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A black powder rocket motor propels a model rocket using black powder. Black powder rocket propellants consist of charcoal, sulfur, and potassium nitrate. Adjustments can be made to the amount of each component to change the rate at which the black powder burns. Black powder rocket motors were created in a primitive form by the Chinese in the early 13th century, and through the years refinements have been made and several uses created. They have been used for weapons and surveillance devices as well as recreation. Black powder rocket motors are only produced in small sizes, to reduce the risk of explosion and a loss of efficiency. Black powder rockets are produced in classes 1/4 A through E. Larger sizes of model rocket motors use ammonium perchlorate composite propellant, or other composite fuels that contain ammonium nitrate. ==History== Black powder is the oldest composite propellant. Its use in rockets actually preceded its use in guns.〔Bedard, Andre. ‘Black Powder Rockets’. Encyclopedia Astronautica. http://www.astronautix.com/〕 The three main components of black powder are charcoal, sulphur, and saltpetre (or potassium nitrate). It is known that by 1045, the Chinese were producing black powder, because many references to the subject were found in The Wu-ching Tsung-yao (Complete Compendium of Military Classics).〔(Nichropulse Rocketry )〕 In the early thirteenth century the Chinese turned black powder propelled objects, formerly only used for entertainment, into weapons of war. The first recorded use of rockets as military weapons was in 1232.〔 The Chinese ‘arrows of fire’ were fired from a sort of catapult launcher. The black powder was packed in a closed tube that had a hole in one end for escaping hot gases, and a long stick as an elementary stability and guidance system. Black powder had a very low specific impulse, however. Refinements in rocket design were made over the next few hundred years, at least on paper. In 1591 a Belgian, Jean Beavie, described and sketched the important idea of multistage rockets. By 1600, rockets were being used in various parts of Europe against cavalry. By 1688, rockets weighing over 120 pounds had been built and fired with success in Germany. These German rockets, carrying 16-pound warheads, used wooden powder cases reinforced with linen. Black powder rockets reached a new level of performance with the introduction of iron hulls and high pressure combustion, developed in India by the engineers of Tipu Sultan. With a range of a kilometer, his rocket-propelled grenades and incendiaries took British invaders by surprise during the Anglo-Mysore Wars.〔Winter, Frank, "The First Golden Age of Rocketry", Smithsonian, 1990〕 Impressed by these weapons, a London lawyer, Sir William Congreve, became fascinated by the challenge of improving rockets.〔http://www.pyroguide.com/index.php?title=Black_powder_rocket〕 He made extensive experimentation with propellants and case design. His systematic approach to the problem resulted in improved range, guidance (stabilization), and incendiary capabilities. The British armed forces used Congreve's new rockets to great advantage during the Napoleonic Wars. In 1939, researchers at the California Institute of Technology seeking to develop a high performance solid rocket motor to assist aircraft take-off, combined black powder with common road asphalt to produce the first true composite motor. This was the birth of the true composite motor and marked the end of the use of black powder in major rocketry applications.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Black powder rocket motor」の詳細全文を読む スポンサード リンク
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