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Star One B4
Star One B4, originally designated Brasilsat B4, is a Brazilian communications satellite which is operated by Star One. It was constructed by the Hughes Space and Communications Company, and is based on the HS-376W satellite bus. It was the penultimate HS-376, and final HS-376W to be launched. Its launch was contracted by Arianespace, using an Ariane 4 44LP-3 carrier rocket. The launch occurred at 23:16 GMT on 17 August 2000, from the ELA-2 launch pad at the Guiana Space Centre. The Nilesat 102 satellite was launched on the same rocket. It was originally built and launched as Brasilsat B4 for Embratel, and was later transferred to Embratel's subsidiary Star One and renamed. Following its launch it raised itself into geostationary orbit by means of its onboard R-4D apogee motor, and was positioned at 75° West for on-orbit testing. This was completed in September 2000, and it was moved to 92° West, arriving in October. It remained at that position until January 2007 when it was r ... [...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] |
H Band (NATO)
The NATO H band is the obsolete designation given to the radio frequencies from 6 000 to 8 000 MHz (equivalent to wavelengths between 5 and 3.75 cm) during the cold war period. Since 1992 frequency allocations, allotment and assignments are in line to NATO Joint Civil/Military Frequency Agreement (NJFA). However, in order to identify military radio spectrum requirements, e.g. for crises management planning, training, Electronic warfare Electronic warfare (EW) is any action involving the use of the electromagnetic spectrum (EM spectrum) or directed energy to control the spectrum, attack an enemy, or impede enemy assaults. The purpose of electronic warfare is to deny the opponen ... activities, or in military operations, this system is still in use. References Radio spectrum Microwave bands {{Wireless-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jonathan's Space Report
''Jonathan's Space Report'' (JSR) is a newsletter about the Space Age, hosted at Jonathan's Space Page. It is written by Jonathan McDowell, a Center for Astrophysics Harvard & Smithsonian astrophysicist. It is updated as McDowell's schedule permits, but he tries to publish two issues each month. Originally the website was hosted on a Harvard University account, but was moved in late 2003 to a dedicated domain. Started in 1989, the newsletter reports on recent space launches, International Space Station activities and space craft developments. McDowell's report occasionally corrects NASA's official web sites, or provides additional data on classified launches that aren't available elsewhere. Associated projects on the JSR web site are: * A catalog of all known geosynchronous satellites and their current positions * A listing of satellite launch attempts * A cross-reference between catalog number and international designation of artificial satellites McDowell has long campaigne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Junk Orbit
Junk may refer to: Arts and entertainment * ''Junk'' (film), a 2000 Japanese horror film * '' J-U-N-K'', a 1920 American film * ''Junk'' (novel), by Melvin Burgess, 1996 * ''Junk'', a novel by Christopher Largen Music Groups * Junk (band), a British pop band Albums * ''Junk'', by Ferry Corsten, 2006 * ''Junk'', by Jejune, 1997 * ''Junk'', by Junk (band), 1995 * ''Junk'' (M83 album), 2016 Songs * "Junk" (song), written by Paul McCartney in 1970 * "Junk", song from Zico Chain's ''Food'' album Other uses in arts and entertainment * '' Junk: Record of the Last Hero'', a shōnen manga series by Kia Asamiya * '' Junk: The Golden Age of Debt'', a play by Ayad Akhtar Finance * Junk bond * Junk status, a debt credit rating People * Bruno Junk (1929–1995), Estonian race walker, two-time Olympic bronze medal winner * Janson Junk (born 1996), American baseball pitcher * Sebastian Junk (born 1983), German Paralympic judoka * Wilhelm Junk (1866–1942), Czech-born antiquarian bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope thermoelectric generators (RTGs). Most satellites also have a method of communication to ground stations, called Transponder (satellite communications), transponders. Many satellites use a Satellite bus, standardized bus to save cost and work, the most popular of which is small CubeSats. Similar satellites can work together as a group, forming Satellite constellation, constellations. Because of the high launch cost to space, satellites are designed to be as lightweight and robust as possible. Most communication satellites are radio Broadcast relay station, relay stations in orbit and carry dozens of transponders, each with a bandwidth of tens of megahertz. Satellites are placed from the surface to orbit by launch vehicles, high enough to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. 34 dBW for most of the Brazilian territory. History In the 1980s, Brazil needed its own satellites to exempt foreigners. As a result of this effort, the Brazilian company Embratel contracted in August 1982 the Canadian Spar Aerospace, Ltd., in partnership with American Hughes, to build its series of "Brasilsat A" satellites, the series consisted of two satellites, the Brasilsat-A1 and the Brasilsat A2. Built by Spar Aerospace, which received US$ 125 million to build under license from Hugh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apogee Motor
An apogee kick motor (AKM) is a rocket motor that is regularly employed on artificial satellites to provide the final impulse to change the trajectory from the transfer orbit into its final (most commonly circular) orbit. For a satellite launched from the Earth, the rocket firing is done at the highest point of the transfer orbit, known as the apogee. An apogee kick motor is used, for example, for satellites launched into a geostationary orbit. As the vast majority of geostationary satellite launches are carried out from spaceports at a significant distance away from Earth's equator, the carrier rocket often only launches the satellite into an orbit with a non-zero inclination approximately equal to the latitude of the launch site. This orbit is commonly known as a "geostationary transfer orbit" or a "geosynchronous transfer orbit". The satellite must then provide thrust to bring forth the needed delta v to reach a geostationary orbit. This is typically done with a fixed onboa ... [...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] |
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] |
Nilesat 102
Nilesat 102 is an Egyptian owned geosynchronous communications satellite that was launched by an Ariane 44LP rocket from Kourou, French Guiana on August 17, 2000, at 23:16 UTC by the European Space Agency. It was manufactured by the European company Matra Marconi Space (Astrium), and started official broadcasting on 12 September 2000 with an expected lifetime of 15 years. The spacecraft weighed 1,827 kg at launch. Manufacture It was manufactured by the European company Matra Marconi Space (Astrium). At launch, the spacecraft weighed 1,827 kg (fully fuelled). The receiver dish diameter is 50 cm to 75 cm. The transponder output power is 100 W and 12 Ku-band transponders with a bandwidth of 33 MHz. The maximum power consumption is 3.06 kW. The satellite utilizes a three axis stabilization system. The satellite is powered by two deployable solar arrays, with the power being stored on batteries. Launch Nilesat 102 was launched by an Ariane 44LP rock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HS-376
The Boeing 376 (sometimes referred to as the BSS-376, and previously as the HS-376) is a communications satellite bus introduced in 1978 by Hughes Space and Communications Company. It was a spin-stabilized bus that the manufacturer claims was the first standardized platform. Design The satellite bus was designed and manufactured by Hughes. This spin-stabilized platform had two main sections. The spinning section was kept rotating at 50 rpm to maintain attitude, and a despun section was used by the payload to maintain radio coverage. The spinning section included the apogee kick motor, most of the attitude control, the power subsystem and the command and telemetry subsystems. The despun section contained the communications payload, including the antennas and transponders. The stock version had a launch mass of , a mass of after reaching geostationary orbit and an 8 to 10-year design life. When stowed for launch, its dimensions were in height and in diameter. With its sol ... [...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] |
