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Cleaning Event
__NOTOC__ A cleaning event is a phenomenon whereby dust is removed from solar panels, in the context of exploration and science rovers on Mars, supposedly by the action of wind. The term cleaning event is used on several NASA webpages; generally supposing that Martian winds have blown dust clear off the probes on Mars, including the solar panels which power them, increasing their energy output. The nature of the cleaning events is not known, but the assumption is that wind blows the dust off the panels. Cleaning events were discovered in 2004 when several times power levels increased by 5% overnight, in contrast to the expectation they would decreasethe added power allowed the missions to continue beyond their expected lifetime. One theory is that wind currents in craters aid in cleaning events, and also if the rover is sloped, this is speculated to help remove dust. The term started being used in 2004 as the Mars Exploration Rovers' (MER) solar panels started to benefit from ...
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Mars Spirit Rover's Solar Panels Covered With Dust - October 2007
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 ...
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Opacity (optics)
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc. An opaque object is neither transparent (allowing all light to pass through) nor translucent (allowing some light to pass through). When light strikes an interface between two substances, in general some may be reflected, some absorbed, some scattered, and the rest transmitted (also see refraction). Reflection can be diffuse, for example light reflecting off a white wall, or specular, for example light reflecting off a mirror. An opaque substance transmits no light, and therefore reflects, scatters, or absorbs all of it. Both mirrors and carbon black are opaque. Opacity depends on the frequency of the light being considered. For instance, some kinds of glass, while transparent in the visual range, are lar ...
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Solar Panel
A solar cell panel, solar electric panel, photo-voltaic (PV) module, PV panel or solar panel is an assembly of photovoltaic solar cells mounted in a (usually rectangular) frame, and a neatly organised collection of PV panels is called a photovoltaic system or solar array. Solar panels capture sunlight as a source of radiant energy, which is converted into electric energy in the form of direct current (DC) electricity. Arrays of a photovoltaic system can be used to generate solar electricity that supplies electrical equipment directly, or grid-connected photovoltaic system, feeds power back into an alternate current (AC) electric grid, grid via an solar inverter, inverter system. History In 1839, the ability of some materials to create an electrical charge from light exposure was first observed by the French physicist Edmond Becquerel. Though these initial solar panels were too inefficient for even simple electric devices, they were used as an instrument to measure light. ...
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Opportunity Rover
''Opportunity'', also known as MER-B (Mars Exploration Rover – B) or MER-1, is a robotic rover that was active on Mars from 2004 until 2018. ''Opportunity'' was operational on Mars for sols (). Launched on July 7, 2003, as part of NASA's Mars Exploration Rover program, it landed in Meridiani Planum on January 25, 2004, three weeks after its twin, '' Spirit'' (MER-A), touched down on the other side of the planet. With a planned 90-sol duration of activity (slightly less than 92.5 Earth days), ''Spirit'' functioned until it got stuck in 2009 and ceased communications in 2010, while ''Opportunity'' was able to stay operational for sols after landing, maintaining its power and key systems through continual recharging of its batteries using solar power, and hibernating during events such as dust storms to save power. This careful operation allowed ''Opportunity'' to operate for 57 times its designed lifespan, exceeding the initial plan by (in Earth time). By June 10, 2018, wh ...
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Spirit Rover
Spirit or spirits may refer to: Liquor and other volatile liquids * Spirits, a.k.a. liquor, distilled alcoholic drinks * Spirit or tincture, an extract of plant or animal material dissolved in ethanol * Volatile (especially flammable) liquids, such as ** Ethanol, also known as drinking alcohol ** Gasoline (or petrol), a clear petroleum-derived flammable liquid that is used primarily as a fuel ** Petroleum ether, liquid hydrocarbon mixtures used chiefly as non-polar solvents ** White spirit or mineral spirits, a common organic solvent used in painting and decorating Spirituality and mood * Spirituality, pertaining to the soul or spirit * Spirit (vital essence), the non-corporeal essence of a being or entity **Vitalism, a belief in some fundamental, non-physical essence which differentiates organisms from inanimate, material objects **'' Pneuma'', an ancient Greek word for 'breath' or 'wind', but also 'spirit' or 'soul' ** Soul, the spiritual part of a living being, often regar ...
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Mars Exploration Rover
NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, '' Spirit'' and '' Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rovers to explore the Martian surface and geology; both landed on Mars at separate locations in January 2004. Both rovers far outlived their planned missions of 90 Martian solar days: MER-A ''Spirit'' was active until March 22, 2010, while MER-B ''Opportunity'' was active until June 10, 2018. Objectives The mission's scientific objective was to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars. The mission is part of NASA's Mars Exploration Program, which includes three previous successful landers: the two Viking program landers in 1976 and Mars Pathfinder probe in 1997. The total cost of building, launching, landing and operating the rovers on the surface for the initial 90-sol primary mission was US$820 mi ...
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Exploration Of Mars
The planet Mars has been explored remotely by spacecraft. Probes sent from Earth, beginning in the late 20th century, have yielded a large increase in knowledge about the Martian system, focused primarily on understanding its geology and habitability potential. Engineering interplanetary journeys is complicated and the exploration of Mars has experienced a high failure rate, especially the early attempts. Roughly sixty percent of all spacecraft destined for Mars failed before completing their missions and some failed before their observations could begin. Some missions have met with unexpected success, such as the twin Mars Exploration Rovers, '' Spirit'' and ''Opportunity'' which operated for years beyond their specification. Current status , there are three operational rovers on the surface of Mars, the ''Curiosity'' and ''Perseverance'' rovers, both operated by the United States of America space agency NASA, as well as the ''Zhurong'' rover, part of the '' Tianwen-1'' ...
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Curiosity (rover)
''Curiosity'' is a car-sized Mars rover designed to explore the Gale crater on Mars as part of NASA's Mars Science Laboratory (MSL) mission. ''Curiosity'' was launched from Cape Canaveral (CCAFS) on November 26, 2011, at 15:02:00 UTC and landed on Aeolis Palus inside Gale crater on Mars on August 6, 2012, 05:17:57 UTC. The Bradbury Landing site was less than from the center of the rover's touchdown target after a journey. Mission goals include an investigation of the Martian climate and geology, assessment of whether the selected field site inside Gale has ever offered environmental conditions favorable for microbial life (including investigation of the role of water), and planetary habitability studies in preparation for human exploration. In December 2012, ''Curiosity'' two-year mission was extended indefinitely, and on August 5, 2017, NASA celebrated the fifth anniversary of the ''Curiosity'' rover landing. On August 6, 2022, a detailed overview of accomplishme ...
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Endeavour Crater
Endeavour is an impact crater located in the Meridiani Planum extraterrestrial plain within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. Endeavour is about in diameter. Using ''Mars Reconnaissance Orbiter'' data, phyllosilicate-bearing outcrops have been detected along its rim. These minerals may have formed under wet conditions in a low-acidic environment during the early history of Mars. There are raised rim segments to the north, east, and southwest. The rim has become worn, rounded and degraded, with infilling of plains material in a manner similar to the Victoria crater. When compared to the surrounding plains, the crater floor shows an enhanced spectral signature of basalt and hematite. The interior contains two groups of dune fields. Images taken since 2008 show evidence of changes in some of the associated formations, which may be evidence of active erosion by the martian wind over a period of two to three years. The plains surrounding the rim ...
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Mars Pathfinder
''Mars Pathfinder'' (''MESUR Pathfinder'') is an American robotic spacecraft that landed a base station with a roving probe on Mars in 1997. It consisted of a lander, renamed the Carl Sagan Memorial Station, and a lightweight, wheeled robotic Mars rover named ''Sojourner'', the first rover to operate outside the Earth–Moon system. Launched on December 4, 1996, by NASA aboard a Delta II booster a month after the '' Mars Global Surveyor'', it landed on July 4, 1997, on Mars's Ares Vallis, in a region called Chryse Planitia in the Oxia Palus quadrangle. The lander then opened, exposing the rover which conducted many experiments on the Martian surface. The mission carried a series of scientific instruments to analyze the Martian atmosphere, climate, and geology and the composition of its rocks and soil. It was the second project from NASA's Discovery Program, which promotes the use of low-cost spacecraft and frequent launches under the motto "cheaper, faster and better" ...
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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 hi ...
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Materials Adherence Experiment
The Materials Adherence Experiment (MAE) was a material science experiment conducted between July 4, 1997 and August 12, 1997 during NASA's ''Mars Pathfinder'' mission. This was a joint experiment between NASA and the Jet Propulsion Laboratory at the California Institute of Technology that consisted of a small module mounted to ''Pathfinder's'' rover ''Sojourner'' that examined the effects of Martian surface dust on solar cells. Purpose Using solar power on the Martian surface is challenging because the Martian atmosphere has a significant amount of dust suspended in it. In addition to blocking sunlight from reaching Mars's surface, dust particles gradually settle out of the air and onto objects. As ''Pathfinder'' was NASA's first Mars surface mission to be solar-powered, the effect of Martian dust settling on solar cells was not well understood before the mission. It was predicted at the time that dust particles in the Martian atmosphere would settle on the solar cells powe ...
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