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Operation Lighthouse (1937)
Operation Lighthouse was the name given to the failed experimental launch of four Aggregate 3 liquid-fuel rockets by Wernher von Braun and Walter Dornberger on the German island of Greifswalder Oie in December 1937. Background and preparation In the summer of 1937 the German Aggregate 3 series of rockets was nearing the testing stage. Several were tested on a special stand at Kummersdorf in an attempt to evaluate guidance systems. These consisted of vanes designed to deflect the rocket exhaust and control the missile's course. On September 1, Dornberger ordered that von Braun's team prepare for a series of test launches in the first part of November from the small island of Greifswalder Oie in an operation he designated "Lighthouse". Von Braun assigned the head of his measurement unit, Gerhard Reisig, to prepare the expedition to the island.Neufeld, M.J. ''Von Braun: Dreamer of Space, Engineer of War''. New York: Knopf, 2007. p 102. In November, rain and snow storms kept the pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregate 3
The Aggregat series (German for "Aggregate") was a set of ballistic missile designs developed in 1933–1945 by a research program of Nazi Germany's Armed Forces (Wehrmacht). Its greatest success was the A4, more commonly known as the V-2. A1 (1933) The A1 was the first rocket design in the Aggregat series. It was designed in 1933 by Wernher von Braun in a German armed forces research program at Kummersdorf headed by Walter Dornberger. The A1 was the grandfather of most modern rockets. The rocket was long, in diameter, and had a takeoff weight of . The engine, designed by Arthur Rudolph, used a pressure-fed rocket propellant system burning ethanol and liquid oxygen, and produced 2.9 kN (660 lbf) of thrust for 16 seconds. The LOX tank was located within the fuel tank and insulated with a fiberglass material. The rocket was stabilized by a 3 axes gyroscope system in the nose, supplied by Kreiselgeräte G.m.b.H. The rocket could not be rotated for stability as with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rabbit
Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit species and its descendants, the world's 305 breeds of domestic rabbit. ''Sylvilagus'' includes 13 wild rabbit species, among them the seven types of cottontail. The European rabbit, which has been introduced on every continent except Antarctica, is familiar throughout the world as a wild prey animal and as a domesticated form of livestock and pet. With its widespread effect on ecologies and cultures, the rabbit is, in many areas of the world, a part of daily life—as food, clothing, a companion, and a source of artistic inspiration. Although once considered rodents, lagomorphs like rabbits have been discovered to have diverged separately and earlier than their rodent cousins and have a number of traits rodents lack, like two extra incis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Experimental Rockets
An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Experiments vary greatly in goal and scale but always rely on repeatable procedure and logical analysis of the results. There also exist natural experimental studies. A child may carry out basic experiments to understand how things fall to the ground, while teams of scientists may take years of systematic investigation to advance their understanding of a phenomenon. Experiments and other types of hands-on activities are very important to student learning in the science classroom. Experiments can raise test scores and help a student become more engaged and interested in the material they are learning, especially when used over time. Experiments can vary from personal and informal natural comparisons (e. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballistic Missile
A ballistic missile is a type of missile that uses projectile motion to deliver warheads on a target. These weapons are guided only during relatively brief periods—most of the flight is unpowered. Short-range ballistic missiles stay within the Earth's atmosphere, while intercontinental ballistic missiles (ICBMs) are launched on a sub-orbital flight. These weapons are in a distinct category from cruise missiles, which are aerodynamically guided in powered flight. Unlike cruise missiles, which are restricted to the atmosphere, it is advantageous for ballistic missiles to avoid the denser parts of the atmosphere and they may travel above the atmosphere into outer space. History The earliest form of ballistic missile dates from the 13th century with its use derived from the history of rockets. In the 14th century, the Ming Chinese navy used an early form of a ballistic missile weapon called the Huolongchushui in naval battles against enemy ships.Needham, Volume 5, Part 7, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatics
Electrostatics is a branch of physics that studies electric charges at rest (static electricity). Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber, (), was thus the source of the word 'electricity'. Electrostatic phenomena arise from the forces that electric charges exert on each other. Such forces are described by Coulomb's law. Even though electrostatically induced forces seem to be rather weak, some electrostatic forces are relatively large. The force between an electron and a proton, which together make up a hydrogen atom, is about 36 orders of magnitude stronger than the gravitational force acting between them. There are many examples of electrostatic phenomena, from those as simple as the attraction of plastic wrap to one's hand after it is removed from a package, to the apparently spontaneous explosion of grain silos, the damage of electronic components during manufacturin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerodynamic Drag
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers (or surfaces) or between a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are nearly independent of velocity, the drag force depends on velocity. Drag force is proportional to the velocity for low-speed flow and the squared velocity for high speed flow, where the distinction between low and high speed is measured by the Reynolds number. Even though the ultimate cause of drag is viscous friction, turbulent drag is independent of viscosity. Drag forces always tend to decrease fluid velocity relative to the solid object in the fluid's path. Examples Examples of drag include the component of the net aerodynamic or hydrodynamic force acting opposite to the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parachute
A parachute is a device used to slow the motion of an object through an atmosphere by creating drag or, in a ram-air parachute, aerodynamic lift. A major application is to support people, for recreation or as a safety device for aviators, who can exit from an aircraft at height and descend safely to earth. A parachute is usually made of a light, strong fabric. Early parachutes were made of silk. The most common fabric today is nylon. A parachute's canopy is typically dome-shaped, but some are rectangles, inverted domes, and other shapes. A variety of loads are attached to parachutes, including people, food, equipment, space capsules, and bombs. History Middle Ages In 852, in Córdoba, Spain, the Moorish man Armen Firman attempted unsuccessfully to fly by jumping from a tower while wearing a large cloak. It was recorded that "there was enough air in the folds of his cloak to prevent great injury when he reached the ground." Early Renaissance The earliest evidence f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pheasant
Pheasants ( ) are birds of several genera within the family (biology), family Phasianidae in the order (biology), order Galliformes. Although they can be found all over the world in introduced (and captive) populations, the pheasant genera native range is restricted to Eurasia. The classification "pheasant" is Paraphyly, paraphyletic, as birds referred to as pheasants are included within both the subfamilies Phasianinae and Peafowl, Pavoninae, and in many cases are more closely related to smaller phasianids, grouse, and turkey (formerly classified in Perdicinae, Grouse, Tetraoninae, and Meleagridinae) than to other pheasants. Pheasants are characterised by strong sexual dimorphism, males being highly decorated with bright colours and adornments such as wattle (anatomy), wattles. Males are usually larger than females and have longer tails. Males play no part in rearing the young. A pheasant's call or cry can be recognised due to the fact it sounds like a rusty sink or valve b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Line
A telephone line or telephone circuit (or just line or circuit industrywide) is a single-user circuit on a telephone communication system. It is designed to reproduce speech of a quality that is understandable. It is the physical wire or other signaling medium connecting the user's telephone apparatus to the telecommunications network, and usually also implies a single telephone number for billing purposes reserved for that user. Telephone lines are used to deliver landline telephone service and Digital subscriber line (DSL) phone cable service to the premises. Telephone overhead lines are connected to the public switched telephone network. The voltage at a subscriber's network interface is typically 48 V between the ring and tip wires, with tip near ground and ring at -48 V. In the United States In 1878, the Bell Telephone Company began to use two-wire circuits, called the local loop, from each user's telephone to end offices which performed any necessary electrical s ... [...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] |
Tar Paper
Tar paper is a heavy-duty paper used in construction. Tar paper is made by impregnating paper or fiberglass mat with tar, producing a waterproof material useful for roof construction. Tar paper is distinguished from roofing felt, which is impregnated with asphalt instead of tar, but these two products are used the same way, and their names are sometimes used informally as synonyms. Description Tar paper has been in use for centuries. Originally, felt was made of recycled rags, but modern felt is made of recycled paper products, typically cardboard, and sawdust. The most common product is #15 felt. Before the oil crisis, felt weighed about per square, hence the asphalt-impregnated felt was called "15-pound felt" (15#). Modern, inorganic mats are no longer the same weight, and to reflect this fact, the new felts are called "number 15 felt" (#15). Modern #15 mats can weigh from pounds per square, depending on the manufacturer and the standard to which felt is made (such as , , or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodents
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for New Zealand, Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/richochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, and hamsters. Rabbits, hares, and pikas, whose incisors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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