Sojourner Rover
''Sojourner'' is a robotic Mars rover that landed in the Ares Vallis channel in the Chryse Planitia region of the Oxia Palus quadrangle on July 4, 1997. ''Sojourner'' was operational on Mars for 92 sols (95 Earth days). It was the first wheeled vehicle to rove on a planet other than Earth and formed part of the ''Mars Pathfinder'' mission. The rover was equipped with front and rear cameras, and hardware that was used to conduct several scientific experiments. It was designed for a mission lasting 7 sols, with a possible extension to 30 sols, and was active for 83 sols (85 Earth days). The rover communicated with Earth through the ''Pathfinder'' base station, which had its last successful communication session with Earth at 3:23 a.m. PDT on September 27, 1997. The last signal from the rover was received on the morning of October 7, 1997. ''Sojourner'' traveled just over by the time communication was lost. Its final confirmed command was to remain stationary ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mars Rover
A Mars rover is a motor vehicle designed to travel on the surface of Mars. Rovers have several advantages over stationary landers: they examine more territory, they can be directed to interesting features, they can place themselves in sunny positions to weather winter months, and they can advance the knowledge of how to perform very remote robotic vehicle control. They serve a different purpose than orbital spacecraft like ''Mars Reconnaissance Orbiter''. A more recent development is the Mars helicopter. , there have been six successful robotically operated Mars rovers; the first five, managed by the American NASA Jet Propulsion Laboratory, were (by date of Mars landing): ''Sojourner'' (1997), ''Spirit'' (2004–2010), ''Opportunity'' (2004–2018), ''Curiosity'' (2012–), and ''Perseverance'' (2021–). The sixth, managed by the China National Space Administration, is ''Zhurong'' (2021–). On January 24, 2016, NASA reported that then current studies on Mars by ''Opportunit ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Jet Propulsion Laboratory
The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States. Founded in the 1930s by Caltech researchers, JPL is owned by NASA and managed by the nearby California Institute of Technology (Caltech). The laboratory's primary function is the construction and operation of planetary robotic spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating the NASA Deep Space Network. Among the laboratory's major active projects are the Mars 2020 mission, which includes the ''Perseverance'' rover and the '' Ingenuity'' Mars helicopter; the Mars Science Laboratory mission, including the ''Curiosity'' rover; the InSight lander (''Interior Exploration using Seismic Investigations, Geodesy and Heat Transport''); the ''Mars Reconnaissance Orbiter''; the ''Juno'' spacecraft orbiting Jupiter; the ''SMAP'' satellite for earth surface s ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Windsock
A windsock (also called a wind cone) is a conical textile tube that resembles a giant sock. It can be used as a basic indicator of wind speed and direction, or as decoration. They are typically used at airports to show the direction and strength of the wind to pilots, and at chemical plants where there is risk of gaseous leakage. They are also sometimes located alongside highways at windy locations. At many airports, windsocks are externally or internally lit at night. Function Wind direction is the direction in which the windsock is pointing. (Wind directions are conventionally specified as the compass point from which the wind originates; so a windsock pointing due north indicates a southerly wind). Wind speed is indicated by the windsock's angle relative to the mounting pole; in low winds it droops; in high winds it flies horizontally. Alternating stripes of high visibility orange and white were initially used to help to estimate wind speed, with each stripe adding 3 knots ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Journal Of Geophysical Research
The ''Journal of Geophysical Research'' is a peer-reviewed scientific journal. It is the flagship journal of the American Geophysical Union. It contains original research on the physical, chemical, and biological processes that contribute to the understanding of the Earth, Sun, and Solar System. It has seven sections: A (Space Physics), B (Solid Earth), C (Oceans), D (Atmospheres), E (Planets), F (Earth Surface), and G (Biogeosciences). All current and back issues are available online for subscribers. History The journal was originally founded under the name ''Terrestrial Magnetism'' by the American Geophysical Union's president Louis Agricola Bauer in 1896. It was renamed to ''Terrestrial Magnetism and Atmospheric Electricity'' in 1899 and in 1948 it acquired its current name. In 1980, three specialized sections were established: ''A: Space Physics'', ''B: Solid Earth'', and ''C: Oceans''. Subsequently, further sections have been added: ''D: Atmospheres'' in 1984, ''E: Planets'' ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Spatial Filter
A spatial filter is an optical device which uses the principles of Fourier optics to alter the structure of a beam of light or other electromagnetic radiation, typically coherent laser light. Spatial filtering is commonly used to "clean up" the output of lasers, removing aberrations in the beam due to imperfect, dirty, or damaged optics, or due to variations in the laser gain medium itself. This filtering can be applied to transmit a pure transverse mode from a multimode laser while blocking other modes emitted from the optical resonator. The term "filtering" indicates that the desirable structural features of the original source pass through the filter, while the undesirable features are blocked. An apparatus which follows the filter effectively sees a higher-quality but lower-powered image of the source, instead of the actual source directly. An example of the use of spatial filter can be seen in advanced setup of micro-Raman spectroscopy. In spatial filtering, a lens is used to ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Stereo Camera
A stereo camera is a type of camera with two or more lenses with a separate image sensor or film frame for each lens. This allows the camera to simulate human binocular vision, and therefore gives it the ability to capture three-dimensional images, a process known as stereo photography. Stereo cameras may be used for making stereoviews and 3D pictures for movies, or for range imaging. The distance between the lenses in a typical stereo camera (the intra-axial distance) is about the distance between one's eyes (known as the intra-ocular distance) and is about 6.35 cm, though a longer base line (greater inter-camera distance) produces more extreme 3-dimensionality. In the 1950s, stereo cameras gained some popularity with the Stereo Realist and similar cameras that employed 135 film to make stereo slides. 3D pictures following the theory behind stereo cameras can also be made more inexpensively by taking two pictures with the same camera, but moving the camera a few in ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mars Pathfinder IMP Camera
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin atmosphere (less than 1% that of Earth's), and has a crust primarily composed of elements similar to Earth's crust, as well as a core made of iron and nickel. Mars has surface features such as impact craters, valleys, dunes and polar ice caps. It has two small and irregularly shaped moons, Phobos and Deimos. Some of the most notable surface features on Mars include Olympus Mons, the largest volcano and highest known mountain in the Solar System and Valles Marineris, one of the largest canyons in the Solar System. The Borealis basin in the Northern Hemisphere covers approximately 40% of the planet and may be a large impact feature. Days and seasons on Mars are comparable to those of Earth, as the planets have a similar rotation period and tilt o ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Kilowatt-hour
A kilowatt-hour (unit symbol: kW⋅h or kW h; commonly written as kWh) is a unit of energy: one kilowatt of power for one hour. In terms of SI derived units with special names, it equals 3.6 megajoules (MJ). Kilowatt-hours are a common billing unit for electrical energy delivered to consumers by electric utilities. Definition The kilowatt-hour is a composite unit of energy equal to one kilowatt (kW) sustained for (multiplied by) one hour. Expressed in the standard unit of energy in the International System of Units (SI), the joule (symbol J), it is equal to 3,600 kilojoules or 3.6 MJ."Half-high dots or spaces are used to express a derived unit formed from two or more other units by multiplication.", Barry N. Taylor. (2001 ed.''The International System of Units.'' (Special publication 330). Gaithersburg, MD: National Institute of Standards and Technology. 20. Unit representations A widely used representation of the kilowatt-hour is "kWh", derived from its compone ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Gallium-arsenide
Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated circuits, infrared light-emitting diodes, laser diodes, solar cells and optical windows. GaAs is often used as a substrate material for the epitaxial growth of other III-V semiconductors, including indium gallium arsenide, aluminum gallium arsenide and others. Preparation and chemistry In the compound, gallium has a +3 oxidation state. Gallium arsenide single crystals can be prepared by three industrial processes: * The vertical gradient freeze (VGF) process. * Crystal growth using a horizontal zone furnace in the Bridgman-Stockbarger technique, in which gallium and arsenic vapors react, and free molecules deposit on a seed crystal at the cooler end of the furnace. * Liquid encapsulated Czochralski (LEC) growth is used for producing high-puri ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Deep Space Network
The NASA Deep Space Network (DSN) is a worldwide Telecommunications network, network of American spacecraft communication ground segment facilities, located in the United States (California), Spain (Madrid), and Australia (Canberra), that supports National Aeronautics and Space Administration, NASA's interplanetary spaceflight, interplanetary spacecraft missions. It also performs radio astronomy, radio and radar astronomy observations for the exploration of the Solar System and the universe, and supports selected Earth-orbiting missions. DSN is part of the NASA Jet Propulsion Laboratory (JPL). General information DSN currently consists of three deep-space communications facilities placed approximately 120 degrees apart around the Earth. They are: * the Goldstone Deep Space Communications Complex () outside Barstow, California, Barstow, California. For details of Goldstone's contribution to the early days of space probe tracking, see Project Space Track (1957-1961), Project ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Kilobit
The kilobit is a multiple of the unit bit for digital information or computer storage. The prefix ''kilo-'' (symbol k) is defined in the International System of Units (SI) as a multiplier of 103 (1 thousand), and therefore, :1 kilobit = = 1000 bits. The kilobit has the unit symbol kbit or kb. Using the common byte size of 8 bits, 1 kbit is equal to 125 bytes. The kilobit is commonly used in the expression of data rates of digital communication circuits as kilobits per second (kbit/s or kb/s), or abbreviated as ''kbps'', as in, for example, ''a 56 kbps PSTN circuit'', or ''a 512 kbit/s broadband Internet connection''. The unit symbol kb (lowercase 'b') is typographically similar to the international standard unit symbol for the kilobyte, i.e. kB (upper case 'B'). The International Electrotechnical Commission (IEC) recommends the symbol bit instead of b. The prefix ''kilo-'' is often used in fields of computer science and information technology wit ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |