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Nahuel 1A
Nahuel 1A was a Spacebus 2000NG satellite manufactured Dornier Satellitensysteme as prime contractor with Aérospatiale of Cannes-Mandelieu supplying the bus. It was launched on January 30, 1997 by an Ariane 44L launcher along companion GE-2. The satellite was located in the 71.8 degrees West slot. It was operated by Nahuelsat S.A., the first satellite operator of Argentina from its ground station in Benavidez, province of Buenos Aires. It was transferred in 2006 ARSAT S.A., along all other Nahuelsat S.A. assets. Satellite mass was wet, dry with a nominal lifetime of 12.33 years. It had eighteen 54 MHz transponders implemented with 55W TWTAs in three Ku band and extended Ku band coverages. Thus, it had 27 transponder equivalent or 972 MHz of Ku Band bandwidth. It was successfully reorbited in June 2010, when most of the on-board propellant depleted, using the remaining propellant and blowdown helium still stored in the propellant tanks. History In the early 1990s ... [...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] |
AMC-2
GE-2, called AMC-2 after 2001, is a privately owned American communications satellite launched in 1997. It was the first of the GE series to be launched outside the United States. It was launched by an Ariane 44L on 30 January 1997 at 22:04:00 UTC, flying from ELA-2, Centre Spatial Guyanais alongside another satellite, Nahuel 1A. It was owned by GE Americom until 2001 when the company was sold to SES (Société Européenne des Satellites). The name of the spacecraft was then changed by SES Americom to AMC-2 in 2001. Overview GE-2 carries 24 Ku-band and 24 C-band transponders. It weighs approximately fully fueled and has a dry mass of . It is stationed at approximately 81° West serving the North America. There is also a plan to relocate the satellite to 85° West orbital position. It is powered by two deployable solar panels which charge the batteries. It uses LEROS-1c Leros ( el, Λέρος) is a Greek island and municipality in the Dodecanese in the southern Aegean Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AMC-5
The AMC-5, originally called GE-5, was a geosynchronous direct-broadcast satellite (DBS) located at 79° West longitude, operated by SES Americom in the Ku-band. It was used by a variety of television customers, including being home to the CBS Newspath service. The satellite was retired and moved to a graveyard orbit on 17 May 2014 after 15 years of service. Payload and specifications Spacecraft design: Aérospatiale Spacebus 2000 Orbital location: 79° West Launch Date: 28 October 1998 Vehicle: Ariane 44L Design life: 15 years Band: Ku-band Ku-band payload: 16 x 54 MHz Transponder type: TWTA, 55 watts Transponder redundancy: 11 for 8 Receiver redundancy: 4 for 2 Coverage: United States, Canada, 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 Guatema ... References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SES Americom
SES Americom was a major commercial satellite operator of North American geosynchronous satellites based in the United States. The company started as RCA Americom in 1975 before being bought by General Electric in 1986 and then later acquired by SES S.A. in 2001. In September 2009, SES Americom and SES New Skies merged into SES World Skies. History RCA American Communications (RCA Americom) was founded in 1975 as an operator of RCA Astro Electronics-built satellites. The company's first satellite; Satcom 1, was launched on 12 December 1975. Satcom 1 was one of the earliest geostationary satellites. Satcom 1 was instrumental in helping early cable TV channels (such as Superstation TBS and CBN) to become initially successful, because these channels distributed their programming to all of the local cable TV headends using the satellite. Additionally, it was the first satellite used by broadcast TV networks in the United States, like American Broadcasting Company (ABC), NBC, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIL-STD-1750A
MIL-STD-1750A or 1750A is the formal definition of a 16-bit computer instruction set architecture (ISA), including both required and optional components, as described by the military standard document MIL-STD-1750A (1980). Since August 1996, it has been inactive for new designs. In addition to the core ISA, the definition defines optional instructions, such as a FPU and MMU. Importantly, the standard does not define the implementation details of a 1750A processor. Internals The 1750A supports 216 16-bit words of memory for the core standard. The standard defines an optional memory management unit that allows 220 16-bit words of memory using 512 page mapping registers (in the I/O space), defining separate instruction and data spaces, and keyed memory access control. Most instructions are 16 bits, although some have a 16-bit extension. The standard computer has 16 general purpose 16-bit registers (0 through 15). Registers 1 through 15 can be used as index registers. Registers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RCA 1802
The COSMAC (Complementary Symmetry Monolithic Array Computer) is an 8-bit microprocessor family introduced by RCA. It is historically notable as the first CMOS microprocessor. The first production model was the two-chip CDP1801R and CDP1801U, which were later combined into the single-chip CDP1802. The 1802 represented the majority of COSMAC production, and today the entire line is known simply as the RCA 1802. The processor design traces its history to an experimental home computer designed by Joseph Weisbecker in the early 1970s, built at his home using TTL components. RCA began development of the CMOS version of the processor design in 1973, sampling it in 1974 with plans to move to a single-chip implementation immediately. Jerry Herzog led the design of the single-chip version, which sampled in 1975 and entered production in 1976. In contrast to most designs of the era, which were fabricated using the NMOS process, the COSMAC was implemented in CMOS form and used static ... [...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] |
Ground Station
A ground station, Earth station, or Earth terminal is a terrestrial radio station designed for extraplanetary telecommunication with spacecraft (constituting part of the ground segment of the spacecraft system), or reception of radio waves from astronomical radio sources. Ground stations may be located either on the surface of the Earth, or in its atmosphere. Earth stations communicate with spacecraft by transmitting and receiving radio waves in the super high frequency (SHF) or extremely high frequency (EHF) bands (e.g. microwaves). When a ground station successfully transmits radio waves to a spacecraft (or vice versa), it establishes a telecommunications link. A principal telecommunications device of the ground station is the parabolic antenna. Ground stations may have either a fixed or itinerant position. Article 1 § III of the International Telecommunication Union (ITU) Radio Regulations describes various types of stationary and mobile ground stations, and their interre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anik (satellite)
The Anik satellites are a series of geostationary communications satellites launched for Telesat Canada for television, voice and data in Canada and other parts of the world, from 1972 through 2013. Some of the later satellites in the series remain operational in orbit, while others have been retired to a graveyard orbit. The naming of the satellite was determined by a national contest, and was won by Julie-Frances Czapla of Saint-Léonard, Québec. In Inuktitut, ''Anik'' means "little brother". Satellites Anik A The Anik A satellites were the world's first national domestic satellites. (Prior to Anik A1's launch, all geosynchronous communications satellites were transcontinental, i.e. Intelsat I and others.) The Anik A fleet of three satellites gave CBC the ability to reach the Canadian North for the first time. Each of the satellites was equipped with 12 C-band transponders, and thus had the capacity for 12 colour television channels. Three channels were allocated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geosynchronous Orbit
A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds (one sidereal day). The synchronization of rotation and orbital period means that, for an observer on Earth's surface, an object in geosynchronous orbit returns to exactly the same position in the sky after a period of one sidereal day. Over the course of a day, the object's position in the sky may remain still or trace out a path, typically in a figure-8 form, whose precise characteristics depend on the orbit's inclination and eccentricity. A circular geosynchronous orbit has a constant altitude of . A special case of geosynchronous orbit is the geostationary orbit, which is a circular geosynchronous orbit in Earth's equatorial plane with both inclination and eccentricity equal to 0. A satellite in a geostationary orbit remains in the same position in the sky to observers on the surface. Communicat ... [...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] |
Transponder Equivalent
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] |
