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Liquid Rocket Propellants
The highest specific impulse chemical rockets use liquid propellants ( liquid-propellant rockets). They can consist of a single chemical (a monopropellant) or a mix of two chemicals, called bipropellants. Bipropellants can further be divided into two categories; hypergolic propellants, which ignite when the fuel and oxidizer make contact, and non-hypergolic propellants which require an ignition source. About 170 different propellants made of liquid fuel have been tested, excluding minor changes to a specific propellant such as propellant additives, corrosion inhibitors, or stabilizers. In the U.S. alone at least 25 different propellant combinations have been flown. As of 2020, no completely new propellant has been used since the mid-1970s. Many factors go into choosing a propellant for a liquid-propellant rocket engine. The primary factors include ease of operation, cost, hazards/environment and performance. History Development in early 20th century Konstantin Tsiolkovsky pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Impulse
Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse is exactly proportional to the effective exhaust gas velocity. A propulsion system with a higher specific impulse uses the mass of the propellant more efficiently. In the case of a rocket, this means less propellant needed for a given delta-v, so that the vehicle attached to the engine can more efficiently gain altitude and velocity. In an atmospheric context, specific impulse can include the contribution to impulse provided by the mass of external air that is accelerated by the engine in some way, such as by an internal turbofan or heating by fuel combustion participation then thrust expansion or by external propeller. Jet engines breathe external air for both combustion and by-pass, and therefore have a much higher specific impulse than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Wilhelm Sander
'' Friedrich Wilhelm Sander (25 August 1885 in Glatz (Kłodzko) – 15 September 1938) was a German pyrotechnics and rocket technology engineer as well as manufacturer remembered for his contributions to rocket-powered flight as key protagonist of the Opel-RAK program. Sander was the son of a professional soldier. He went to school in Uslar on the southwestern edge of the Solling and then learned to be a mechanical engineer. At the Technikum Strelitz in Altstrelitz in Mecklenburg he became an engineer around 1908/09. In 1909 Sander moved to Bremerhaven. Here he worked in various areas. In 1920 he took over the company of master gunsmith H. G. Cordes in Bremerhaven, who had existed from 1853 and was known as the inventor of the whaling cannon. Sander soon expanded the factory's products to include signal rockets. From 1925, the Sander line-throwing rocket pistols designed by him for the rescue of shipwrecked people belonged to the equipment of the rescue stations and boats of the G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypergolic Propellant
A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. The main advantages of hypergolic propellants are that they can be stored as liquids at room temperature and that engines which are powered by them are easy to ignite reliably and repeatedly. Common hypergolic propellants are difficult to handle due to their extreme toxicity and/or corrosiveness. In contemporary usage, the terms "hypergol" and "hypergolic propellant" usually mean the most common such propellant combination: dinitrogen tetroxide plus hydrazine and/or its relatives monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH). History In 1935, Hellmuth Walter discovered that hydrazine hydrate was hypergolic with high-test peroxide of 80-83%. He was probably the first to discover this phenomenon, and set to work d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%–6% by weight) in water for consumer use, and in higher concentrations for industrial use. Concentrated hydrogen peroxide, or " high-test peroxide", decomposes explosively when heated and has been used as a propellant in rocketry. Hydrogen peroxide is a reactive oxygen species and the simplest peroxide, a compound having an oxygen–oxygen single bond. It decomposes slowly when exposed to light, and rapidly in the presence of organic or reactive compounds. It is typically stored with a stabilizer in a weakly acidic solution in a dark bottle to block light. Hydrogen peroxide is found in biological systems including the human body. Enzymes that use or decompose hydrogen peroxide are classified as peroxidases. Properties The boiling poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V-2 Rocket
The V-2 (german: Vergeltungswaffe 2, lit=Retaliation Weapon 2), with the technical name ''Aggregat 4'' (A-4), was the world’s first long-range guided ballistic missile. The missile, powered by a liquid-propellant rocket engine, was developed during the Second World War in Nazi Germany as a "vengeance weapon" and assigned to attack Allied cities as retaliation for the Allied bombings of German cities. The rocket also became the first artificial object to travel into space by crossing the Kármán line (edge of space) with the vertical launch of MW 18014 on 20 June 1944. Research into military use of long-range rockets began when the graduate studies of Wernher von Braun attracted the attention of the Wehrmacht. A series of prototypes culminated in the A-4, which went to war as the . Beginning in September 1944, over 3,000 were launched by the Wehrmacht against Allied targets, first London and later Antwerp and Liège. According to a 2011 BBC documentary, the attacks from r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wernher Von Braun
Wernher Magnus Maximilian Freiherr von Braun ( , ; 23 March 191216 June 1977) was a German and American aerospace engineer and space architect. He was a member of the Nazi Party and Allgemeine SS, as well as the leading figure in the development of rocket technology in Nazi Germany and later a pioneer of rocket and space technology in the United States. As a young man, von Braun worked in Nazi Germany's rocket development program. He helped design and co-developed the V-2 rocket at Peenemünde during World War II. Following the war, he was secretly moved to the United States, along with about 1,600 other German scientists, engineers, and technicians, as part of Operation Paperclip. He worked for the United States Army on an intermediate-range ballistic missile program, and he developed the rockets that launched the United States' first space satellite Explorer 1 in 1958. He worked with Walt Disney on a series of films, which popularized the idea of human space travel in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verein Für Raumschiffahrt
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''Verein'' is a German word, sometimes translated as ''union'', ''club'' or ''association'', and may refer to: * ''Eingetragener Verein'' (e. V.), a registered voluntary association under German law * Swiss Verein, a voluntary association under Swiss law, not necessarily registered See also * Association (other) * Verein für Socialpolitik, a society of economists in the German-speaking area * Voluntary association A voluntary group or union (also sometimes called a voluntary organization, common-interest association, association, or society) is a group of individuals who enter into an agreement, usually as volunteering, volunteers, to form a body (or organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kummersdorf
Kummersdorf is the name of an estate near Luckenwalde, around 25 km south of Berlin, in the Brandenburg region of Germany. Until 1945 Kummersdorf hosted the weapon office of the German Army which ran a development centre for future weapons as well as an artillery range. Early history In 1871, the Prussian ministry of war decided to move the artillery test range at Tegel to the Kummersdorf Forest. The new range became operational on 15 October 1875 when it was connected with the Royal Prussian Military Railway. In 1880, the first firing experiments took place on the 12 km southeast-northwest firing range. These experiments investigated the effectiveness of various fortifications, and the effects of weapons and projectiles. Total size of the Kummersdorf Firing Range was 878.1 hectares. In 1913, the dropping of bombs from the LZ 13 Hansa airship and Wright biplanes was investigated. In the 1920s, secret development started in the areas of artillery, armored forces, mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Dornberger
Major-General Dr. Walter Robert Dornberger (6 September 1895 – 26 June 1980) was a German Army artillery officer whose career spanned World War I and World War II. He was a leader of Nazi Germany's V-2 rocket programme and other projects at the Peenemünde Army Research Centre. Dornberger was born in Gießen and enlisted in 1914. In October 1918, as an artillery lieutenant Dornberger was captured by United States Marines and spent two years in a French prisoner of war camp, mostly in solitary confinement because of repeated escape attempts. In the late 1920s, Dornberger completed an engineering course with distinction at the Berlin Technical Institute, and in the Spring of 1930,Dornberger's detailed account of the V2 project was one of the first to be published by a major participant. Dornberger graduated after five years with an MS degree in mechanical engineering from the '' Technische Hochschule Charlottenburg'' in Berlin. In 1935, Dornberger received an honorary doc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heereswaffenamt
''Waffenamt'' (WaA) was the German Army Weapons Agency. It was the centre for research and development of the Weimar Republic and later the Third Reich for weapons, ammunition and army equipment to the German Reichswehr and then Wehrmacht The ''Wehrmacht'' (, ) were the unified armed forces of Nazi Germany from 1935 to 1945. It consisted of the ''Heer'' (army), the ''Kriegsmarine'' (navy) and the ''Luftwaffe'' (air force). The designation "''Wehrmacht''" replaced the previous .... It was founded 8 November 1919 as ''Reichwaffenamt'' (RWA), and 5 May 1922 the name was changed to ''Heereswaffenamt'' (HWA). The task of overseeing Germany's gigantic pre-World War II rearmament program was given to the ''Heeresabnahmestelle'' (the Army Acceptance Organization, commonly referred to as the ''Abnahme''), a subsidiary of the ''Heereswaffenamt''. By 1940 the ''Abnahme'' consisted of 25,000 personnel in five departments in 16 inspection areas, augmented by specially selected plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
