1.
NASA
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President Dwight D. Eisenhower established NASA in 1958 with a distinctly civilian orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29,1958, disestablishing NASAs predecessor, the new agency became operational on October 1,1958. Since that time, most US space exploration efforts have led by NASA, including the Apollo Moon landing missions, the Skylab space station. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle, the agency is also responsible for the Launch Services Program which provides oversight of launch operations and countdown management for unmanned NASA launches. NASA shares data with various national and international such as from the Greenhouse Gases Observing Satellite. Since 2011, NASA has been criticized for low cost efficiency, from 1946, the National Advisory Committee for Aeronautics had been experimenting with rocket planes such as the supersonic Bell X-1. In the early 1950s, there was challenge to launch a satellite for the International Geophysical Year. An effort for this was the American Project Vanguard, after the Soviet launch of the worlds first artificial satellite on October 4,1957, the attention of the United States turned toward its own fledgling space efforts. This led to an agreement that a new federal agency based on NACA was needed to conduct all non-military activity in space. The Advanced Research Projects Agency was created in February 1958 to develop technology for military application. On July 29,1958, Eisenhower signed the National Aeronautics and Space Act, a NASA seal was approved by President Eisenhower in 1959. Elements of the Army Ballistic Missile Agency and the United States Naval Research Laboratory were incorporated into NASA, earlier research efforts within the US Air Force and many of ARPAs early space programs were also transferred to NASA. In December 1958, NASA gained control of the Jet Propulsion Laboratory, NASA has conducted many manned and unmanned spaceflight programs throughout its history. Some missions include both manned and unmanned aspects, such as the Galileo probe, which was deployed by astronauts in Earth orbit before being sent unmanned to Jupiter, the experimental rocket-powered aircraft programs started by NACA were extended by NASA as support for manned spaceflight. This was followed by a space capsule program, and in turn by a two-man capsule program. This goal was met in 1969 by the Apollo program, however, reduction of the perceived threat and changing political priorities almost immediately caused the termination of most of these plans. NASA turned its attention to an Apollo-derived temporary space laboratory, to date, NASA has launched a total of 166 manned space missions on rockets, and thirteen X-15 rocket flights above the USAF definition of spaceflight altitude,260,000 feet. The X-15 was an NACA experimental rocket-powered hypersonic research aircraft, developed in conjunction with the US Air Force, the design featured a slender fuselage with fairings along the side containing fuel and early computerized control systems
2.
Satellite bus
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A satellite bus or spacecraft bus is the general model on which multiple-production satellite spacecraft are often based. The bus is the infrastructure of a spacecraft, usually providing locations for the payload, a bus-derived satellite would be used as opposed to a one-off, or specially produced satellite, such as Prospero X-3. Bus-derived satellites are usually customized to customer requirements, for example with specialized sensors or transponders, comparison of satellite buses Service module Satellite Glossary JWST Observatory, The Spacecraft Bus Spitzers Spacecraft Bus Gunters Space Page, Spacecraft buses
3.
Orbital Sciences Corporation
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It was headquartered in Dulles, Virginia and publicly traded on the New York Stock Exchange with the ticker symbol OA. Orbital also provided satellite subsystems and space-related technical services to government agencies and laboratories, on April 29,2014, Orbital Sciences announced that it would merge with Alliant Techsystems to create a new company called Orbital ATK, Inc. The merger was completed on February 9,2015 and Orbital Sciences ceased to exist as an independent entity, Orbital was founded and incorporated in 1982 by three friends who had met earlier while at Harvard Business School—David W. Thompson, Bruce Ferguson and Scott Webster. In 1985, Orbital procured its first contract for providing up to four Transfer Orbital Stage vehicles to NASA, in 1987, the seeds for the ORBCOMM constellation were planted when Orbital began investigating a system using Low Earth orbit satellites to collect data from remote locations. In 1988, Orbital acquired Space Data Corporation in Arizona- one of the leading suppliers of suborbital rockets- thereby broadening its rocket business. This was followed by the opening of a new facility in Chandler, in 1990, the company successfully carried out eight space missions, highlighted by the initial launch of the Pegasus rocket, the worlds first privately developed space launch vehicle. Shortly following the successful Pegasus launch, Orbital conducted an IPO in 1990, in 1993, Orbital established its current headquarters in Dulles, Virginia followed by the acquisition of Fairchild Space and Defense Corporation in 1994. In the same year, Orbital successfully conducted the launch of the Taurus rocket. In the early 2000s, Orbital continued expanding its missile defense systems business with a $900 million award to develop, build, test and support interceptor booster vehicles. In 2006 Orbital conducted its 500th mission since the founding with a diverse portfolio of products that included satellites, launch vehicles. Orbital is currently on-track to deliver on this contract with its Cygnus spacecraft and Antares rocket following the success of Cygnus Orb-D1, the new company will be called Orbital ATK, Inc. and will serve U. S. Orbital was a provider of small- to medium-class satellites, since the companys founding in 1982, Orbital has delivered 150 spacecraft to commercial, military and civil customers worldwide. To date, these spacecraft have amassed well over 1000 years of on-orbit operations, the Communications & Imaging Satellites developed by Orbital are smaller and more affordable. Earth imagery and high resolution digital imaging satellites such as the OrbView series are developed and manufactured by Orbital. In the last 10 years, Orbital has built more scientific, Orbitals space launch vehicles are considered the industry standard for boosting small payloads to orbit. The Minotaur ground-launched rockets combine Pegasus upper stages with either government-supplied or commercially available first-stage rocket motors to boost larger payloads to orbit, Minotaur IV combines decommissioned Peacekeeper rocket motors with proven Orbital avionics and fairings to provide increased lifting capacity for government-sponsored payloads. With the development of the Antares space launch vehicle, Orbital is extending its capabilities to provide launch services for U. S. government. The inaugural launch of Antares occurred on April 21,2013 from Wallops Flight Facility at Wallops Island, Orbital is also a major provider of suborbital target and interceptor launch vehicles for the U. S. missile defense systems
4.
Pegasus (rocket)
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The Pegasus is an air-launched rocket developed by Orbital ATK, formerly Orbital Sciences Corporation. Capable of carrying payloads of up to 443 kilograms into low Earth orbit, Pegasus first flew in 1990. The vehicle consists of three solid propellant stages and an optional monopropellant fourth stage, Pegasus is released from its carrier aircraft at approximately 40,000 ft, and its first stage has wings and a tail to provide lift and attitude control while in the atmosphere. The Pegasuss three Orion solid motors were developed by Hercules Aerospace specifically for the Pegasus launcher, additionally, wing and tail assemblies and a payload fairing were developed. Most of the Pegasus was designed by a led by Dr. Antonio Elias. The wing was designed by Burt Rutan, mass,18,500 kg,23,130 kg Length,16.9 m,17.6 m Diameter,1.27 m Wing span,6. Soon after development began, several government and military orders were placed, the first successful Pegasus launch occurred on April 5,1990 with NASA test pilot and former astronaut Gordon Fullerton in command of the carrier aircraft. Initially, a NASA-owned B-52 Stratofortress NB-008 served as the carrier aircraft, by 1994, Orbital had transitioned to their Stargazer L-1011, a converted airliner which was formerly owned by Air Canada. Initially, the Pegasus program had a failure rate, about 40% until 1997. It lost six different cargoes, starting with 7 microsatellites on its second attempt, included was at least partial failure of three out of four Space Test Experiment Platform efforts in the 1990s, on three separate launches. The Pegasus XL, introduced in 1994 has lengthened stages to increase payload performance, in the Pegasus XL, the first and second stages are lengthened into the Orion 50SXL and Orion 50XL, respectively. Higher stages are unchanged, flight operations are similar, the wing is strengthened slightly to handle the higher weight. The standard Pegasus has been discontinued, the Pegasus XL is still being produced, Pegasus has flown 42 missions in both configurations as of June 28,2013. Of these,37 were considered successful launches, dual payloads can be launched, with a canister that encloses the lower spacecraft and mounts the upper spacecraft. The upper spacecraft deploys, the canister opens, then the lower spacecraft separates from the third-stage adapter, since the fairing is unchanged for cost and aerodynamic reasons, each of the two payloads must be relatively compact. For their work in developing the rocket, the Pegasus team led by Dr. Antonio Elias was awarded the 1991 National Medal of Technology by U. S. President George H. W. Bush. The initial launch price offered was US$6 million, without options or a HAPS maneuvering stage, with the enlargement to Pegasus XL and the associated improvements to the vehicle, baseline prices increased. In addition, customers usually purchase additional services, such as testing, design and analysis
5.
Stargazer (aircraft)
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Stargazer, registration number N140SC, is a Lockheed L-1011 TriStar built in 1974, that was modified in 1994 to be used by Orbital Sciences as a mother ship launch pad for Pegasus rockets. As of June 2012,35 rockets have launched from it, using the Pegasus-H. The first Pegasus launch to use Stargazer was conducted on 27 June 1994, previous launches used the NASA-operated Boeing NB-52B Balls 8, which was also used for four subsequent launches, as the original Pegasus could not be launched from Stargazer due to clearance issues. A modified version, the Pegasus-H, was introduced to rectify this, in addition to Pegasus launches, Stargazer was used for captive tests and transportation of the X-34 hypersonic research aircraft, however, drop tests used Balls 8. Orbital Sciences also offer the aircraft for research flights and it is capable of carrying a 23,000 kilograms payload to an altitude of 12,800 metres. Pegasus launches using Stargazer are usually conducted from Vandenberg Air Force Base, in 2015, Stargazer was re-painted to reflect Orbital Sciences merger with Alliant Techsystems. Scaled Composites White Knight LauncherOne Cosmic Girl
6.
Bucholz Army Airfield
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Bucholz Army Airfield is a United States Army airfield located on Kwajalein Island, Kwajalein Atoll, Marshall Islands. Its position is ideal for refueling during trans-Pacific flights, and the airport is available to civilians through Air Marshall Islands, Bucholz Army Airfield was initially built by the Japanese in 1943 as part of a large naval base. It came under air attacks in late 1943 to neutralize the island. The atoll was assaulted by American forces on 31 January 1944, employing the hard-learned lessons of the Battle of Tarawa, the United States launched a successful twin assault on the main islands of Kwajalein in the south and Roi-Namur in the north. The Japanese defenders put up a stiff resistance though outnumbered and under-prepared, the determined Japanese defense left only 51 survivors of an original garrison of 3,500. After the seizure from the Japanese, Kwajalein was developed into a major American base, from Kwajalein, the heavy bombers struck at enemy targets in the Marshall Islands. The USAAF combat units remained until late 1944 until being moved forwards into the Marianas, being assigned to airfields on Guam, the United States then used Kwajalein as a maintenance and supply hub, supplying forward bases with supplies and equipment. Later, in the 1950s and 1960s, Bucholz became part of the Atomic Energy Commission Pacific Testing Area, American civilians and their families who reside at the military installations in Kwajalein are able to enjoy this environment with few restrictions. As of 2009, Bucholz Army Airfield is still operated by the United States Army, all civil and military operations require 24 hours prior permission, and passengers transiting through Kwajalein on the same aircraft are not permitted to deplane. List of United States Army airfields USAAF in the Central Pacific This article incorporates public domain material from the Air Force Historical Research Agency website http, Air Force Combat Units Of World War II. Maxwell AFB, Alabama, Office of Air Force History, www. pacificwrecks. com USAKA Airfield Services Bucholz Army Airfield Pictures of Airport AirNav airport information for PKWA
7.
Geocentric orbit
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A geocentric orbit or Earth orbit involves any object orbiting the Earth, such as the Moon or artificial satellites. In 1997 NASA estimated there were approximately 2,465 artificial satellite orbiting the Earth and 6,216 pieces of space debris as tracked by the Goddard Space Flight Center. Over 16,291 previously launched objects have decayed into the Earths atmosphere, altitude as used here, the height of an object above the average surface of the Earths oceans. Analemma a term in astronomy used to describe the plot of the positions of the Sun on the celestial sphere throughout one year, apogee is the farthest point that a satellite or celestial body can go from Earth, at which the orbital velocity will be at its minimum. Eccentricity a measure of how much an orbit deviates from a perfect circle, eccentricity is strictly defined for all circular and elliptical orbits, and parabolic and hyperbolic trajectories. Equatorial plane as used here, an imaginary plane extending from the equator on the Earth to the celestial sphere, escape velocity as used here, the minimum velocity an object without propulsion needs to have to move away indefinitely from the Earth. An object at this velocity will enter a parabolic trajectory, above this velocity it will enter a hyperbolic trajectory, impulse the integral of a force over the time during which it acts. Inclination the angle between a plane and another plane or axis. In the sense discussed here the reference plane is the Earths equatorial plane, orbital characteristics the six parameters of the Keplerian elements needed to specify that orbit uniquely. Orbital period as defined here, time it takes a satellite to make one orbit around the Earth. Perigee is the nearest approach point of a satellite or celestial body from Earth, sidereal day the time it takes for a celestial object to rotate 360°. For the Earth this is,23 hours,56 minutes,4.091 seconds, solar time as used here, the local time as measured by a sundial. Velocity an objects speed in a particular direction, since velocity is defined as a vector, both speed and direction are required to define it. The following is a list of different geocentric orbit classifications, Low Earth orbit - Geocentric orbits ranging in altitude from 160 kilometers to 2,000 kilometres above mean sea level. At 160 km, one revolution takes approximately 90 minutes, medium Earth orbit - Geocentric orbits with altitudes at apogee ranging between 2,000 kilometres and that of the geosynchronous orbit at 35,786 kilometres. Geosynchronous orbit - Geocentric circular orbit with an altitude of 35,786 kilometres, the period of the orbit equals one sidereal day, coinciding with the rotation period of the Earth. The speed is approximately 3,000 metres per second, high Earth orbit - Geocentric orbits with altitudes at apogee higher than that of the geosynchronous orbit. A special case of high Earth orbit is the elliptical orbit
8.
Semi-major and semi-minor axes
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In geometry, the major axis of an ellipse is its longest diameter, a line segment that runs through the center and both foci, with ends at the widest points of the perimeter. The semi-major axis is one half of the axis, and thus runs from the centre, through a focus. Essentially, it is the radius of an orbit at the two most distant points. For the special case of a circle, the axis is the radius. One can think of the axis as an ellipses long radius. The semi-major axis of a hyperbola is, depending on the convention, thus it is the distance from the center to either vertex of the hyperbola. A parabola can be obtained as the limit of a sequence of ellipses where one focus is fixed as the other is allowed to move arbitrarily far away in one direction. Thus a and b tend to infinity, a faster than b, the semi-minor axis is a line segment associated with most conic sections that is at right angles with the semi-major axis and has one end at the center of the conic section. It is one of the axes of symmetry for the curve, in an ellipse, the one, in a hyperbola. The semi-major axis is the value of the maximum and minimum distances r max and r min of the ellipse from a focus — that is. In astronomy these extreme points are called apsis, the semi-minor axis of an ellipse is the geometric mean of these distances, b = r max r min. The eccentricity of an ellipse is defined as e =1 − b 2 a 2 so r min = a, r max = a. Now consider the equation in polar coordinates, with one focus at the origin, the mean value of r = ℓ / and r = ℓ /, for θ = π and θ =0 is a = ℓ1 − e 2. In an ellipse, the axis is the geometric mean of the distance from the center to either focus. The semi-minor axis of an ellipse runs from the center of the ellipse to the edge of the ellipse, the semi-minor axis is half of the minor axis. The minor axis is the longest line segment perpendicular to the axis that connects two points on the ellipses edge. The semi-minor axis b is related to the axis a through the eccentricity e. A parabola can be obtained as the limit of a sequence of ellipses where one focus is fixed as the other is allowed to move arbitrarily far away in one direction
9.
Orbital eccentricity
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The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is an orbit, values between 0 and 1 form an elliptical orbit,1 is a parabolic escape orbit. The term derives its name from the parameters of conic sections and it is normally used for the isolated two-body problem, but extensions exist for objects following a rosette orbit through the galaxy. In a two-body problem with inverse-square-law force, every orbit is a Kepler orbit, the eccentricity of this Kepler orbit is a non-negative number that defines its shape. The limit case between an ellipse and a hyperbola, when e equals 1, is parabola, radial trajectories are classified as elliptic, parabolic, or hyperbolic based on the energy of the orbit, not the eccentricity. Radial orbits have zero angular momentum and hence eccentricity equal to one, keeping the energy constant and reducing the angular momentum, elliptic, parabolic, and hyperbolic orbits each tend to the corresponding type of radial trajectory while e tends to 1. For a repulsive force only the trajectory, including the radial version, is applicable. For elliptical orbits, a simple proof shows that arcsin yields the projection angle of a circle to an ellipse of eccentricity e. For example, to view the eccentricity of the planet Mercury, next, tilt any circular object by that angle and the apparent ellipse projected to your eye will be of that same eccentricity. From Medieval Latin eccentricus, derived from Greek ἔκκεντρος ekkentros out of the center, from ἐκ- ek-, eccentric first appeared in English in 1551, with the definition a circle in which the earth, sun. Five years later, in 1556, a form of the word was added. The eccentricity of an orbit can be calculated from the state vectors as the magnitude of the eccentricity vector, e = | e | where. For elliptical orbits it can also be calculated from the periapsis and apoapsis since rp = a and ra = a, where a is the semimajor axis. E = r a − r p r a + r p =1 −2 r a r p +1 where, rp is the radius at periapsis. For Earths annual orbit path, ra/rp ratio = longest_radius / shortest_radius ≈1.034 relative to center point of path, the eccentricity of the Earths orbit is currently about 0.0167, the Earths orbit is nearly circular. Venus and Neptune have even lower eccentricity, over hundreds of thousands of years, the eccentricity of the Earths orbit varies from nearly 0.0034 to almost 0.058 as a result of gravitational attractions among the planets. The table lists the values for all planets and dwarf planets, Mercury has the greatest orbital eccentricity of any planet in the Solar System. Such eccentricity is sufficient for Mercury to receive twice as much solar irradiation at perihelion compared to aphelion, before its demotion from planet status in 2006, Pluto was considered to be the planet with the most eccentric orbit
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Apsis
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An apsis is an extreme point in an objects orbit. The word comes via Latin from Greek and is cognate with apse, for elliptic orbits about a larger body, there are two apsides, named with the prefixes peri- and ap-, or apo- added to a reference to the thing being orbited. For a body orbiting the Sun, the point of least distance is the perihelion, the terms become periastron and apastron when discussing orbits around other stars. For any satellite of Earth including the Moon the point of least distance is the perigee, for objects in Lunar orbit, the point of least distance is the pericynthion and the greatest distance the apocynthion. For any orbits around a center of mass, there are the terms pericenter and apocenter, periapsis and apoapsis are equivalent alternatives. A straight line connecting the pericenter and apocenter is the line of apsides and this is the major axis of the ellipse, its greatest diameter. For a two-body system the center of mass of the lies on this line at one of the two foci of the ellipse. When one body is larger than the other it may be taken to be at this focus. Historically, in systems, apsides were measured from the center of the Earth. In orbital mechanics, the apsis technically refers to the distance measured between the centers of mass of the central and orbiting body. However, in the case of spacecraft, the family of terms are used to refer to the orbital altitude of the spacecraft from the surface of the central body. The arithmetic mean of the two limiting distances is the length of the axis a. The geometric mean of the two distances is the length of the semi-minor axis b, the geometric mean of the two limiting speeds is −2 ε = μ a which is the speed of a body in a circular orbit whose radius is a. The words pericenter and apocenter are often seen, although periapsis/apoapsis are preferred in technical usage, various related terms are used for other celestial objects. The -gee, -helion and -astron and -galacticon forms are used in the astronomical literature when referring to the Earth, Sun, stars. The suffix -jove is occasionally used for Jupiter, while -saturnium has very rarely used in the last 50 years for Saturn. The -gee form is used as a generic closest approach to planet term instead of specifically applying to the Earth. During the Apollo program, the terms pericynthion and apocynthion were used when referring to the Moon, regarding black holes, the term peri/apomelasma was used by physicist Geoffrey A. Landis in 1998 before peri/aponigricon appeared in the scientific literature in 2002
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Orbital inclination
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Orbital inclination measures the tilt of an objects orbit around a celestial body. It is expressed as the angle between a plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the equator, the plane of the orbit is the same as the Earths equatorial plane. The general case is that the orbit is tilted, it spends half an orbit over the northern hemisphere. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°, the inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planets equator, for planets in the Solar System, the plane of reference is usually the ecliptic, the plane in which the Earth orbits the Sun. This reference plane is most practical for Earth-based observers, therefore, Earths inclination is, by definition, zero. Inclination could instead be measured with respect to another plane, such as the Suns equator or the invariable plane, the inclination of orbits of natural or artificial satellites is measured relative to the equatorial plane of the body they orbit, if they orbit sufficiently closely. The equatorial plane is the perpendicular to the axis of rotation of the central body. An inclination of 30° could also be described using an angle of 150°, the convention is that the normal orbit is prograde, an orbit in the same direction as the planet rotates. Inclinations greater than 90° describe retrograde orbits, thus, An inclination of 0° means the orbiting body has a prograde orbit in the planets equatorial plane. An inclination greater than 0° and less than 90° also describe prograde orbits, an inclination of 63. 4° is often called a critical inclination, when describing artificial satellites orbiting the Earth, because they have zero apogee drift. An inclination of exactly 90° is an orbit, in which the spacecraft passes over the north and south poles of the planet. An inclination greater than 90° and less than 180° is a retrograde orbit, an inclination of exactly 180° is a retrograde equatorial orbit. For gas giants, the orbits of moons tend to be aligned with the giant planets equator, the inclination of exoplanets or members of multiple stars is the angle of the plane of the orbit relative to the plane perpendicular to the line-of-sight from Earth to the object. An inclination of 0° is an orbit, meaning the plane of its orbit is parallel to the sky. An inclination of 90° is an orbit, meaning the plane of its orbit is perpendicular to the sky
12.
Longitude of the ascending node
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The longitude of the ascending node is one of the orbital elements used to specify the orbit of an object in space. It is the angle from a direction, called the origin of longitude, to the direction of the ascending node. The ascending node is the point where the orbit of the passes through the plane of reference. Commonly used reference planes and origins of longitude include, For a geocentric orbit, Earths equatorial plane as the plane. In this case, the longitude is called the right ascension of the ascending node. The angle is measured eastwards from the First Point of Aries to the node, for a heliocentric orbit, the ecliptic as the reference plane, and the First Point of Aries as the origin of longitude. The angle is measured counterclockwise from the First Point of Aries to the node, the angle is measured eastwards from north to the node. pp.40,72,137, chap. In the case of a star known only from visual observations, it is not possible to tell which node is ascending. In this case the orbital parameter which is recorded is the longitude of the node, Ω, here, n=<nx, ny, nz> is a vector pointing towards the ascending node. The reference plane is assumed to be the xy-plane, and the origin of longitude is taken to be the positive x-axis, K is the unit vector, which is the normal vector to the xy reference plane. For non-inclined orbits, Ω is undefined, for computation it is then, by convention, set equal to zero, that is, the ascending node is placed in the reference direction, which is equivalent to letting n point towards the positive x-axis. Kepler orbits Equinox Orbital node perturbation of the plane can cause revolution of the ascending node
13.
Argument of periapsis
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The argument of periapsis, symbolized as ω, is one of the orbital elements of an orbiting body. Parametrically, ω is the angle from the ascending node to its periapsis. For specific types of orbits, words such as perihelion, perigee, periastron, an argument of periapsis of 0° means that the orbiting body will be at its closest approach to the central body at the same moment that it crosses the plane of reference from South to North. An argument of periapsis of 90° means that the body will reach periapsis at its northmost distance from the plane of reference. Adding the argument of periapsis to the longitude of the ascending node gives the longitude of the periapsis, however, especially in discussions of binary stars and exoplanets, the terms longitude of periapsis or longitude of periastron are often used synonymously with argument of periapsis. In the case of equatorial orbits, the argument is strictly undefined, where, ex and ey are the x- and y-components of the eccentricity vector e. In the case of circular orbits it is assumed that the periapsis is placed at the ascending node. Kepler orbit Orbital mechanics Orbital node
14.
Mean anomaly
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In celestial mechanics, the mean anomaly is an angle used in calculating the position of a body in an elliptical orbit in the classical two-body problem. Define T as the time required for a body to complete one orbit. In time T, the radius vector sweeps out 2π radians or 360°. The average rate of sweep, n, is then n =2 π T or n =360 ∘ T, define τ as the time at which the body is at the pericenter. From the above definitions, a new quantity, M, the mean anomaly can be defined M = n, because the rate of increase, n, is a constant average, the mean anomaly increases uniformly from 0 to 2π radians or 0° to 360° during each orbit. It is equal to 0 when the body is at the pericenter, π radians at the apocenter, if the mean anomaly is known at any given instant, it can be calculated at any later instant by simply adding n δt where δt represents the time difference. Mean anomaly does not measure an angle between any physical objects and it is simply a convenient uniform measure of how far around its orbit a body has progressed since pericenter. The mean anomaly is one of three parameters that define a position along an orbit, the other two being the eccentric anomaly and the true anomaly. Define l as the longitude, the angular distance of the body from the same reference direction. Thus mean anomaly is also M = l − ϖ, mean angular motion can also be expressed, n = μ a 3, where μ is a gravitational parameter which varies with the masses of the objects, and a is the semi-major axis of the orbit. Mean anomaly can then be expanded, M = μ a 3, and here mean anomaly represents uniform angular motion on a circle of radius a
15.
Explorers program
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The Explorers program is a United States space exploration program that provides flight opportunities for physics, geophysics, heliophysics, and astrophysics investigations from space. Over 90 space missions have launched since 1958, and it is still active. Starting with Explorer 6, it has operated by NASA, with regular collaboration with a variety of other institutions. The Explorers program was the United Statess first successful attempt to launch an artificial satellite. It began as a U. S. Army proposal to place a satellite into orbit during the International Geophysical Year, however. The Explorers program was reestablished to catch up with the Soviet Union after that nations launch of Sputnik 1 on October 4,1957. Explorer 1 was launched on January 31,1958, besides being the first U. S. satellite, it is known for discovering the Van Allen radiation belt. Over the years, NASA has launched a series of Explorers spacecraft carrying a variety of scientific investigations. These missions have also investigated air density, radio astronomy, geodesy, various space telescopes have made a variety of discoveries, including the first known Earth Trojan asteroid. The Explorers Program Office at Goddard Space Flight Center in Greenbelt, Maryland, Explorers categories have included MIDEX, SMEX, UNEX, and others. A subprogram called Missions of Opportunity has funded instruments on non-NASA missions, launchers used for these missions include Jupiter C, Juno II, various Thor rockets such as the Thor-Able, Scout, various Delta and Delta II rockets of the Delta rocket family, and Pegasus. The Medium-Class Explorer program is an effort within NASA to fund space exploration missions that cost no more than US$180 million, list of MIDEX missions The Small Explorer program is an effort within NASA to fund space exploration missions that cost no more than US$120 million. The first set of three SMEX missions were launched between 1992 and 1998, the second set of two missions were launched in 1998 and 1999. These missions were managed by the Small Explorer Project Office at NASAs Goddard Space Flight Center, list of SMEX missions Investigations characterized by definition, development, mission operations, and data analysis costs not to exceed $15. 0M total cost to NASA. UNEX missions will be launched by a variety of low cost methods, list of UNEX missions The Missions of Opportunity program provides funding for science instruments or hardware components of onboard non-NASA space missions. MO missions have a total NASA cost of under $55 million, list of MO missions Explorers name numbers can be found in the NSSDC master catalog, typically assigned to each spacecraft in a mission. These numbers were not officially assigned until after 1975, many missions are proposed, but not selected. For example, in 2011, the Explorers program received 22 full missions solicitations,20 Missions of Opportunity, Missions of Opportunity are small collaborative missions with spacecraft not operated by NASA, such as an additional instrument
16.
Aeronomy of Ice in the Mesosphere
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The Aeronomy of Ice in the Mesosphere is a satellite to conduct a 26-month study of noctilucent clouds. It is the ninetieth Explorer program mission and is part of the NASA-funded Small Explorer program, on April 25,2007 AIM was boosted into a 600 km high polar orbit by a Pegasus-XL rocket, which was air-launched from the Lockheed L-1011 Stargazer aircraft operated by Orbital Sciences. The AIM satellite is a 200 kg,1.4 m by 1, the AIM mission will help determine what factors — temperature, water vapor, and dust particles — lead to the formation of these clouds. The clouds seem to be a recent phenomenon, they were first seen in 1885. The clouds always occur during the season near the poles. Scientists have found that the start of the Southern season can vary up to a month however, AIM home SOFIE Instrument and science description, view or download data AIM Mission Profile by NASAs Solar System Exploration
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Wide-field Infrared Survey Explorer
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Wide-field Infrared Survey Explorer is a NASA infrared-wavelength astronomical space telescope launched in December 2009, and placed in hibernation in February 2011 when its transmitter turned off. WISE discovered thousands of planets and numerous star clusters. Its observations also supported the discovery of the first Y Dwarf, WISE performed an all-sky astronomical survey with images in 3.4,4.6,12 and 22 μm wavelength range bands, over ten months using a 40 cm diameter infrared telescope in Earth orbit. After its hydrogen coolant depleted, a mission extension called NEOWISE was conducted to search for near-Earth objects such as comets. The All-Sky data including processed images, source catalogs and raw data, was released to the public on March 14,2012, in August 2013, NASA announced it would reactivate the WISE telescope for a new three-year mission to search for asteroids that could collide with Earth. Science operations and data processing for WISE and NEOWISE take place at the Infrared Processing, the mission was planned to create infrared images of 99 percent of the sky, with at least eight images made of each position on the sky in order to increase accuracy. The spacecraft was placed in a 525 km, circular, polar, Sun-synchronous orbit for its mission, during which it has taken 1.5 million images. Each image covers a 47-arcminute field of view, which means a 6-arcsecond resolution, each area of the sky was scanned at least 10 times at the equator, the poles were scanned at theoretically every revolution due to the overlapping of the images. The produced image library contains data on the local Solar System, the Milky Way, among the objects WISE studied are asteroids, cool, dim stars such as brown dwarfs, and the most luminous infrared galaxies. Stellar nurseries, which are covered by interstellar dust, are detectable in infrared, Infrared measurements from the WISE astronomical survey have been particularly effective at unveiling previously undiscovered star clusters. Examples of such embedded star clusters are Camargo 18, Camargo 440, Majaess 101, in addition, galaxies of the young Universe and interacting galaxies, where star formation is intensive, are bright in infrared. On this wavelength the interstellar gas clouds are also detectable, as well as proto-planetary discs, WISE satellite was expected to find at least 1,000 of those proto-planetary discs. WISE was not able to detect Kuiper belt objects, because their temperatures are too low and it was able to detect any objects warmer than 70–100 K. A Neptune-sized object would be out to 700 AU, a Jupiter-mass object out to 1 light year. A larger object of 2–3 Jupiter masses would be visible at a distance of up to 7–10 light years and that translates to about 1000 new main-belt asteroids per day, and 1–3 NEOs per day. The peak of magnitude distribution for NEOs will be about 21–22 V, WISE would detect each typical Solar System object 10–12 times over about 36 hours in intervals of 3 hours. Construction of the WISE telescope was divided between Ball Aerospace & Technologies, SSG Precision Optronics, Inc, DRS and Rockwell, Lockheed Martin, and Space Dynamics Laboratory. The program was managed through the Jet Propulsion Laboratory, the WISE instrument was built by the Space Dynamics Laboratory in Logan, Utah
18.
Solar System
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The Solar System is the gravitationally bound system comprising the Sun and the objects that orbit it, either directly or indirectly. Of those objects that orbit the Sun directly, the largest eight are the planets, with the remainder being significantly smaller objects, such as dwarf planets, of the objects that orbit the Sun indirectly, the moons, two are larger than the smallest planet, Mercury. The Solar System formed 4.6 billion years ago from the collapse of a giant interstellar molecular cloud. The vast majority of the mass is in the Sun. The four smaller inner planets, Mercury, Venus, Earth and Mars, are terrestrial planets, being composed of rock. The four outer planets are giant planets, being more massive than the terrestrials. All planets have almost circular orbits that lie within a flat disc called the ecliptic. The Solar System also contains smaller objects, the asteroid belt, which lies between the orbits of Mars and Jupiter, mostly contains objects composed, like the terrestrial planets, of rock and metal. Beyond Neptunes orbit lie the Kuiper belt and scattered disc, which are populations of trans-Neptunian objects composed mostly of ices, within these populations are several dozen to possibly tens of thousands of objects large enough that they have been rounded by their own gravity. Such objects are categorized as dwarf planets, identified dwarf planets include the asteroid Ceres and the trans-Neptunian objects Pluto and Eris. In addition to two regions, various other small-body populations, including comets, centaurs and interplanetary dust clouds. Six of the planets, at least four of the dwarf planets, each of the outer planets is encircled by planetary rings of dust and other small objects. The solar wind, a stream of charged particles flowing outwards from the Sun, the heliopause is the point at which pressure from the solar wind is equal to the opposing pressure of the interstellar medium, it extends out to the edge of the scattered disc. The Oort cloud, which is thought to be the source for long-period comets, the Solar System is located in the Orion Arm,26,000 light-years from the center of the Milky Way. For most of history, humanity did not recognize or understand the concept of the Solar System, the invention of the telescope led to the discovery of further planets and moons. The principal component of the Solar System is the Sun, a G2 main-sequence star that contains 99. 86% of the known mass. The Suns four largest orbiting bodies, the giant planets, account for 99% of the mass, with Jupiter. The remaining objects of the Solar System together comprise less than 0. 002% of the Solar Systems total mass, most large objects in orbit around the Sun lie near the plane of Earths orbit, known as the ecliptic
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Outer space
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Outer space or just space, is the void that exists between celestial bodies, including Earth. The baseline temperature, as set by the radiation from the Big Bang, is 2.7 kelvins. In most galaxies, observations provide evidence that 90% of the mass is in a form, called dark matter. Data indicates that the majority of the mass-energy in the universe is a poorly understood vacuum energy of space which astronomers label dark energy. Intergalactic space takes up most of the volume of the Universe, there is no firm boundary where outer space starts. However the Kármán line, at an altitude of 100 km above sea level, is used as the start of outer space in space treaties. The framework for international law was established by the Outer Space Treaty. This treaty precludes any claims of sovereignty and permits all states to freely explore outer space. Despite the drafting of UN resolutions for the uses of outer space. Humans began the exploration of space during the 20th century with the advent of high-altitude balloon flights. Earth orbit was first achieved by Yuri Gagarin of the Soviet Union in 1961, due to the high cost of getting into space, manned spaceflight has been limited to low Earth orbit and the Moon. Outer space represents an environment for human exploration because of the dual hazards of vacuum. Microgravity also has an effect on human physiology that causes both muscle atrophy and bone loss. In addition to health and environmental issues, the economic cost of putting objects, including humans. In 350 BCE, Greek philosopher Aristotle suggested that nature abhors a vacuum and this concept built upon a 5th-century BCE ontological argument by the Greek philosopher Parmenides, who denied the possible existence of a void in space. Based on this idea that a vacuum could not exist, in the West it was held for many centuries that space could not be empty. As late as the 17th century, the French philosopher René Descartes argued that the entirety of space must be filled, in ancient China, there were various schools of thought concerning the nature of the heavens, some of which bear a resemblance to the modern understanding. In the 2nd century, astronomer Zhang Heng became convinced that space must be infinite, extending well beyond the mechanism that supported the Sun, the surviving books of the Hsüan Yeh school said that the heavens were boundless, empty and void of substance
20.
Small Explorer program
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The Small Explorer program is an effort within NASA to fund space exploration missions that cost no more than US$120 million. Extending the larger Explorers program, it was started in 1989, the first set of three SMEX missions were launched between 1992 and 1998. The second set of two missions were launched in 1998 and 1999 and these missions were managed by the Small Explorer Project Office at NASAs Goddard Space Flight Center
21.
Southwest Research Institute
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Southwest Research Institute, headquartered in San Antonio, Texas, is one of the oldest and largest independent, nonprofit, applied research and development organizations in the United States. Founded in 1947 by oil businessman Thomas Slick, Jr. SwRI provides contract research and development services to government, swRI’s mission statement is, Benefiting government, industry and the public through innovative science and technology. The institute consists of a number of divisions that offer multidisciplinary, problem-solving services in a variety of areas in engineering. These projects are funded almost equally between the government and commercial sectors, at the close of fiscal year 2015, the SwRI staff numbered 2,708 employees and total revenue was $592 million. The institute provided $7.2 million to fund innovative research through its internally sponsored R&D program. S, SwRI initiates contracts with clients based on consultations and prepares a formal proposal outlining the scope of work. Subject to client wishes, programs are kept confidential, as part of a long-held tradition, patent rights arising from sponsored research are often assigned to the client. SwRI generally retains the rights to institute-funded advancements, the institute’s headquarters occupy more than two million square feet of office and laboratory space on more than 1,200 acres in San Antonio. The institute also provides environmental monitoring expertise at a munitions disposal site at the Umatilla Army Depot in Hermiston, Oregon, official website Quick facts Product certification directory Southwest Research Institute from the Handbook of Texas Online Form 990 Filed with IRS
22.
Los Alamos National Laboratory
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Los Alamos National Laboratory is one of two laboratories in the United States in which classified work towards the design of nuclear weapons has been undertaken. LANL is a United States Department of Energy national laboratory, managed and operated by Los Alamos National Security, located in Los Alamos, the laboratory is one of the largest science and technology institutions in the world. It conducts multidisciplinary research in such as national security, space exploration, renewable energy, medicine, nanotechnology. General Leslie Groves wanted a central laboratory at a location for safety. It should be at least 200 miles from international boundaries and west of the Mississippi, major John Dudley suggested Oak City, Utah or Jemez Springs, New Mexico but both were rejected. Manhattan Project scientific director J. Robert Oppenheimer had spent much time in his youth in the New Mexico area, Dudley had rejected the school as not meeting Groves’ criteria, but as soon as Groves saw it he said in effect This is the place. Oppenheimer became the laboratorys first director, during the Manhattan Project, Los Alamos hosted thousands of employees, including many Nobel Prize-winning scientists. The location was a total secret and its only mailing address was a post office box, number 1663, in Santa Fe, New Mexico. Eventually two other post office boxes were used,180 and 1539, also in Santa Fe, though its contract with the University of California was initially intended to be temporary, the relationship was maintained long after the war. The work of the laboratory culminated in the creation of several devices, one of which was used in the first nuclear test near Alamogordo, New Mexico, codenamed Trinity. The other two were weapons, Little Boy and Fat Man, which were used in the attacks on Hiroshima, the Laboratory received the Army-Navy ‘E’ Award for Excellence in production on October 16,1945. Many of the original Los Alamos luminaries chose to leave the laboratory, in the years since the 1940s, Los Alamos was responsible for the development of the hydrogen bomb, and many other variants of nuclear weapons. In 1952, Lawrence Livermore National Laboratory was founded to act as Los Alamos competitor, Los Alamos and Livermore served as the primary classified laboratories in the U. S. national laboratory system, designing all the countrys nuclear arsenal. Additional work included basic research, particle accelerator development, health physics. Many nuclear tests were undertaken in the Marshall Islands and at the Nevada Test Site, during the late-1950s, a number of scientists including Dr. J. Robert Bob Beyster left Los Alamos to work for General Atomics in San Diego. Three major nuclear-related accidents have occurred at LANL, criticality accidents occurred in August 1945 and May 1946, and a third accident occurred during an annual physical inventory in December 1958. Several buildings associated with the Manhattan Project at Los Alamos were declared a National Historic Landmark in 1965, Los Alamos nuclear work is currently thought to relate primarily to computer simulations and stockpile stewardship. The development of the Dual-Axis Radiographic Hydrodynamic Test Facility will allow complex simulations of nuclear tests to take place without full explosive yields, the lab has made intense efforts for humanitarian causes through its scientific research in medicine
23.
Lockheed Martin
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Lockheed Martin is an American global aerospace, defense, security and advanced technologies company with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995 and it is headquartered in Bethesda, Maryland, in the Washington, DC, area. Lockheed Martin employs 126,000 people worldwide, Marillyn Hewson is the current President and Chief Executive Officer. Lockheed Martin is one of the largest companies in the aerospace, defense, security and it is the worlds largest defense contractor based on revenue for fiscal year 2014. In 2013, 78% of Lockheed Martins revenues came from sales, it topped the list of US federal government contractors. In 2009 US government contracts accounted for $38.4 billion, foreign government contracts $5.8 billion, Lockheed Martin operates in five business segments, Aeronautics, Information Systems & Global Solutions, Missiles and Fire Control, Rotary and Mission Systems, and Space Systems. The company also invests in healthcare systems, renewable energy systems, intelligent energy distribution, merger talks between Lockheed Corporation and Martin Marietta began in March 1994, with the companies announcing their $10 billion planned merger on August 30,1994. The deal was finalized on March 15,1995, when the two companies approved the merger. The segments of the two companies not retained by the new company formed the basis for the present L-3 Communications, Lockheed Martin also later spun off the materials company Martin Marietta Materials. Both companies contributed important products to the new portfolio, Lockheed products included the Trident missile, P-3 Orion, F-16 Fighting Falcon, F-22 Raptor, C-130 Hercules, A-4AR Fightinghawk and the DSCS-3 satellite. Martin Marietta products included Titan rockets, Sandia National Laboratories, Space Shuttle External Tank, Viking 1 and Viking 2 landers, the Transfer Orbit Stage and various satellite models. On April 22,1996, Lockheed Martin completed the acquisition of Loral Corporations defense electronics and system integration businesses for $9.1 billion, the remainder of Loral became Loral Space & Communications. Lockheed Martin abandoned plans for a $8, the development of the spacecraft cost $193.1 million. In May 2001, Lockheed Martin sold Lockheed Martin Control Systems to BAE Systems, on November 27,2000, Lockheed completed the sale of its Aerospace Electronic Systems business to BAE Systems for $1.67 billion, a deal announced in July 2000. This group encompassed Sanders Associates, Fairchild Systems, and Lockheed Martin Space Electronics & Communications. In 2001, Lockheed Martin won the contract to build the F-35 Lightning II, in 2001, Lockheed Martin settled a nine–year investigation conducted by NASAs Office of Inspector General with the assistance of the Defense Contract Audit Agency. The company paid the United States government $7.1 million based on allegations that its predecessor, Lockheed Engineering Science Corporation, submitted false lease costs claims to NASA. On August 31,2006, Lockheed Martin won a $3.9 billion contract from NASA to design and build the CEV capsule, in 2009, NASA reduced the capsule crew requirements from the initial six seats to four for transport to the International Space Station
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Moon
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The Moon is an astronomical body that orbits planet Earth, being Earths only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, following Jupiters satellite Io, the Moon is second-densest satellite among those whose densities are known. The average distance of the Moon from the Earth is 384,400 km, the Moon is thought to have formed about 4.51 billion years ago, not long after Earth. It is the second-brightest regularly visible celestial object in Earths sky, after the Sun and its surface is actually dark, although compared to the night sky it appears very bright, with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its cycle of phases have made the Moon an important cultural influence since ancient times on language, calendars, art. The Moons gravitational influence produces the ocean tides, body tides, and this matching of apparent visual size will not continue in the far future. The Moons linear distance from Earth is currently increasing at a rate of 3.82 ±0.07 centimetres per year, since the Apollo 17 mission in 1972, the Moon has been visited only by uncrewed spacecraft. The usual English proper name for Earths natural satellite is the Moon, the noun moon is derived from moone, which developed from mone, which is derived from Old English mōna, which ultimately stems from Proto-Germanic *mǣnōn, like all Germanic language cognates. Occasionally, the name Luna is used, in literature, especially science fiction, Luna is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of our moon. The principal modern English adjective pertaining to the Moon is lunar, a less common adjective is selenic, derived from the Ancient Greek Selene, from which is derived the prefix seleno-. Both the Greek Selene and the Roman goddess Diana were alternatively called Cynthia, the names Luna, Cynthia, and Selene are reflected in terminology for lunar orbits in words such as apolune, pericynthion, and selenocentric. The name Diana is connected to dies meaning day, several mechanisms have been proposed for the Moons formation 4.51 billion years ago, and some 60 million years after the origin of the Solar System. These hypotheses also cannot account for the angular momentum of the Earth–Moon system. This hypothesis, although not perfect, perhaps best explains the evidence, eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, and Jeff Taylor challenged fellow lunar scientists, You have eighteen months. Go back to your Apollo data, go back to computer, do whatever you have to. Dont come to our conference unless you have something to say about the Moons birth, at the 1984 conference at Kona, Hawaii, the giant impact hypothesis emerged as the most popular. Afterward there were only two groups, the giant impact camp and the agnostics. Giant impacts are thought to have been common in the early Solar System, computer simulations of a giant impact have produced results that are consistent with the mass of the lunar core and the present angular momentum of the Earth–Moon system
25.
Solar wind
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The solar wind is a stream of charged particles released from the upper atmosphere of the Sun. This plasma consists of electrons, protons and alpha particles with thermal energies between 1.5 and 10 keV. Embedded within the plasma is the interplanetary magnetic field. The solar wind varies in density, temperature and speed over time and its particles can escape the Suns gravity because of their high energy resulting from the high temperature of the corona, which in turn is a result of the coronal magnetic field. At a distance of more than a few radii from the sun. The flow of the wind is no longer supersonic at the termination shock. The Voyager 2 spacecraft crossed the shock more than five times between 30 August and 10 December 2007, Voyager 2 crossed the shock about a billion kilometers closer to the Sun than the 13.5 billion kilometer distance where Voyager 1 came upon the termination shock. The spacecraft moved outward through the shock into the heliosheath. Other related phenomena include the aurora, the tails of comets that always point away from the Sun. The existence of flowing outward from the Sun to the Earth was first suggested by British astronomer Richard C. In 1859, Carrington and Richard Hodgson independently made the first observation of what would later be called a solar flare, george FitzGerald later suggested that matter was being regularly accelerated away from the Sun and was reaching the Earth after several days. In 1910 British astrophysicist Arthur Eddington essentially suggested the existence of the wind, without naming it. The idea never caught on even though Eddington had also made a similar suggestion at a Royal Institution address the previous year. In the latter case, he postulated that the material consisted of electrons while in his study of Comet Morehouse he supposed them to be ions. The first person to suggest that the material consisted of both ions and electrons was Kristian Birkeland. His geomagnetic surveys showed that activity was nearly uninterrupted. In 1916, Birkeland proposed that, From a physical point of view it is most probable that solar rays are neither exclusively negative nor positive rays, in other words, the solar wind consists of both negative electrons and positive ions. Three years later in 1919, Frederick Lindemann also suggested that particles of both polarities, protons as well as electrons, come from the Sun
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Energetic neutral atom
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This constitutes the far-flung edge of the solar system. The solar wind consists of ripped-apart atoms flying out of the Sun and this is mostly hydrogen, that is, bare electrons and protons, with a little bit of other kinds of nuclei, mostly helium. The space between systems is similar, but they come from other stars in our galaxy. These charged particles can be redirected by magnetic fields, for instance, but, every so often, a few of them steal electrons from neutral atoms they run into. At that point, they become neutral, although theyre still moving very fast and these are called Energetic Neutral Atoms. ENA images are constructed from the detection of these energetic neutral atoms, Earths magnetosphere preserves Earths atmosphere and protects us from cell-damaging radiation. This region of space weather is the site of geomagnetic storms that disrupt communications systems, a deeper understanding of this region is vitally important. The heliosphere protects the entire Solar System from the majority of cosmic rays but is so remote that only an imaging technique such as ENA imaging will reveal its properties. The heliospheres structure is due to the interaction between the solar wind and cold gas from the local interstellar medium. The creation of ENAs by space plasmas was predicted but their discovery was both deliberate and serendipitous, while some early efforts were made at detection, their signatures also explained inconsistent findings by ion detectors in regions of expected low ion populations. Ion detectors were co-opted for further ENA detection experiments in other low-ion regions, however, the development of dedicated ENA detectors entailed overcoming significant obstacles in both skepticism and technology. Although ENAs were observed in space from the 1960s through 1980s, today, dedicated ENA instruments have provided detailed magnetospheric images from Venus, Mars, Jupiter, and Saturn. Cassinis ENA images of Saturn revealed a unique magnetosphere with complex interactions that have yet to be fully explained, the first ever images of the heliospheric boundary, published in October 2009, were made by the ENA instruments aboard the IBEX and Cassini spacecraft. These images are very exciting because they challenge existing theories about the region, the most abundant ion in space plasmas is the hydrogen ion—a bare proton with no excitable electrons to emit visible photons. The occasional visibility of other ions is not sufficient for imaging purposes. ENAs are created in charge-exchange collisions between hot solar plasma ions and a neutral background gas. These charge-exchange processes occur with frequency in planetary magnetospheres and at the edge of the heliosphere. In a charge-exchange collision between a high energy plasma ion and a neutral atom, the ion steals electrons from the neutral atom, producing a cold ion
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Collimator
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A collimator is a device that narrows a beam of particles or waves. To narrow can mean either to cause the directions of motion to become aligned in a specific direction. An English physicist Henry Kater was the inventor of the floating collimator and he reported about his invention in January 1825. In his report, Kater mentioned previous work in area by Carl Friedrich Gauss. In optics, a collimator may consist of a mirror or lens with some type of light source and/or an image at its focus. This can be used to replicate a target focused at infinity with little or no parallax, in lighting, collimators are typically designed using the principles of nonimaging optics. A surveying camera may be collimated by setting its fiduciary markers so that they define the principal point, optical collimators are also used as gun sights in the collimator sight, which is a simple optical collimator with a cross hair or some other reticle at its focus. The viewer only sees an image of the reticle, adding a beam splitter allows the viewer to see the reticle and the field of view, making a reflector sight. Collimators may be used with laser diodes and CO2 cutting lasers, proper collimation of a laser source with long enough coherence length can be verified with a shearing interferometer. In neutron, X-ray, and gamma ray optics, a collimator is a device that filters a stream of rays so that only those traveling parallel to a direction are allowed through. Collimators are also used with radiation detectors in nuclear power stations for monitoring sources of radioactivity, the figure to the right illustrates how a Söller collimator is used in neutron and X-ray machines. The upper panel shows a situation where a collimator is not used, in both panels the source of radiation is to the right, and the image is recorded on the gray plate at the left of the panels. The resultant image will be so blurred and indistinct as to be useless, in the lower panel of the figure, a collimator has been added. This can be something simple e. g. air, or if mechanical strength is needed then aluminium may be used. If this forms part of an assembly, the sandwich may be curved. This allows energy selection in addition to collimation - the curvature of the collimator, only rays that are travelling nearly parallel to the holes will pass through them—any others will be absorbed by hitting the plate surface or the side of a hole. This ensures that rays are recorded in their place on the plate. A collimator in this instance is most commonly made of tungsten, for instance, the thinnest walls on the sides of a 4 HVL tungsten collimator 13 mm thick will reduce the intensity of radiation passing through them by 88. 5%
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Hydrogen
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Hydrogen is a chemical element with chemical symbol H and atomic number 1. With a standard weight of circa 1.008, hydrogen is the lightest element on the periodic table. Its monatomic form is the most abundant chemical substance in the Universe, non-remnant stars are mainly composed of hydrogen in the plasma state. The most common isotope of hydrogen, termed protium, has one proton, the universal emergence of atomic hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, since hydrogen readily forms covalent compounds with most nonmetallic elements, most of the hydrogen on Earth exists in molecular forms such as water or organic compounds. Hydrogen plays an important role in acid–base reactions because most acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a charge when it is known as a hydride. The hydrogen cation is written as though composed of a bare proton, Hydrogen gas was first artificially produced in the early 16th century by the reaction of acids on metals. Industrial production is mainly from steam reforming natural gas, and less often from more energy-intensive methods such as the electrolysis of water. Most hydrogen is used near the site of its production, the two largest uses being fossil fuel processing and ammonia production, mostly for the fertilizer market, Hydrogen is a concern in metallurgy as it can embrittle many metals, complicating the design of pipelines and storage tanks. Hydrogen gas is flammable and will burn in air at a very wide range of concentrations between 4% and 75% by volume. The enthalpy of combustion is −286 kJ/mol,2 H2 + O2 →2 H2O +572 kJ Hydrogen gas forms explosive mixtures with air in concentrations from 4–74%, the explosive reactions may be triggered by spark, heat, or sunlight. The hydrogen autoignition temperature, the temperature of spontaneous ignition in air, is 500 °C, the detection of a burning hydrogen leak may require a flame detector, such leaks can be very dangerous. Hydrogen flames in other conditions are blue, resembling blue natural gas flames, the destruction of the Hindenburg airship was a notorious example of hydrogen combustion and the cause is still debated. The visible orange flames in that incident were the result of a mixture of hydrogen to oxygen combined with carbon compounds from the airship skin. H2 reacts with every oxidizing element, the ground state energy level of the electron in a hydrogen atom is −13.6 eV, which is equivalent to an ultraviolet photon of roughly 91 nm wavelength. The energy levels of hydrogen can be calculated fairly accurately using the Bohr model of the atom, however, the atomic electron and proton are held together by electromagnetic force, while planets and celestial objects are held by gravity. The most complicated treatments allow for the effects of special relativity
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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
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Ion
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An ion is an atom or a molecule in which the total number of electrons is not equal to the total number of protons, giving the atom or molecule a net positive or negative electrical charge. Ions can be created, by chemical or physical means. In chemical terms, if an atom loses one or more electrons. If an atom gains electrons, it has a net charge and is known as an anion. Ions consisting of only a single atom are atomic or monatomic ions, because of their electric charges, cations and anions attract each other and readily form ionic compounds, such as salts. In the case of ionization of a medium, such as a gas, which are known as ion pairs are created by ion impact, and each pair consists of a free electron. The word ion comes from the Greek word ἰόν, ion, going and this term was introduced by English physicist and chemist Michael Faraday in 1834 for the then-unknown species that goes from one electrode to the other through an aqueous medium. Faraday also introduced the words anion for a charged ion. In Faradays nomenclature, cations were named because they were attracted to the cathode in a galvanic device, arrhenius explanation was that in forming a solution, the salt dissociates into Faradays ions. Arrhenius proposed that ions formed even in the absence of an electric current, ions in their gas-like state are highly reactive, and do not occur in large amounts on Earth, except in flames, lightning, electrical sparks, and other plasmas. These gas-like ions rapidly interact with ions of charge to give neutral molecules or ionic salts. These stabilized species are commonly found in the environment at low temperatures. A common example is the present in seawater, which are derived from the dissolved salts. Electrons, due to their mass and thus larger space-filling properties as matter waves, determine the size of atoms. Thus, anions are larger than the parent molecule or atom, as the excess electron repel each other, as such, in general, cations are smaller than the corresponding parent atom or molecule due to the smaller size of its electron cloud. One particular cation contains no electrons, and thus consists of a single proton - very much smaller than the parent hydrogen atom. Since the electric charge on a proton is equal in magnitude to the charge on an electron, an anion, from the Greek word ἄνω, meaning up, is an ion with more electrons than protons, giving it a net negative charge. A cation, from the Greek word κατά, meaning down, is an ion with fewer electrons than protons, there are additional names used for ions with multiple charges
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Ultraviolet
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Ultraviolet is an electromagnetic radiation with a wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays. UV radiation constitutes about 10% of the light output of the Sun. It is also produced by electric arcs and specialized lights, such as lamps, tanning lamps. Consequently, the effects of UV are greater than simple heating effects. Suntan, freckling and sunburn are familiar effects of over-exposure, along with risk of skin cancer. Living things on dry land would be damaged by ultraviolet radiation from the Sun if most of it were not filtered out by the Earths atmosphere. More-energetic, shorter-wavelength extreme UV below 121 nm ionizes air so strongly that it is absorbed before it reaches the ground, Ultraviolet is also responsible for the formation of bone-strengthening vitamin D in most land vertebrates, including humans. The UV spectrum thus has both beneficial and harmful to human health. Ultraviolet rays are invisible to most humans, the lens in a human eye ordinarily filters out UVB frequencies or higher, and humans lack color receptor adaptations for ultraviolet rays. Under some conditions, children and young adults can see ultraviolet down to wavelengths of about 310 nm, near-UV radiation is visible to some insects, mammals, and birds. Small birds have a fourth color receptor for ultraviolet rays, this gives birds true UV vision, reindeer use near-UV radiation to see polar bears, who are poorly visible in regular light because they blend in with the snow. UV also allows mammals to see urine trails, which is helpful for animals to find food in the wild. The males and females of some species look identical to the human eye. Ultraviolet means beyond violet, violet being the color of the highest frequencies of visible light, Ultraviolet has a higher frequency than violet light. He called them oxidizing rays to emphasize chemical reactivity and to them from heat rays. The terms chemical and heat rays were eventually dropped in favour of ultraviolet and infrared radiation, in 1878 the effect of short-wavelength light on sterilizing bacteria was discovered. By 1903 it was known the most effective wavelengths were around 250 nm, in 1960, the effect of ultraviolet radiation on DNA was established. The discovery of the ultraviolet radiation below 200 nm, named vacuum ultraviolet because it is absorbed by air, was made in 1893 by the German physicist Victor Schumann
32.
Solid-propellant rocket
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A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants. The earliest rockets were solid-fuel rockets powered by gunpowder, they were used in warfare by the Chinese, Indians, Mongols and Persians, all rockets used some form of solid or powdered propellant up until the 20th century, when liquid-propellant rockets offered more efficient and controllable alternatives. Solid rockets are used today in model rockets and on larger applications for their simplicity and reliability. Since solid-fuel rockets can remain in storage for periods, and then reliably launch on short notice. Solids are, however, frequently used as boosters to increase payload capacity or as spin-stabilized add-on upper stages when higher-than-normal velocities are required. Solid rockets are used as launch vehicles for low Earth orbit payloads under 2 tons or escape payloads up to 500 kilograms. A simple solid rocket motor consists of a casing, nozzle, grain, the grain behaves like a solid mass, burning in a predictable fashion and producing exhaust gases. The nozzle dimensions are calculated to maintain a design chamber pressure, once ignited, a simple solid rocket motor cannot be shut off, because it contains all the ingredients necessary for combustion within the chamber in which they are burned. More advanced solid rocket motors can not only be throttled but also be extinguished, also, pulsed rocket motors that burn in segments and that can be ignited upon command are available. Design begins with the total impulse required, which determines the fuel/oxidizer mass, grain geometry and chemistry are then chosen to satisfy the required motor characteristics. The following are chosen or solved simultaneously, the results are exact dimensions for grain, nozzle, and case geometries, The grain burns at a predictable rate, given its surface area and chamber pressure. The chamber pressure is determined by the orifice diameter and grain burn rate. Allowable chamber pressure is a function of casing design, the length of burn time is determined by the grain web thickness. The grain may or may not be bonded to the casing, case-bonded motors are more difficult to design, since the deformation of the case and the grain under flight must be compatible. Common modes of failure in rocket motors include fracture of the grain, failure of case bonding. All of these produce an increase in burn surface area and a corresponding increase in exhaust gas production rate and pressure. Another failure mode is casing seal failure, seals are required in casings that have to be opened to load the grain. Once a seal fails, hot gas will erode the escape path and this was the cause of the Space Shuttle Challenger disaster
33.
Magnetosphere
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A magnetosphere is the region of space surrounding an astronomical object in which charged particles are controlled by that objects magnetic field. The magnetic field near the surface of many astronomical objects resembles that of a dipole, the field lines farther away from the surface can be significantly distorted by the flow of electrically conducting plasma emitted from a nearby star. Study of Earths magnetosphere began in 1600, when William Gilbert discovered that the field on the surface of Earth resembled that on a terrella. In the 1940s, Walter M. Elsasser proposed the model of dynamo theory, through the use of magnetometers, scientists were able to study the variations in Earths magnetic field as functions of both time and latitude and longitude. Beginning in the late 1940s, rockets were used to study cosmic rays, in 1958, Explorer 1, the first of the Explorer series of space missions, was launched to study the intensity of cosmic rays above the atmosphere and measure the fluctuations in this activity. This mission observed the existence of the Van Allen radiation belt, also in 1958, Eugene Parker proposed the idea of the solar wind. The term magnetosphere was proposed by Thomas Gold in 1959, the Explorer 12 mission led to the observation by Cahill and Amazeen in 1963 of a sudden decrease in the strength of the magnetic field near the noon meridian, later named the magnetopause. In 1983, the International Cometary Explorer observed the magnetotail, or the distant magnetic field, the distance at which a planet can withstand the solar wind pressure is called the Chapman–Ferraro distance. Mercury, Earth, Jupiter, Ganymede, Saturn, Uranus, a magnetosphere is classified as induced when R C F ≪ R P, or when the solar wind is not opposed by the objects magnetic field. In this case, the solar wind interacts with the atmosphere or ionosphere of the planet, when R C F ≈ R P, the planet itself and its magnetic field both contribute. It is possible that Mars is of this type, the bow shock forms the outermost layer of the magnetosphere, the boundary between the magnetosphere and the ambient medium. For stars, this is usually the boundary between the wind and interstellar medium, for planets, the speed of the solar wind there decreases as it approaches the magnetopause. The magnetosheath is the region of the magnetosphere between the bow shock and the magnetopause and it is formed mainly from shocked solar wind, though it contains a small amount of plasma from the magnetosphere. It is an area exhibiting high particle flux, where the direction. This is caused by the collection of solar wind gas that has effectively undergone thermalization and it acts as a cushion that transmits the pressure from the flow of the solar wind and the barrier of the magnetic field from the object. The magnetopause is the area of the magnetosphere wherein the pressure from the magnetic field is balanced with the pressure from the solar wind. It is the convergence of the solar wind from the magnetosheath with the magnetic field of the object. Because both sides of this convergence contain magnetized plasma, the interactions between them are complex, the structure of the magnetopause depends upon the Mach number and beta of the plasma, as well as the magnetic field
34.
Telemetry
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Telemetry is an automated communications process by which measurements and other data are collected at remote or inaccessible points and transmitted to receiving equipment for monitoring. The word is derived from Greek roots, tele = remote, systems that need external instructions and data to operate require the counterpart of telemetry, telecommand. Many modern telemetry systems take advantage of the low cost and ubiquity of GSM networks by using SMS to receive, a telemeter is a device used to remotely measure any quantity. It consists of a sensor, a path, and a display, recording. Telemeters are the devices used in telemetry. Electronic devices are used in telemetry and can be wireless or hard-wired. Other technologies are possible, such as mechanical, hydraulic. Telemetry may be commutated to allow the transmission of data streams in a fixed frame. Telemetering information over wire had its origins in the 19th century, One of the first data-transmission circuits was developed in 1845 between the Russian Tsars Winter Palace and army headquarters. In 1874, French engineers built a system of weather and snow-depth sensors on Mont Blanc that transmitted real-time information to Paris, in 1901 the American inventor C. Michalke patented the selsyn, a circuit for sending synchronized rotation information over a distance, in 1906 a set of seismic stations were built with telemetering to the Pulkovo Observatory in Russia. In 1912, Commonwealth Edison developed a system of telemetry to monitor electrical loads on its power grid, the Panama Canal used extensive telemetry systems to monitor locks and water levels. Wireless telemetry made early appearances in the radiosonde, developed concurrently in 1930 by Robert Bureau in France, mochanovs system modulated temperature and pressure measurements by converting them to wireless Morse code. In the US and the USSR, the Messina system was replaced with better systems. Early Soviet missile and space telemetry systems which were developed in the late 1940s used either pulse-position modulation or pulse-duration modulation, in the United States, early work employed similar systems, but were later replaced by pulse-code modulation. Later Soviet interplanetary probes used redundant radio systems, transmitting telemetry by PCM on a decimeter band, telemetry has been used by weather balloons for transmitting meteorological data since 1920. Telemetry is used to transmit drilling mechanics and formation evaluation information uphole, in real time and these services are known as Measurement while drilling and Logging while drilling. Information acquired thousands of feet below ground, while drilling, is sent through the hole to the surface sensors
35.
Vandenberg Air Force Base
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Vandenberg Air Force Base is a United States Air Force Base 9.2 miles northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command, Vandenberg AFB is a Department of Defense space and missile testing base, with a mission of placing satellites into polar orbit from the West Coast using expendable boosters. Wing personnel also support the Services LGM-30G Minuteman III Intercontinental Ballistic Missile Force Development Evaluation program, in addition to its military mission, the base also leases launch pad facilities to SpaceX, as well as 100 acres leased to the California Spaceport in 1995. Established in 1941, the base is named in honor of former Air Force Chief of Staff General Hoyt Vandenberg, the host unit at Vandenberg AFB is the 30th Space Wing. The 30th SW is home to the Western Range, manages Department of Defense space and missile testing, Wing personnel also support the Air Forces Minuteman III Intercontinental Ballistic Missile Force Development Test and Evaluation program. The Western Range begins at the boundaries of Vandenberg and extends westward from the California coast to the Western Pacific. Operations involve dozens of federal and commercial interests, the wing is organized into operations, launch, mission support and medical groups, along with several directly assigned staff agencies. 30th Launch Group The 30th Launch Group is responsible for booster and satellite technical oversight and launch processing activities to launch, integration. The group consists of a military, civilian and contractor team with more than 250 personnel directly supporting operations from the Western Range. 1st Air and Space Test Squadron 4th Space Launch Squadron 30th Operations Group The 30th Operations Group provides the capability for West Coast spacelift. Operations professionals are responsible for operating and maintaining the Western Range for spacelift, missile test launch, aeronautical, 30th Mission Support Group The 30th Mission Support Group supports the third largest Air Force Base in the United States. It is also responsible for quality-of-life needs, housing, personnel, services, civil engineering, contracting, 30th Medical Group The 30th Medical Group provides medical, dental, bio-environmental and public health services for people assigned to Vandenberg Air Force Base, their families and retirees. It is Vandenbergs only National Historic Landmark that is open for scheduled tours through the 30th Space Wings Public Affairs office. The current display area is made up of two exhibits, the Chronology of the Cold War and the Evolution of Technology, there are plans to evolve the center in stages from the current exhibit areas as restorations of additional facilities are completed. In 1941 the United States Army sought more and better training centers for the development of its armored. In March 1941, the Army acquired approximately 86,000 acres of open ranch lands along the Central Coast of California between Lompoc and Santa Maria, most of the land was purchased. Smaller parcels were obtained either by lease, license, or as easements, with its flat plateau, surrounding hills, numerous canyons, and relative remoteness from populated areas, the Army was convinced it had found the ideal training location. Construction of the Army camp began in September 1941, although its completion was still months away, the Army activated the camp on 5 October, and named it Camp Cooke in honor of Major General Phillip St. George Cooke
36.
California
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California is the most populous state in the United States and the third most extensive by area. Located on the western coast of the U. S, California is bordered by the other U. S. states of Oregon, Nevada, and Arizona and shares an international border with the Mexican state of Baja California. Los Angeles is Californias most populous city, and the second largest after New York City. The Los Angeles Area and the San Francisco Bay Area are the nations second- and fifth-most populous urban regions, California also has the nations most populous county, Los Angeles County, and its largest county by area, San Bernardino County. The Central Valley, an agricultural area, dominates the states center. What is now California was first settled by various Native American tribes before being explored by a number of European expeditions during the 16th and 17th centuries, the Spanish Empire then claimed it as part of Alta California in their New Spain colony. The area became a part of Mexico in 1821 following its war for independence. The western portion of Alta California then was organized as the State of California, the California Gold Rush starting in 1848 led to dramatic social and demographic changes, with large-scale emigration from the east and abroad with an accompanying economic boom. If it were a country, California would be the 6th largest economy in the world, fifty-eight percent of the states economy is centered on finance, government, real estate services, technology, and professional, scientific and technical business services. Although it accounts for only 1.5 percent of the states economy, the story of Calafia is recorded in a 1510 work The Adventures of Esplandián, written as a sequel to Amadis de Gaula by Spanish adventure writer Garci Rodríguez de Montalvo. The kingdom of Queen Calafia, according to Montalvo, was said to be a land inhabited by griffins and other strange beasts. This conventional wisdom that California was an island, with maps drawn to reflect this belief, shortened forms of the states name include CA, Cal. Calif. and US-CA. Settled by successive waves of arrivals during the last 10,000 years, various estimates of the native population range from 100,000 to 300,000. The Indigenous peoples of California included more than 70 distinct groups of Native Americans, ranging from large, settled populations living on the coast to groups in the interior. California groups also were diverse in their organization with bands, tribes, villages. Trade, intermarriage and military alliances fostered many social and economic relationships among the diverse groups, the first European effort to explore the coast as far north as the Russian River was a Spanish sailing expedition, led by Portuguese captain Juan Rodríguez Cabrillo, in 1542. Some 37 years later English explorer Francis Drake also explored and claimed a portion of the California coast in 1579. Spanish traders made unintended visits with the Manila galleons on their trips from the Philippines beginning in 1565
37.
Lockheed L-1011 TriStar
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The Lockheed L-1011 TriStar, commonly referred to as the L-1011 or TriStar, is a medium-to-long-range, wide-body trijet airliner by Lockheed Corporation. It was the third wide-body airliner to enter commercial operations, after the Boeing 747, the airliner has a seating capacity up to 400 passengers and a range over 4,000 nautical miles. Its trijet configuration has three Rolls-Royce RB211 engines with one engine under each wing, and an engine, center-mounted with an S-duct air inlet embedded in the tail. The aircraft has a capability, an automated descent control system. The L-1011 TriStar was produced in two fuselage lengths, the original L-1011-1 first flew in November 1970, and entered service with Eastern Air Lines in 1972. The shortened, longer range L-1011-500 first flew in 1978, the original-length TriStar was also produced as the high gross weight L-1011-100, up-rated engine L-1011-200, and further upgraded L-1011-250. Post-production conversions for the L-1011-1 with increased takeoff weights included the L-1011-50 and L-1011-150, between 1968 and 1984, Lockheed manufactured a total of 250 TriStars, assembled at the Lockheed plant located at the Palmdale Regional Airport in southern California north of Los Angeles. The aircrafts sales were hampered by two years of delays due to developmental and financial problems at Rolls-Royce plc, the manufacturer of the TriStars engines. After production ended, Lockheed withdrew from the aircraft business due to its below-target sales. Lockheed had not produced civilian airliners since 1961 with the L-188 Electra, in the 1950s the Electra was designed for turboprop propulsion, which Lockheed had successfully used on the C-130 Hercules military transport. Lockheed won contracts for jet military transports with the C-141 StarLifter, Boeing lost the military contract, but its private venture 747 captured what would become a much larger civilian airliner market for wide-body airliners. Having experienced difficulties with some of their programs, Lockheed was eager to re-enter the civilian market with a smaller wide-body jet. The aircraft was conceived as a jumbo twin, but a three-engine design was ultimately chosen to give the aircraft enough thrust to take off from existing runways. The design featured an interior with a maximum of 400 passengers, a three-engine layout, low noise emissions, improved reliability. A further major difference between the L-1011 and the DC-10 was Lockheeds selection of the Rolls-Royce RB211 as the engine for the L-1011. As originally designed, the RB211 turbofan was an advanced design with a carbon fiber fan. This made the L-1011 more efficient, a selling point. The L-1011 and DC-10s engineering approach differed greatly, by contrast Lockheed would take the most advanced technology of the day and when that technology was lacking, Lockheed created it for the L-1011
38.
Kwajalein Atoll
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Kwajalein Atoll is part of the Republic of the Marshall Islands. The southernmost and largest island in the atoll is named Kwajalein Island, the total land area of the atoll amounts to just over 6 square miles. The atoll lies in the Ralik Chain,2,100 nautical miles southwest of Honolulu, Hawaii, Kwajalein is one of the worlds largest coral atolls as measured by area of enclosed water. Comprising 97 islands and islets, it has an area of 16.4 km² and surrounds one of the largest lagoons in the world. The average height above sea level for all the islands is about 1.8 metres, Islands often have alternate names, the first is the Marshallese name, the second was assigned somewhat arbitrarily by the US Navy prior to their attack on the atoll during World War II. The original name was considered too difficult for English speakers to properly differentiate among the islands, the latter has often been retained by English speakers. The exception to this is Kwajalein itself, which is close to the native name, the atoll is 2,100 miles from Honolulu,2,000 miles from Australia, and 2,100 miles from Japan. Kwajalein Island is about 500 miles north of the equator, Kwajalein Island is the southernmost and largest of the islands in the atoll. The area is about 1.2 square miles and it is 2.5 miles long and averages about 800 yards wide. To enlarge the island, the Americans placed fill at both the part of the island above the pier, the northern part extending towards Ebeye. The northern extension was used for housing, the remainder for industrial purposes, some 13,500 Marshallese citizens live on the atoll, most of them on Ebeye Island. The water temperature averages 81 °F degrees, underwater visibility is typically 100 feet on the ocean side of the atoll. SAR Pass is closest to Kwajalein on the West reef and this pass is manmade and was created in the mid-1950s. It is very narrow and shallow compared to the passes in the lagoon and is only used by small boats. South Pass is on the West reef, north of SAR Pass, Gea Pass is a deep water pass between Gea and Ninni islands. Bigej Pass is the first pass on the East reef north of Kwajalein, other islands in the atoll, Directly north of the eastern end of Kwajalein is Ebeye. It is not part of the Reagan Test Site, it is a Marshallese island-city with shops, restaurants and it has the largest population in the atoll, with approximately 13,000 residents living on 80 acres of land. Inhabitants are mostly Marshall Islanders but include a population of migrants and volunteers from other island groups
39.
Pacific Ocean
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The Pacific Ocean is the largest and deepest of the Earths oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean in the south and is bounded by Asia and Australia in the west, the Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 metres. Both the center of the Water Hemisphere and the Western Hemisphere are in the Pacific Ocean, the oceans current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521, as he encountered favourable winds on reaching the ocean. He called it Mar Pacífico, which in both Portuguese and Spanish means peaceful sea, important human migrations occurred in the Pacific in prehistoric times. Long-distance trade developed all along the coast from Mozambique to Japan, trade, and therefore knowledge, extended to the Indonesian islands but apparently not Australia. By at least 878 when there was a significant Islamic settlement in Canton much of trade was controlled by Arabs or Muslims. In 219 BC Xu Fu sailed out into the Pacific searching for the elixir of immortality, from 1404 to 1433 Zheng He led expeditions into the Indian Ocean. The east side of the ocean was discovered by Spanish explorer Vasco Núñez de Balboa in 1513 after his expedition crossed the Isthmus of Panama and he named it Mar del Sur because the ocean was to the south of the coast of the isthmus where he first observed the Pacific. Later, Portuguese explorer Ferdinand Magellan sailed the Pacific East to West on a Castilian expedition of world circumnavigation starting in 1519, Magellan called the ocean Pacífico because, after sailing through the stormy seas off Cape Horn, the expedition found calm waters. The ocean was often called the Sea of Magellan in his honor until the eighteenth century, sailing around and east of the Moluccas, between 1525 and 1527, Portuguese expeditions discovered the Caroline Islands, the Aru Islands, and Papua New Guinea. In 1542–43 the Portuguese also reached Japan, in 1564, five Spanish ships consisting of 379 explorers crossed the ocean from Mexico led by Miguel López de Legazpi and sailed to the Philippines and Mariana Islands. The Manila galleons operated for two and a half centuries linking Manila and Acapulco, in one of the longest trade routes in history, Spanish expeditions also discovered Tuvalu, the Marquesas, the Cook Islands, the Solomon Islands, and the Admiralty Islands in the South Pacific. In the 16th and 17th century Spain considered the Pacific Ocean a Mare clausum—a sea closed to other naval powers, as the only known entrance from the Atlantic the Strait of Magellan was at times patrolled by fleets sent to prevent entrance of non-Spanish ships. On the western end of the Pacific Ocean the Dutch threatened the Spanish Philippines, Spain also sent expeditions to the Pacific Northwest reaching Vancouver Island in southern Canada, and Alaska. The French explored and settled Polynesia, and the British made three voyages with James Cook to the South Pacific and Australia, Hawaii, and the North American Pacific Northwest, one of the earliest voyages of scientific exploration was organized by Spain in the Malaspina Expedition of 1789–1794. It sailed vast areas of the Pacific, from Cape Horn to Alaska, Guam and the Philippines, New Zealand, Australia, and the South Pacific. Growing imperialism during the 19th century resulted in the occupation of much of Oceania by other European powers, and later, Japan, in Oceania, France got a leading position as imperial power after making Tahiti and New Caledonia protectorates in 1842 and 1853 respectively. After navy visits to Easter Island in 1875 and 1887, Chilean navy officer Policarpo Toro managed to negotiate an incorporation of the island into Chile with native Rapanui in 1888, by occupying Easter Island, Chile joined the imperial nations
40.
Coordinated Universal Time
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Coordinated Universal Time, abbreviated to UTC, is the primary time standard by which the world regulates clocks and time. It is within about 1 second of mean time at 0° longitude. It is one of closely related successors to Greenwich Mean Time. For most purposes, UTC is considered interchangeable with GMT, the first Coordinated Universal Time was informally adopted on 1 January 1960. This change also adopted leap seconds to simplify future adjustments, a number of proposals have been made to replace UTC with a new system that would eliminate leap seconds, but no consensus has yet been reached. Leap seconds are inserted as necessary to keep UTC within 0.9 seconds of universal time, see the Current number of leap seconds section for the number of leap seconds inserted to date. The official abbreviation for Coordinated Universal Time is UTC and this abbreviation arose from a desire by the International Telecommunication Union and the International Astronomical Union to use the same abbreviation in all languages. English speakers originally proposed CUT, while French speakers proposed TUC, the compromise that emerged was UTC, which conforms to the pattern for the abbreviations of the variants of Universal Time. Time zones around the world are expressed using positive or negative offsets from UTC, the westernmost time zone uses UTC−12, being twelve hours behind UTC, the easternmost time zone, theoretically, uses UTC+12, being twelve hours ahead of UTC. In 1995, the nation of Kiribati moved those of its atolls in the Line Islands from UTC-10 to UTC+14 so that the country would all be on the same day. UTC is used in internet and World Wide Web standards. The Network Time Protocol, designed to synchronise the clocks of computers over the internet, computer servers, online services and other entities that rely on having a universally accepted time use UTC as it is more specific than GMT. If only limited precision is needed, clients can obtain the current UTC from a number of official internet UTC servers, for sub-microsecond precision, clients can obtain the time from satellite signals. UTC is also the standard used in aviation, e. g. for flight plans. Weather forecasts and maps all use UTC to avoid confusion about time zones, the International Space Station also uses UTC as a time standard. Amateur radio operators often schedule their radio contacts in UTC, because transmissions on some frequencies can be picked up by many time zones, UTC is also used in digital tachographs used on large goods vehicles under EU and AETR rules. UTC divides time into days, hours, minutes and seconds, days are conventionally identified using the Gregorian calendar, but Julian day numbers can also be used. Each day contains 24 hours and each hour contains 60 minutes, the number of seconds in a minute is usually 60, but with an occasional leap second, it may be 61 or 59 instead
41.
Equator
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The Equator usually refers to an imaginary line on the Earths surface equidistant from the North Pole and South Pole, dividing the Earth into the Northern Hemisphere and Southern Hemisphere. The Equator is about 40,075 kilometres long, some 78. 7% lies across water and 21. 3% over land, other planets and astronomical bodies have equators similarly defined. Generally, an equator is the intersection of the surface of a sphere with the plane that is perpendicular to the spheres axis of rotation. The latitude of the Earths equator is by definition 0° of arc, the equator is the only line of latitude which is also a great circle — that is, one whose plane passes through the center of the globe. The plane of Earths equator when projected outwards to the celestial sphere defines the celestial equator, in the cycle of Earths seasons, the plane of the equator passes through the Sun twice per year, at the March and September equinoxes. To an observer on the Earth, the Sun appears to travel North or South over the equator at these times, light rays from the center of the Sun are perpendicular to the surface of the Earth at the point of solar noon on the Equator. Locations on the Equator experience the quickest sunrises and sunsets because the sun moves nearly perpendicular to the horizon for most of the year. The Earth bulges slightly at the Equator, the diameter of the Earth is 12,750 kilometres. Because the Earth spins to the east, spacecraft must also launch to the east to take advantage of this Earth-boost of speed, seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earths axis relative to the plane of revolution. During the year the northern and southern hemispheres are inclined toward or away from the sun according to Earths position in its orbit, the hemisphere inclined toward the sun receives more sunlight and is in summer, while the other hemisphere receives less sun and is in winter. At the equinoxes, the Earths axis is not tilted toward the sun, instead it is perpendicular to the sun meaning that the day is about 12 hours long, as is the night, across the whole of the Earth. Near the Equator there is distinction between summer, winter, autumn, or spring. The temperatures are usually high year-round—with the exception of high mountains in South America, the temperature at the Equator can plummet during rainstorms. In many tropical regions people identify two seasons, the wet season and the dry season, but many places close to the Equator are on the oceans or rainy throughout the year, the seasons can vary depending on elevation and proximity to an ocean. The Equator lies mostly on the three largest oceans, the Pacific Ocean, the Atlantic Ocean, and the Indian Ocean. The highest point on the Equator is at the elevation of 4,690 metres, at 0°0′0″N 77°59′31″W and this is slightly above the snow line, and is the only place on the Equator where snow lies on the ground. At the Equator the snow line is around 1,000 metres lower than on Mount Everest, the Equator traverses the land of 11 countries, it also passes through two island nations, though without making a landfall in either. Starting at the Prime Meridian and heading eastwards, the Equator passes through, Despite its name, however, its island of Annobón is 155 km south of the Equator, and the rest of the country lies to the north
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