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AsiaSat 1
AsiaSat 1 was a Hong Kong communications satellite, which was owned, and was operated, by the Hong Kong based Asia Satellite Telecommunications Company. It was positioned in geostationary orbit at a longitude of 100.5° East. It spent its operational life at 100.5° East, from where it was used to provide fixed satellite services, including broadcasting, audio and data transmission, to Asia and the Pacific Ocean. Satellite description AsiaSat 1 was built by Hughes Space and Communications. It is based on the HS-376 satellite bus. At launch, it had a mass of , and a design life of thirteen years. It carries twenty four C-band transponders. Launch The launch of AsiaSat 1 was contracted to the China Great Wall Industry Corporation (CGWIC), and used a Long March 3 launch vehicle. The launch was conducted from Xichang Launch Area 3 (LA-3) at the Xichang Satellite Launch Centre at 13:30:02 UTC on 7 April 1990. Westar 6 Westar 6 was launched from the space shuttle in Februa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Westar 6
Westar was a fleet of geosynchronous communications satellites operating in the C band which were launched by Western Union from 1974 to 1984. There were seven Westar satellites in all, with five of them launched and operating under the Westar name. Background Westar 1 (launched on April 13, 1974) has the distinction of being the USA's first commercially launched geosynchronous communications satellite, following North America's first geosynchronous communications satellite, Canada's Anik A1 in 1972. Westar 1 was put into orbit at 99° W in the Clarke belt (99° W now being the home of Galaxy 16). Westar 2 was launched shortly afterward on October 10, 1974. Westar 3, the first satellite to use TDMA switched data, was launched on August 10, 1979. Westars 1, 2 and 3 were built by Hughes using the HS 333 platform of spin-scan stabilized satellites. They only had 12 transponders on board, as opposed to later C-band communications satellites having 24, and even contem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continents of Asia and Oceania in the west and the Americas in the east. At in area (as defined with a southern Antarctic border), this largest division of the World Ocean—and, in turn, the hydrosphere—covers about 46% of Earth's water surface and about 32% of its total surface area, larger than Earth's entire land area combined .Pacific Ocean . '' Britannica Concise.'' 2008: Encyclopædia Britannica, Inc. The centers of both the |
Spacecraft Launched In 1990
A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, planetary exploration, and transportation of humans and cargo. All spacecraft except single-stage-to-orbit vehicles cannot get into space on their own, and require a launch vehicle (carrier rocket). On a sub-orbital spaceflight, a space vehicle enters space and then returns to the surface without having gained sufficient energy or velocity to make a full Earth orbit. For orbital spaceflights, spacecraft enter closed orbits around the Earth or around other celestial bodies. Spacecraft used for human spaceflight carry people on board as crew or passengers from start or on orbit (space stations) only, whereas those used for robotic space missions operate either autonomously or telerobotically. Robotic spacecraft used to support scientific re ... [...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 Oceania (, , ) is a region, geographical region that includes Australasia, Melanesia, Micronesia, and Polynesia. Spanning the Eastern Hemisphere, Eastern and Western Hemisphere, Western hemispheres, Oceania is estimated to have a land area of .... 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 PAS-22, AsiaSat 3. Launch AsiaSat 3S was launched for AsiaSat by a Proton-K / Blok D, DM-2M launch vehicle on 21 March 1999, at 00:09:30 Coordinated Universal Time, 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 (IEEE), C-band and Ku band, Ku-band Transpon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Payload Assist Module
The Payload Assist Module (PAM) is a modular upper stage designed and built by McDonnell Douglas (now Boeing), using Thiokol Star-series solid propellant rocket motors. The PAM was used with the Space Shuttle, Delta, and Titan launchers and carried satellites from low Earth orbit to a geostationary transfer orbit or an interplanetary course. The payload was spin stabilized by being mounted on a rotating plate. Originally developed for the Space Shuttle, different versions of the PAM were developed: * PAM-A (Atlas class), development terminated; originally to be used on both the Atlas and Space Shuttle * PAM-D (Delta class), uses a Star-48B rocket motor * PAM-DII (Delta class), uses a Star-63 rocket motor * PAM-S (Special) as a kick motor for the space probe ''Ulysses'' The PAM-D module, used as the third stage of the Delta II rocket, was the last version in use. As of 2018, no PAM is in active use on any rockets. 2001 re-entry incident On January 12, 2001, a PAM-D module re-e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xichang Satellite Launch Centre
The Xichang Satellite Launch Center (XSLC), also known as the Xichang Space Center, is a spaceport of China. It is located in Zeyuan Town (), approximately northwest of Xichang, Liangshan Yi Autonomous Prefecture in Sichuan. The facility became operational in 1984 and is used to launch numerous civil, scientific, and military payloads annually. It is notable as the site of Sino-European space cooperation, with the launch of the first of two Double Star scientific satellites in December 2003. Chinese officials have indicated interest in conducting additional international satellite launches from XSLC. In 1996, a fatal accident occurred when the rocket carrying the Intelsat 708 satellite failed on launch from the Xichang Satellite Launch Center. Also, a 2007 test of an anti-satellite missile was launched from the center. History China's first crewed space program In order to support the Chinese Project 714 crewed space program in the 1960s, the construction of a new space ce ... [...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 pad, launch pads, supported by a missile launch control center, 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 spaceflight, 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 spaceflight, 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-propellant rocket, solid fuel, liquid hydrogen, kerosene, liquid oxygen, or Hypergolic propellants. Launch vehicles are cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transponder (satellite Communications)
A communications satellite's transponder is the series of interconnected units that form a communications channel between the receiving and the transmitting antennas. It is mainly used in satellite communication to transfer the received signals. A transponder is typically composed of: * an input band-limiting device (an input band-pass filter), * an input low-noise amplifier (LNA), designed to amplify the signals received from the Earth station (normally very weak, because of the large distances involved), * a frequency translator (normally composed of an oscillator and a frequency mixer) used to convert the frequency of the received signal to the frequency required for the transmitted signal, * an output band-pass filter, * a power amplifier (this can be a traveling-wave tube or a solid-state amplifier). Most communication satellites are radio relay stations in orbit and carry dozens of transponders, each with a bandwidth of tens of megahertz. Most transponders operate on a ... [...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 TabletSat * ... [...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) ; Frequency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longitude
Longitude (, ) is a geographic coordinate that specifies the east–west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (λ). Meridians are semicircular lines running from pole to pole that connect points with the same longitude. The prime meridian defines 0° longitude; by convention the International Reference Meridian for the Earth passes near the Royal Observatory in Greenwich, England on the island of Great Britain. Positive longitudes are east of the prime meridian, and negative ones are west. Because of the Earth's rotation, there is a close connection between longitude and time measurement. Scientifically precise local time varies with longitude: a difference of 15° longitude corresponds to a one-hour difference in local time, due to the differing position in relation to the Sun. Comparing local time to an absolute measure of time allows ... [...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 sat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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