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AsiaSat 7
AsiaSat 7 is a Hong Kong communications satellite, which is operated by the Hong Kong based Asia Satellite Telecommunications Company (AsiaSat). It is positioned in geostationary orbit at a longitude of 105° East of the Greenwich Meridian, where it serves as a back-up for the AsiaSat 5 satellite and replaced AsiaSat 3S. It is used to provide fixed satellite services, including broadcasting, telephone and broadband very small aperture terminal (VSAT) communications, to Asia and the Pacific Ocean region. Satellite description Space Systems/Loral and AsiaSat announced in May 2009, that it has been chosen to provide a new communications satellite, named AsiaSat 5C. In early 2010, the satellite was renamed AsiaSat 7. At launch, AsiaSat 7 had a mass of , and was expected to operate for fifteen years. It carries 26 C-band and 14 Ku-band transponders. Launch AsiaSat 7 was built by Space Systems/Loral, and is based on the LS-1300 satellite bus. It is being launched by Interna ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AsiaSat 5
AsiaSat 5 is a Hong Kong communications satellite, which is operated by the Hong Kong based Asia Satellite Telecommunications Company (AsiaSat). It is positioned in geostationary orbit at a longitude of 100.5° East of the Greenwich Meridian, where it replaced the AsiaSat 2 satellite. It is used to provide fixed satellite services, including broadcasting, telephone and broadband very small aperture terminal (VSAT) communications, to Asia and the Pacific Ocean region. Background The launch was originally scheduled to be conducted by Land Launch (SSL-1300LL satellite bus), using a Zenit-3SLB launch vehicle. The satellite was subsequently re-awarded to ILS after Land Launch were unable to guarantee that the satellite could be launched by August 2009, in order to be in orbit before AsiaSat 2 ceased operations. Satellite description Space Systems/Loral (SS/L), announced in May 2005 that it has been chosen by AsiaSat. At launch, AsiaSat 5 had a mass of , and was expected to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbekistan to the south, and Turkmenistan to the southwest, with a coastline along the Caspian Sea. Its capital is Astana, known as Nur-Sultan from 2019 to 2022. Almaty, Kazakhstan's largest city, was the country's capital until 1997. Kazakhstan is the world's largest landlocked country, the largest and northernmost Muslim-majority country by land area, and the ninth-largest country in the world. It has a population of 19 million people, and one of the lowest population densities in the world, at fewer than 6 people per square kilometre (15 people per square mile). The country dominates Central Asia economically and politically, generating 60 percent of the region's GDP, primarily through its oil and gas industry; it also has vast minera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multistage Rocket
A multistage rocket or step rocket is a launch vehicle that uses two or more rocket ''stages'', each of which contains its own engines and propellant. A ''tandem'' or ''serial'' stage is mounted on top of another stage; a ''parallel'' stage is attached alongside another stage. The result is effectively two or more rockets stacked on top of or attached next to each other. Two-stage rockets are quite common, but rockets with as many as five separate stages have been successfully launched. By jettisoning stages when they run out of propellant, the mass of the remaining rocket is decreased. Each successive stage can also be optimized for its specific operating conditions, such as decreased atmospheric pressure at higher altitudes. This ''staging'' allows the thrust of the remaining stages to more easily accelerate the rocket to its final speed and height. In serial or tandem staging schemes, the first stage is at the bottom and is usually the largest, the second stage and subseq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Launch Vehicle
A launch vehicle or carrier rocket is a rocket designed to carry a payload ( spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and systems such as vehicle assembly and fueling. Launch vehicles are engineered with advanced aerodynamics and technologies, which contribute to large operating costs. An orbital launch vehicle must lift its payload at least to the boundary of space, approximately and accelerate it to a horizontal velocity of at least . Suborbital vehicles launch their payloads to lower velocity or are launched at elevation angles greater than horizontal. Practical orbital launch vehicles are multistage rockets which use chemical propellants such as solid fuel, liquid hydrogen, kerosene, liquid oxygen, or Hypergolic propellants. Launch vehicles are classified by their orbital payload capacity, ranging from small-, medium-, heavy- to super-heavy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Launch Services
International Launch Services, Inc. (ILS) is a joint venture with exclusive rights to the worldwide sale of commercial Angara and Proton rocket launch services. Proton launches take place at the Baikonur Cosmodrome in Kazakhstan while Angara is launched from the Plesetsk and Vostochny Cosmodrome in Russia. Ownership ILS was formed in 1995 as a private spaceflight partnership between Lockheed Martin (LM), Khrunichev and Energia. ILS initially co-marketed non-military launches on both the American Atlas and the Russian Proton expendable launch vehicles. With the Atlas V launch of the SES Astra 1KR satellite on 20 April 2006, ILS had made 100 launches, 97 of which were successful. In September 2006, Lockheed-Martin announced its intention to sell its ownership interests in Lockheed Khrunichev Energia International, Inc. (LKEI) and International Launch Services, Inc. (ILS) to Space Transport Inc. Space Transport Inc. was formed specifically for this transaction by Mario Lemme ... [...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 * SPUTNIX ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very Small Aperture Terminal
A very-small-aperture terminal (VSAT) is a two-way satellite ground station with a dish antenna that is smaller than 3.8 meters. The majority of VSAT antennas range from 75 cm to 1.2 m. Bit rates, in most cases, range from 4 kbit/s up to 16 Mbit/s. VSATs access satellites in geosynchronous orbit or geostationary orbit to relay data from small remote Earth stations (terminals) to other terminals (in mesh topology) or master Earth station "hubs" (in star topology). VSATs are used to transmit narrowband data (e.g., point-of-sale transactions using credit cards, polling or RFID data, or SCADA), or broadband data (for the provision of satellite Internet access to remote locations, VoIP or video). VSATs are also used for transportable, on-the-move (utilising phased array antennas) or mobile maritime communications. History The concept of the geostationary orbit was originated by Russian theorist Konstantin Tsiolkovsky, who wrote articles on space travel around the beginning of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixed Satellite Services
Fixed-satellite service (short: FSS | also: fixed-satellite radiocommunication service) is – according to ''article 1.21'' of the International Telecommunication Union's (ITU) Radio Regulations (RR) – defined as ''A radiocommunication service between earth stations at given positions, when one or more satellites are used; the given position may be a specified fixed point or any fixed point within specified areas; in some cases this service includes satellite-to-satellite links, which may also be operated in the inter-satellite service; the fixed-satellite service may also include feeder links for other space radiocommunication services.'' Classification This ''radiocommunication service'' is classified in accordance with ''ITU Radio Regulations'' (article 1) as follows: Fixed service (article 1.20) * (article 1.21) * Inter-satellite service (article 1.22) * Earth exploration-satellite service (article 1.51) ** Meteorological-satellite service (article 1.52) ; Freq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AsiaSat 3S
AsiaSat 3S, was a geosynchronous communications satellite for AsiaSat of Hong Kong to provide communications and television services all across Asia, the Middle East and Oceania. Background In March 1998, AsiaSat ordered a replacement satellite, for US$195 million, from Hughes Space and Communications. Designated AsiaSat 3S, the new satellite is a replica of AsiaSat 3. Launch AsiaSat 3S was launched for AsiaSat by a Proton-K / DM-2M launch vehicle on 21 March 1999, at 00:09:30 UTC, destined for an orbital location at 105.5° East. A replacement for Asiasat 3, placed in the wrong orbit by a Proton launch in 1997, Asiasat 3S carried C-band and Ku-band transponders. The Blok DM-2M upper stage placed the satellite in a Geostationary transfer orbit (GTO). Asiasat's on-board R4D-11-300 apogee engine was then used to raise perigee to geostationary altitude. It replaced AsiaSat 1 on 8 May 1999. Mission It was replaced by AsiaSat 7 AsiaSat 7 is a Hong Kong communicati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenwich Meridian
The historic prime meridian or Greenwich meridian is a geographical reference line that passes through the Royal Observatory, Greenwich, in London, England. The modern IERS Reference Meridian widely used today is based on the Greenwich meridian, but differs slightly from it. This prime meridian (at the time, one of many) was first established by Sir George Airy in 1851, and by 1884, over two-thirds of all ships and tonnage used it as the reference meridian on their charts and maps. In October of that year, at the behest of US President Chester A. Arthur, 41 delegates from 25 nations met in Washington, D.C., United States, for the International Meridian Conference. This conference selected the meridian passing through Greenwich as the world standard prime meridian due to its popularity. However, France abstained from the vote, and French maps continued to use the Paris meridian for several decades. In the 18th century, London lexicographer Malachy Postlethwayt publi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geostationary Orbit
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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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