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GSAT-3
GSAT-3, also known as EDUSAT, was a communications satellite which was launched on 20 September 2004 by the Indian Space Research Organisation. EDUSAT is the first Indian satellite built exclusively to serve the educational sector. It is mainly intended to meet the demand for an interactive satellite-based distance education system for the country. EDUSAT carries five Ku band transponders providing spot beams, one Ku band transponder providing a national beam and six extended C band transponders providing national coverage beams. EDUSAT was successfully launched into a Geosynchronous Transfer Orbit (GTO) on the first operational launch of the Geosynchronous Satellite Launch Vehicle, which flew from the First Launch Pad at the Satish Dhawan Space Centre in Sriharikota. EDUSAT was initially placed into a transfer orbit with a perigee of and an apogee of and a period of 10.5 hours, inclined at 19.2 degrees to the equator. EDUSAT was decommissioned in September 2010 and r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSAT
The GSAT (Geosynchronous Satellite) satellites are India's indigenously developed communications satellites, used for digital audio, data and video broadcasting. As of 5 December 2018, 20 GSAT satellites of ISRO have been launched out of which 14 satellites are in service. History The GSAT series of geosynchronous satellites A geosynchronous satellite is a satellite in geosynchronous orbit, with an orbital period the same as the Earth's rotation period. Such a satellite returns to the same position in the sky after each sidereal day, and over the course of a day t ... is a system developed by ISRO with an objective to make India self-reliant in broadcasting services. The repertoire of 10 GSAT satellites, a total of 168 transponders (out of which 95 transponders are leased out to provide services to the broadcasters) in the C, Extended C and Ku-bands provides services to telecommunications, television broadcasting, weather forecasting, disaster warning and search and rescue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
I-2K
I-2K is a satellite bus developed by Indian Space Research Organisation (ISRO), and marketed by Antrix Corporation. It is a standard bus for 2,000 kg class satellites; the 'I' in I-2K stands for INSAT, a group of communication satellites developed and launched by ISRO. The satellite buses developed by ISRO are specifically developed for small and medium weight satellites. I-2K spacecraft bus can supply DC power up to 3000 watts. I-2K platform is targeted towards satellites in liftoff mass in range of 1500–2500 kg. List of satellites launched using I-2K platform * INSAT series ( 3B 3C 3D 3DR 3E 4C 4CR) * IRS series ( 1C 1D P3) * GSAT series ( 1 2 3 (EDUSAT) 4 5P 6 6A 7 7A 9 14 31) * HYLAS-1 HYLAS (or HYLAS-1) is a British satellite in geostationary orbit. HYLAS, which is an acronym for ''Highly Adaptable Satellite'', is a communications satellite and was launched by the European Ariane 5 launch vehicle from the Guyana Space C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISRO
The Indian Space Research Organisation (ISRO; ) is the national space agency of India, headquartered in Bengaluru. It operates under the Department of Space (DOS) which is directly overseen by the Prime Minister of India, while the Chairman of ISRO acts as the executive of DOS as well. ISRO is India's primary agency for performing tasks related to space-based applications, space exploration and the development of related technologies. It is one of six government space agencies in the world which possess full launch capabilities, deploy cryogenic engines, launch extraterrestrial missions and operate large fleets of artificial satellites. The Indian National Committee for Space Research (INCOSPAR) was established by Jawaharlal Nehru under the Department of Atomic Energy (DAE) in 1962, on the urging of scientist Vikram Sarabhai, recognising the need in space research. INCOSPAR grew and became ISRO in 1969, within DAE. In 1972, the government of India set up a Space Commission and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSAT-4
GSAT-4, also known as HealthSat, was an experimental communication and navigation satellite launched in April 2010 by the Indian Space Research Organisation on the maiden flight of the Geosynchronous Satellite Launch Vehicle Mk.II rocket. It failed to reach orbit after the rocket's third stage malfunctioned. The third stage was the first Indian-built cryogenic-fuelled upper stage, and was making its first flight. The ISRO suspects that the failure was caused by the third stage not igniting. Satellite Weighing around two tons, GSAT-4 carried a multi-channel, Ka-band, bent pipe and regenerative transponder, and a navigation payload in the C, L1, and L5 bands. Designed to guide civil and military aircraft, GSAT-4 was to have employed several new technologies such as a bus management unit, miniaturised dynamically tuned gyros, lithium-ion battery, 70 volt bus for Ka-band travelling-wave tube amplifiers, and electric propulsion. GSAT-4 also incorporated technological experiments like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSAT-2
GSAT-2 was an experimental communication satellite built by the Indian Space Research Organisation (ISRO) and launched on one of the first GSLVs. The satellite was positioned at 48 deg east longitude in the geo-stationary orbit. Payloads GSAT-2 carried four C-band transponders, two Ku band transponders and a Mobile Satellite Service (MSS) payload operating in S-band forward link and C-band return link. Besides the communication payloads, GSAT-2 carried the following four piggyback experimental payloads: *Total Radiation Dose Monitor (TRDM) to compare the estimated radiation doses inside the satellite with the directly measured radiation doses using a Radiation Sensitive Field Effect Transistor (RADFET) *Surface Charge Monitor (SCM) to indicate the state of the charging environment in the vicinity of the spacecraft * Solar X-ray Spectrometer (SOXS) to study the solar flare emission in 4 keV - 60 keV energy range using state of the art semiconductor devices and Phoswich Scintilla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Space Research Organisation
The Indian Space Research Organisation (ISRO; ) is the national space agency of India, headquartered in Bengaluru. It operates under the Department of Space (DOS) which is directly overseen by the Prime Minister of India, while the Chairman of ISRO acts as the executive of DOS as well. ISRO is India's primary agency for performing tasks related to space-based applications, space exploration and the development of related technologies. It is one of six government space agencies in the world which possess full launch capabilities, deploy cryogenic engines, launch extraterrestrial missions and operate large fleets of artificial satellites. The Indian National Committee for Space Research (INCOSPAR) was established by Jawaharlal Nehru under the Department of Atomic Energy (DAE) in 1962, on the urging of scientist Vikram Sarabhai, recognising the need in space research. INCOSPAR grew and became ISRO in 1969, within DAE. In 1972, the government of India set up a Space Commission a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communication 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] |
Apogee
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. The barycenter of the two bodies may lie well within the bigger body—e.g., the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perigee
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. The barycenter of the two bodies may lie well within the bigger body—e.g., the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graveyard Orbit
A graveyard orbit, also called a junk orbit or disposal orbit, is an orbit that lies away from common operational orbits. One significant graveyard orbit is a supersynchronous orbit well beyond geosynchronous orbit. Some satellites are moved into such orbits at the end of their operational life to reduce the probability of colliding with operational spacecraft and generating space debris. Overview A graveyard orbit is used when the change in velocity required to perform a de-orbit maneuver is too large. De-orbiting a geostationary satellite requires a delta-v of about , whereas re-orbiting it to a graveyard orbit only requires about . For satellites in geostationary orbit and geosynchronous orbits, the graveyard orbit is a few hundred kilometers beyond the operational orbit. The transfer to a graveyard orbit beyond geostationary orbit requires the same amount of fuel as a satellite needs for about three months of stationkeeping. It also requires a reliable attitude control ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geosynchronous Transfer Orbit
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites that are destined for 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. 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 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. Instead extra fuel is added to the satellite, the launch vehicle la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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