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Boost Phase
A ballistic missile goes through several distinct phases of flight that are common to almost all such designs. They are, in order: * boost phase when the main boost rocket or upper stages are firing; * post-boost phase when any last-minute changes to the trajectory are made by the upper stage or warhead bus and the warheads, and any decoys are released; * midcourse which represents most of the flight when the objects coast; and * terminal phase as the warhead approaches its target and, for longer-ranged missiles, begins to reenter the atmosphere. These phases are particularly important when discussing ballistic missile defense concepts. Each phase has a different level of difficulty in performing an interception, as well as a different outcome in terms of its effect on the attack as a whole. For instance, defenses that take place during the terminal phase are often the simplest to build in technical terms as they require only short-range missiles and radars. However, terminal d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Project Excalibur
Project Excalibur was a Lawrence Livermore National Laboratory (LLNL) Cold Warera research program to develop an X-ray laser system as a ballistic missile defense (BMD) for the United States. The concept involved packing large numbers of expendable lasers around a nuclear device, which would orbit in space. During an attack, the device would be detonated, with the X-rays released focused by each laser to destroy multiple incoming target missiles. Because the system would be deployed above the Earth's atmosphere, the X-rays could reach missiles thousands of kilometers away, providing protection over a wide area. Anti-ballistic missile (ABM) systems of the time only attacked the enemy nuclear warheads after they were released by ICBMs. A single ICBM could carry as many as a dozen warheads, so dozens of defense missiles were required per attacking missile. A single Excalibur device contained up to fifty lasers and could potentially destroy a corresponding number of missiles, with al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nike-X
Nike-X was an anti-ballistic missile (ABM) system designed in the 1960s by the United States Army to protect major cities in the United States from attacks by the Soviet Union's intercontinental ballistic missile (ICBM) fleet during the Cold War. The X in the name referred to its experimental basis and was supposed to be replaced by a more appropriate name when the system was put into production. This never came to pass; in 1967 the Nike-X program was canceled and replaced by a much lighter defense system known as Sentinel program, Sentinel. The Nike-X system was developed in response to limitations of the earlier LIM-49 Nike Zeus, Nike Zeus system. Zeus' radars could only track single targets, and it was calculated that a salvo of only four ICBMs would have a 90% chance of hitting a Zeus base. The attacker could also use radar reflectors or high-altitude nuclear explosions to obscure the warheads until they were too close to attack, making a single-warhead attack highly likely t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag (physics)
In fluid dynamics, drag, sometimes referred to as fluid resistance, is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers, two solid surfaces, or between a fluid and a solid surface. Drag forces tend to decrease fluid velocity relative to the solid object in the fluid's path. Unlike other resistive forces, drag force depends on velocity. Drag force is proportional to the relative velocity for low-speed flow and is proportional to the velocity squared for high-speed flow. This distinction between low and high-speed flow is measured by the Reynolds number. Drag is instantaneously related to vorticity dynamics through the Josephson-Anderson relation. Examples Examples of drag include: * Net force, Net Aerodynamic force, aerodynamic or Fluid dynamics, hydrodynamic force: Drag acting opposite to the direction of movement of a solid object such as cars, aircraft, and boat hulls. * Viscou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Warhead
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter. Nuclear bombs have had yields between 10 tons (the W54) and 50 megatons for the Tsar Bomba (see TNT equivalent). Yields in the low kilotons can devastate cities. A thermonuclear weapon weighing as little as can release energy equal to more than 1.2 megatons of TNT (5.0 PJ). Apart from the blast, effects of nuclear weapons include firestorms, extreme heat and ionizing radiation, radioactive nuclear fallout, an electromagnetic pulse, and a radar blackout. The first nuclear weapons were developed by the Allied Manhattan Project during World War II. Their production continues to require a large scientific and industrial complex, primari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine-launched Ballistic Missile
A submarine-launched ballistic missile (SLBM) is a ballistic missile capable of being launched from Ballistic missile submarine, submarines. Modern variants usually deliver multiple independently targetable reentry vehicles (MIRVs), each of which carries a thermonuclear weapon, nuclear warhead and allows a single launched missile to strike several targets. Submarine-launched ballistic missiles operate in a different way from submarine-launched cruise missiles. Modern submarine-launched ballistic missiles are closely related to intercontinental ballistic missiles (ICBMs), with ranges of over , and in many cases SLBMs and ICBMs may be part of the same family of weapons. History Origins The first practical design of a submarine-based launch platform was developed by the Germans near the end of World War II involving a launch tube which contained a V-2 rocket, V-2 ballistic missile variant and was towed behind a submarine, known by the code-name V-2 rocket#Unfulfilled plans, ''Prüfs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intercontinental Ballistic Missile
An intercontinental ballistic missile (ICBM) is a ballistic missile with a range (aeronautics), range greater than , primarily designed for nuclear weapons delivery (delivering one or more Thermonuclear weapon, thermonuclear warheads). Conventional weapon, Conventional, Chemical weapon, chemical, and Biological agent, biological weapons can also be delivered with varying effectiveness, but have never been deployed on ICBMs. Most modern designs support multiple independently targetable reentry vehicle (MIRVs), allowing a single missile to carry several warheads, each of which can strike a different target. The Nuclear weapons of the United States, United States, Russia and weapons of mass destruction, Russia, China and weapons of mass destruction, China, France and weapons of mass destruction, France, India and weapons of mass destruction, India, the United Kingdom and weapons of mass destruction, United Kingdom, Nuclear weapons and Israel, Israel, and North Korea and weapons of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
State Of The Art
The state of the art (SOTA or SotA, sometimes cutting edge, leading edge, or bleeding edge) refers to the highest level of general development, as of a device, technique, or scientific field achieved at a particular time. However, in some contexts it can also refer to a level of development reached at any particular time as a result of the common methodologies employed at the time. The term has been used since 1910, and has become both a common term in advertising and marketing, and a legally significant phrase with respect to both patent law and tort liability. In advertising, the phrase is often used to convey that a product is made with the best or latest available technology, but it has been noted that "the term 'state of the art' requires little proof on the part of advertisers", as it is considered mere puffery. The use of the term in patent law "does not connote even superiority, let alone the superlative quality the ad writers would have us ascribe to the term". Orig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Seeking Missile
Infrared homing is a passive weapon guidance system which uses the infrared (IR) light emission from a target to track and follow it seamlessly. Missiles which use infrared seeking are often referred to as "heat-seekers" since infrared is radiated strongly by hot bodies. Many objects such as people, vehicle engines and aircraft generate and emit heat and so are especially visible in the infrared wavelengths of light compared to objects in the background. Infrared seekers are passive devices, which, unlike radar, provide no indication that they are tracking a target. That makes them suitable for sneak attacks during visual encounters or over longer ranges when they are used with a forward looking infrared or similar cueing system. Heat-seekers are extremely effective: 90% of all United States air combat losses between 1984 and 2009 were caused by infrared-homing missiles. They are, however, subject to a number of simple countermeasures, most notably by dropping flares behin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brilliant Pebbles
Brilliant Pebbles was a space-based ballistic missile defense (BMD) system proposed by Lowell Wood and Edward Teller of the Lawrence Livermore National Laboratory (LLNL) in 1987, near the end of the Cold War. The system would consist of thousands of small satellites, each with missiles similar to conventional heat seeking missiles, placed in low Earth orbit constellations so that hundreds would be above the Soviet Union at all times. If the Soviets launched their ICBM fleet, the pebbles would detect their rocket motors using infrared seekers and collide with them. Because the pebble strikes the ICBM before the latter could release its warheads, each pebble could destroy several warheads with one shot. Brilliant Pebbles is named as a play on "Smart Rocks," a concept promoted by Daniel O. Graham under the Strategic Defense Initiative (SDI). Smart Rocks envisioned large orbital battle stations equipped with powerful sensors and carrying numerous small missiles. However, deployi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine
A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or informally to refer to remotely operated vehicles and Autonomous underwater vehicle, robots, or to medium-sized or smaller vessels (such as the midget submarine and the wet sub). Submarines are referred to as ''boats'' rather than ''ships'' regardless of their size. Although experimental submarines had been built earlier, submarine design took off during the 19th century, and submarines were adopted by several navies. They were first used widely during World War I (1914–1918), and are now used in many navy, navies, large and small. Their military uses include: attacking enemy surface ships (merchant and military) or other submarines; aircraft carrier protection; Blockade runner, blockade running; Ballistic missile submarine, nuclear deterrenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Laser
An X-ray laser can be created by several methods either in hot, dense plasmas or as a free-electron laser in an accelerator. This article describes the x-ray lasers in plasmas, only. The plasma x-ray lasers rely on stimulated emission to generate or amplify coherent, directional, high-brightness electromagnetic radiation in the near X-ray or extreme ultraviolet region of the spectrum, that is, usually from ~3 nanometers to several tens of nanometers (nm) wavelength. Because of high gain in the lasing medium and short upper-state lifetimes (1–100 ps), X-ray lasers usually operate without mirrors; the beam of X-rays is generated by a single pass through the gain medium. The emitted radiation, based on amplified spontaneous emission, has relatively low spatial coherence. The line is mostly Doppler broadened, which depends on the ions' temperature. As the common visible-light laser transitions between electronic or vibrational states correspond to energies up to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
