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Telkom-1
Telkom-1 was a geosynchronous communications satellite built by Lockheed Martin, ( Sunnyvale, California), for Indonesia's state-owned telecommunications company, PT Telekomunikasi Indonesia Tbk (PT Telkom). It operated for almost 18 years, more than two years past designed lifetime of 15 years. Launch Telkom-1 was successfully launched 12 August 1999, by an Ariane-42P H10-3, from Centre Spatial Guyanais, pad ELA-2, Kourou, French Guiana, at 22:52 UTC and positioned in geostationary orbit, at 108° East for replaced Palapa-B2R. Satellite description Based on Lockheed Martin A2100A satellite bus, Telkom-1 features communications satellite technology, with 24 C-band and 12 Enhanced C-band transponders. The new spacecraft replaced on-orbit Palapa-B2R satellite, improve communications coverage across Indonesia, and allow PT Telkom to expand its coverage area into Southeast Asia and the Indian subcontinent. Launch had been delayed because of problems with comsat manuf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telkom-2
Telkom-2 was a geosynchronous communications satellite built by Orbital Sciences Corporation (OSC) for Indonesia's state-owned telecommunications company, PT Telekomunikasi Indonesia Tbk (PT Telkom). Telkom-2 was successfully launched on 16 November 2005, at 23:46:00 UTC and positioned in geostationary orbit, at 118° East for replaced Palapa-B4. History Based on Orbital's highly successful and flight-proven STAR-2 satellite bus, Telkom-2 featured state-of-the-art communications satellite technology, and 24 C-band transponders. The new spacecraft replaced PT Telkom's on-orbit Palapa-B4 satellite, improved communications coverage across Indonesia, and allowed PT Telkom to expand its coverage area into southeast Asia and the Indian subcontinent. Orbital also supplemented Telkom's existing ground station, and offered extensive mission operations support. There were several postponements prior to Telkom-2's launch. Three launch delays happened in November 2005 due to technic ... [...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] |
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] |
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] |
Telkom-4
Telkom 4 also known as Merah Putih, is an Indonesian geostationary communication satellite built by Space Systems/Loral that is located at an orbital position of 108° East and is operated by PT Telekomunikasi Indonesia Tbk. This satellite is based on the SSL 1300 satellite bus and has a life expectancy of 16 years, this satellite was launched on 7 August 2018, at 05:18 UTC or 12:18 Jakarta Time, using the SpaceX Falcon 9 Block 5 launcher from Cape Canaveral Air Force Station, Florida, United States. Satellite description This satellite carries 60 active transponders consisting of 24 C-Band transponders and 12 Extended C-Band transponders which will serve the Southeast Asia region, including Indonesia, as well as 24 C-Band transponders which will reach the South Asia region. The satellite relies on the SSL 1300 satellite bus with a design life of 16 years with up to 21 years of fuel remaining. The development of the Merah Putih Satellite involves two U.S. companies, namely S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Panels On Spacecraft
Spacecraft operating in the inner Solar System usually rely on the use of power electronics-managed photovoltaic solar panels to derive electricity from sunlight. Outside the orbit of Jupiter, solar radiation is too weak to produce sufficient power within current solar technology and spacecraft mass limitations, so radioisotope thermoelectric generators (RTGs) are instead used as a power source.NASA JPL Publication: Basics of Space Flight, Chapter 11. Typical Onboard Systems, Electrical Power Supply and Distribution Subsystems, History The first practical silicon-based solar cells were introduced by Bell Labs in April 1954. They were initially about 6% efficient, but improvements began to raise this number almost immediately. Bell had been interested in the idea as a system to provide power at remote telephone repeater stations, but the cost of the devices was far too high to be practical in this role. Aside from small experimental kits and uses, the cells remained largely unus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Subcontinent
The Indian subcontinent is a list of the physiographic regions of the world, physiographical region in United Nations geoscheme for Asia#Southern Asia, Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian Ocean from the Himalayas. Geopolitically, it includes the countries of Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka."Indian subcontinent". ''Oxford Dictionary of English, New Oxford Dictionary of English'' () New York: Oxford University Press, 2001; p. 929: "the part of Asia south of the Himalayas which forms a peninsula extending into the Indian Ocean, between the Arabian Sea and the Bay of Bengal. Historically forming the whole territory of Greater India, the region is now divided into three countries named Bangladesh, India and Pakistan." The terms ''Indian subcontinent'' and ''South Asia'' are often used interchangeably to denote the region, although the geopolitical term of South Asia frequently includes Afghanist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consisting of the regions that are situated south of mainland China, east of the Indian subcontinent, and north-west of mainland Australia. Southeast Asia is bordered to the north by East Asia, to the west by South Asia and the Bay of Bengal, to the east by Oceania and the Pacific Ocean, and to the south by Australia (continent), Australia and the Indian Ocean. Apart from the British Indian Ocean Territory and two out of atolls of Maldives, 26 atolls of Maldives in South Asia, Maritime Southeast Asia is the only other subregion of Asia that lies partly within the Southern Hemisphere. Mainland Southeast Asia is completely in the Northern Hemisphere. East Timor and the southern portion of Indonesia are the only parts that are south of the Equator. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coverage (telecommunication)
In telecommunications, the coverage of a radio station is the geographic area where the station can communicate. Broadcasters and telecommunications companies frequently produce coverage maps to indicate to users the station's intended service area. Coverage depends on several factors, such as orography (i.e. mountains) and buildings, technology, radio frequency and perhaps most importantly for two-way telecommunications the sensitivity and transmit efficiency of the consumer equipment. Some frequencies provide better regional coverage, while other frequencies penetrate better through obstacles, such as buildings in cities. The ability of a mobile phone to connect to a base station depends on the strength of the signal. That may be boosted by higher power transmissions, better antennas, taller antenna masts or alternative solutions like in-building picocells. Normal Macro-Cell signals need to be boosted to pass through buildings, which is a particular problem designing networks f ... [...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] |
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