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N-SAT-110
JCSAT-110, also known as N-SAT 110, JCSAT-7, Superbird-5 and Superbird-D, is a Japanese geostationary communications satellite which was operated by JSAT Corporation and Space Communications Corporation until both companies merged into SKY Perfect JSAT, SKY Perfect JSAT Group in 2008. It is positioned in geostationary orbit at a longitude of 110° East, from where it is used to provide communications services to Japan. Satellite description The spacecraft was designed and manufactured by Lockheed Martin Space Systems, Lockheed Martin on the Lockheed Martin A2100, A2100-AX satellite bus. It had a launch mass of with a dry mass of and a 13-year design life. As most satellites based on the A2100-AX platform, it uses a LEROS, LEROS-1C liquid apogee engine (LAE) for Orbital maneuver, orbit raising. When stowed for launch, the satellite was high. Its dual wing Solar panels on spacecraft, solar panels gave a power generation capability of 8.3 kW at the end of its design life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JSAT Corporation
JSAT Corporation (JSAT) was the first private Japanese satellite operator, which owned the JSAT satellites, as well as operated and partially owned the N-Star with NTT DoCoMo. Its origins can be traced to the funding of Japan Communications Satellite Company (JCSAT) and Satellite Japan Corporation in 1985. Both companies merged into Japan Satellite Systems Inc. in 1993. In 2000 the company was renamed as JSAT Corporation and was listed in the First Section of the Tokyo Stock Exchange. On September 1, 2008, the company was merged into the SKY Perfect JSAT Group. History With the opening of the Japanese satellite communications market to private investment, Japan Communications Satellite Company (JCSAT) and Satellite Japan Corporation were founded in 1985. In June of the same year, JCSAT awarded an order to Hughes Space and Communications for two identical satellites, JCSAT-1 and JCSAT-2, based on the spin-stabilized HS-393 satellite bus. JCSAT-1, the first commercial Japane ... [...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] |
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] |
Traveling-wave Tube
A traveling-wave tube (TWT, pronounced "twit") or traveling-wave tube amplifier (TWTA, pronounced "tweeta") is a specialized vacuum tube that is used in electronics to amplify radio frequency (RF) signals in the microwave range. The TWT belongs to a category of "linear beam" tubes, such as the klystron, in which the radio wave is amplified by absorbing power from a beam of electrons as it passes down the tube. Although there are various types of TWT, two major categories are: *''Helix TWT'' - in which the radio waves interact with the electron beam while traveling down a wire helix which surrounds the beam. These have wide bandwidth, but output power is limited to a few hundred watts. *''Coupled cavity TWT'' - in which the radio wave interacts with the beam in a series of cavity resonators through which the beam passes. These function as narrowband power amplifiers. A major advantage of the TWT over some other microwave tubes is its ability to amplify a wide range of frequencies ... [...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] |
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] |
Orbital Maneuver
In spaceflight, an orbital maneuver (otherwise known as a burn) is the use of propulsion systems to change the orbit of a spacecraft. For spacecraft far from Earth (for example those in orbits around the Sun) an orbital maneuver is called a ''deep-space maneuver (DSM)''. The rest of the flight, especially in a transfer orbit, is called ''coasting''. General Rocket equation The Tsiolkovsky rocket equation, or ideal rocket equation is an equation that is useful for considering vehicles that follow the basic principle of a rocket: where a device that can apply acceleration to itself (a thrust) by expelling part of its mass with high speed and moving due to the conservation of momentum. Specifically, it is a mathematical equation that relates the delta-v (the maximum change of speed of the rocket if no other external forces act) with the effective exhaust velocity and the initial and final mass of a rocket (or other reaction engine.) For any such maneuver (or journey involvin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LEROS
Leros ( el, Λέρος) is a Greek island and municipality in the Dodecanese in the southern Aegean Sea. It lies (171 nautical miles) from Athens's port of Piraeus, from which it can be reached by an 9-hour ferry ride or by a 45-minute flight from Athens, and about 20 miles to Turkey. Leros is part of the Kalymnos regional unit. The island has been also called in it, Lero. This island has population of 7,988 Geography The municipality has an area of . The municipality includes the populated offshore island of Farmakonisi (pop. 10), as well as several uninhabited islets, including Levitha and Kinaros, and had a 2011 census population of 7,917, although this figure swells to over 15,000 during the summer peak. The island has a coastline of . It is known for its imposing medieval castle of the Knights of Saint John possibly built on a Byzantine fortress. Nearby islands are Patmos, Lipsi, Kalymnos, and the small islands of Agia Kyriaki and Farmakos. In ancient times it was c ... [...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] |
Lockheed Martin Space Systems
Lockheed Martin Space is one of the four major business divisions of Lockheed Martin. It has its headquarters in Littleton, Colorado, with additional sites in Valley Forge, Pennsylvania; Sunnyvale, California; Santa Cruz, California; Huntsville, Alabama; and elsewhere in the United States and United Kingdom. The division currently employs about 16,000 people, and its most notable products are commercial and military satellites, space probes, missile defense systems, NASA's Orion spacecraft, and the Space Shuttle external tank. History The Lockheed Missile Systems Division was established in Van Nuys, Van Nuys, California, in late 1953 to consolidate work on the Lockheed X-17 and Lockheed X-7, X-7. The X-17 was a three-stage solid-fuel research rocket designed to test the effects of high mach atmospheric reentry. The X-17 was also used as the booster for the Operation Argus series of three high-altitude nuclear tests conducted in the Atlantic Ocean, South Atlantic in 1958. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longitude
Longitude (, ) is a geographic coordinate that specifies the east–west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (λ). Meridians are semicircular lines running from pole to pole that connect points with the same longitude. The prime meridian defines 0° longitude; by convention the International Reference Meridian for the Earth passes near the Royal Observatory in Greenwich, England on the island of Great Britain. Positive longitudes are east of the prime meridian, and negative ones are west. Because of the Earth's rotation, there is a close connection between longitude and time measurement. Scientifically precise local time varies with longitude: a difference of 15° longitude corresponds to a one-hour difference in local time, due to the differing position in relation to the Sun. Comparing local time to an absolute measure of time allows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
