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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. Model The satellite had the shape of a cylinder, where on its top was a directional antenna that opened after the launching of the satellite, had the rotation stabilized of 50 to 55 rpm, its movers used like propellant 136 kilograms of hydrazine and was fed by solar cells that supplied 982 watts at the beginning of its operation phase, using two NiCd batteries as power reserves. It carried 24 C-band transmitters with 6 spare transmitters. They provided an Effective Isotropically Radiated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunication
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of transmission may be divided into communication channels for multiplexing, allowing for a single medium to transmit several concurrent Session (computer science), communication sessions. Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the electrical telegraph, telegraph, telephone, television, and radio. Early telecommunication networks used metal wires as the medium for transmitting signals. These networks were used for telegraphy and telephony for many decades. In the first decade of the 20th century, a revolution in wireless communication began with breakthroughs including those made in radio communications by Guglielmo Marconi, who won the 1909 Nobel Prize in Physics. Othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion of the Americas. South America is bordered on the west by the Pacific Ocean, on the north and east by the Atlantic Ocean, and to the south by the Drake Passage; North America and the Caribbean Sea lie to the northwest. The continent includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territory, dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one administrative division, internal territory: French Guiana. The Dutch Caribbean ABC islands (Leeward Antilles), ABC islands (Aruba, Bonaire, and Curaçao) and Trinidad and Tobago are geologically located on the South-American continental shel ... [...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 at developing 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 Aérospatiale (whose former assets now form Airbus) with the development of all Ariane launchers and of the testing facilities, while Arianespace handled production, operations and marketing after its creation in 1980. Arianespace launches Ariane rockets from the Guiana Space Centre at Kourou in French Guiana. As a result of the merger in 2000 that founded Airbus, the new corporation's space branch an ... [...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 satelli ... [...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 A rocket (from , and so named for its shape) is a vehicle that uses jet propulsion to accelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely ... 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 Aircraft Company, Hughes would divide the work with Promon Engenharia SA of São Paulo. Br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Dollar
The United States dollar (Currency symbol, symbol: Dollar sign, $; ISO 4217, currency code: USD) is the official currency of the United States and International use of the U.S. dollar, several other countries. The Coinage Act of 1792 introduced the U.S. dollar at par with the Spanish dollar, Spanish silver dollar, divided it into 100 cent (currency), cents, and authorized the Mint (facility), 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 U.S. dollar was originally defined under a bimetallism, bimetallic standard of (0.7734375 troy ounces) fine silver or, from Coinage Act of 1834, 1834, fine gold, or $20.67 per troy ounce. The Gold Standard Act of 1900 linked the dollar solely to gold. From 1934, its equivalence to gold was revised to $35 per troy ounce. In 1971 all links to gold were repealed. The U.S. dollar became an important intern ... [...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, also known as a photovoltaic cell (PV cell), is an electronic device that converts the energy of light directly into electricity by means of the photovoltaic effect.Solar Cells chemistryexplained.com It is a type of photoelectric cell, a device whose electrical characteristics (such as Electric current, current, voltage, or Electrical resistance and conductance, resistance) vary when it is exposed to light. Individual solar cell devices are often the electrical building blocks of solar panel, photovoltaic modules, known colloquially as "solar panels". Almost all commercial PV cells consist of crystalline silicon, with a market share of 95%. Cadmium telluride thin-film solar cells account for the remainder. The common single-junction silicon solar cell can produce a maximum open-circuit voltage o ... [...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 hazardous unless handled in solution as, for example, hydrazine hydrate (). Hydrazine is mainly used as a foaming agent in preparing Polymeric foam, polymer foams, but applications also include its uses as a precursor (chemistry), precursor to pharmaceuticals and agrochemicals, as well as a long-term storable propellant for in-outer space, space spacecraft propulsion. Additionally, hydrazine is used in various rocket propellant, rocket fuels and to prepare the gas precursors used in airbags. 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. , approximately 120,000 tons of hydrazine hydrate (corresponding to a 64% solution of hydrazine in water by weight) we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revolutions Per Minute
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or r⋅min−1) is a unit of rotational speed (or rotational frequency) for rotating machines. One revolution per minute is equivalent to hertz. Standards ISO 80000-3:2019 defines a physical quantity called ''rotation'' (or ''number of revolutions''), dimensionless, whose instantaneous rate of change is called ''rotational frequency'' (or ''rate of rotation''), with units of reciprocal seconds (s−1). A related but distinct quantity for describing rotation is ''angular frequency'' (or ''angular speed'', the magnitude of angular velocity), for which the SI unit is the radian per second (rad/s). Although they have the same dimensions (reciprocal time) and base unit (s−1), the hertz (Hz) and radians per second (rad/s) are special names used to express two different but proportional ISQ quantities: frequency and angular frequency, respectively. The conversions between a frequency and an angular frequency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graveyard Orbit
A graveyard orbit, also called a junk orbit or disposal orbit, is an Orbit (physics), 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 Spacecraft retirement, 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 Orbital maneuver, 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 Orbital s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacebus
Spacebus is a satellite bus produced at the Cannes Mandelieu Space Center in France by Thales Alenia Space. Spacebuses are typically used for geostationary communications satellites, and seventy-four have been launched since development started in the 1980s. Spacebus was originally produced by Aérospatiale and later passed to Alcatel Alenia Space. In 2006, it was sold to Thales Group as Thales Alenia Space. The first Spacebus satellite, Arabsat-1A, was launched in 1985. Since then, seventy-four have been launched, with one more completed, and six outstanding orders. The launch of the 50th Spacebus satellite, Star One C1, occurred in November 2007.Christian Lardier, « Ariane-5 : un tir de l'industrie européenne – le 50e Spacebus », dans ''Air & Cosmos'', N° 2100, du 16 novembre 2007 It was a Spacebus 3000B3, launched by an Ariane 5 rocket flying from the Guiana Space Centre in Kourou, French Guiana. Several variants have been built: the early Spacebus 100 and Spacebus 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
