1.
Spaceplane
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A spaceplane is an aerospace vehicle that operates as an aircraft in Earths atmosphere, as well as a spacecraft when it is in space. Typically, it takes the form of a spacecraft equipped with wings, the propulsion to reach space may be purely rocket based or may use the assistance of airbreathing jet engines. The spaceflight is then followed by an unpowered glide return to landing, all five are considered rocket gliders. As of 2015, only these aircraft and rockets have succeeded in reaching space, three are vertical takeoff horizontal landing vehicles relying upon rocket lift for the ascent phase in reaching space and atmospheric lift for reentry, descent and landing. Of the five vehicles, three have been piloted by astronauts, with the Buran and X-37 flying unmanned missions, significant features distinguish spaceplanes from spacecraft. All aircraft utilize aerodynamic surfaces in order to generate lift, for spaceplanes a variety of wing shapes can be used. Delta wings are common, but straight wings, lifting bodies, typically the force of lift generated by these surfaces is many times that of the drag that they induce. The Space Shuttle thermal protection system, for example, protects the orbiter from surface temperatures that could reach as high as 1,650 °C. A spaceplane operates as an aircraft in Earths atmosphere, Aircraft may land on firm runways, helicopter landing pads, or even water, snow or ice. To land, the airspeed and the rate of descent are reduced such that the aircraft descends at a slow rate to allow for a gentle touch down. Landing is accomplished by slowing down and descending and this speed reduction is accomplished by reducing thrust and/or inducing a greater amount of drag using flaps, landing gear or speed brakes. Splashdown is a technical feat to accomplish, requiring only the deployment of a parachute. Project Geminis original concept design was as a spaceplane, with paraglider, however, this concept was abandoned in favor of parachute splashdowns, because of expensive technical failures during testing and development. Whereas Project Geminis splashdown parachutes took only 5 months to develop in 1963, all spaceplanes to date have used rocket engines with chemical fuels. As the orbital insertion burn has to be done in space, a difference between rocket based and air-breathing aerospace plane launch systems is that aerospace plane designs typically include minimal oxidizer storage for propulsion. Air-breathing aerospace plane designs include engine inlets so they can use oxygen for combustion. Since the mass of the oxidizer is, at takeoff, the single largest mass of most rocket designs, types of air breathing engines proposed for spaceplanes include scramjet, liquid air cycle engines, precooled jet engines, pulse detonation engine and ramjets. Some engine designs combine several types of features into a combined cycle
2.
Scaled Composites
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Scaled Composites is an American aerospace company founded by Burt Rutan and currently owned by Northrop Grumman that is located at the Mojave Spaceport, Mojave, California, United States. It is known for designs, for its use of non-metal, composite materials. Scaled Composites was established in 1982 and purchased by the Beech Aircraft Corporation in 1985, in 1988, Beechs parent company, Raytheon, sold Scaled back to Rutan, who then sold it to Wyman-Gordon. After Wyman-Gordon was acquired by Precision Castparts Corp, Rutan and ten investors re-acquired the company as Scaled Composites, LLC. Northrop Grumman, a shareholder in the company with a 40% stake. Both companies said Northrop Grummans acquisition would not affect Scaled Composites strategy or involve replacing Burt Rutan as senior manager, the acquisition by Northrop Grumman was completed on August 24,2007. Before forming Scaled Composites, Burt Rutan had designed several aircraft for amateur builders, including the VariEze and he also designed the Beechcraft Starship, which was, however, a commercial failure. These aircraft were distinctive because of their configuration, winglets. Before SpaceShipOne, Rutan was best known for his Voyager aircraft, which his brother, Dick Rutan, the company announced in April 2003 that it was working on a privately funded spacecraft, in an attempt to win the Ansari X PRIZE for the first private, manned spaceflight. This experimental rocket-powered spacecraft was given the name SpaceShipOne, on December 17,2003, they announced SpaceShipOnes first supersonic flight, the first flight of its kind by a privately funded aircraft. SpaceShipOne successfully made this flight, reaching 68,000 feet and 930 mph, the craft was taken aloft by the White Knight carrier aircraft. On the same day, Paul Allen, one of the founders of Microsoft, on April 1,2004, the U. S. Department of Transportation issued the company what it called the worlds first license for a sub-orbital manned rocket flight. The Mojave Airport, operating part-time as Mojave Spaceport, is the point for SpaceShipOne. SpaceShipOne performed the first privately funded human spaceflight on June 21,2004, Flight 16P on September 29,2004 and Flight 17P on October 4,2004 won the X-Prize for Scaled Composites and SpaceShipOne. Scaled Composites Model 351, is being built for Stratolaunch Systems to provide a platform from which air-launch space missions can be staged, with a wingspan of 117 m, the design has the longest wingspan of any airplane to date. Each of the twin fuselages of the aircraft is 238 feet long and will be supported by 12 main landing gear wheels and it will require 12,000 feet of runway to lift-off. This model which utilized a slightly longer fuselage, larger span, the Rutan Aircraft Factory sold over 600 plan sets for the VariViggen to homebuilders, and eventually about 20 of the aircraft were built. Following the crash of one in New Brunswick, Canada in September 2006 due to wing tank fuel contamination, the prototype aircraft, N27VV, was donated to the EAA AirVenture Museum in 1988
3.
Burt Rutan
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Elbert Leander Burt Rutan is a retired American aerospace engineer noted for his originality in designing light, strong, unusual-looking, energy-efficient aircraft. With his VariEze design, Rutan is responsible for popularizing the canard configuration, Rutan has five aircraft on display in the National Air and Space Museum in Washington, D. C. United States, SpaceShipOne, the Virgin Atlantic GlobalFlyer, Voyager, Quickie, born in 1943 in Estacada, Oregon,30 miles southeast of Portland, and raised in Dinuba, California, Burt Rutan displayed an early interest in aircraft design. By the time he was eight years old he was designing and building model aircraft and his first solo flight piloting an airplane was in an Aeronca Champ in 1959. In 1965 he graduated third in his class from the California Polytechnic State University with a BS degree in aeronautical engineering and he left to become Director of Development of the BD-5 aircraft for Bede Aircraft in Newton, Kansas, a position he held until 1974. In June 1974, Rutan returned to California to establish the Rutan Aircraft Factory, in this business he designed and developed prototypes for several aircraft, mostly intended for amateur builders. His first design, executed while he was still at Bede, was the VariViggen, the canard would become a feature of many Rutan designs, notably the very popular VariEze and Long-EZ. In April 1982, Rutan founded Scaled Composites, LLC, which has one of the worlds pre-eminent aircraft design. Scaled Composites is headquartered in Mojave, California, at the Mojave Air & Space Port and that same year, Beechcraft contracted Rutans Scaled Composites to refine the design and build the prototype Beechcraft Starship. In a 2010 interview, Rutan articulated his motivation for developing suborbital technology projects with SpaceShipOne and he was developing suborbital spaceflight technology because in this we can achieve some breakthroughs, making such flight orders of magnitude safer and orders of magnitude more affordable. Rutan is married to Tonya Rutan and he retired from Scaled Composites in April 2011. That same year, he recognized as a Living Legend of Aviation. In 2012, Rutan spoke on Innovation and the Space Race to the World Affairs Council, flying magazine ranked him at number 18 on their 2013 list,51 Heroes of Aviation. Rutan was also a recipient of the prestigious Wright Brothers Memorial Trophy in 2015, in a 45-year career, each of Rutans designs have often been quite dissimilar from their predecessors. His airplanes and spacecraft take on all types of shapes and sizes. In all, Rutan has come up with 367 individual concepts — of which 45 have flown, VariViggen and VariViggen SP In 1968, he began building his first design, the VariViggen, which first flew in April 1972. It had the wing, forward canard, and pusher configuration design elements which became his trademarks. In lieu of wind tunnel testing, Rutan developed aerodynamic parameters for the VariViggen using a model rigged atop his station wagon, the VariViggen was the Rutan model 27
4.
Mojave Aerospace Ventures
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Mojave Aerospace Ventures is a company founded by Paul Allen and Burt Rutan to handle the commercial spinoffs from the Tier One project. It owns the intellectual property arising from Tier One, and it is in turn owned by Paul Allen, in 2004, it signed a deal with Virgin Galactic to develop the Virgin SpaceShip, a suborbital spacecraft, for space tourism. Virgin Group and Scaled have subsequently formed a joint venture, The Spaceship Company, the structure of Mojave Aerospace Ventures appears to be the basis of the deal between Allen and Rutan for the funding of Tier One. The company owns all the property of the Tier One project, such as patents. Allen, the source of funding for Tier One, is the majority owner. Rutan, having developed the technology, owns a minority stake and this stands in contrast to the company more usually associated with Tier One, Scaled Composites, which, as of 2007, is owned by Northrop Grumman. MAV serves to separate Tier One spinoffs from Scaled Composites, Mojave Aerospace Ventures is part of Allens Vulcan Aerospace. On September 25,2004 MAV agreed on a joint venture with Richard Bransons newly formed company Virgin Galactic, the initial plan is to build five Virgin SpaceShips, based on scaling up the SpaceShipOne design. The spacecraft would be manufactured by The Spaceship Company, the designs for the Tier 1b customer suborbital spaceflight vehicles are referred to as SpaceShipTwo and its carrier aircraft is White Knight Two. A further application of the Tier One technology is for Allens Stratolaunch Systems with its Stratolaunch carrier aircraft Roc
5.
SpaceShipTwo
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The Scaled Composites Model 339 SpaceShipTwo is an air-launched suborbital spaceplane type designed for space tourism. It is manufactured by The Spaceship Company, a California-based company owned by Virgin Galactic, SpaceShipTwo is carried to its launch altitude by a Scaled Composites White Knight Two, before being released to fly on into the upper atmosphere powered by its rocket engine. It then glides back to Earth and performs a conventional runway landing, the spaceship was officially unveiled to the public on 7 December 2009 at the Mojave Air and Space Port in California. On 29 April 2013, after three years of unpowered testing, the first one constructed successfully performed its first powered test flight. The spaceplane could also be used to carry payloads for NASA. On 31 October 2014 during a test flight, VSS Enterprise, a preliminary investigation suggested the feathering system, the crafts descent device, deployed too early. One pilot was killed, the other was treated for a shoulder injury after parachuting from the stricken spacecraft. The second SpaceShipTwo spacecraft, VSS Unity, was unveiled on 19 February 2016, the vehicle is currently undergoing flight testing. The SpaceShipTwo project is based in part on technology developed for the first-generation SpaceShipOne, the Spaceship Company licenses this technology from Mojave Aerospace Ventures, a joint venture of Paul Allen and Burt Rutan, the designer of the predecessor technology. SpaceShipTwo is a low-aspect-ratio passenger spaceplane and its capacity will be eight people — six passengers and two pilots. SpaceShipTwo will reach 4,200 km/h, using a hybrid rocket engine — the RocketMotorTwo. It launches from its ship, White Knight Two, at an altitude of 15,000 metres. After 70 seconds, the engine cuts out and the spacecraft will coast to its peak altitude. SpaceShipTwos crew cabin is 3.7 m long and 2.3 m in diameter, the wing span is 8.2 m, the length is 18 m and the tail height is 4.6 m. SpaceShipTwo uses a feathered reentry system, feasible due to the low speed of reentry, in contrast, other orbital spacecraft re-enter at orbital speeds, closer to 25,000 km/h, using heat shields. SpaceShipTwo is furthermore designed to re-enter the atmosphere at any angle and it will decelerate through the atmosphere, switching to a gliding position at an altitude of 24 km, and will take 25 minutes to glide back to the spaceport. SpaceShipTwo and White Knight Two are, respectively, roughly twice the size of the first-generation SpaceShipOne and mother ship White Knight, SpaceShipTwo has 43 and 33 cm -diameter windows for the passengers viewing pleasure, and all seats will recline back during landing to decrease the discomfort of G-forces. Reportedly, the craft can land safely even if a failure occurs during flight
6.
National Air and Space Museum
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The National Air and Space Museum of the Smithsonian Institution, also called the NASM, is a museum in Washington, D. C. It holds the largest collection of aircraft and spacecraft in the world. It was established in 1946 as the National Air Museum and opened its building on the National Mall near LEnfant Plaza in 1976. In 2014, the museum saw approximately 6.7 million visitors, the museum contains the Apollo 11 module, the Friendship 7 capsule which was flown by John Glenn, the Bell X-1 which broke the sound barrier, and the Wright brothers plane near the entrance. The National Air and Space Museum is a center for research into the history and science of aviation and spaceflight, as well as science and terrestrial geology. Almost all space and aircraft on display are originals or the original backup craft and it operates an annex, the Steven F. Udvar-Hazy Center, at Dulles International Airport, which opened in 2003 and itself encompasses 760,000 square feet. The museum currently conducts restoration of its collection at the Paul E. St, the mass of the museum is similar to the National Gallery of Art across the National Mall, and uses the same pink Tennessee marble as the National Gallery. Built by Gilbane Building Company, the museum was completed in 1976, the west glass wall of the building is used for the installation of airplanes, functioning as a giant door. The Air and Space Museum was originally called the National Air Museum when formed on August 12,1946 by an act of Congress and signed into law by President Harry S. Truman. The String fellow steam engine intended for aircraft was added to the collection in 1889, some pieces were on display in the Arts and Industries Building, some were stored in the Aircraft Building, a large temporary metal shed in the Smithsonian Castles south yard. Larger missiles and rockets were displayed outdoors in what was known as Rocket Row, the shed housed a large Martin bomber, a LePere fighter-bomber, and an Aeromarine 39B floatplane. Still, much of the collection remained in storage due to a lack of display space, the current Garber Facility was ceded to the Smithsonian by the Maryland-National Capital Park and Planning Commission in 1952 after the curator Paul E. Garber spotted the wooded area from the air. Bulldozers from Fort Belvoir and prefabricated buildings from the United States Navy kept the initial costs low, the Steven F. Udvar-Hazy Center opened in 2003, funded by a private donation. The museum also holds the mirror for the Hubble which. The Smithsonian has also promised the International Cometary Explorer, which is currently in a solar orbit that occasionally brings it back to Earth. The Air and Space Museum announced a renovation of its main entrance hall. The renovation to the hall was funded by a $30 million donation from Boeing. The gift, which will be paid over seven years, is the largest corporate donation ever received by the Air, Boeing had previously given donations totaling $58 million
7.
Air launch
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Air launching is the practice of releasing a rocket, missile, parasite aircraft or other aircraft payload from a mother ship or launch aircraft. The payload craft or missile is often tucked under the wing of the mother ship. It may also be stored within a bay, beneath the main fuselage or even on the back of the carrier aircraft. One of the earliest uses of air launching used an airship as a carrier and these planes would connect to their mothership through a trapeze-like rig, mounted to the top of the upper wing, that attached to a hook dangling from the bottom of the dirigible above. Fighters could be launched and retrieved this way, giving the airship the speed and striking power of fixed-wing craft, while giving the fighters the range. With advances in technology, especially in range, the value of a dirigible mothership was reduced. The parasite fighter concept was revived several times, in an attempt to solve the problem of how to protect bombers from fighter attack. Air launch is used for rocket-powered craft, allowing them to conserve their fuel until lifted to altitude by a larger aircraft. The B-29, B-50, and B-52 have all served in the role for research programs such as the Bell X-1. In the 1960s the SR-71 aircraft was used to launch the Lockheed D-21/M-21 drone to speeds of up to Mach 3, however, this added a degree of difficulty due to the shock wave pattern around an aircraft at supersonic speeds. After three successful tests, the resulted in a collision with the carrier aircraft, in which both craft were destroyed and one crew member drowned. These aircraft were used throughout the Space Shuttle Program to transport the shuttles across long distances. The Pegasus launch vehicle became the first air-launched orbital rocket when it was launched on April 5,1990 by the private company Orbital Sciences Corp. from a NASA-owned B-52 Stratofortress and it has flown more than 40 times since, launched mostly from the companys own Lockheed L-1011. Building on its success, Orbital Sciences is developing the Pegasus II launcher that will drop from a launch aircraft called the Roc. Capacity to low-earth orbit is projected to be 13,500 pounds In the early 2000s, recently, the air launch method has gained popularity with commercial launch providers. The Ansari X-Prize $10 Million purse was won by a led by Burt Rutans Scaled Composites. AirLaunch LLC developed QuickReach small satellite launch system that validated the concept by dropping a test payload in-flight from the bay of an unmodified C-17 aircraft. Archived from the original on 24 July 2011
8.
Rocket-powered aircraft
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A rocket-powered aircraft or rocket plane is an aircraft that uses a rocket engine for propulsion, sometimes in addition to airbreathing jet engines. Rocket planes can achieve higher speeds than similarly sized jet aircraft. Unhindered by the need for oxygen from the atmosphere, they are suitable for very high-altitude flight and they are also capable of delivering much higher acceleration and shorter takeoffs. Rockets have been used simply to assist the main propulsion in the form of jet assisted take off also known as rocket assisted take off, not all rocket planes are of the conventional takeoff like normal aircraft. Some types have been air-launched from another plane, while other types have taken off vertically - nose in the air, rocket-powered flight was pioneered in Germany. The first aircraft to fly under rocket power was the Lippisch Ente, the Ente had previously been flown as a glider. The next year, in 1929, the Opel RAK.1 became the first purpose-built rocket plane to fly. The Heinkel He 176 was the world’s first aircraft to be propelled solely by a liquid-propellant rocket engine, the first rocket plane ever to be mass-produced was the Messerschmitt Me 163 interceptor in 1944, one of several German World War II attempts at rocket-powered aircraft. The Bachem Ba 349 Natter vertical takeoff manned rocket interceptor aircraft flew in prototype form, projects which never even reached the prototype stage include the Zeppelin Rammer, the Fliegende Panzerfaust and the Focke-Wulf Volksjäger. The Japanese also produced approximately 850 Yokosuka MXY7 Ohka rocket-powered suicide attack aircraft in World War II, a rocket assisted P-51D Mustang was developed by North American Aviation that could attain 515 mph. The engine ran on fumaric acid and aniline which was stored in two 75 gallon under wing drop tanks, the plane was tested in flight in April 1945. The rocket engine could run for about a minute, in 1946, the Soviet Mikoyan-Gurevich I-270 was built partly using technology developed by Sergei Korolev in 1943 and 1932. In 1947 the rocket-powered Bell X-1 was the first aircraft to break the speed of sound in level flight, the North American X-15 and X-15A2 designs were used for around a decade and eventually reached Mach 6.7 and over 100 km in altitude. In the 1950s the British developed mixed power designs to cover the gap that existed in then-current turbojet designs. The Saunders-Roe SR.53 was a design and was due to be developed into production when economics forced curtailment of most British aircraft programmes in the late 1950s. The advancement of the engine output, the advent of missiles. The development of Soviet rockets and satellites was the force behind the development of NASAs space program. Another similar program was ISINGLASS which was to be a rocket launched from a Boeing B-52 Stratofortress carrier, which was intended to achieve Mach 22
9.
Sub-orbital spaceflight
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For example, the path of an object launched from Earth that reaches 100 km above sea level, and then falls back to Earth, is considered a sub-orbital spaceflight. Some sub-orbital flights have been undertaken to test spacecraft and launch vehicles later intended for orbital spaceflight, other vehicles are specifically designed only for sub-orbital flight, examples include manned vehicles such as the X-15 and SpaceShipOne, and unmanned ones such as ICBMs and sounding rockets. Flights which attain sufficient velocity to go into low Earth orbit, examples of this include Yuri Gagarins Vostok 1, and flights of the Fractional Orbital Bombardment System. Usually a rocket is used, but experimental sub-orbital spaceflight has also achieved with a space gun. By one definition a sub-orbital spaceflight reaches a higher than 100 km above sea level. The US military and NASA award astronaut wings to those flying above 50 mi, during freefall the trajectory is part of an elliptic orbit as given by the orbit equation. The perigee distance is less than the radius of the Earth R including atmosphere, hence the ellipse intersects the Earth, the major axis is vertical, the semi-major axis a is more than R/2. The specific orbital energy ϵ is given by, ε = − μ2 a > − μ R where μ is the standard gravitational parameter, to minimize the required delta-v, the high-altitude part of the flight is made with the rockets off. The maximum speed in a flight is attained at the lowest altitude of this free-fall trajectory, if ones goal is simply to reach space, for example in competing for the Ansari X Prize, horizontal motion is not needed. In this case the lowest required delta-v, to reach 100 km altitude, is about 1.4 km/s, for sub-orbital spaceflights covering a horizontal distance the maximum speed and required delta-v are in between those of a vertical flight and a LEO. The maximum speed at the ends of the trajectory are now composed of a horizontal. The higher the horizontal distance covered, the greater both speeds will be, for the V-2 rocket, just reaching space but with a range of about 330 km, the maximum speed was 1.6 km/s. Scaled Composites SpaceShipTwo which is under development will have a similar free-fall orbit, for larger ranges, due to the elliptic orbit the maximum altitude can even be considerably more than for a LEO. It should be noted that any spaceflight that returns to the surface, including sub-orbital ones, the speed at the start of the reentry is basically the maximum speed of the flight. The aerodynamic heating caused will vary accordingly, it is less for a flight with a maximum speed of only 1 km/s than for one with a maximum speed of 7 or 8 km/s. Let θ be half the angle that the projectile is to go around the earth, the minimum-delta-v trajectory corresponds to an ellipse with one focus at the centre of the earth and the other at the point halfway between the launch point and the destination point. Longer ranges will have lower apogees in the minimal-delta-v solution and we see that the Δv increases with range, leveling off at 7.9 km/s as the range approaches 20000 km. The minimum-delta-v trajectory for going halfway around the world corresponds to a circular orbit just above the surface, see lower for the time of flight
10.
Hybrid-propellant rocket
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A hybrid-propellant rocket is a rocket with a rocket motor which uses rocket propellants in two different phases. - one solid and the other either gas or liquid, the hybrid rocket concept can be traced back at least 75 years. Hybrid rockets avoid some of the disadvantages of solid rockets like the dangers of propellant handling, because it is difficult for the fuel and oxidizer to be mixed intimately, hybrid rockets tend to fail more benignly than liquids or solids. Like liquid rocket engines, hybrid rocket motors can be shut down easily, the theoretical specific impulse performance of hybrids is generally higher than solid motors and lower than liquid engines. I s p as high as 400s has been measured in a rocket using metalized fuels. Hybrid systems are more complex than solid ones, but they avoid significant hazards of manufacturing, shipping and handling solid rocket motors by storing the oxidizer, the first work on hybrid rockets was performed in the late 1930s at I. G. Farben in Germany and concurrently at the California Rocket Society in the United States, leonid Andrussow, working in Germany, first thought of the idea for a hybrid propellant rocket. O. Lutz, W. Noeggerath, and Andrussow tested a 10 kilonewtons hybrid rocket using a coal. Oberth also worked on a rocket motor using LOX as the oxidizer. The high heat of sublimation of carbon prevented these rocket motors from operating efficiently, in the 1940s, the California Pacific Rocket Society used LOX in combination with several different fuel types, including wood, wax, and rubber. The most successful of these tests was with the rubber fuel, in June 1951, a LOX/rubber rocket was flown to an altitude of 9 kilometres. Two major efforts occurred in the 1950s, One of these efforts was by G. Moore and K. Berman at General Electric. The duo used 90% H2O2 and polyethylene in a rod and tube grain design and they drew several significant conclusions from their work. The fuel grain had uniform burning, grain cracks did not affect combustion, like it does with solid rocket motors. The fuel surface acted as a holder, which encouraged stable combustion. The oxidizer could be throttled with one valve, and an oxidizer to fuel ratio helped simplify combustion. The negative observations were low burning rates and that the instability of peroxide was problematic for safety reasons. Another effort that occurred in the 1950s was development of a reverse hybrid, in a standard hybrid rocket motor, the solid material is the fuel
11.
Atmospheric entry
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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. Technologies and procedures allowing the atmospheric entry, descent and landing of spacecraft are collectively abbreviated as EDL. Atmospheric drag and aerodynamic heating can cause atmospheric breakup capable of completely disintegrating smaller objects and these forces may cause objects with lower compressive strength to explode. Manned space vehicles must be slowed to subsonic speeds before parachutes or air brakes may be deployed, such vehicles have kinetic energies typically between 50 and 1800 MJoules, and atmospheric dissipation is the only way of expending the kinetic energy. While the high temperature generated at the surface of the shield is due to adiabatic compression. Other smaller energy losses include black body radiation directly from the hot gasses, ballistic warheads and expendable vehicles do not require slowing at re-entry, and in fact, are made streamlined so as to maintain their speed. Uncontrolled, objects accelerate through the atmosphere at extreme velocities under the influence of Earths gravity, most controlled objects enter at hypersonic speeds due to their suborbital, orbital, or unbounded trajectories. Various advanced technologies have developed to enable atmospheric reentry and flight at extreme velocities. Practical development of systems began as the range and reentry velocity of ballistic missiles increased. For early short-range missiles, like the V-2, stabilization and aerodynamic stress were important issues, medium-range missiles like the Soviet R-5, with a 1200 km range, required ceramic composite heat shielding on separable reentry vehicles. The first ICBMs, with ranges of 8000 to 12,000 km, were possible with the development of modern ablative heat shields. In the U. S. this technology was pioneered by H. Julian Allen at Ames Research Center, over the decades since the 1950s, a rich technical jargon has grown around the engineering of vehicles designed to enter planetary atmospheres. It is recommended that the review the jargon glossary before continuing with this article on atmospheric reentry. When atmospheric entry is part of a landing or recovery, particularly on a planetary body other than Earth, entry is part of a phase referred to as entry, descent and landing. When the atmospheric entry returns to the body that the vehicle had launched from. These four shadowgraph images represent early reentry-vehicle concepts, if the reentry vehicle is made blunt, air cannot get out of the way quickly enough, and acts as an air cushion to push the shock wave and heated shock layer forward. Since most of the hot gases are no longer in contact with the vehicle. The Allen and Eggers discovery, though initially treated as a secret, was eventually published in 1958
12.
Twin tail
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A twin tail is a specific type of vertical stabilizer arrangement found on the empennage of some aircraft. Two vertical stabilizers—often smaller on their own than a conventional tail would be—are mounted at the outside of the aircrafts horizontal stabilizer. Separating the control surfaces allows for additional rudder area or vertical surface without requiring a single tail. On multi-engine propeller designs twin fin and rudders operating in the propeller slipstream give greater rudder authority and improved control at low airspeeds, a twin tail can also simplify hangar requirements, give dorsal gunners enhanced firing area, and in some cases reduce the aircrafts weight. It also affords a degree of one tail is damaged. Many canard aircraft designs incorporate twin tails on the tips of the main wing, very occasionally, three or more tails are used, as on the Breguet Deux-Ponts, Lockheed Constellation and Boeing 314 Clipper. A very unusual design can be seen on the E-2 Hawkeye and this arrangement was chosen for the stringent size limitations of carrier-based aircraft. Significant aircraft with twin tails include the Consolidated B-24 Liberator, Handley-Page Halifax, Avro Lancaster, the arrangement is not limited to World War II-vintage aircraft, however. Airbus has filed a patent for a new, twin-tail, trijet design, cruciform tail Pelikan tail T-tail V-tail
13.
Drag (physics)
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In fluid dynamics, drag is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two layers or a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are independent of velocity. Drag force is proportional to the velocity for a laminar flow, even though the ultimate cause of a drag is viscous friction, the turbulent drag is independent of viscosity. Drag forces always decrease fluid velocity relative to the object in the fluids path. In the case of viscous drag of fluid in a pipe, in physics of sports, the drag force is necessary to explain the performance of runners, particularly of sprinters. Types of drag are generally divided into the categories, parasitic drag, consisting of form drag, skin friction, interference drag, lift-induced drag. The phrase parasitic drag is used in aerodynamics, since for lifting wings drag it is in general small compared to lift. For flow around bluff bodies, form and interference drags often dominate, further, lift-induced drag is only relevant when wings or a lifting body are present, and is therefore usually discussed either in aviation or in the design of semi-planing or planing hulls. Wave drag occurs either when an object is moving through a fluid at or near the speed of sound or when a solid object is moving along a fluid boundary. Drag depends on the properties of the fluid and on the size, shape, at low R e, C D is asymptotically proportional to R e −1, which means that the drag is linearly proportional to the speed. At high R e, C D is more or less constant, the graph to the right shows how C D varies with R e for the case of a sphere. As mentioned, the equation with a constant drag coefficient gives the force experienced by an object moving through a fluid at relatively large velocity. This is also called quadratic drag, the equation is attributed to Lord Rayleigh, who originally used L2 in place of A. Sometimes a body is a composite of different parts, each with a different reference areas, in the case of a wing the reference areas are the same and the drag force is in the same ratio to the lift force as the ratio of drag coefficient to lift coefficient. Therefore, the reference for a wing is often the area rather than the frontal area. For an object with a surface, and non-fixed separation points—like a sphere or circular cylinder—the drag coefficient may vary with Reynolds number Re. For an object with well-defined fixed separation points, like a disk with its plane normal to the flow direction
14.
Human spaceflight
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Human spaceflight is space travel with a crew or passengers aboard the spacecraft. The first human spaceflight was launched by the Soviet Union on 12 April 1961 as a part of the Vostok program, humans have been continuously present in space for 16 years and 153 days on the International Space Station. All early human spaceflight was crewed, where at least some of the passengers acted to carry out tasks of piloting or operating the spacecraft, after 2015, several human-capable spacecraft are being explicitly designed with the ability to operate autonomously. Since the retirement of the US Space Shuttle in 2011, only Russia and China have maintained human spaceflight capability with the Soyuz program, currently, all expeditions to the International Space Station use Soyuz vehicles, which remain attached to the station to allow quick return if needed. The United States is developing commercial crew transportation to facilitate access to ISS and low Earth orbit. While spaceflight has typically been an activity, commercial spaceflight has gradually been taking on a greater role. NASA has also played a role to stimulate private spaceflight through programs such as Commercial Orbital Transportation Services, the vehicles used for these services could then serve both NASA and potential commercial customers. Commercial resupply of ISS began two years after the retirement of the Shuttle, and commercial crew launches could begin by 2017 and these rockets were large enough to be adapted to carry the first artificial satellites into low Earth orbit. The USSR launched the first human in space, Yuri Gagarin into an orbit in Vostok 1 on a Vostok 3KA rocket. The US launched its first astronaut, Alan Shepard on a flight aboard Freedom 7 on a Mercury-Redstone rocket. Unlike Gagarin, Shepard manually controlled his spacecrafts attitude, and landed inside it, the first American in orbit was John Glenn aboard Friendship 7, launched 20 February 1962 on a Mercury-Atlas rocket. The USSR launched five more cosmonauts in Vostok capsules, including the first woman in space, the US launched a total of two astronauts in suborbital flight and four in orbit through 1963. US President John F. Kennedy raised the stakes of the Space Race by setting the goal of landing a man on the Moon, Geminis objective was to support Apollo by developing American orbital spaceflight experience and techniques to be used in the Moon mission. They were able to launch two orbital flights in 1964 and 1965 and achieved the first spacewalk, made by Alexei Leonov on Voskhod 2 on 8 March 1965, but Voskhod did not have Geminis capability to maneuver in orbit, and the program was terminated. In July 1969, Apollo 11 accomplished Kennedys goal by landing Neil Armstrong and Buzz Aldrin on the Moon 21 July, a total of six Apollo missions landed 12 men to walk on the Moon through 1972, half of which drove electric powered vehicles on the surface. The crew of Apollo 13, Lovell, Jack Swigert, and Fred Haise, survived a catastrophic in-flight spacecraft failure, meanwhile, the USSR secretly pursued human lunar orbiting and landing programs. On losing the Moon race, they concentrated on the development of stations, using the Soyuz as a ferry to take cosmonauts to. They started with a series of Salyut sortie stations from 1971 to 1986, after the Apollo program, the US launched the Skylab sortie space station in 1973, manning it for 171 days with three crews aboard Apollo spacecraft
15.
Private spaceflight
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Private spaceflight is flight beyond the Kármán line —or the development of new spaceflight technology—that is conducted and paid for by an entity other than a government agency. The European Space Agency was formed in 1975, largely following the model of space technology development. Later on, large defense contractors began to develop and operate space launch systems, Private spaceflight in Earth orbit includes communications satellites, satellite television, satellite radio, astronaut transport and sub-orbital and orbital space tourism. In the 2000s, entrepreneurs began designing and—by the 2010s, deploying—competitive space systems to the national-monopoly governmental systems of the decades of the space age. These new offerings have brought about significant market competition in space launch services after 2010 that had not been present previously, planned private spaceflights beyond Earth orbit include personal spaceflights around the Moon. Two private orbital habitat prototypes are already in Earth orbit, with versions to follow. Planned private spaceflights beyond Earth orbit include solar sailing prototypes, Spaceflight was thus the monopoly province of a small group of national governments. Both the U. S. civilian space program and Soviet space program were operated using mainly military pilots as astronauts, during this period, no commercial space launches were available to private operators, and no private organization was able to offer space launches. Eventually, private organizations were able to offer and purchase space launches, thus beginning the period of private spaceflight. The first phase of private operation was the launch of the first commercial communications satellites. Communications Satellite Act of 1962 opened the way to commercial consortia owning and operating their own satellites, last ones counts the manned programs also - most famous and important of them are suborbital flights of Virgin Galactic and orbital flights of SpaceX and other COTS participants. Development of alternatives to government-provided space launch services began in earnest in the 2000s, lower prices for launch services after 2010, and published prices for standard launch services, have brought about significant space launch market competition that had not been present previously. In June 2013, British newspaper The Independent claimed that the race is flaring back into life. On 26 March 1980, the European Space Agency created Arianespace, Arianespace produces, operates and markets the Ariane launcher family. By 1995 Arianespace lofted its 100th satellite and by 1997 the Ariane rocket had its 100th launch, arianespaces 23 shareholders represent scientific, technical, financial and political entities from 10 different European countries. OTRAG, a German company founded in 1975, which proposed a radically different, under political pressure, the project was discontinued in the 1980s. Zero2infinity, a Spanish aerospace company, is developing a high-altitude balloon-based launch vehicle termed a bloostar to launch small satellites to orbit for customers, yet one of NASAs early actions was to effectively ban private space flight through a mountain of red tape. From the beginning, though, this met significant opposition not only by the private sector, in 1962, Congress passed its first law pushing back the prohibition on private involvement in space, the Communications Satellite Act of 1962
16.
Ansari X Prize
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It was modeled after early 20th-century aviation prizes, and aimed to spur development of low-cost spaceflight. $10 million was awarded to the winner, and more than $100 million was invested in new technologies in pursuit of the prize, several other X Prizes have since been announced by the X Prize Foundation, promoting further development in space exploration and other technological fields. In reading the book, The Spirit of St. Louis during 1994, Peter Diamandis realized that such a prize, as a space prize, might be just what was needed to bring space travel to the general public, to jump-start a commercial space industry. Diamandis developed a fully formed idea for a suborbital space barnstorming prize, the X Prize was first publicly proposed by Diamandis in an address to the NSS International Space Development Conference in 1995. The competition goal was adopted from the SpaceCub project, demonstration of a vehicle capable of flying a pilot to the edge of space. This goal was selected to help encourage the industry in the private sector. It aimed to demonstrate that spaceflight can be affordable and accessible to corporations and civilians, opening the door to commercial spaceflight, NASA is developing a similar prize program called Centennial Challenges to generate innovative solutions to space technology problems. — website Len Cormiers PanAero, Inc, some sources mention two other companies, AeroAstro* Cerulean Freight Forwarding Co. but do not mention Whalen Aeronautics Inc. The Tier One project made two competitive flights, X1 on September 29,2004, piloted by Mike Melvill to 102.9 km. They thus won the prize, which was awarded on November 6,2004, as of 2011, the trophy is on display in the Saint Louis Science Center in St. Louis, Missouri. It was the first flight of a monopropellant rocket. They have not announced a revised timetable, on August 8,2004, Space Transport Corporations Rubicon 1 and Armadillo Aerospaces unnamed test vehicle, in two separate unmanned test launches, both crashed and were destroyed. On February 15,2005, AERA Corporation announced its plans to send seven paying passengers into space as early as 2006, anousheh Ansari and Amir Ansari, the official sponsors of the competition. First USA, US$1,000,000 New Spirit of St. Louis Organization Danforth Foundation, US$500,000 Tom Clancy, mcDonnell Andrew Taylor Andrew Beal St. The Foundation has developed into a non-profit prize institute that conceives, designs, the funding for the US$10,000,000 prize was unconventional in being backed by an insurance policy to guarantee that the $10 million is in place on the day that the prize is won. Diamandis referred to this as an insurance policy. The success of the X Prize competition has spurred spin-offs that are set up in the same way, an independent spin-off called the N-Prize was started by Cambridge Microbiologist Paul H. Dear in 2007, designed to research into low-cost orbital launchers
17.
Mother ship
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A mother ship, mothership or mother-ship is a large vehicle that leads, serves, or carries other smaller vehicles. A mother ship may be a ship, aircraft, or spacecraft. Examples include bombers converted to experimental aircraft to altitudes where they can conduct their research. A mother ship may also be used to smaller craft. A smaller vessel serving or caring for larger craft is called a tender. The term mother ship dates back to the 19th-century whaling trade when small, fast ships were used to chase, the dead meat from several boats was then brought back to the larger, slower ship for processing and storage until the return to land. This model enabled a far more efficient method of whaling, though whaling is much lower-scale than in earlier days, the single large storage ship model is still used extensively by fishermen. Such ships are known today as factory ships, in many languages, such as Chinese, Finnish and Japanese, the word mother ship refers to an aircraft carrier, see 母艦. During World War II, the German Type XIV submarine or Milchkuh was a type of large submarine used to resupply the U-boats, mother ships can carry small submersibles and submarines to an area of ocean to be explored. Somalian pirates use mother ships to extend the reach of their attacking speed boats into the Indian Ocean, in aviation, motherships have been used in the airborne aircraft carrier, air launch and captive carry roles. Some large long-range aircraft act as motherships to parasite aircraft, a mothership may also form the larger component of a composite aircraft. During the age of the airships, the United States built two rigid airships, USS Akron and USS Macon, with onboard hangars able to house a number of Curtiss F9C Sparrowhawk biplane fighters. These airborne aircraft carriers operated successfully for several years and these airships utilized an internal hangar bay using a trapeze to hold the aircraft. In the air launch role, a carrier aircraft or mother ship carries a smaller payload aircraft to a launch point. During World War II the Japanese Mitsubishi G4M bomber was used to carry the rocket-powered Yokosuka MXY7 Ohka aircraft, used for kamikaze attacks, germany also planned a jet-carrying bomber, called the Daimler-Benz Project C. In the USA, NASA has used converted bombers as launch platforms for experimental aircraft, notable among these was the use during the 1960s of a modified Boeing B-52 Stratofortress for the repeated launching of the North American X-15. In a captive carry arrangement the payload craft, such as a rocket, missile, aeroplane or spaceplane, does not separate from the carrier aircraft. Notable examples include, A pair of modified Boeing 747s known as the Shuttle Carrier Aircraft, were used by NASA to transport the Space Shuttle orbiter, the Soviet Union developed and used the Antonov An-225 Mriya to ferry the Buran spacecraft
18.
Scaled Composites White Knight
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The Scaled Composites Model 318 White Knight is a jet-powered carrier aircraft used to launch the Scaled Composites SpaceShipOne experimental spacecraft. It was developed by Scaled Composites as part of its Tier One program, the aircraft was subsequently offered by Scaled on a contract basis as a research testbed, and was used for drop tests of the Boeing X-37 spaceplane from June 2005 until April 2006. It is also the predecessor to White Knight Two, the Scaled Composites model number for White Knight is 318. White Knight is registered with the Federal Aviation Administration as N318SL, the White Knight carrier airplane was designed around the twin afterburning J-85 engines, which were selected for their availability and low cost. The aircraft was a new independent design. White Knight first flew on August 1,2002, the flight was aborted shortly after takeoff due to a problem with the outboard wing spoilers. These trailing edge spoilers were designed to increase the glide slope so that the White Knight vehicle could act as a flying simulator for training of SpaceShipOne pilots. During the first flight, the mechanical over-center torque was insufficient to maintain the spoilers in the closed position, the spoilers deployed into the free stream and began a limit cycle forcing the pilot to abort. The spoilers were subsequently disabled completely and the desire for a glide slope matching SpaceShipOne was abandoned. White Knight next flew on August 5,2002, and this time performed well, development proceeded over the next few months. With White Knight developed and evaluated, on April 18,2003, White Knight, subsequently, White Knight flew as part of the Tier One program that won the Ansari X Prize on October 4,2004. Afterwards, White Knight was used to carry and launch DARPAs experimental X-37 spaceplane for its approach and it was followed up by the White Knight Two, which has a similar but larger design. Flights of White Knight are numbered, starting with flight 1 on August 1,2002, flights where SpaceShipOne was carried also get one or two appended letters. An appended C indicates that the flight was a captive carry, if the flight actually flown differs in category from the intended flight, then two letters are appended, the first giving the intended mission and the second the mission actually performed. White Knight was contracted to perform both captive carry and drop test flights of the DARPA/Boeing X-37, first captive carry flight was on June 21,2005, and first drop was on April 7,2006. In late 2006, White Knight flew a seven-flight test program of the Adaptive Compliant Wing developed by FlexSys Inc with funding by the Air Force Research Laboratory. A laminar flow test article was mounted vertically under White Knights centerline pylon for the 20-flight-hour research program that tested the flexible wings aerodynamic characteristics. In July 2014 White Knight made its final planned flight, arriving at Paine Field in Everett, Washington, to become part of the Flying Heritage Collection
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Paul Allen
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Paul Gardner Allen is an American business magnate, investor and philanthropist. He is best known as the co-founder of Microsoft, alongside Bill Gates, as of August 2016, he was estimated to be the 40th richest person in the world, with an estimated net worth of $18.6 billion. Allen is the founder and Chairman of Vulcan Inc. which manages his various business, Allen also has a multibillion-dollar investment portfolio including technology and media companies, real estate holdings, and stakes in other companies. He owns two sports teams, the Seattle Seahawks of the National Football League and the Portland Trail Blazers of the National Basketball Association. He is also part-owner of the Seattle Sounders FC, which joined Major League Soccer in 2009 and he is also the founder of Allen Institute for Brain Science, Institute for Artificial Intelligence, Institute for Cell Science, and Vulcan Aerospace. Paul Allen was born on January 21,1953 in Seattle, Washington to Kenneth Sam Allen, Allen attended Lakeside School, a private school in Seattle, where he befriended Bill Gates, three years younger, with whom he shared an enthusiasm for computers. They used Lakesides Teletype terminal to develop their skills on several time-sharing computer systems. Allen later convinced Gates to drop out of Harvard University in order to create Microsoft, Gates explained his official status with Harvard that. if things hadnt worked out, I could always go back to school. In Albuquerque, New Mexico, Paul Allen with his friend Bill Gates, in 1975, Allen came up with the original name of Micro-Soft, as recounted in a 1995 Fortune magazine article. As a result of this transaction, Microsoft was able to secure a contract to supply the DOS that would run on IBMs PC line. This contract with IBM was the watershed in Microsoft history that led to Allens and Gates wealth, Allen effectively left Microsoft in 1982 due to serious illness. Vulcan Capital is an investment-arm of Allens Seattle-based Vulcan Inc. which manages his personal fortune, in 2013, Allen opened a new Vulcan Capital office in Palo Alto, California to focus on making new investments in emerging technology and internet companies. Recent investments include Redfin, Decide. com and Audience Inc, patents, Paul Allen holds 43 patents from the United States Patent and Trademark Office. The startup behind the mobile app Saga, SportStream, an app for sports fans. Ticketmaster, In 1993, Paul Allen invested $243 million to acquire 80% of Ticketmaster, in 1997, Home Shopping Network acquired 47. 5% of Allens stock in exchange for $209 million worth of their own stock. Allen confirmed that he was the investor behind Burt Rutans Scaled Composites SpaceShipOne suborbital commercial spacecraft on October 4,2004. SpaceShipOne climbed to an altitude of 377,591 feet and was the first privately funded effort to put a civilian in suborbital space. It won the Ansari X Prize competition and received the $10 million prize, on December 13,2011, Allen announced the creation of Stratolaunch Systems
20.
Wright brothers
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They made the first controlled, sustained flight of a powered, heavier-than-air aircraft on December 17,1903, four miles south of Kitty Hawk, North Carolina. In 1904–05 the brothers developed their flying machine into the first practical fixed-wing aircraft, although not the first to build and fly experimental aircraft, the Wright brothers were the first to invent aircraft controls that made fixed-wing powered flight possible. The brothers fundamental breakthrough was their invention of three-axis control, which enabled the pilot to steer the aircraft effectively and this method became and remains standard on fixed-wing aircraft of all kinds. From the beginning of their work, the Wright brothers focused on developing a reliable method of pilot control as the key to solving the flying problem. This approach differed significantly from other experimenters of the time who put emphasis on developing powerful engines. Using a small wind tunnel, the Wrights also collected more accurate data than any before, enabling them to design and build wings. Their first U. S. patent,821,393, did not claim invention of a machine, but rather. They gained the skills essential for their success by working for years in their shop with printing presses, bicycles, motors. Their work with bicycles in particular influenced their belief that a vehicle like a flying machine could be controlled and balanced with practice. From 1900 until their first powered flights in late 1903, they conducted extensive tests that also developed their skills as pilots. Their bicycle shop employee Charlie Taylor became an important part of the team, the Wright brothers status as inventors of the airplane has been subject to counter-claims by various parties. Much controversy persists over the competing claims of early aviators. The Wright brothers were two of seven born to Milton Wright, of English and Dutch ancestry, and Susan Catherine Koerner, of German. Wilbur was born near Millville, Indiana, in 1867, Orville in Dayton, Ohio, the other Wright siblings were Reuchlin, Lorin, Katharine, and twins Otis and Ida. In elementary school, Orville was given to mischief and was once expelled, the direct paternal ancestry goes back to a Samuel Wright who sailed to America and settled in Massachusetts in 1636. In 1878 their father, who traveled often as a bishop in the Church of the United Brethren in Christ, the device was based on an invention of French aeronautical pioneer Alphonse Pénaud. Made of paper, bamboo and cork with a band to twirl its rotor. Wilbur and Orville played with it until it broke, and then built their own, in later years, they pointed to their experience with the toy as the spark of their interest in flying
21.
SpaceShipOne flight 15P
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Flight 15P of SpaceShipOne was the first privately funded human spaceflight. It took place on June 21,2004 and it was the fourth powered test flight of the Tier One program, the previous three test flights having reached much lower altitudes. The flight carried only its pilot, Mike Melvill, who became the first non-governmental astronaut. This flight was a full-altitude test, but not itself a competitive flight for the Ansari X Prize, problems were encountered during the flight, but later corrected, paving the way for SpaceShipOne to make competitive flights later in 2004. All times are in PDT, which is seven hours behind UTC and this was the local civil time at the spaceport on the day of the flight. All measurements are first stated in the U. S. customary units in which they were originally reported, taxiing for takeoff from Mojave Spaceport was originally planned for 06,30, because the wind conditions in that area are most favorable in the early morning. Taxiing actually started at 06,37, and the flight took off at 06,47, after an ascent to 47,000 feet coupled with the White Knight airplane, the SpaceShipOne craft separated at 07,50 and immediately ignited its rocket. Shortly after ignition, at about 60,000 feet, the craft unexpectedly rolled 90 degrees to the left, when the pilot attempted to correct it, it rolled 90 degrees to the right. The pilot levelled the craft out, and proceeded with the climb, the correction of the roll excursion, using full trim, caused a pitch trim tab to run up against a stop. This caused the trim actuator, as designed, to stop operating for a 3 s timeout, not realising what had happened, the pilot and controllers interpreted this as failure of the trim actuator, and they switched to a backup system. Spacecraft attitude was problematic during the climb, and not corrected until the start of re-entry. During the burn, a new aerodynamic fairing installed around the rocket nozzle overheated, became too soft and this caused a loud bang, which the pilot reported, but did not cause a flight problem. The rocket burn lasted for 76 seconds, at burn-out the altitude was 180,000 feet, the Mach number was 2.9, and the speed was 2150 mph. The planned apogee altitude was 360,000 feet, but due to the problem encountered during the climb the craft actually attained only 328,491 feet. In doing so it passed the boundary to space at 100 km, making the flight, as planned and it can be calculated that the altitude exceeded 100 km for approximately 10.23 s. Around apogee the craft experienced about 3 1⁄2 minutes of weightlessness, pilot Mike Melvill opened a bag of M&Ms and watched them float around the capsule in free fall. The craft re-entered the atmosphere 22 miles south of its planned 5 by 5 mile re-entry zone, the pilot finally corrected the spacecraft attitude at this point, using a backup trim system. The craft reached Mach 2.9 and experienced deceleration of 5.0 g during descent, the craft switched to gliding configuration at an altitude of 57,000 feet, then returned to the spaceport and landed safely at 08,14
22.
Mike Melvill
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Michael Winston Mike Melvill is a world-record-breaking pilot and one of the test pilots for SpaceShipOne, the experimental spaceplane developed by Scaled Composites. Melvill piloted SpaceShipOne on its first flight past the edge of space, flight 15P on June 21,2004, thus becoming the first commercial astronaut and he was also the pilot on SpaceShipOnes flight 16P, the first competitive flight in the Ansari X Prize competition. Mike Melvill grew up in Durban, South Africa and attended Hilton College, in 1978, he met aerospace designer and Scaled Composites founder Burt Rutan when he flew to California to show Rutan the VariViggen he had built at his home. Rutan then hired him on the spot, in 1982, he was named Rutans lead test pilot. In 1997, Melvill and Dick Rutan, Burts brother, flew two Long-Eze aircraft that they built side-by-side around the world and this around the world in 80 nights flight was called The Spirit of EAA Friendship World Tour, and some legs of it lasted for over 14 hours. Later in his career he became Vice President/General Manager at Scaled Composites, Melvill is the sole or joint holder of nine FAI aviation world records in various categories. He was awarded the Iven C, kincheloe Award in 1999 for high altitude, developmental flight-testing of the model 281 Proteus aircraft. Through SpaceShipOne flight 15P in 2004, he is known as the first privately funded human spaceflight mission pilot to reach space
23.
Mojave Air and Space Port
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The Mojave Air and Space Port, also known as the Civilian Aerospace Test Centre, is located in Mojave, California, at an elevation of 2,791 feet. It is the first facility to be licensed in the United States for horizontal launches of reusable spacecraft, in 1935, Kern County established the Mojave Airport a half mile east of town to serve the gold and silver mining industry in the area. The airport consisted of two runways, one of which was oiled, but it lacked any fueling or servicing facilities. In 1941, the Civil Aeronautics Board began improvements to the airport for defense purposes that included two 4,500 x 150-ft. Kern County agreed the airport could be taken over by the military in the event of war, following the Japanese attack on Pearl Harbor in December 1941, the United States Marine Corps took over the airport and expanded it into Marine Corps Auxiliary Air Station Mojave. The two existing runways were extended and a third one added, barracks were constructed to house 2,734 male and 376 female military personnel. Civilian employment at the base would peak at 176, the Marines would eventually spend more than $7 million on the base, which totaled 2,312 acres. Many of the Corps World War II aces received their training at Mojave. During World War II, Mojave hosted 29 aircraft squadrons, four Carrier Aircraft Service Detachments, at its peak, the air station had 145 training and other aircraft. Mojave also had a 75 x 156 foot swimming pool that was used to train aviators in emergency water egress, the bases 900-seat auditorium hosted several USO shows that featured Bob Hope, Frances Langford and Marilyn Maxwell. With the end of World War II, MCAAS was disestablished on February 7,1946, the Navy used the airport for drone operations for less than a year, closing it on January 1,1947. The base remained closed for four years until the outbreak of the Korean War, Mojave was reactivated as an auxiliary landing field to MCAS El Toro. The airport was recommissioned as a MCAAS on December 31,1953, Squadrons used Mojave for ordnance training when El Toro had bad weather. Marine Corps reserve units were deployed to Mojave for two-week periods. MCAAS Mojave personnel peaked at 400 military and 200 civilians during this period, in 1961, after the Marine Corps transferred operations to MCAS El Centro, Kern County obtained title to the airport. In February 1972, the East Kern Airport District was formed to administer the airport, to a great extent EKAD was the brainchild of Kern County rancher and aviator Dan Sabovich, who heavily lobbied the state for the airport districts creation and ran EKAD until 2002. During the 1970s, commuter air carrier Golden West Airlines provided scheduled service operated with de Havilland Canada DHC-6 Twin Otter turboprops direct to Los Angeles. On November 20,2012, the EKAD Board of Directors voted to change the name of the district to the Mojave Air, officials said that the spaceport name is well known around the world, but EKAD is not
24.
Commercial astronaut
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A commercial astronaut is a person trained to command, pilot, or serve as a crew member of a privately funded spacecraft. This is distinct from an otherwise non-government astronaut who flies while representing a non-government corporation, the criteria for determining who has achieved human spaceflight vary. The FAI defines spaceflight as any flight over 100 kilometers of altitude, in the United States, professional, military, and commercial astronauts who travel above an altitude of 80 kilometers are eligible to be awarded astronaut wings. Until 2003, professional space travelers were sponsored and trained exclusively by governments, however, with the first sub-orbital flight of the privately funded Scaled Composites Tier One in 2004, the commercial astronaut category was created. With the advent of commercial space flight ventures in the U. S. the FAA has been faced with the task of developing a certification process for the pilots of commercial spacecraft. The Commercial Space Launch Amendments Act has led to the issuance of draft guidelines by the FAA in February 2005 for the administration of vehicle, two Commercial Astronaut awards have been made. They are SpaceShipOne pilots Mike Melvill and Brian Binnie, Astronaut Astronauts for Hire List of private spaceflight companies NewSpace Pilot certification in the United States Private spaceflight Space Adventures Space colonization Space tourism
25.
Scaled Composites Tier One
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Tier One was a Scaled Composites 1990s–2004 program of suborbital human spaceflight using the reusable spacecraft SpaceShipOne and its launcher White Knight. The craft was designed by Burt Rutan, and the project was funded 20 million US Dollars by Paul Allen, in 2004 it made the first privately funded human spaceflight and won the 10 million US Dollars Ansari X Prize for the first non-governmental reusable manned spacecraft. The objective of the project was to develop technology for low-cost routine access to space, SpaceShipOne was not itself intended to carry paying passengers, but was envisioned that there would be commercial spinoffs, initially in space tourism. The company Mojave Aerospace Ventures was formed to manage exploitation of the technology. A deal with Virgin Galactic could see routine space tourism in the late 2010s using a spacecraft based on Tier One technology, in addition to an office-based mission control, Tier One has a mobile mission control center. This is relatively small, built into a large road-going truck and it bears the Scaled Composites logo, but no other overt indication of its link to Tier One. Its primary function is to monitor and record test data, and to end it is equipped with computers. SpaceShipOnes avionics displays are duplicated in mission control, telemetry data is received on a Data Reduction System, which automatically directs radio antennas to point at the craft being monitored. The telemetry system has a range of about 280 km, the control center is equipped to communicate with Scaled Composites offices, as well as the aircraft and spacecraft. The control center maintains an atmosphere for its staff, and can be hooked up to provide temperature control for the White Knight. The physical structure of control also provides easier access to the White Knight cabin. Unlike the solid fuel, the nitrous oxide oxidiser is handled as a bulk commodity, Tier One therefore has a mobile delivery system for nitrous oxide, which they call MONODS. MONODS is built on a trailer, which can be carried by road in conventional manner. It consists principally of a 6.5 m3 tank, a control unit. The nitrous oxide is stored at room temperature, at a pressure of 4.8 MPa, MONODS is refilled from a commercial supplier, which uses 50 m3 tankers and delivers the nitrous oxide at about −17 °C and 2 MPa. MONODS heats the nitrous oxide to room temperature, increasing its pressure, Tier One has a mobile thrust test stand, known as the Test Stand Trailer. The test stand replicates the essential components of the spacecraft. It has a tank and associated fittings identical to the one used in flight
26.
North American X-15
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The X-15 set speed and altitude records in the 1960s, reaching the edge of outer space and returning with valuable data used in aircraft and spacecraft design. During the X-15 program,13 flights by eight pilots met the Air Force spaceflight criterion by exceeding the altitude of 50 miles, thus qualifying these pilots as being astronauts. The Air Force pilots qualified for astronaut wings immediately, while the pilots were eventually awarded NASA astronaut wings in 2005,35 years after the last X-15 flight. The only Navy pilot in the X-15 program never took the aircraft above the requisite 50 mile altitude and so as a result, of the 199 X-15 missions, two flights qualified as true space flights per the international definition of a spaceflight by exceeding 100 kilometers in altitude. The X-15 was based on a study from Walter Dornberger for the National Advisory Committee for Aeronautics for a hypersonic research aircraft. The requests for proposal were published on 30 December 1954 for the airframe, the X-15 was built by two manufacturers, North American Aviation was contracted for the airframe in November 1955, and Reaction Motors was contracted for building the engines in 1956. Like many X-series aircraft, the X-15 was designed to be carried aloft, Air Force NB-52A, The High and Mighty One, and NB-52B, The Challenger served as carrier planes for all X-15 flights. Release took place at an altitude of about 8.5 miles, the X-15 fuselage was long and cylindrical, with rear fairings that flattened its appearance, and thick, dorsal and ventral wedge-fin stabilizers. Parts of the fuselage were heat-resistant nickel alloy, the retractable landing gear comprised a nose-wheel carriage and two rear skids. The skids did not extend beyond the fin, which required the pilot to jettison the lower fin just before landing. The X-15 was a program and changes were made to various systems over the course of the program. Alternatively, if the engine was not started the pilot went directly to a landing. The main rocket engine operated only for a short part of the flight. Without main engine thrust, the X-15s instruments and control surfaces remained functional, because the X-15 also had to be controlled in an environment where there was too little air for aerodynamic flight control surfaces, it had a reaction control system that used rocket thrusters. There were two different X-15 pilot control setups, one used three joysticks, the other, one joystick, the X-15 type with multiple control sticks for the pilot included a traditional rudder and stick, and another joystick on the left which sent commands to the reaction control system. A third joystick on the side was used during high-G maneuvers to augment the center stick. In addition to input, the X-15 Stability Augmentation System sent inputs to the aerodynamic controls to help the pilot maintain attitude control. The reaction control system could be operated in two modes, manual and automatic, the automatic mode used a feature called Reaction Augmentation System that helped stabilize the vehicle at high altitude
27.
Space Shuttle
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The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated by the U. S. National Aeronautics and Space Administration, as part of the Space Shuttle program. Its official program name was Space Transportation System, taken from a 1969 plan for a system of reusable spacecraft of which it was the only item funded for development, the first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982. Five complete Shuttle systems were built and used on a total of 135 missions from 1981 to 2011, the Shuttle fleets total mission time was 1322 days,19 hours,21 minutes and 23 seconds. Shuttle components included the Orbiter Vehicle, a pair of solid rocket boosters. The Shuttle was launched vertically, like a rocket, with the two SRBs operating in parallel with the OVs three main engines, which were fueled from the ET. The SRBs were jettisoned before the vehicle reached orbit, and the ET was jettisoned just before orbit insertion, at the conclusion of the mission, the orbiter fired its OMS to de-orbit and re-enter the atmosphere. The orbiter then glided as a spaceplane to a landing, usually at the Shuttle Landing Facility of KSC or Rogers Dry Lake in Edwards Air Force Base. After landing at Edwards, the orbiter was back to the KSC on the Shuttle Carrier Aircraft. The first orbiter, Enterprise, was built in 1976 for use in Approach, four fully operational orbiters were initially built, Columbia, Challenger, Discovery, and Atlantis. Of these, two were lost in accidents, Challenger in 1986 and Columbia in 2003, with a total of fourteen astronauts killed. A fifth operational orbiter, Endeavour, was built in 1991 to replace Challenger, the Space Shuttle was retired from service upon the conclusion of Atlantiss final flight on July 21,2011. Nixons post-Apollo NASA budgeting withdrew support of all components except the Shuttle. The vehicle consisted of a spaceplane for orbit and re-entry, fueled by liquid hydrogen and liquid oxygen tanks. The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982, all launched from the Kennedy Space Center, Florida. The system was retired from service in 2011 after 135 missions, the program ended after Atlantis landed at the Kennedy Space Center on July 21,2011. Major missions included launching numerous satellites and interplanetary probes, conducting space science experiments, the first orbiter vehicle, named Enterprise, was built for the initial Approach and Landing Tests phase and lacked engines, heat shielding, and other equipment necessary for orbital flight. A total of five operational orbiters were built, and of these and it was used for orbital space missions by NASA, the US Department of Defense, the European Space Agency, Japan, and Germany. The United States funded Shuttle development and operations except for the Spacelab modules used on D1, sL-J was partially funded by Japan
28.
Aircraft pilot
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A pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Other aircrew members such as attendants, mechanics and ground crew, are not classified as aviators. In recognition of the qualifications and responsibilities, most militaries and many airlines worldwide award aviator badges to their pilots. The first recorded use of the aviator was in 1887, as a variation of aviation, from the Latin avis. The term aviatrix, now archaic, was used for a female aviator. These terms were used more in the days of aviation, when airplanes were extremely rare. For example, a 1905 reference work described the Wright brothers first airplane, The weight, the Aéro-Club de France delivered the first certificate to Louis Blériot in 1908—followed by Glenn Curtiss, Léon Delagrange, and Robert Esnault-Pelterie. The absolute authority given to the pilot in command derives from that of a ships captain, when flying for an airline, pilots are usually referred to as airline pilots, with the pilot in command often referred to as the captain. While the flight decks of U. S. and European airliners do have ex-military pilots, military training and flying, while rigorous, is fundamentally different in many ways from civilian piloting. Pilots licensing in Canada is similar to the United States, the Aeronautics Act of 1985 and Canadian Aviation Regulations provide rules for pilots in Canada. Retirement age is provided by each airline with some set to age 60, in 1930, the Air Commerce Act established pilot licensing requirements for American civil aviation. Commercial airline pilots in the United States have a retirement age of 65. Military pilots fly with the forces of a government or nation-state. Their tasks involve combat and non-combat operations, including direct hostile engagements, military pilots undergo specialized training, often with weapons. Examples of military pilots include fighter pilots, bomber pilots, transport pilots, military pilots also serve as flight crews on aircraft for government personnel, such as Air Force One and Air Force Two in the United States. Military pilots are trained with a different syllabus than civilian pilots and this is due to the different aircraft, flight goals, flight situations and chains of responsibility. Many military pilots do transfer to civilian-pilot qualification after they leave the military, the person controlling a remotely piloted UAV may be referred to as its pilot or operator. Most jurisdictions have restrictions on the use of UAVs which have limited their use in controlled airspace, UAVs have mostly been limited to military
29.
Rocket
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A rocket is a missile, spacecraft, aircraft or other vehicle that obtains thrust from a rocket engine. Rocket engine exhaust is formed entirely from propellant carried within the rocket before use, Rocket engines work by action and reaction and push rockets forward simply by expelling their exhaust in the opposite direction at high speed, and can therefore work in the vacuum of space. In fact, rockets work more efficiently in space than in an atmosphere, multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Compared with airbreathing engines, rockets are lightweight and powerful and capable of generating large accelerations. To control their flight, rockets rely on momentum, airfoils, auxiliary engines, gimballed thrust, momentum wheels, deflection of the exhaust stream, propellant flow, spin. Rockets for military and recreational uses date back to at least 13th century China, significant scientific, interplanetary and industrial use did not occur until the 20th century, when rocketry was the enabling technology for the Space Age, including setting foot on the Earths moon. Rockets are now used for fireworks, weaponry, ejection seats, launch vehicles for satellites, human spaceflight. Chemical rockets are the most common type of high power rocket, chemical rockets store a large amount of energy in an easily released form, and can be very dangerous. However, careful design, testing, construction and use minimizes risks, the first gunpowder-powered rockets were developed in Song China, by the 13th century. The Chinese rocket technology was adopted by the Mongols and the invention was spread via the Mongol invasions to the Near East, medieval and early modern rockets were used militarily as incendiary weapons in sieges. An early Chinese text to mention the use of rockets was the Huolongjing, between 1270 and 1280, Hasan al-Rammah wrote al-furusiyyah wa al-manasib al-harbiyya, which included 107 gunpowder recipes,22 of which are for rockets. In Europe, Konrad Kyeser described rockets in his military treatise Bellifortis around 1405. The name Rocket comes from the Italian rocchetta, meaning bobbin or little spindle, the Italian term was adopted into German in the mid 16th century by Leonhard Fronsperger and Conrad Haas, and by the early 17th century into English. Artis Magnae Artilleriae pars prima, an important early work on rocket artillery. The first iron-cased rockets were developed in the late 18th century in the Kingdom of Mysore, in 1814, Francis Scott Key wrote the line rockets red glare while held captive on a British ship that was laying siege to Fort McHenry. The first mathematical treatment of the dynamics of rocket propulsion is due to William Moore, in 1815, Alexander Dmitrievich Zasyadko constructed rocket-launching platforms, which allowed rockets to be fired in salvos, and gun-laying devices. William Hale in 1844 greatly increased the accuracy of rocket artillery, the Congreve rocket was further improved by Edward Mounier Boxer in 1865. Konstantin Tsiolkovsky first speculated on the possibility of manned spaceflight with rocket technology, robert Goddard in 1920 published proposed improvements to rocket technology in A Method of Reaching Extreme Altitudes
30.
Aerodynamics
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Aerodynamics, from Greek ἀήρ aer + δυναμική, the study of the motion of air, particularly its interaction with a solid object, such as an airplane wing. Aerodynamics is a sub-field of fluid dynamics and gas dynamics, the term aerodynamics is often used synonymously with gas dynamics, the difference being that gas dynamics applies to the study of the motion of all gases, and is not limited to air. The formal study of aerodynamics began in the sense in the eighteenth century. Most of the efforts in aerodynamics were directed toward achieving heavier-than-air flight. Recent work in aerodynamics has focused on issues related to flow, turbulence. Fundamental concepts of continuum, drag, and pressure gradients appear in the work of Aristotle, in 1726, Sir Isaac Newton became the first person to develop a theory of air resistance, making him one of the first aerodynamicists. In 1757, Leonhard Euler published the more general Euler equations which could be applied to both compressible and incompressible flows, the Euler equations were extended to incorporate the effects of viscosity in the first half of the 1800s, resulting in the Navier-Stokes equations. The Navier-Stokes equations are the most general governing equations of fluid flow, in 1871, Francis Herbert Wenham constructed the first wind tunnel, allowing precise measurements of aerodynamic forces. Drag theories were developed by Jean le Rond dAlembert, Gustav Kirchhoff, in 1889, Charles Renard, a French aeronautical engineer, became the first person to reasonably predict the power needed for sustained flight. Otto Lilienthal, the first person to become successful with glider flights, was also the first to propose thin, curved airfoils that would produce high lift. Building on these developments as well as carried out in their own wind tunnel. During the time of the first flights, Frederick W. Lanchester, Martin Wilhelm Kutta, Kutta and Zhukovsky went on to develop a two-dimensional wing theory. Expanding upon the work of Lanchester, Ludwig Prandtl is credited with developing the mathematics behind thin-airfoil, as aircraft speed increased, designers began to encounter challenges associated with air compressibility at speeds near or greater than the speed of sound. The differences in air flows under such conditions leds to problems in control, increased drag due to shock waves. The ratio of the speed to the speed of sound was named the Mach number after Ernst Mach who was one of the first to investigate the properties of supersonic flow. Theodore von Kármán and Hugh Latimer Dryden introduced the term transonic to describe flow speeds around Mach 1 where drag increases rapidly, by the time the sound barrier was broken, aerodynamicists understanding of the subsonic and low supersonic flow had matured. The Cold War prompted the design of an line of high performance aircraft. Understanding the motion of air around an object enables the calculation of forces, in many aerodynamics problems, the forces of interest are the fundamental forces of flight, lift, drag, thrust, and weight
31.
Runway
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According to the International Civil Aviation Organization, a runway is a defined rectangular area on a land aerodrome prepared for the landing and takeoff of aircraft. Runways may be a surface or a natural surface. Runways are named by a number between 01 and 36, which is generally the magnetic azimuth of the heading in decadegrees. This heading differs from true north by the magnetic declination. A runway numbered 09 points east, runway 18 is south, runway 27 points west, when taking off from or landing on runway 09, a plane would be heading 90°. A runway can normally be used in both directions, and is named for each separately, e. g. runway 33 in one direction is runway 15 when used in the other. The two numbers usually differ by 18, Runway Zero Three Left becomes Runway Two One Right when used in the opposite direction. In some countries, if parallel runways are too close to each other, at large airports with four or more parallel runways some runway identifiers are shifted by 10 degrees to avoid the ambiguity that would result with more than three parallel runways. For example, in Los Angeles, this results in runways 6L, 6R, 7L. At Dallas/Fort Worth International Airport, there are five parallel runways, named 17L, 17C, 17R, 18L, for clarity in radio communications, each digit in the runway name is pronounced individually, runway three six, runway one four, etc. A leading zero, for example in runway zero six or runway zero one left, is included for all ICAO, however, most U. S. civil aviation airports drop the leading zero as required by FAA regulation. This also includes some military airfields such as Cairns Army Airfield and this American anomaly may lead to inconsistencies in conversations between American pilots and controllers in other countries. It is very common in a such as Canada for a controller to clear an incoming American aircraft to, for example, runway 04. In flight simulation programs those of American origin might apply U. S. usage to airports around the world, for example, runway 05 at Halifax will appear on the program as the single digit 5 rather than 05. Runway designations change over time because the magnetic poles slowly drift on the Earths surface, depending on the airport location and how much drift takes place, it may be necessary over time to change the runway designation. As runways are designated with headings rounded to the nearest 10 degrees, for example, if the magnetic heading of a runway is 233 degrees, it would be designated Runway 23. If the magnetic heading changed downwards by 5 degrees to 228, if on the other hand the original magnetic heading was 226, and the heading decreased by only 2 degrees to 224, the runway should become Runway 22. Because the drift itself is slow, runway designation changes are uncommon
32.
Graphite
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Graphite, archaically referred to as plumbago, is a crystalline form of carbon, a semimetal, a native element mineral, and one of the allotropes of carbon. Graphite is the most stable form of carbon under standard conditions, therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds. Highly ordered pyrolytic graphite or more correctly highly oriented pyrolytic graphite refers to graphite with a spread between the graphite sheets of less than 1°. The name graphite fiber is sometimes used to refer to carbon fibers or carbon fiber-reinforced polymer. Graphite occurs in rocks as a result of the reduction of sedimentary carbon compounds during metamorphism. It also occurs in rocks and in meteorites. Minerals associated with graphite include quartz, calcite, micas and tourmaline, in meteorites it occurs with troilite and silicate minerals. Small graphitic crystals in meteoritic iron are called cliftonite, Graphite is not mined in the United States, but U. S. production of synthetic graphite in 2010 was 134 kt valued at $1.07 billion. Graphite has a layered, planar structure, the individual layers are called graphene. In each layer, the atoms are arranged in a honeycomb lattice with separation of 0.142 nm. Atoms in the plane are bonded covalently, with three of the four potential bonding sites satisfied. The fourth electron is free to migrate in the plane, making graphite electrically conductive, however, it does not conduct in a direction at right angles to the plane. Bonding between layers is via weak van der Waals bonds, which allows layers of graphite to be easily separated, the two known forms of graphite, alpha and beta, have very similar physical properties, except for that the graphene layers stack slightly differently. The alpha graphite may be flat or buckled. The alpha form can be converted to the form through mechanical treatment. The acoustic and thermal properties of graphite are highly anisotropic, since phonons propagate quickly along the tightly-bound planes, graphites high thermal stability and electrical and thermal conductivity facilitate its widespread use as electrodes and refractories in high temperature material processing applications. However, in oxygen containing atmospheres graphite readily oxidizes to form CO2 at temperatures of 700 °C, Graphite is an electric conductor, consequently, useful in such applications as arc lamp electrodes. It can conduct electricity due to the vast electron delocalization within the carbon layers and these valence electrons are free to move, so are able to conduct electricity
33.
Epoxy
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Epoxy is either any of the basic components or the cured end products of epoxy resins, as well as a colloquial name for the epoxide functional group. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups, Epoxy resins may be reacted either with themselves through catalytic homopolymerisation, or with a wide range of co-reactants including polyfunctional amines, acids, phenols, alcohols and thiols. These co-reactants are often referred to as hardeners or curatives, reaction of polyepoxides with themselves or with polyfunctional hardeners forms a thermosetting polymer, often with high mechanical properties, temperature and chemical resistance. Epoxy resins are low molecular weight pre-polymers or higher molecular weight polymers which contain at least two epoxide groups. The epoxide group is sometimes referred to as a glycidyl or oxirane group. A wide range of epoxy resins are produced industrially, the raw materials for epoxy resin production are today largely petroleum derived, although some plant derived sources are now becoming commercially available. Epoxy resins are polymeric or semi-polymeric materials, and as such rarely exist as pure substances, high purity grades can be produced for certain applications, e. g. using a distillation purification process. One downside of high purity liquid grades is their tendency to form crystalline solids due to their highly regular structure, an important criterion for epoxy resins is the epoxide content. Epoxies are typically cured with stoichiometric or near-stoichiometric quantities of curative to achieve maximum physical properties, use of blending, additives and fillers is often referred to as formulating. Important epoxy resins are produced from combining epichlorohydrin and bisphenol A to give bisphenol A diglycidyl ethers, as the molecular weight of the resin increases, the epoxide content reduces and the material behaves more and more like a thermoplastic. Very high molecular weight polycondensates form a class known as phenoxy resins and these resins do however contain hydroxyl groups throughout the backbone, which may also undergo other cross-linking reactions, e. g. with aminoplasts, phenoplasts and isocyanates. Bisphenol F may also undergo epoxidation in a fashion to bisphenol A. Compared to DGEBA, bisphenol F epoxy resins have lower viscosity and a higher mean epoxy content per gramme, reaction of phenols with formaldehyde and subsequent glycidylation with epichlorohydrin produces epoxidised novolacs, such as epoxy phenol novolacs and epoxy cresol novolacs. These are highly viscous to solid resins with typical mean epoxide functionality of around 2 to 6, the high epoxide functionality of these resins forms a highly crosslinked polymer network displaying high temperature and chemical resistance, but low flexibility. Aliphatic epoxy resins are typically formed by glycidylation of aliphatic alcohols or polyols, the resulting resins may be monofunctional, difunctional, or higher functionality. These resins typically display low viscosity at room temperature and are referred to as reactive diluents. They are rarely used alone, but are employed to modify the viscosity of other epoxy resins. This has led to the term ‘modified epoxy resin’ to denote those containing viscosity-lowering reactive diluents, a related class is cycloaliphatic epoxy resin, which contains one or more cycloaliphatic rings in the molecule
34.
Composite material
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The individual components remain separate and distinct within the finished structure. The new material may be preferred for reasons, common examples include materials which are stronger, lighter. More recently, researchers have begun to actively include sensing, actuation, computation and communication into composites. The most advanced examples perform routinely on spacecraft and aircraft in demanding environments, the earliest man-made composite materials were straw and mud combined to form bricks for building construction. Ancient brick-making was documented by Egyptian tomb paintings, wattle and daub is one of the oldest man-made composite materials, at over 6000 years old. Concrete is also a material, and is used more than any other man-made material in the world. As of 2006, about 7.5 billion cubic metres of concrete are made each year—more than one metre for every person on Earth. 2181–2055 BC and was used for death masks Cob Mud Bricks, concrete was described by Vitruvius, writing around 25 BC in his Ten Books on Architecture, distinguished types of aggregate appropriate for the preparation of lime mortars. For structural mortars, he recommended pozzolana, which were volcanic sands from the beds of Pozzuoli brownish-yellow-gray in colour near Naples. Natural cement-stones, after burning, produced cements used in concretes from post-Roman times into the 20th century, the glass fiber is relatively strong and stiff, whereas the polymer is ductile. Thus the resulting fiberglass is relatively stiff, strong, flexible, concrete is the most common artificial composite material of all and typically consists of loose stones held with a matrix of cement. Concrete is a material, and will not compress or shatter even under quite a large compressive force. However, concrete cannot survive tensile loading, therefore, to give concrete the ability to resist being stretched, steel bars, which can resist high stretching forces, are often added to concrete to form reinforced concrete. Fibre-reinforced polymers or FRPs include carbon-fiber-reinforced polymer or CFRP, and glass-reinforced plastic or GRP, if classified by matrix then there are thermoplastic composites, short fiber thermoplastics, long fibre thermoplastics or long fibre-reinforced thermoplastics. There are numerous thermoset composites, including paper composite panels, many advanced thermoset polymer matrix systems usually incorporate aramid fibre and carbon fibre in an epoxy resin matrix. Shape memory polymer composites are high-performance composites, formulated using fibre or fabric reinforcement and they can also be reheated and reshaped repeatedly without losing their material properties. These composites are ideal for such as lightweight, rigid, deployable structures, rapid manufacturing. Although high strain composites exhibit many similarities to shape memory polymers, Composites can also use metal fibres reinforcing other metals, as in metal matrix composites or ceramic matrix composites, which includes bone, cermet and concrete
35.
Chord (aeronautics)
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In aeronautics, chord refers to the imaginary straight line joining the leading and trailing edges of an aerofoil. The chord length is the distance between the edge and the point on the leading edge where the chord intersects the leading edge. The point on the edge that is used to define the chord can be defined as either the surface point of minimum radius. The wing, horizontal stabilizer, vertical stabilizer and propeller of an aircraft are all based on sections. The chord of a wing, stabilizer and propeller is determined by measuring the distance between leading and trailing edges in the direction of the airflow, the term chord is also applied to the width of wing flaps, ailerons and rudder on an aircraft. The term is applied to aerofoils in gas turbine engines such as turbojet, turboprop. Most wings are not rectangular so they have a different chord at different positions along their span, to give a characteristic figure that can be compared among various wing shapes, the mean aerodynamic chord, or MAC, is used. The MAC is somewhat complex to calculate, because most wings vary in chord over the span. This means that lift is generated on the wider inner portions. Standard mean chord is defined as wing area divided by wing span, SMC = S b, thus, the SMC is the chord of a rectangular wing with the same area and span as those of the given wing. This is a geometric figure and is rarely used in aerodynamics. Mean aerodynamic chord is defined as, MAC =2 S ∫0 b 2 c 2 d y, other terms are as for SMC. The MAC is a representation of the whole wing. The pressure distribution over the wing can be reduced to a single lift force on. Therefore, not only the length but also the position of MAC is often important. In particular, the position of center of mass of an aircraft is measured relative to the MAC. Note that the figure to the right implies that the MAC occurs at a point where leading or trailing edge sweep changes, in general, this is not the case. Any shape other than a simple trapezoid requires evaluation of the above integral, the ratio of the length of a rectangular-planform wing to its chord is known as the aspect ratio, an important indicator of the lift-induced drag the wing will create
36.
Kilogram
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The kilogram or kilogramme is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype of the Kilogram. The avoirdupois pound, used in both the imperial and US customary systems, is defined as exactly 0.45359237 kg, making one kilogram approximately equal to 2.2046 avoirdupois pounds. Other traditional units of weight and mass around the world are also defined in terms of the kilogram, the gram, 1/1000 of a kilogram, was provisionally defined in 1795 as the mass of one cubic centimeter of water at the melting point of ice. The final kilogram, manufactured as a prototype in 1799 and from which the IPK was derived in 1875, had an equal to the mass of 1 dm3 of water at its maximum density. The kilogram is the only SI base unit with an SI prefix as part of its name and it is also the only SI unit that is still directly defined by an artifact rather than a fundamental physical property that can be reproduced in different laboratories. Three other base units and 17 derived units in the SI system are defined relative to the kilogram, only 8 other units do not require the kilogram in their definition, temperature, time and frequency, length, and angle. At its 2011 meeting, the CGPM agreed in principle that the kilogram should be redefined in terms of the Planck constant, the decision was originally deferred until 2014, in 2014 it was deferred again until the next meeting. There are currently several different proposals for the redefinition, these are described in the Proposed Future Definitions section below, the International Prototype Kilogram is rarely used or handled. In the decree of 1795, the term gramme thus replaced gravet, the French spelling was adopted in the United Kingdom when the word was used for the first time in English in 1797, with the spelling kilogram being adopted in the United States. In the United Kingdom both spellings are used, with kilogram having become by far the more common, UK law regulating the units to be used when trading by weight or measure does not prevent the use of either spelling. In the 19th century the French word kilo, a shortening of kilogramme, was imported into the English language where it has used to mean both kilogram and kilometer. In 1935 this was adopted by the IEC as the Giorgi system, now known as MKS system. In 1948 the CGPM commissioned the CIPM to make recommendations for a practical system of units of measurement. This led to the launch of SI in 1960 and the subsequent publication of the SI Brochure, the kilogram is a unit of mass, a property which corresponds to the common perception of how heavy an object is. Mass is a property, that is, it is related to the tendency of an object at rest to remain at rest, or if in motion to remain in motion at a constant velocity. Accordingly, for astronauts in microgravity, no effort is required to hold objects off the cabin floor, they are weightless. However, since objects in microgravity still retain their mass and inertia, the ratio of the force of gravity on the two objects, measured by the scale, is equal to the ratio of their masses. On April 7,1795, the gram was decreed in France to be the weight of a volume of pure water equal to the cube of the hundredth part of the metre
37.
SpaceShipOne flight 14P
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Flight 14P of SpaceShipOne was its third powered flight, which occurred on May 13,2004. SpaceShipOne was released from White Knight at an altitude of 46,000 feet, after ten seconds the rocket was lit, for a 55 second burn. At burn-out the altitude was 150,000 feet and the Mach number was 2.5, the craft then coasted to an apogee altitude of 211,400 feet. At one point during the flight, the avionics computer froze up and had to be rebooted, melvill flew the aircraft manually until the computer became operable again. During reentry, the craft attained Mach 1.9 and deceleration of 3.5 g, the craft switched to glider configuration at 55,000 feet. The craft returned to the spaceport and landed safely, scaled Composites public flight log SpaceShipOne video footage
38.
Reaction control system
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A reaction control system is a spacecraft system that uses thrusters to provide attitude control, and sometimes translation. An RCS is capable of providing small amounts of thrust in any desired direction or combination of directions, an RCS is also capable of providing torque to allow control of rotation. RCS systems often use combinations of large and small thrusters, to different levels of response. Because spacecraft only contain an amount of fuel and there is little chance to refill them. For stationkeeping, some spacecraft use high-specific-impulse engines such as arcjets, ion thrusters, to control orientation, a few spacecraft, including the ISS, use momentum wheels which spin to control rotational rates on the vehicle. The Mercury space capsule and Gemini re-entry module both used groupings of nozzles to provide attitude control, the thrusters were located off their center of gravity, thus providing a torque to rotate the capsule. The Gemini capsule was also capable of adjusting its re-entry course by rolling, the Gemini spacecraft was also equipped with a hypergolic Orbit Attitude and Maneuvering System, which made it the first manned spacecraft with translation as well as rotation capability. In-orbit attitude control was achieved by firing pairs of eight 25-pound-force thrusters located around the circumference of its adapter module at the aft end. Lateral translation control was provided by four 100-pound-force thrusters around the circumference at the end of the adaptor module. The Apollo Command Module had a set of twelve hypergolic thrusters for attitude control, the Apollo Service Module and Lunar Module each had a set of sixteen R-4D hypergolic thrusters, grouped into external clusters of four, to provide both translation and attitude control. The clusters were located near the centers of gravity, and were fired in pairs in opposite directions for attitude control. A pair of translation thrusters are located at the rear of the Soyuz spacecraft and these act in pairs to prevent the spacecraft from rotating. The thrusters for the directions are mounted close to the center of mass of the spacecraft. Those for pitch and yaw are located in the nose, forward of the cockpit and those for roll are located at the wingtips. The X-20, which would have gone into orbit, continued this pattern, unlike these, the Space Shuttle Orbiter had many more thrusters, as it was required to carry out docking maneuvers in orbit. Shuttle thrusters were grouped in the nose of the vehicle and on each of the two aft Orbital Maneuvering System pods. No nozzles interrupted the heat shield on the underside of the craft, instead, the nose RCS nozzles which control positive pitch were mounted on the side of the vehicle, the downward-facing negative pitch thrusters were located in the OMS pods mounted in the tail/afterbody. The International Space Station uses electrically powered reaction control gyroscopes for attitude control, with RCS thruster systems as backup
39.
Elevon
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Elevons are aircraft control surfaces that combine the functions of the elevator and the aileron, hence the name. They are frequently used on aircraft such as flying wings. An elevon that is not part of the wing. The word elevon is a portmanteau of elevator and aileron, elevons are installed on each side of the aircraft at the trailing edge of the wing. When moved in the direction they will cause a pitching force to be applied to the airframe. When moved differentially, they cause a rolling force to be applied. These forces may be applied simultaneously by appropriate positioning of the elevons e. g. one wings elevons completely down, an aircraft with elevons is controlled as though the pilot still has separate aileron and elevator surfaces at his disposal, controlled by the yoke or stick. The inputs of the two controls are mixed either mechanically or electronically to provide the position for each elevon. They were also used on the Avro Vulcan, Northrop Grumman B-2 Spirit, Concorde and the Space Shuttle Orbiter. However, the drawback is that when the elevons move up in unison to raise the pitch of the aircraft, generating additional lift, they reduce the camber. Camber is desirable when generating high levels of lift, and so reduce the maximum lift. These may be used in unmanned aerial vehicles and 6th generation fighter aircraft. Two promising approaches are flexible wings, and fluidics, in flexible wings, much or all of a wing surface can change shape in flight to deflect air flow. The X-53 Active Aeroelastic Wing is a NASA effort, the Adaptive Compliant Wing is a military and commercial effort. In this use, fluidics promises lower mass, costs, and very low inertia and response times, aileron Flaperon Delta Wing Flying wing Spoileron Stabilator
40.
Aviation
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Aviation is the practical aspect or art of aeronautics, being the design, development, production, operation and use of aircraft, especially heavier than air aircraft. The word aviation was coined by French writer and former naval officer Gabriel La Landelle in 1863, from the verb avier, itself derived from the Latin word avis and the suffix -ation. The modern age of aviation began with the first untethered human lighter-than-air flight on November 21,1783, the practicality of balloons was limited because they could only travel downwind. It was immediately recognized that a steerable, or dirigible, balloon was required, jean-Pierre Blanchard flew the first human-powered dirigible in 1784 and crossed the English Channel in one in 1785. Rigid airships became the first aircraft to transport passengers and cargo over great distances, the best known aircraft of this type were manufactured by the German Zeppelin company. The most successful Zeppelin was the Graf Zeppelin and it flew over one million miles, including an around-the-world flight in August 1929. However, the dominance of the Zeppelins over the airplanes of that period, the Golden Age of the airships ended on May 6,1937 when the Hindenburg caught fire, killing 36 people. The cause of the Hindenburg accident was blamed on the use of hydrogen instead of helium as the lift gas. An internal investigation by the manufacturer revealed the coating used to protect the material over the frame was highly flammable. Changes to the coating formulation reduced the risk of further Hindenburg type accidents, although there have been periodic initiatives to revive their use, airships have seen only niche application since that time. In 1799 Sir George Cayley set forth the concept of the airplane as a fixed-wing flying machine with separate systems for lift, propulsion. Seven years later, on 14 October 1897, Aders Avion III was tested without success in front of two officials from the French War ministry, the report on the trials was not publicized until 1910, as they had been a military secret. In November 1906 Ader claimed to have made a flight on 14 October 1897. Although widely believed at the time, these claims were later discredited, however, the most widely accepted date is December 17,1903 by the Wright brothers. The Wright brothers were the first to fly in a powered and controlled aircraft, previous flights were gliders or free flight, but the Wright brothers combined both, setting the new standard in aviation records. Aircraft began to transport people and cargo as designs grew larger, the Wright brothers took aloft the first passenger, Charles Furnas, one of their mechanics, on May 14,1908. By the beginning of World War II, many towns and cities had built airports, the war brought many innovations to aviation, including the first jet aircraft and the first liquid-fueled rockets. Manufacturers such as Cessna, Piper, and Beechcraft expanded production to provide aircraft for the new middle-class market
41.
Shuttlecock
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A shuttlecock is a high-drag projectile used in the sport of badminton. The name is from the Victorian times, when Badminton was first discovered and it has an open conical shape, the cone is formed from 16 or so overlapping feathers, usually goose or duck, embedded into a rounded cork base. The cork is covered with thin leather, to ensure that shuttlecocks rotate consistently, only feathers from the birds left wings are used. The shuttlecocks shape makes it extremely aerodynamically stable, regardless of initial orientation, it will turn to fly cork first, and remain in the cork-first orientation. The name shuttlecock is frequently shortened to shuttle, the feathers are brittle, shuttlecocks break easily and often need to be replaced several times during a game. For this reason, synthetic shuttlecocks have been developed that replace the feathers with a plastic skirt, players often refer to synthetic shuttlecocks as plastics and feathered shuttlecocks as feathers. Feather shuttles need to be properly humidified for at least 4 hours prior to play in order to fly the distance at the proper speed. Properly humidified feathers flex during play, enhancing the speed change. Dry feathers are brittle and break easily, causing the shuttle to wobble, saturated feathers are mushy, making the feather cone narrow too much when strongly hit, which causes the shuttle to fly overly far and fast. Humidification boxes are used, but a simple moist sponge inserted in the feather end of the closed shuttle tube will work nicely. Water should never touch the cork of the shuttle, shuttles are tested prior to play to make sure they fly true and at the proper speed, and cover the proper distance. Different weights of shuttles are used to compensate for atmospheric conditions. Both humidity and height above sea level affect shuttle flight, the cost of good quality feathers is similar to that of good quality plastics, but plastics are far more durable, typically lasting many matches without any impairment to their flight. Shuttles are easily damaged and should be replaced every three or four games, and sooner if they are damaged and do not fly straight and this interferes with the game, as the impairment on the flight of the shuttle may misdirect the direction of the shuttlecock. Most experienced and skillful players greatly prefer feathers, and serious tournaments or leagues are played using feather shuttlecocks of the highest quality. Experienced players generally prefer the feel of feathered shuttlecocks and assert that they are able to control the flight of feathers better than that of plastics, in Asia, where feather shuttlecocks are more affordable than in Europe and North America, plastic shuttlecocks are hardly used at all. The playing characteristics of plastics and feathers are substantially different, plastics fly more slowly on initial impact, but slow down less towards the end of their flight. While feathers tend to drop straight down on a shot, plastics never quite return to a straight drop
42.
Feather
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Feathers are epidermal growths that form the distinctive outer covering, or plumage, on birds. They are considered the most complex integumentary structures found in vertebrates and they are among the characteristics that distinguish the extant birds from other living groups. Although feathers cover most parts of the body of birds, they arise only from certain well-defined tracts on the skin and they aid in flight, thermal insulation, and waterproofing. In addition, coloration helps in communication and protection, plumology is the name for the science that is associated with the study of feathers. Feathers are among the most complex integumentary appendages found in vertebrates and are formed in tiny follicles in the epidermis, or outer skin layer, that produce keratin proteins. There are two types of feather, vaned feathers which cover the exterior of the body. The pennaceous feathers are vaned feathers, also called contour feathers, pennaceous feathers arise from tracts and cover the entire body. In some passerines, filoplumes arise exposed beyond the contour feathers on the neck, the remiges, or flight feathers of the wing, and rectrices, the flight feathers of the tail are the most important feathers for flight. A typical vaned feather features a main shaft, called the rachis, fused to the rachis are a series of branches, or barbs, the barbs themselves are also branched and form the barbules. These barbules have minute hooks called barbicels for cross-attachment, down feathers are fluffy because they lack barbicels, so the barbules float free of each other, allowing the down to trap air and provide excellent thermal insulation. At the base of the feather, the rachis expands to form the hollow tubular calamus which inserts into a follicle in the skin, the basal part of the calamus is without vanes. This part is embedded within the follicle and has an opening at the base. Hatchling birds of species have a special kind of natal down feathers which are pushed out when the normal feathers emerge. Flight feathers are stiffened so as to work against the air in the downstroke, feathers insulate birds from water and cold temperatures. They may also be plucked to line the nest and provide insulation to the eggs, the individual feathers in the wings and tail play important roles in controlling flight. Some species have a crest of feathers on their heads, although feathers are light, a birds plumage weighs two or three times more than its skeleton, since many bones are hollow and contain air sacs. Color patterns serve as camouflage against predators for birds in their habitats, as with fish, the top and bottom colors may be different, in order to provide camouflage during flight. Striking differences in patterns and colors are part of the sexual dimorphism of many bird species and are particularly important in selection of mating pairs
43.
Mid-air retrieval
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Mid-air retrieval is a technique used in atmospheric reentry when the reentering vehicle is incapable of a satisfactory unassisted landing. The vehicle is slowed by means of parachutes, and then a specially-equipped aircraft matches the vehicles trajectory and this is a risky technique, and so is only used when other forms of landing are infeasible. These risks can be mitigated somewhat, for example, multiple recovery aircraft can be used, the need for human aviators to perform a manoeuvre which would normally be classed as a stunt may in the future be avoided by advances in unmanned aerial vehicles. The first successful use of mid-air recovery was on 19 August 1960. This was the first successful recovery of film from an orbiting satellite, notable uses of the technique, The early-1960s era Corona reconnaissance satellite returned delicate film capsules to Earth that required mid-air retrieval by a JC-130 Hercules & HC-130 airlifter. These aircraft were manned by a crew of 10 personnel, the crew consisted of two pilots, one flight engineer, two telemetry operators, one winch operator, and four riggers. The telemetry operators would acquire the location of the satellite and relay the info to the pilots, once visually acquired the pilots would head on course to the satellite descending towards the Pacific Ocean. One could visually acquire the satellite and its parachute at an altitude of approximately 50,000 ft, the winch operator and the riggers would deploy the retrieving apparatus called the Loop, which consisted of high quality nylon rope with a series of brass hooks spliced into the apparatus. The whole snatching operation by the pilots was done visually, the winch operator and the four riggers would deploy the loop. Once contact was made between the parachute and the loop the line would pay out and stop. The winch then was put into gear and the process commenced. The crews acquired these skills by practicing almost daily on practice missions, the weights were 200 lb. in the early 70s and later to the conical parachute system which weighed in at 1,100 lb. Its parachutes failed to deploy, leading to a high speed impact with the desert floor which shattered the delicate wafers holding the solar wind samples. An early design for SpaceShipOne called for a shape that would have made it incapable of landing independently. This was deemed too risky, and the design made the spacecraft capable of independent horizontal landing while cleverly retaining the desired aerodynamic qualities for the early part of reentry. During the Cold War, Lockheed HC-130 Hercules airlifters were used to recover instrument packages from unmanned spy balloons and reconnaissance drones. The United Launch Alliances proposed Vulcan rocket is intended to have the engines on its first stage recovered in midair by helicopter so that it can be reused for further launches. In DARPAs proposed Gremlin unmanned aerial vehicle program, the UAVs are to be launched from a carrier aircraft and recovered in midair after their mission by a modified C-130 transport
44.
Flight dynamics
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Flight dynamics is the study of the performance, stability, and control of vehicles flying through the air or in outer space. It is concerned with how forces acting on the vehicle influence its speed, in fixed-wing aircraft, the changing orientation of the vehicle with respect to the local air flow is represented by two critical parameters, angle of attack and angle of sideslip. These angles describe the direction of airspeed, important because they are the principal source of modulations in the aerodynamic forces. Spacecraft flight dynamics involve three forces, propulsive, gravitational, and lift and drag, because aerodynamic forces involved with spacecraft flight are very small, this leaves gravity as the dominant force. These angles are the product of the equations of motion. For all flight vehicles, these two sets of dynamics, rotational and translational, operate simultaneously and in a fashion to evolve the vehicles state trajectory. This section focuses on fixed-wing aircraft, flight dynamics is the science of air-vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the center of mass, known as roll, pitch and yaw. Aircraft engineers develop control systems for a vehicles orientation about its center of mass, for example, a pitching moment is a vertical force applied at a distance forward or aft from the center of gravity of the aircraft, causing the aircraft to pitch up or down. Roll, pitch and yaw refer, in context, to rotations about the respective axes starting from a defined equilibrium state. The equilibrium roll angle is known as wings level or zero bank angle, a fixed-wing aircraft increases or decreases the lift generated by the wings when it pitches nose up or down by increasing or decreasing the angle of attack. The roll angle is known as bank angle on a fixed-wing aircraft. The forces acting on spacecraft are of three types, propulsive force, gravitational force exerted by the Earth and other celestial bodies, the vehicles attitude must be taken into account because of its effect on the aerodynamic and propulsive forces. There are other reasons, unrelated to flight dynamics, for controlling the attitude in non-powered flight. Also, most of a flight time is usually unpowered
45.
SpaceShipOne flight 16P
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Flight 16P of SpaceShipOne was a spaceflight in the Tier One program that took place on September 29,2004. It was the first competitive flight in the Ansari X PRIZE competition to demonstrate a non-governmental reusable manned spacecraft, a serious roll excursion occurred during boost, so the flight did not achieve the expected altitude. However, it exceeded 100 km altitude, making it a successful X PRIZE flight, X PRIZE rules required that the date and place of competitive flights be announced to the X PRIZE Foundation at least 60 days before the flight. Due to problems encountered during flight 15P on June 21,2004, Scaled Composites did not immediately set a date for their competitive flights, by July 7,2004 Burt Rutan reported that the faults had been resolved and the next flights would be competitive. On July 27,2004, the X PRIZE Foundation announced that Scaled Composites had given notice that they would make their first competitive flight on September 29,2004. The pilot initially selected for the flight due to stress about two weeks before the flight, after his wife gave birth and he also fell ill. Mike Melvill, who also piloted SpaceShipOnes sole previous spaceflight, stepped in to fly in his place, the choice of pilot was not publicly announced until about two hours before planned takeoff. Melvill was seen as a choice, because after the previous flight he had said he wanted to take a break from flying SpaceShipOne. Under Ansari X PRIZE rules, the flight was required to carry 180 kg payload, Scaled Composites announced early on that this, their first X PRIZE flight, would carry inanimate payload rather than live passengers. The value of items increases enormously if the item has flown in space. The teddy bear being carried for charity will be auctioned at a higher price than it would otherwise command. Scaled Composites employees were made to sign a contract forbidding them from selling the mementos they put on the flight, SpaceShipOne and White Knight bore several logos for the flight. All times are in PDT, which is seven hours behind UTC and this was the local civil time at the spaceport on the day of the flight. All measurements are first stated in the U. S. customary units in which they were originally reported, the flight was planned to take off from Mojave Spaceport in the early morning, when wind conditions are most favourable. Takeoff was scheduled for 06,47, but was delayed because of winds gusting to 50 mph, White Knight, carrying SpaceShipOne, taxied to the runway at 07,00, and took off at 07,11. After takeoff, White Knight and SpaceShipOne ascended to the launch altitude, at 08,09 SpaceShipOne was released, glided for 6 s, then went into nose-up attitude and the rocket motor was ignited. The rocket motor was capable of burning for approximately 87 s and it was planned to shut off the motor at an altitude of 345,000 feet, presumably to avoid pushing the envelope too far. The spacecraft started rolling rapidly 50 s into the burn, while travelling at Mach 2.7 and this was probably due to, or at least exacerbated by, pilot error
46.
Sea level
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Mean sea level is an average level of the surface of one or more of Earths oceans from which heights such as elevations may be measured. A common and relatively straightforward mean sea-level standard is the midpoint between a low and mean high tide at a particular location. Sea levels can be affected by factors and are known to have varied greatly over geological time scales. The careful measurement of variations in MSL can offer insights into ongoing climate change, the term above sea level generally refers to above mean sea level. Precise determination of a sea level is a difficult problem because of the many factors that affect sea level. Sea level varies quite a lot on several scales of time and this is because the sea is in constant motion, affected by the tides, wind, atmospheric pressure, local gravitational differences, temperature, salinity and so forth. The easiest way this may be calculated is by selecting a location and calculating the mean sea level at that point, for example, a period of 19 years of hourly level observations may be averaged and used to determine the mean sea level at some measurement point. One measures the values of MSL in respect to the land, hence a change in MSL can result from a real change in sea level, or from a change in the height of the land on which the tide gauge operates. In the UK, the Ordnance Datum is the sea level measured at Newlyn in Cornwall between 1915 and 1921. Prior to 1921, the datum was MSL at the Victoria Dock, in Hong Kong, mPD is a surveying term meaning metres above Principal Datum and refers to height of 1. 230m below the average sea level. In France, the Marégraphe in Marseilles measures continuously the sea level since 1883 and it is used for a part of continental Europe and main part of Africa as official sea level. Elsewhere in Europe vertical elevation references are made to the Amsterdam Peil elevation, satellite altimeters have been making precise measurements of sea level since the launch of TOPEX/Poseidon in 1992. A joint mission of NASA and CNES, TOPEX/Poseidon was followed by Jason-1 in 2001, height above mean sea level is the elevation or altitude of an object, relative to the average sea level datum. It is also used in aviation, where some heights are recorded and reported with respect to sea level, and in the atmospheric sciences. An alternative is to base height measurements on an ellipsoid of the entire Earth, in aviation, the ellipsoid known as World Geodetic System 84 is increasingly used to define heights, however, differences up to 100 metres exist between this ellipsoid height and mean tidal height. The alternative is to use a vertical datum such as NAVD88. When referring to geographic features such as mountains on a topographic map, the elevation of a mountain denotes the highest point or summit and is typically illustrated as a small circle on a topographic map with the AMSL height shown in metres, feet or both. In the rare case that a location is below sea level, for one such case, see Amsterdam Airport Schiphol
47.
Oxygen
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Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the group on the periodic table and is a highly reactive nonmetal. By mass, oxygen is the third-most abundant element in the universe, after hydrogen, at standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. This is an important part of the atmosphere and diatomic oxygen gas constitutes 20. 8% of the Earths atmosphere, additionally, as oxides the element makes up almost half of the Earths crust. Most of the mass of living organisms is oxygen as a component of water, conversely, oxygen is continuously replenished by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide. Oxygen is too reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. Another form of oxygen, ozone, strongly absorbs ultraviolet UVB radiation, but ozone is a pollutant near the surface where it is a by-product of smog. At low earth orbit altitudes, sufficient atomic oxygen is present to cause corrosion of spacecraft, the name oxygen was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion. One of the first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium. In his work Pneumatica, Philo observed that inverting a vessel over a burning candle, Philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass. Many centuries later Leonardo da Vinci built on Philos work by observing that a portion of air is consumed during combustion and respiration, Oxygen was discovered by the Polish alchemist Sendivogius, who considered it the philosophers stone. In the late 17th century, Robert Boyle proved that air is necessary for combustion, English chemist John Mayow refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus. From this he surmised that nitroaereus is consumed in both respiration and combustion, Mayow observed that antimony increased in weight when heated, and inferred that the nitroaereus must have combined with it. Accounts of these and other experiments and ideas were published in 1668 in his work Tractatus duo in the tract De respiratione. Robert Hooke, Ole Borch, Mikhail Lomonosov, and Pierre Bayen all produced oxygen in experiments in the 17th and the 18th century but none of them recognized it as a chemical element. This may have been in part due to the prevalence of the philosophy of combustion and corrosion called the phlogiston theory, which was then the favored explanation of those processes. Established in 1667 by the German alchemist J. J. Becher, one part, called phlogiston, was given off when the substance containing it was burned, while the dephlogisticated part was thought to be its true form, or calx. The fact that a substance like wood gains overall weight in burning was hidden by the buoyancy of the combustion products
