants of the British Empire which, at its height in the 1920s, encompassed a quarter of the world's land mass and was the largest empire in history. British influence can be observed in the language and political systems of many of its former colonies; the United Kingdom is a developed country and has the world's fifth-largest economy by nominal GDP and ninth-largest economy by purchasing power parity. It has a high-income economy and has a high Human Development Index rating, ranking 14th in the world, it was the world's first industrialised country and the world's foremost power during the 19th and early 20th centuries. The UK remains a great power, with considerable economic, military and political influence internationally, it is sixth in military expenditure in the world. It has been a permanent member of the United Nations Security Council since its first session in 1946.
It has been a leading member state of the European Union and its predecessor, the European Economic Community, since 1973. The United Kingdom is a member of the Commonwealth of Nations, the Council of Europe, the G7, the G20, NATO, the Organisation for Economic Co-operation and Development and the World Trade Organization; the 1707 Acts of Union declared that the kingdoms of England and Scotland were "United into One Kingdom by the Name of Great Britain". The term "United Kingdom" has been used as a description for the former kingdom of Great Britain, although its official name from 1707 to 1800 was "Great Britain"; the Acts of Union 1800 united the kingdom of Great Britain and the kingdom of Ireland in 1801, forming the United Kingdom of Great Britain and Ireland. Following the partition of Ireland and the independence of the Irish Free State in 1922, which left Northern Ireland as the only part of the island of Ireland within the United Kingdom, the name was changed to the "United Kingdom of Great Britain and Northern Ireland".
Although the United Kingdom is a sovereign country, Scotland and Northern Ireland are widely referred to as countries. The UK Prime Minister's website has used the phrase "countries within a country" to describe the United Kingdom; some statistical summaries, such as those for the twelve NUTS 1 regions of the United Kingdom refer to Scotland and Northern Ireland as "regions". Northern Ireland is referred to as a "province". With regard to Northern Ireland, the descriptive name used "can be controversial, with the choice revealing one's political preferences"; the term "Great Britain" conventionally refers to the island of Great Britain, or politically to England and Wales in combination. However, it is sometimes used as a loose synonym for the United Kingdom as a whole; the term "Britain" is used both as a synonym for Great Britain, as a synonym for the United Kingdom. Usage is mixed, with the BBC preferring to use Britain as shorthand only for Great Britain and the UK Government, while accepting that both terms refer to the United K
In modern language, a missile known as a guided missile, is a guided self-propelled system, as opposed to an unguided self-propelled munition, referred to as a rocket. Missiles have four system components: targeting or missile guidance, flight system and warhead. Missiles come in types adapted for different purposes: surface-to-surface and air-to-surface missiles, surface-to-air missiles, air-to-air missiles, anti-satellite weapons. All known existing missiles are designed to be propelled during powered flight by chemical reactions inside a rocket engine, jet engine, or other type of engine. Non-self-propelled airborne explosive devices are referred to as shells and have a shorter range than missiles. In ordinary British-English usage predating guided weapons, a missile is such as objects thrown at players by rowdy spectators at a sporting event; the first missiles to be used operationally were a series of missiles developed by Nazi Germany in World War II. Most famous of these are the V-1 flying bomb and V-2 rocket, both of which used a simple mechanical autopilot to keep the missile flying along a pre-chosen route.
Less well known were a series of anti-shipping and anti-aircraft missiles based on a simple radio control system directed by the operator. However, these early systems in World War II were only built in small numbers. Guided missiles have a number of different system components: Guidance system Targeting system Flight system Engine Warhead The most common method of guidance is to use some form of radiation, such as infrared, lasers or radio waves, to guide the missile onto its target; this radiation may emanate from the target, it may be provided by the missile itself, or it may be provided by a friendly third party. The first two are known as fire-and-forget as they need no further support or control from the launch vehicle/platform in order to function. Another method is to use a TV guidance, with a visible light or infrared picture produced in order to see the target; the picture may be used either by a human operator who steering the missile onto its target or by a computer doing much the same job.
One of the more bizarre guidance methods instead used a pigeon to steer a missile to its target. Some missiles have a home-on-jam capability to guide itself to a radar-emitting source. Many missiles use a combination of two or more of the methods to improve accuracy and the chances of a successful engagement. Another method is to target the missile by knowing the location of the target and using a guidance system such as INS, TERCOM or satellite guidance; this guidance system guides the missile by knowing the missile's current position and the position of the target, calculating a course between them. This job can be performed somewhat crudely by a human operator who can see the target and the missile and guide it using either cable- or radio-based remote control, or by an automatic system that can track the target and the missile. Furthermore, some missiles use initial targeting, sending them to a target area, where they will switch to primary targeting, using either radar or IR targeting to acquire the target.
Whether a guided missile uses a targeting system, a guidance system or both, it needs a flight system. The flight system uses the data from the targeting or guidance system to maneuver the missile in flight, allowing it to counter inaccuracies in the missile or to follow a moving target. There are two main systems: aerodynamic maneuvering. Missiles are powered by an engine either a type of rocket engine or jet engine. Rockets are of the solid propellant type for ease of maintenance and fast deployment, although some larger ballistic missiles use liquid-propellant rockets. Jet engines are used in cruise missiles, most of the turbojet type, due to its relative simplicity and low frontal area. Turbofans and ramjets are the only other common forms of jet engine propulsion, although any type of engine could theoretically be used. Long-range missiles may have multiple engine stages in those launched from the surface; these stages may all be of similar types or may include a mix of engine types − for example, surface-launched cruise missiles have a rocket booster for launching and a jet engine for sustained flight.
Some missiles may have additional propulsion from another source at launch. Missiles have one or more explosive warheads, although other weapon types may be used; the warheads of a missile provide its primary destructive power. Warheads are most of the high explosive type employing shaped charges to exploit the accuracy of a guided weapon to destroy hardened targets. Other warhead types include submunitions, nuclear weapons, biological or radiological weapons or kinetic energy penetrators. Warheadless missiles are used for testing and training purposes. Missiles are categorized by their launch platform and intended target. In broadest terms, these will either be surface or air, t
World War I
World War I known as the First World War or the Great War, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. Contemporaneously described as "the war to end all wars", it led to the mobilisation of more than 70 million military personnel, including 60 million Europeans, making it one of the largest wars in history, it is one of the deadliest conflicts in history, with an estimated nine million combatants and seven million civilian deaths as a direct result of the war, while resulting genocides and the 1918 influenza pandemic caused another 50 to 100 million deaths worldwide. On 28 June 1914, Gavrilo Princip, a Bosnian Serb Yugoslav nationalist, assassinated the Austro-Hungarian heir Archduke Franz Ferdinand in Sarajevo, leading to the July Crisis. In response, on 23 July Austria-Hungary issued an ultimatum to Serbia. Serbia's reply failed to satisfy the Austrians, the two moved to a war footing. A network of interlocking alliances enlarged the crisis from a bilateral issue in the Balkans to one involving most of Europe.
By July 1914, the great powers of Europe were divided into two coalitions: the Triple Entente—consisting of France and Britain—and the Triple Alliance of Germany, Austria-Hungary and Italy. Russia felt it necessary to back Serbia and, after Austria-Hungary shelled the Serbian capital of Belgrade on the 28th, partial mobilisation was approved. General Russian mobilisation was announced on the evening of 30 July; when Russia failed to comply, Germany declared war on 1 August in support of Austria-Hungary, with Austria-Hungary following suit on 6th. German strategy for a war on two fronts against France and Russia was to concentrate the bulk of its army in the West to defeat France within four weeks shift forces to the East before Russia could mobilise. On 2 August, Germany demanded free passage through Belgium, an essential element in achieving a quick victory over France; when this was refused, German forces invaded Belgium on 3 August and declared war on France the same day. On 12 August and France declared war on Austria-Hungary.
In November 1914, the Ottoman Empire entered the war on the side of the Alliance, opening fronts in the Caucasus and the Sinai Peninsula. The war was fought in and drew upon each power's colonial empire as well, spreading the conflict to Africa and across the globe; the Entente and its allies would become known as the Allied Powers, while the grouping of Austria-Hungary and their allies would become known as the Central Powers. The German advance into France was halted at the Battle of the Marne and by the end of 1914, the Western Front settled into a battle of attrition, marked by a long series of trench lines that changed little until 1917. In 1915, Italy opened a front in the Alps. Bulgaria joined the Central Powers in 1915 and Greece joined the Allies in 1917, expanding the war in the Balkans; the United States remained neutral, although by doing nothing to prevent the Allies from procuring American supplies whilst the Allied blockade prevented the Germans from doing the same the U. S. became an important supplier of war material to the Allies.
After the sinking of American merchant ships by German submarines, the revelation that the Germans were trying to incite Mexico to make war on the United States, the U. S. declared war on Germany on 6 April 1917. Trained American forces would not begin arriving at the front in large numbers until mid-1918, but the American Expeditionary Force would reach some two million troops. Though Serbia was defeated in 1915, Romania joined the Allied Powers in 1916 only to be defeated in 1917, none of the great powers were knocked out of the war until 1918; the 1917 February Revolution in Russia replaced the Tsarist autocracy with the Provisional Government, but continuing discontent at the cost of the war led to the October Revolution, the creation of the Soviet Socialist Republic, the signing of the Treaty of Brest-Litovsk by the new government in March 1918, ending Russia's involvement in the war. This allowed the transfer of large numbers of German troops from the East to the Western Front, resulting in the German March 1918 Offensive.
This offensive was successful, but the Allies rallied and drove the Germans back in their Hundred Days Offensive. Bulgaria was the first Central Power to sign an armistice—the Armistice of Salonica on 29 September 1918. On 30 October, the Ottoman Empire capitulated. On 4 November, the Austro-Hungarian empire agreed to the Armistice of Villa Giusti after being decisively defeated by Italy in the Battle of Vittorio Veneto. With its allies defeated, revolution at home, the military no longer willing to fight, Kaiser Wilhelm abdicated on 9 November and Germany signed an armistice on 11 November 1918. World War I was a significant turning point in the political, cultural and social climate of the world; the war and its immediate aftermath sparked numerous uprisings. The Big Four (Britain, the United States, It