Project 640
Project 640 was a missile defense development programme of the People's Republic of China that started in 1964. The programme pursued processes and technologies related to command and control, sensors, and weapons - including anti-ballistic missiles (ABM), lasers, and anti-satellite satellites. The goal of deploying or testing a complete system in the mid-1970s was unrealistic. Technical challenges, economic constraints and competing programmes slowed progress in the 1970s. Project 640 formally ended in 1982 without a system being developed. Some areas of research, including anti-satellite weapons and lasers, continued under 863 Program which started in the late-1980s. History In late-1963 and early-1964, Mao Zedong received reports on the use of missiles and lasers for missile defense. Mao voiced his approval for missile defence research in the "640" directive in February 1964; this was referenced by the project as 640. A high-level technical meeting in March 1964 chose ABMs as ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Missile Defense
Missile defense is a system, weapon, or technology involved in the detection, tracking, interception, and also the destruction of attacking missiles. Conceived as a defense against nuclear-armed intercontinental ballistic missiles (ICBMs), its application has broadened to include shorter-ranged non-nuclear tactical and theater missiles. China, France, India, Iran, Israel, Italy, Russia, Taiwan, the United Kingdom and the United States have all developed such air defense systems. Missile defense categories Missile defense can be divided into categories based on various characteristics: type/range of missile intercepted, the trajectory phase where the intercept occurs, and whether intercepted inside or outside the Earth's atmosphere: Type/range of missile intercepted These types/ranges include strategic, theater and tactical. Each entails unique requirements for intercept, and a defensive system capable of intercepting one missile type frequently cannot intercept others. H ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Phased Array
In antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving the antennas. In a simple array antenna, the radio frequency current from the transmitter is fed to multiple individual antenna elements with the proper phase relationship so that the radio waves from the separate elements combine ( superpose) to form beams, to increase power radiated in desired directions and suppress radiation in undesired directions. In a phased array, the power from the transmitter is fed to the radiating elements through devices called ''phase shifters'', controlled by a computer system, which can alter the phase or signal delay electronically, thus steering the beam of radio waves to a different direction. Since the size of an antenna array must extend many wavelengths to achieve the high gain needed for narrow bea ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Nanjing
Nanjing (; , Mandarin pronunciation: ), alternately romanized as Nanking, is the capital of Jiangsu province of the People's Republic of China. It is a sub-provincial city, a megacity, and the second largest city in the East China region. The city has 11 districts, an administrative area of , and a total recorded population of 9,314,685 . Situated in the Yangtze River Delta region, Nanjing has a prominent place in Chinese history and culture, having served as the capital of various Chinese dynasties, kingdoms and republican governments dating from the 3rd century to 1949, and has thus long been a major center of culture, education, research, politics, economy, transport networks and tourism, being the home to one of the world's largest inland ports. The city is also one of the fifteen sub-provincial cities in the People's Republic of China's administrative structure, enjoying jurisdictional and economic autonomy only slightly less than that of a province. Nanjing has be ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Fourth Ministry Of Machine Building
The Fourth Ministry of Machine Building (中华人民共和国第四机械工业部), one of the central offices in the People's Republic of China, who oversaw the electronics industry. It was established in 1963. In March 1993, became part of the Ministry of Machine Building and Electronics Industries. In March 1998, an independent Ministry of the Electronics Industry. See also *First Ministry of Machine-Building of the PRC *Second Ministry of Machine-Building of the PRC, ministry of nuclear industry *Third Ministry of Machine-Building of the PRC, ministry of aviation industry *Fifth Ministry of Machine-Building of the PRC, ministry of tank equipment and artillery *Sixth Ministry of Machine-Building of the PRC, ministry of shipbuilding *Seventh Ministry of Machine-Building of the PRC, ministry of space industry *Eighth Ministry of Machine-Building of the PRC Eighth Ministry of Machine-Building of the PRC (中华人民共和国第八机械工业部), one of the central offices in th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it is polarizing, and bonds aluminium forms tend towards covalency. The strong affinity tow ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Chinese Academy Of Sciences
The Chinese Academy of Sciences (CAS); ), known by Academia Sinica in English until the 1980s, is the national academy of the People's Republic of China for natural sciences. It has historical origins in the Academia Sinica during the Republican era and was formerly also known by that name. Collectively known as the "Two Academies (两院)" along with the Chinese Academy of Engineering, it functions as the national scientific think tank and academic governing body, providing advisory and appraisal services on issues stemming from the national economy, social development, and science and technology progress. It is headquartered in Xicheng District, Beijing, with branch institutes all over mainland China. It has also created hundreds of commercial enterprises, Lenovo being one of the most famous. CAS is the world's largest research organization. It had 60,000 researchers in 2018 and 114 institutes in 2016, and has been consistently ranked among the top research organizations ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Atmospheric Entry
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entry of astronomical objects, space debris, or bolides; and ''controlled entry'' (or ''reentry'') of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric ''entry, descent, and landing'' of spacecraft are collectively termed as ''EDL''. Objects entering an atmosphere experience atmospheric drag, which puts mechanical stress on the object, and aerodynamic heating—caused mostly by compression of the air in front of the object, but also by drag. These forces can cause loss of mass (ablation) or even complete disintegration of smaller objects, and objects with lower compressive strength can explode. Crewed space vehicles must be slowed to subsonic speed ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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G-force
The gravitational force equivalent, or, more commonly, g-force, is a measurement of the type of force per unit mass – typically acceleration – that causes a perception of weight, with a g-force of 1 g (not gram in mass measurement) equal to the conventional value of gravitational acceleration on Earth, ''g'', of about . Since g-forces indirectly produce weight, any g-force can be described as a "weight per unit mass" (see the synonym specific weight). When the g-force is produced by the surface of one object being pushed by the surface of another object, the reaction force to this push produces an equal and opposite weight for every unit of each object's mass. The types of forces involved are transmitted through objects by interior mechanical stresses. Gravitational acceleration (except certain electromagnetic force influences) is the cause of an object's acceleration in relation to free fall. The g-force experienced by an object is due to the vector sum of all ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cannon-launched Guided Projectile
Cannon-launched guided projectiles (CLGP) are precision-guided munitions launched by howitzers, mortars, tank guns, and naval guns. Those projectile main propulsion system is the initial kinetic shoot, directed as much as possible toward the target. A secondary GPS or geocoordinates-based system then corrects the trajectory to increase target accuracy and fall closer to the target. This system relies on electronic guidance and pre-programmed coordinates, submitted to the round before its launch. CLGP are intended to supplement and not supplant conventional rounds, providing additional accuracy when needed. For example, the INVAR missile system on the T-90 MBT. Systems capable of firing CLGPs * 120×570mm NATO **Arjun MBT **Merkava *120 mm mortar ** PLL-05 * 125 mm smoothbore ammunition **T-64 **T-72 **T-80 **T-90 *152 mm **M60A2 **M551 Sheridan **MBT-70 List of CLGPs Tank * 105x617mm NATO ** LAHAT ** FALARICK * 120×570mm NATO ** LAHAT ** KSTAM ** SAMHO (planned ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Penetration Aid
A penetration aid (or "penaid") is a device or tactic used to increase an intercontinental ballistic missile (ICBM) warhead's chances of penetrating a target's defenses. These can consist of both ''physical devices'' carried within the ICBM (as part of its payload), as well as ''tactics'' that accompany its launch or flight path, operate as either passive or active counters, and may include one or more of the following concepts: * The missile booster can have a short burn time, and/or (if existing) the MIRV bus carrying the nuclear warheads can have some form of stealth technology, thereby hindering detection before the warhead reentry vehicles are released. * MIRV and MRV (instead of single warhead missiles) themselves largely improve penetration since there are many more warheads to destroy than missiles, which may saturate the defensive system's stock of weapons. However, these technologies are very demanding since they require the ability to highly miniaturize both the physics ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ramjet
A ramjet, or athodyd (aero thermodynamic duct), is a form of airbreathing jet engine that uses the forward motion of the engine to produce thrust. Since it produces no thrust when stationary (no ram air) ramjet-powered vehicles require an assisted take-off like a rocket assist to accelerate it to a speed where it begins to produce thrust. Ramjets work most efficiently at supersonic speeds around and can operate up to speeds of . Ramjets can be particularly useful in applications requiring a small and simple mechanism for high-speed use, such as missiles. The US, Canada, and UK had widespread ramjet powered missile defenses during the 1960s onward, such as the CIM-10 Bomarc and Bloodhound. Weapon designers are looking to use ramjet technology in artillery shells to give added range; a 120 mm mortar shell, if assisted by a ramjet, is thought to be able to attain a range of . They have also been used successfully, though not efficiently, as tip jets on the ends of helicopt ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |