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Brasilsat A2
Brasilsat A2 was a Brazilian geostationary communication satellite belonging to the Brasilsat family. It was built by Spar Aerospace in partnership with Hughes. For most of its useful life it was located in the orbital position of 70 degrees west longitude and was operated by Star One, a subsidiary company of Embratel. The satellite was based on the platform HS-376 and its life expectancy was 8 years. The same was out of commission in February 2004 and was transferred to the graveyard orbit. 34 dBW for most of the Brazilian territory. History In the 1980s, Brazil needed its own satellites to exempt foreigners. As a result of this effort, the Brazilian company Embratel contracted in August 1982 the Canadian Spar Aerospace, Ltd., in partnership with American Hughes, to build its series of "Brasilsat A" satellites, the series consisted of two satellites, the Brasilsat-A1 and the Brasilsat A2. Built by Spar Aerospace, which received US$ 125 million to build under license from Hugh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunication
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that feasible with the human voice, but with a similar scale of expediency; thus, slow systems (such as postal mail) are excluded from the field. The transmission media in telecommunication have evolved through numerous stages of technology, from beacons and other visual signals (such as smoke signals, semaphore telegraphs, signal flags, and optical heliographs), to electrical cable and electromagnetic radiation, including light. Such transmission paths are often divided into communication channels, which afford the advantages of multiplexing multiple concurrent communication sessions. ''Telecommunication'' is often used in its plural form. Other examples of pre-modern long-distance communication included audio messages, such as coded drumb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geostationary
A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitude above Earth's equator ( in radius from Earth's center) and following the direction of Earth's rotation. An object in such an orbit has an orbital period equal to Earth's rotational period, one sidereal day, and so to ground observers it appears motionless, in a fixed position in the sky. The concept of a geostationary orbit was popularised by the science fiction writer Arthur C. Clarke in the 1940s as a way to revolutionise telecommunications, and the first satellite to be placed in this kind of orbit was launched in 1963. Communications satellites are often placed in a geostationary orbit so that Earth-based satellite antennas do not have to rotate to track them but can be pointed permanently at the position in the sky where the sate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Guiana
French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas departments and regions of France, overseas department/region and single territorial collectivity of France on the northern Atlantic Ocean, Atlantic coast of South America in the Guianas. It borders Brazil to the east and south and Suriname to the west. With a land area of , French Guiana is the second-largest Regions of France, region of France (more than one-seventh the size of Metropolitan France) and the largest Special member state territories and the European Union, outermost region within the European Union. It has a very low population density, with only . (Its population is less than that of Metropolitan France.) Half of its 294,436 inhabitants in 2022 lived in the metropolitan area of Cayenne, its Prefectures in France, capital. 98.9% of the land territory of French Guiana is covered by forests, a large part of which is Old-growth forest, primeval Tropical r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ariane Rocket
Ariane is a series of European civilian expendable launch vehicles for space launch use. The name comes from the French spelling of the mythological character Ariadne. France first proposed the Ariane project and it was officially agreed upon at the end of 1973 after discussions between France, Germany and the UK. The project was Western Europe's second attempt to develop its own launcher following the unsuccessful Europa project. The Ariane project was code-named L3S (the French abbreviation for third-generation substitution launcher). The European Space Agency (ESA) charged Airbus Defence and Space with the development of all Ariane launchers and of the testing facilities, while Arianespace, a 32.5% CNES (French government space agency) commercial subsidiary created in 1980, handles production, operations and marketing. Arianespace launches Ariane rockets from the Guiana Space Centre at Kourou in French Guiana. Ariane versions Ariane 1 was a three-stage launcher, derived fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brasilsat B2
Brasilsat B2 is a Brazilian communications satellite launched on 28 March 1995, at 23:14:19 UTC, by an Ariane 44LP H10+ launch vehicle at Kourou in French Guiana. History The Boeing Company contracted the acquisition of three satellites from Hughes Electronics Corporation. As part of the contract, Hughes would divide the work with Promon Engenharia SA of São Paulo. Brasilsat B1 and B2 were tested by the National Institute for Space Research (INPE) of São José dos Campos, Brasilsat B3 and B4 were tested in the Hughes laboratories. The contract also included renovation of sensor equipment and telemetry, provided by Guaratiba Center for Satellite Signaling, located in Rio de Janeiro, as well as automation and installation of security equipment in the Tanguá Control Station. Current status In January 2008, Brasilsat B2 was moved from its former orbital position at 65° West to 92° West. Brasilsat B2 is now in inclined orbit at 63° West. Of the four Brasilsat satellite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brasilsat B1
Brasilsat B1 is a Brazilian communications satellite launched on August 10, 1994, by an Ariane rocket model 44LP at Guiana Space Centre which is located in Kourou, French Guiana. History It was constructed by the United States and Brazil and is classified as a second generation satellite. It is larger and more powerful than the previous generation of satellites. The Boeing Company (which chose to expand its presence in another aerospace field of satellite communications by purchasing Hughes Electronics Corporation, the builder of Brasilsat B1 and B2) contracted the acquisition of three satellites from Hughes. As part of the contract, Hughes would divide the work with Promon Engenharia SA of São Paulo. Brasilsat B1 and B2 were tested by the Institute of Space Research - INPE of São José dos Campos, Brasilsat B3 and B4 were tested in the Hughes laboratories. The contract also included renovation of sensor equipment and telemetry, provided by Guaratiba Center for Satellite Si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Dollar
The United States dollar ( symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official currency of the United States and several other countries. The Coinage Act of 1792 introduced the U.S. dollar at par with the Spanish silver dollar, divided it into 100 cents, and authorized the minting of coins denominated in dollars and cents. U.S. banknotes are issued in the form of Federal Reserve Notes, popularly called greenbacks due to their predominantly green color. The monetary policy of the United States is conducted by the Federal Reserve System, which acts as the nation's central bank. The U.S. dollar was originally defined under a bimetallic standard of (0.7735 troy ounces) fine silver or, from 1837, fine gold, or $20.67 per troy ounce. The Gold Standard Act of 1900 linked the dollar solely to gold. From 1934, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brasilsat-A1
Brasilsat A1 was a Brazilian communications satellite which was operated by Embratel. It was constructed by the Spar Aerospace, and is based on the HS-376 satellite bus. The Brasilsat A1 was off duty in March 2002 and was transferred to the graveyard orbit. Specifications The satellite had the shape of a cylinder, where at its top was located a directional antenna that opened after the launching of the satellite. The satellite had a mass in orbit of 671 kg, had a rotation stabilized between 50 and 55 rpm, its propellers used as a propellant 136 kg of hydrazine and was powered by solar cells that supplied 982 Watts at the beginning of its phase of operation, using two NiCd batteries as power reserve. It carried 24 C-band transmitters with six spare transmitters. They provided an effective incident radiated power (EIRP) of 34 dBW for most of the Brazilian territory. * Lead contractor: Spar Aerospace * Model used: HS-376 * Mass at launch: 1,195 kg * Mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Cell
A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.Solar Cells chemistryexplained.com It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as , , or resistance, vary when exposed to light. Individual solar cell devices are often the electrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine hydrate (). Hydrazine is mainly used as a foaming agent in preparing polymer foams, but applications also include its uses as a precursor to polymerization catalysts, pharmaceuticals, and agrochemicals, as well as a long-term storable propellant for in-space spacecraft propulsion. Additionally, hydrazine is used in various rocket fuels and to prepare the gas precursors used in air bags. Hydrazine is used within both nuclear and conventional electrical power plant steam cycles as an oxygen scavenger to control concentrations of dissolved oxygen in an effort to reduce corrosion. the world hydrazine hydrate market amounted to $350 million. About two million tons of hydrazine hydrate were used in foam blowing agents in 2015. Hydrazines r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revolutions Per Minute
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionless unit equal to 1, which it refers to as a revolution, but does not define the revolution as a unit. It defines a unit of rotational frequency equal to s−1. The superseded standard ISO 80000-3:2006 did however state with reference to the unit name 'one', symbol '1', that "The special name revolution, symbol r, for this unit is widely used in specifications on rotating machines." The International System of Units (SI) does not recognize rpm as a unit, and defines the unit of frequency, Hz, as equal to s−1. :\begin 1~&\text &&=& 60~&\text \\ \frac~&\text &&=& 1~&\text \end A corresponding but distinct quantity for describing rotation is angular velocity, for which the SI unit is the ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graveyard Orbit
A graveyard orbit, also called a junk orbit or disposal orbit, is an orbit that lies away from common operational orbits. One significant graveyard orbit is a supersynchronous orbit well beyond geosynchronous orbit. Some satellites are moved into such orbits at the end of their operational life to reduce the probability of colliding with operational spacecraft and generating space debris. Overview A graveyard orbit is used when the change in velocity required to perform a de-orbit maneuver is too large. De-orbiting a geostationary satellite requires a delta-v of about , whereas re-orbiting it to a graveyard orbit only requires about . For satellites in geostationary orbit and geosynchronous orbits, the graveyard orbit is a few hundred kilometers beyond the operational orbit. The transfer to a graveyard orbit beyond geostationary orbit requires the same amount of fuel as a satellite needs for about three months of stationkeeping. It also requires a reliable attitude control d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
