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Project Nike
Project Nike (Greek: Nike (mythology), Νίκη, "Victory") was a United States Army, U.S. Army project proposed in May 1945 by Bell Laboratories, to develop a line-of-sight (missile), line-of-sight anti-aircraft missile system. The project delivered the United States' first operational anti-aircraft missile system, the MIM-3 Nike Ajax, Nike Ajax, in 1953. Many technologies and rocket systems used for developing the Nike Ajax were re-used in other projects, many given the "Nike" name (after Nike (mythology), Nike, the goddess of victory from Greek mythology). The missile's first-stage solid rocket booster became the basis for many types of rocket, including the Nike-Hercules Missile, Nike Hercules missile and NASA's Nike Smoke rocket, used for upper-atmosphere research. History Project Nike began in 1944 when the United States Department of War, War Department demanded a new air defense system to fight jet aircraft that flew too high and fast for anti-aircraft guns. Two propos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog Computer
An analog computer or analogue computer is a type of computation machine (computer) that uses physical phenomena such as Electrical network, electrical, Mechanics, mechanical, or Hydraulics, hydraulic quantities behaving according to the mathematical principles in question (''analog signals'') to Scientific modelling, model the problem being solved. In contrast, digital computers represent varying quantities symbolically and by discrete values of both time and amplitude (digital signals). Analog computers can have a very wide range of complexity. Slide rules and nomograms are the simplest, while naval gunfire control computers and large hybrid digital/analog computers were among the most complicated. Complex mechanisms for process control and protective relays used analog computation to perform control and protective functions. Analog computers were widely used in scientific and industrial applications even after the advent of digital computers, because at the time they were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staging (rocketry)
A multistage rocket or step rocket is a launch vehicle that uses two or more rocket ''stages'', each of which contains its own engines and propellant. A ''tandem'' or ''serial'' stage is mounted on top of another stage; a ''parallel'' stage is attached alongside another stage. The result is effectively two or more rockets stacked on top of or attached next to each other. Two-stage rockets are quite common, but rockets with as many as five separate stages have been successfully launched. By jettisoning stages when they run out of propellant, the mass of the remaining rocket is decreased. Each successive stage can also be optimized for its specific operating conditions, such as decreased atmospheric pressure at higher altitudes. This ''staging'' allows the thrust of the remaining stages to more easily accelerate the rocket to its final velocity and height. In serial or tandem staging schemes, the first stage is at the bottom and is usually the largest, the second stage and subse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UDMH
Unsymmetrical dimethylhydrazine (abbreviated as UDMH; also known as 1,1-dimethylhydrazine, heptyl or Geptil) is a chemical compound with the formula H2NN(CH3)2 that is primarily used as a rocket propellant. At room temperature, UDMH is a colorless liquid, with a sharp, fishy, ammonia-like smell typical of organic amines. Samples turn yellowish on exposure to air and absorb oxygen and carbon dioxide. It is miscible with water, ethanol, and kerosene. At concentrations between 2.5% and 95% in air, its vapors are flammable. It is not sensitive to shock. Symmetrical dimethylhydrazine (1,2-dimethylhydrazine) also exists, but it is not as useful. UDMH can be oxidized in air to form many different substances, including toxic ones. Synthesis In 1875, UDMH was first prepared by Emil Fischer, who discovered and named the class of hydrazines, by reducing N-Nitrosodimethylamine with zinc in boiling acetic acid. Fischer's student Edward Renouf later studied UDMH more extensively as part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IRFNA
Red fuming nitric acid (RFNA) is a storable oxidizer used as a rocket propellant. It consists of nitric acid (), dinitrogen tetroxide () and a small amount of water. The color of red fuming nitric acid is due to the dinitrogen tetroxide, which breaks down partially to form nitrogen dioxide. The nitrogen dioxide dissolves until the liquid is saturated, and produces toxic fumes with a suffocating odor. RFNA increases the flammability of combustible materials and is highly exothermic when reacting with water. Since nitrogen dioxide is a product of decomposition of nitric acid, its addition stabilizes nitric acid in accordance with Le Chatelier's principle. Addition of dinitrogen tetroxide also increases oxidizing power and lowers the freezing point. It is usually used with an inhibitor (with various, sometimes secret, substances, including hydrogen fluoride; any such combination is called ''inhibited RFNA'', ''IRFNA'') because nitric acid attacks most container materials. Hy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Rocket Propellant
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. 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 proposed the use of liquid propellants in 1903, in his article ''Exploration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Booster Rocket
A booster is a rocket (or rocket engine) used either in the first stage of a multistage rocket, multistage launch vehicle or in parallel with longer-burning sustainer engine, sustainer rockets to augment the space vehicle's takeoff thrust and payload capability. Boosters are traditionally necessary to launch spacecraft into low Earth orbit (absent a single-stage-to-orbit design), and are especially important for a space vehicle to go beyond Earth orbit. The booster is dropped to fall back to Earth once its fuel is expended, a point known as ''booster engine cut-off'' (BECO). Following separation event, booster separation, the rest of the launch vehicle continues flight with its core or upper-stage engines. The booster may be recovered, refurbished and reused, as was the case of the steel casings used for the Space Shuttle Space Shuttle Solid Rocket Booster, Solid Rocket Boosters. Drop-away engines The SM-65 Atlas rocket used three engines, one of which was fixed to the fuel tan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid-fuel Rocket
A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses Rocket propellant#Solid chemical propellants, solid propellants (fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder. The inception of gunpowder rockets in warfare can be credited to the ancient Chinese, and in the 13th century, the Mongols played a pivotal role in facilitating their westward adoption. All rockets used some form of solid or powdered propellant until the 20th century, when liquid-propellant rockets offered more efficient and controllable alternatives. Because of their simplicity and reliability, solid rockets are still used today in military armaments worldwide, model rockets, solid rocket boosters and on larger applications. Since solid-fuel rockets can remain in storage for an extended period without much propellant degradation, and since they almost always launch reliably, they have been frequently used in military applications such as missiles. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McDonnell Douglas
McDonnell Douglas Corporation was a major American Aerospace manufacturer, aerospace manufacturing corporation and defense contractor, formed by the merger of McDonnell Aircraft and the Douglas Aircraft Company in 1967. Between then and its own merger with Boeing in 1997, it produced well-known commercial and military aircraft, such as the McDonnell Douglas DC-10, DC-10 and the McDonnell Douglas MD-80, MD-80 airliners, the McDonnell Douglas F-15 Eagle, F-15 Eagle air superiority fighter, and the McDonnell Douglas F/A-18 Hornet, F/A-18 Hornet multirole combat aircraft, multirole fighter. The corporation's headquarters were at St. Louis Lambert International Airport, near St. Louis, Missouri. History Background The company was formed from the firms of James Smith McDonnell and Donald Wills Douglas, Sr., Donald Wills Douglas in 1967. Both men were of Scottish ancestry, were graduates of the Massachusetts Institute of Technology, and had worked for the aircraft manufacturer Glenn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Electric
Western Electric Co., Inc. was an American electrical engineering and manufacturing company that operated from 1869 to 1996. A subsidiary of the AT&T Corporation for most of its lifespan, Western Electric was the primary manufacturer, supplier, and purchasing agent for all telephone equipment for the Bell System from 1881 until 1984, when Breakup of the Bell System, the Bell System was dismantled. Because the Bell System had a near-total monopoly over telephone service in the United States for much of the 20th century, Western Electric's equipment was widespread across the country. The company was responsible for many technological innovations, as well as developments in industrial management. History 19th century In 1856, George Shawk, a craftsman and telegraph maker, purchased an electrical engineering business in Cleveland, Ohio. In January 1869, Shawk had partnered with Enos M. Barton in the former Western Union repair shop of Cleveland, to manufacture burglar alarms, fire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulse-position Modulation
Pulse-position modulation (PPM) is a form of signal modulation in which ''M'' message bits are encoded by transmitting a single pulse in one of 2^M possible required time shifts. This is repeated every ''T'' seconds, such that the transmitted bit rate is M/T bits per second. It is primarily useful for optical communications systems, which tend to have little or no multipath interference. History An ancient use of pulse-position modulation was the Greek hydraulic semaphore system invented by Aeneas Stymphalus around 350 B.C. that used the water clock principle to time signals. In this system, the draining of water acts as the timing device, and torches are used to signal the pulses. The system used identical water-filled containers whose drain could be turned on and off, and a float with a rod marked with various predetermined codes that represented military messages. The operators would place the containers on hills so they could be seen from each other at a distance. To send ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transponder
In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend of ''transmitter'' and ''responder''. In air navigation or radio frequency identification, a flight transponder is an automated transceiver in an aircraft that emits a coded identifying signal in response to an interrogating received signal. In a communications satellite, a satellite transponder receives signals over a range of uplink frequencies, usually from a satellite ground station; the transponder amplifies them, and re-transmits them on a different set of downlink frequencies to receivers on Earth, often without changing the content of the received signal or signals. Satellite/broadcast communications A communications satellite’s channels are called transponders because each is a separate transceiver or repeater. With digital video data compression and multiplexing, several video and audio channels may travel through a single tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
