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Satcom (satellite)
Satcom, a portmanteau of satellite communications, was a brand of artificial geo-stationary communications satellites originally developed and operated by RCA American Communications ( RCA Americom) that facilitated wide-area telecommunications by receiving radio signals from Earth, amplifying them, and relaying them back down to terrestrial receivers. Satcom was one of the early geostationary satellites; the first were the Syncom series, in 1964. The first Satcom satellite, Satcom 1, was launched on 13 December 1975. The last satellite, Satcom K2, was placed into orbit on 27 November 1985 and was de-orbited in February 2002. Satcom was first superseded and then replaced by the GE series of satellites. The Satcom system passed to General Electric with its purchase of RCA in 1986. RCA Americom became GE American Communications (GE Americom) and the satellite construction division became GE Astro Space. GE Astro Space was sold to Martin Marietta (now Lockheed Martin Spac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freeform (TV Channel)
Freeform may refer to: __NOTOC__ Computers *Freeform surface modelling, via computer-aided design (CAD) *Freeform solid modeling, via computer-aided design (CAD) *Freeform machine, 3D printing * Freeform, a collaborative application developed by Apple Inc. Entertainment * Freeform composition *Freeform (TV channel), an American television channel *Free-form radio, in which the disc jockey is given total control over what music to play *Freeform Five, UK electro-house band *Freeform jazz, free jazz, subgenre where artists improvise without any preset form or rhythm *Freeform Portland, a Portland listener-supported radio station *Freeform role-playing game, a type of role-playing game with minimal or no rules * Freeform, Electronic music genre Other uses *Freeform crochet and knitting Freeform crochet and knitting is a seemingly random combination of crochet, knitting and in some cases other fibre arts to make a piece that is not constrained by patterns, colours, stitches or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geostationary Transfer Orbit
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellite, Satellites that are destined for geosynchronous orbit, 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 orbit, 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 geostationary orbit, 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. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta 3000
The Delta 3000 series was an American expendable launch system which was used to conduct 38 orbital launches between 1975 and 1989. It was a member of the Delta family of rockets. Several variants existed, which were differentiated by a four digit numerical code. Configurations The first stage was the RS-27 powered Extended Long Tank Thor, first flown on the 2000-series. Three or nine Castor-4 solid rocket boosters (SRB) were attached to increase thrust at lift-off, replacing the less powerful Castor-2 boosters used on earlier models. Two second stages were available; the Delta-P, which had been flown on the Delta 1000 and 2000 series, or the Delta-K, an uprated version with the Aerojet engine. Some launches used a three-stage configuration in order to reach higher orbits. A Star-37D, Star-37E, or Star-48B PAM-D could be used as an upper stage. Launches with PAM-D upper stages were designated ''Delta 3XX0 PAM-D'', rather than assigning a code to the upper stage for use in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
COSPAR ID
The International Designator, also known as COSPAR ID, is an international identifier assigned to artificial objects in space. It consists of the launch year, a three-digit incrementing launch number of that year and up to a three-letter code representing the sequential identifier of a piece in a launch. In TLE format the first two digits of the year and the dash are dropped. For example1990-037Ais the Space Shuttle ''Discovery'' on mission STS-31, which carried the Hubble Space Telescope1990-037B into space. This launch was the 37th known successful launch worldwide in 1990. The designation system has been generally known as the COSPAR system, named for the Committee on Space Research (COSPAR) of the International Council for Science. COSPAR subsumed the first designation system, devised at Harvard University. That system used letters of the Greek alphabet to designate artificial satellites. This was based on the scientific naming convention for natural satellites. For exampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GE 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, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breakup Of The Bell System
The breakup of the Bell System was mandated on January 8, 1982, by an agreed consent decree providing that AT&T Corporation would, as had been initially proposed by AT&T, relinquish control of the Bell Operating Companies, which had provided local telephone service in the United States. This effectively took the monopoly that was the Bell System and split it into entirely separate companies that would continue to provide telephone service. AT&T would continue to be a provider of long-distance service, while the now-independent Regional Bell Operating Companies (RBOCs), nicknamed the "Baby Bells", would provide local service, and would no longer be directly supplied with equipment from AT&T subsidiary Western Electric. This divestiture was initiated by the filing in 1974 by the United States Department of Justice of an antitrust lawsuit against AT&T. AT&T was, at the time, the sole provider of telephone service throughout most of the United States. Furthermore, most telephonic eq ... [...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 ยง 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] |
AT&T
AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile telephone services in the U.S. , AT&T was ranked 13th on the ''Fortune'' 500 rankings of the largest United States corporations, with revenues of $168.8 billion. During most of the 20th century, AT&T had a monopoly on phone service in the United States. The company began its history as the American District Telegraph Company, formed in St. Louis in 1878. After expanding services to Arkansas, Kansas, Oklahoma and Texas, through a series of mergers, it became Southwestern Bell Telephone Company in 1920, which was then a subsidiary of American Telephone and Telegraph Company. The latter was a successor of the original Bell Telephone Company founded by Alexander Graham Bell in 1877. The American Bell Telephone Company formed the American Teleph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Broadcasting Company
The American Broadcasting Company (ABC) is an American commercial broadcast television network. It is the flagship property of the ABC Entertainment Group division of The Walt Disney Company. The network is headquartered in Burbank, California, on Riverside Drive, directly across the street from Walt Disney Studios and adjacent to the Roy E. Disney Animation Building. The network's secondary offices, and headquarters of its news division, are in New York City, at its broadcast center at 77 West 66th Street on the Upper West Side of Manhattan. Since 2007, when ABC Radio (also known as Cumulus Media Networks) was sold to Citadel Broadcasting, ABC has reduced its broadcasting operations almost exclusively to television. It is the fifth-oldest major broadcasting network in the world and the youngest of the American Big Three television networks. The network is sometimes referred to as the Alphabet Network, as its initialism also represents the first three letters of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ted Turner
Robert Edward "Ted" Turner III (born November 19, 1938) is an American entrepreneur, television producer, media proprietor, and philanthropist. He founded the Cable News Network (CNN), the first 24-hour United States cable news, cable news channel. In addition, he founded WPCH-TV, WTBS, which pioneered the superstation concept in cable television, which later became TBS (U.S. TV channel), TBS. As a philanthropist, he gave $1 billion to create the United Nations Foundation, a public charity to broaden U.S. support for the UN. Turner serves as Chair (official), Chairman of the United Nations Foundation board of directors. Additionally, in 2001, Turner co-founded the Nuclear Threat Initiative with US Senator Sam Nunn (D-GA). NTI is a non-partisan organization dedicated to reducing global reliance on, and preventing the proliferation of nuclear, chemical, and biological weapons. He currently serves as Co-Chairman of the Board of Directors. Turner's media empire began with his fat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cable Television Headend
A cable television headend is a master facility for receiving television signals for processing and distribution over a cable television system. A headend facility may be staffed or unstaffed and is typically surrounded by some type of security fencing. The building is typically sturdy and purpose-built to provide security, cooling, and easy access for the electronic equipment used to receive and re-transmit video over the local cable infrastructure. One can also find head ends in power-line communication (PLC) substations and Internet communications networks. Reception Nearly all cable TV systems carry subscription content that is relayed from a satellite in geosynchronous orbit. Encrypted to prevent unauthorized use, this content is uplinked from one or more earth stations operated by various content delivery companies. The content is then analog or digitally modulated and transmitted through the cable network (the OSP or "OutSide Plant") to subscriber homes by means of coa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
