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Galaxy 11
Galaxy 11 is an American geostationary communications satellite which is operated by Intelsat. It is located in geostationary orbit at a longitude of 32.8 degrees east, where it serves as a backup to the Intelsat 802 spacecraft. It was originally operated at 99° West and later spent most of its operational life at 91° West, from where it was used to provide communications services to Brazil and North America. Galaxy 11 was built for PanAmSat by Hughes Space and Communications, and is based on the HS-702 satellite bus. It was the first HS-702 to be launched, and the first satellite to be equipped with an XIPS propulsion system. It carries 24 G/H band and 40 J band (IEEE C and s respectively) transponders, and at launch it had a mass of , with an expected operational lifespan of around 15 years. As the first HS-702 to fly, Galaxy 11 was one of the six which were launched before a design flaw in the type's solar arrays was discovered. Solar concentrators, used to increase the amoun ... [...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 communications sate ... [...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] |
1999 In Spaceflight
The table below shows 208 satellite launches were made in 1999. 81 ''(39%)'' of these launches were communications satellites. Launches , colspan=8, January , - , colspan=8, February , - , colspan=8, March , - , colspan=8, April , - , colspan=8, May , - , colspan=8, June , - , colspan=8, July , - , colspan=8, August , - , colspan=8, September , - , colspan=8, October , - , colspan=8, November , - , colspan=8, December , - Deep Space Rendezvous EVAs References Footnotes {{DEFAULTSORT:1999 In Spaceflight Spaceflight by year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keldysh Institute Of Applied Mathematics
The Keldysh Institute of Applied Mathematics (russian: Институт прикладной математики им. М.В.Келдыша) is a research institute specializing in computational mathematics. It was established to solve computational tasks related to government programs of nuclear and fusion energy, space research and missile technology. The Institute is a part of the Department of Mathematical Sciences of the Russian Academy of Sciences. The main direction of activity of the institute is the use of computer technology to solve complex scientific and technical issues of practical importance. Since 2016, development of mathematical and computational methods for biological research, as well as a direct solution to the problems of computational biology with the use of such methods, has also been included in the circle of scientific activities of the institute. Scientific activity Nuclear physics Prominent theoretical physicist Yakov Borisovich Zel'dovich headed one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Scientific Optical Network
The International Scientific Optical Network or ISON (russian: Международная научная оптическая сеть, Пулковская кооперация оптических наблюдателей) is an international project, currently consisting of about 30 telescopes at about 20 observatories in about ten countries (Russia, Ukraine (Andrushivka), Georgia (Abastumani), Uzbekistan, Tajikistan, Moldova, Spain (Teide), Switzerland ( Zimmerwald), Bolivia (Tarija), USA ( Mayhill), Italy (Collepardo)) which have organized to detect, monitor and track objects in space. Other observatories include the "ISON-Kislovodsk Observatory", located near Kislovodsk, North Caucasus, Russia, with the observatory code D00. ISON is managed by the Keldysh Institute of Applied Mathematics, part of the Russian Academy of Sciences. It was credited for the discovery of comets C/2010 X1 (Elenin) and C/2012 S1 (ISON), the latter popularly known as Comet ISON. The minor planet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DemoSat
A DemoSat is a boilerplate spacecraft used to test a carrier rocket without risking a real satellite on the launch. They are most commonly flown on the maiden flights of rockets, but have also been flown on return-to-flight missions after launch failures. Defunct satellites from cancelled programmes may be flown as DemoSats, for example the maiden flight of the Soyuz-2 rocket placed an obsolete Zenit-8 satellite onto a sub-orbital trajectory in order to test the rocket's performance. See also *Boilerplate (spaceflight)
A boilerplate spacecraft, also known as a mass simulator, is a nonfunctional ...
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Zenit-3SL
The Zenit-3SL is an expendable carrier rocket operated by Sea Launch. First flown in 1999, it has been launched 36 times, with three failures and one partial failure. It is a member of the Zenit family of rockets, and is built by the Yuzhnoye Design Bureau. RKK Energia produces the Block DM-SL upper stage, whilst the payload fairing is produced by Boeing. Launches are conducted from the Ocean Odyssey platform anchored on the equator in the Pacific Ocean, at a point with 154°W longitude, about 370 kilometres east of Kiritimati. The Zenit-3SL design began in the late 1980s as the Zenit-3, a proposed replacement for the Proton-K, which would have used a Zenit-2 rocket with a Block D upper stage. This proposal was shelved after the dissolution of the Soviet Union, as Russia inherited the space programme, however the Zenit was manufactured in Ukrainian SSR. Boeing became involved in the programme in 1994. The design was subsequently modified, with a modified version of the Block DM r ... [...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 launc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R-4D
The R-4D is a small hypergolic rocket engine, originally designed by Marquardt Corporation for use as a reaction control system thruster on vehicles of the Apollo crewed Moon landing program. Today, Aerojet Rocketdyne manufactures and markets modern versions of the R-4D. History Developed as an attitude control thruster for the Apollo Command/Service Module and Lunar Module in the 1960s, each unit for the modules employed four quadruple clusters (pods). It was first flown on AS-201 in February 1966. Approximately 800 were produced during the Apollo program. Post-Apollo, modernized versions of the R-4D have been used in a variety of spacecraft, including the U.S. Navy's Leasat, Insat 1, Intelsat 6, Italsat, and BulgariaSat-1. It has also been used on Japan's H-II Transfer Vehicle and the European Automated Transfer Vehicle, both of which deliver cargo to the International Space Station. It is also used on the Orion spacecraft Design The R-4D is a fuel-film cooled engine. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geosynchronous Transfer Orbit
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites that are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step for reaching their final orbit. A GTO is highly elliptic. Its perigee (closest point to Earth) is typically as high as low Earth orbit (LEO), while its apogee (furthest point from Earth) is as high as geostationary (or equally, a geosynchronous) orbit. That makes it a Hohmann transfer orbit between LEO and GSO. Larson, Wiley J. and James R. Wertz, eds. Space Mission Design and Analysis, 2nd Edition. Published jointly by Microcosm, Inc. (Torrance, CA) and Kluwer Academic Publishers (Dordrecht/Boston/London). 1991. While some GEO satellites are launched direct to that orbit, often the launch vehicle lacks the power to put both the rocket and the satellite into that orbit. Instead extra fuel is added to the satellite, the launch vehicle la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US 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, its equi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Concentrator
Concentrated solar power (CSP, also known as concentrating solar power, concentrated solar thermal) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight into a receiver. Electricity is generated when the concentrated light is converted to heat (solar thermal energy), which drives a heat engine (usually a steam turbine) connected to an electrical power generator or powers a thermochemical reaction. CSP had a global total installed capacity of 6,800 MW in 2021, up from 354 MW in 2005. Spain accounted for almost one third of the world's capacity, at 2,300 MW, despite no new capacity entering commercial operation in the country since 2013. The United States follows with 1,740 MW. Interest is also notable in North Africa and the Middle East, as well as China and India. The global market was initially dominated by parabolic-trough plants, which accounted for 90% of CSP plants at one point. Since about 2010, central po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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