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Horizons-1
Horizons-1, also known as Galaxy 13, is a geostationary communications satellite operated by Intelsat and SKY Perfect JSAT (JSAT) which was designed and manufactured by Boeing on the BSS-601 platform. It has Ku-band and C-band payload and was used to replace Galaxy 9 at the 127.0° West longitude. It covers North America, Puerto Rico, Alaska, Hawaii and Mexico. Satellite description The spacecraft was designed and manufactured by Boeing on the BSS-601 satellite bus. It had a launch mass of and a mass of at the beginning of its 15-year design life. When stowed for launch, it measured of height and on its sides. Its solar panels span when fully deployed and, with its antennas in fully extended configuration it is wide. It had two wings with four solar panels each that used dual-junction GsAs solar cells. Its power system generated 9.9 kW of power at beginning of life and 8.9 kW at the end of its design life and had a 30-cell NiH battery for surviving solar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horizons Satellite
Horizons Satellite is a joint venture between Intelsat and SKY Perfect JSAT Group. Originally formed in 2001, pursuant to a memorandum of understanding between JSAT Corporation and PanAmSat for the launch of Horizons-1, it was renewed for Horizons-2. JSAT later merged into the SKY Perfect JSAT Group and PanAmSat was acquired by Intelsat, but the companies continued with the relationship, with the order for Horizons-3e. Both companies also launched a joint satellite, Intelsat 15/ JCSAT-85, but instead of the equal share agreement of this joint venture, JSAT owns a specific payload of 5 transponders out of the 22 Ku band transponders of the spacecraft. History On August 1, 2001, JSAT Corporation announced an equal share joint venture with PanAmSat, called Horizons Satellite. On September 4, 2001, it ordered from Boeing its first satellite, Horizons-1/Galaxy 13. It was a spacecraft with 24 C band and 24 Ku band transponders. It had a 10 kW power generation capacity and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Launch
Sea Launch was a multinational—Norway, Russia, Ukraine, United States—spacecraft launch company founded in 1995 that provided orbital launch services from 1999–2014. The company used a mobile maritime launch platform for equatorial launches of commercial payloads on specialized Zenit-3SL rockets from a former mobile/floating oil drilling rig renamed ''Odyssey''. By 2014, it had assembled and launched thirty-two rockets, with an additional three failures and one partial failure. All commercial payloads were communications satellites intended for geostationary transfer orbit with such customers as EchoStar, DirecTV, XM Satellite Radio, PanAmSat, and Thuraya. The approach Sea Launch LLC used was to assemble the launcher on a purpose-built ship '' Sea Launch Commander'' in Nimitz Rd., Long Beach, California, USA. The assembled spacecraft was then positioned on top of the self-propelled ''Odyssey'' floating launch platform and moved to the equatorial Pacific Ocean for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horizons-2
Horizons-2 is a communications satellite owned by Horizons Satellite, a joint venture between SKY Perfect JSAT Group and Intelsat. Its orbital slot is located at 74° west longitude. Launch Horizons-2 was launched from the Guiana Space Centre — along with the Rascom-QAF 1 spacecraft — aboard an Arianespace Ariane 5-GS. Launch occurred at 21:42 GMT on 21 December 2007. Platform and payload Horizons-2 was built by Orbital Sciences Corporation based on its STAR-2 satellite platform, which will generate 3.5 kilowatts of payload power by means of two solar arrays, each equipped with three panels of UJT gallium arsenide cells. The solar arrays charge two lithium ion batteries with capacities of at least 3,850 watt-hours. The spacecraft is 3-axis stabilized, with a zero momentum system. Hydrazine-fuelled monopropellant thrusters are used for stationkeeping, with an IHI Ihi, Ehee (Nepal Bhasa:ईही) is a ceremony in the Newar community in Nepal in which pre-adolescent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-junction Solar Cell
Multi-junction (MJ) solar cells are solar cells with multiple p–n junctions made of different semiconductor materials. Each material's p-n junction will produce electric current in response to different wavelengths of light. The use of multiple semiconducting materials allows the absorbance of a broader range of wavelengths, improving the cell's sunlight to electrical energy conversion efficiency. Traditional single-junction cells have a maximum theoretical efficiency of 33.16%. Theoretically, an infinite number of junctions would have a limiting efficiency of 86.8% under highly concentrated sunlight. As of 2008 the best lab examples of traditional crystalline silicon (c-Si) solar cells had efficiencies between 20% and 25%, while lab examples of multi-junction cells have demonstrated performance over 46% under concentrated sunlight. Commercial examples of tandem cells are widely available at 30% under one-sun illumination, and improve to around 40% under concentrated sunlight. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., it borders the Canadian province of British Columbia and the Yukon territory to the east; it also shares a maritime border with the Russian Federation's Chukotka Autonomous Okrug to the west, just across the Bering Strait. To the north are the Chukchi and Beaufort Seas of the Arctic Ocean, while the Pacific Ocean lies to the south and southwest. Alaska is by far the largest U.S. state by area, comprising more total area than the next three largest states ( Texas, California, and Montana) combined. It represents the seventh-largest subnational division in the world. It is the third-least populous and the most sparsely populated state, but by far the continent's most populous territory located mostly north of the 60th paralle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state geographically located within the tropics. Hawaii comprises nearly the entire Hawaiian archipelago, 137 volcanic islands spanning that are physiographically and ethnologically part of the Polynesian subregion of Oceania. The state's ocean coastline is consequently the fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Kauai, Oahu, Molokai, Lānai, Kahoolawe, Maui, and Hawaii—the last of these, after which the state is named, is often called the "Big Island" or "Hawaii Island" to avoid confusion with the state or archipelago. The uninhabited Northwestern Hawaiian Islands make up most of the Papahānaumokuākea Marine National Monument, the United States' largest prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mexico
Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Mexico covers ,Mexico '' The World Factbook''. . making it the world's 13th-largest country by area; with approximately 12 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Bus
A satellite bus (or spacecraft bus) is the main body and structural component of a satellite or spacecraft, in which the payload and all scientific instruments are held. Bus-derived satellites are opposed to specially produced satellites. Bus-derived satellites are usually customized to customer requirements, for example with specialized sensors or transponders, in order to achieve a specific mission. They are commonly used for geosynchronous satellites, particularly communications satellites, but are also used in spacecraft which occupy lower orbits, occasionally including low Earth orbit missions. Examples Some satellite bus examples include: * Boeing DS&S 702 * Lockheed Martin Space Systems A2100 * Alphabus * INVAP ARSAT-3K * Airbus D&S Eurostar * ISRO's I-1K, I-2K, I-3K, I-4K, I-6K, and Indian Mini Satellite bus * NASA Ames MCSB * SSL 1300 * Orbital ATK GEOStar * Mitsubishi Electric DS2000 * Spacecraft bus of the James Webb Space Telescope * SP ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. Many communications satellites are in geostationary orbit above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently. The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by the curve of the Earth. The purpose of communicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Plate, North American Tectonic Plate, Greenland is included as a part of North America geographically. North America covers an area of about , about 16.5% of Earth's land area and about 4.8% of its total surface. North America is the third-largest continent by area, following Asia and Africa, and the list of continents and continental subregions by population, fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in List of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's population. In Americas (terminology)#Human ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickel–hydrogen Battery
A nickel–hydrogen battery (NiH2 or Ni–H2) is a rechargeable electrochemical power source based on nickel and hydrogen. It differs from a nickel–metal hydride (NiMH) battery by the use of hydrogen in gaseous form, stored in a pressurized cell at up to 1200 psi (82.7 bar) pressure. The nickel–hydrogen battery was patented on February 25, 1971 by Alexandr Ilich Kloss and Boris Ioselevich Tsenter in the United States. NiH2 cells using 26% potassium hydroxide (KOH) as an electrolyte have shown a service life of 15 years or more at 80% depth of discharge (DOD) The energy density is 75 Wh/ kg, 60 Wh/dm3 specific power 220 W/kg. 15 years) in satellite applications. The cells can tolerate overcharging and accidental polarity reversal, and the hydrogen pressure in the cell provides a good indication of the state of charge. However, the gaseous nature of hydrogen means that the volume efficiency is relatively low (60-100 Wh/L for an IPV (individua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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