|
JCSAT-11
JCSAT-11, was a geostationary communications satellite ordered by JSAT Corporation (now SKY Perfect JSAT Group) which was designed and manufactured by Lockheed Martin on the A2100 platform. The satellite was designated to be used as an on-orbit, but was lost on launch failure. Satellite description The spacecraft was designed and manufactured by Lockheed Martin on the A2100AX satellite bus. It had a launch mass of and a 15-year design life. A near copy of JCSAT-3A, it was to be used as an on orbit spare. As most satellites based on the A2100 platform, it uses a LEROS-1C LAE for orbit raising. Its solar panels span when fully deployed and, with its antennas in fully extended configuration it is wide. Its payload is composed of eighteen 27 MHz and twelve 36 MHz Ku band plus twelve C band transponders, for a total bandwidth of 1,350 MHz. Its high-power amplifiers had an output power of 127 Watts on Ku band and 48 Watts on C band. History On October 3, ... [...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] |
JCSAT-RA
JCSAT-RA, previously known as JCSAT-12, is a Japanese geostationary communications satellite, which is operated by SKY Perfect JSAT Group. Details It was ordered to replace the JCSAT-11 satellite which was lost in a launch failure on a Proton-M/Briz-M rocket in 2007, and is currently used as an on-orbit spare satellite; a role in which it replaced the older JCSAT-R spacecraft, providing a reserve for if one of the company's other satellites fails. It is a satellite, which was constructed by Lockheed Martin based on the A2100AX satellite bus, with the same configuration as JCSAT-10 and JCSAT-11. The contract to build JCSAT-12 was awarded on 6 September 2007, the day after JCSAT-11 failed to reach orbit. It was launched, along with the Australian Optus D3 satellite, by Arianespace. An Ariane 5ECA rocket was used for the launch, which occurred from ELA-3 at the Guiana Space Centre in Kourou, French Guiana. The launch took place at 22:09 GMT on 21 August 2009, at the start of a 60- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JCSAT-12
JCSAT-RA, previously known as JCSAT-12, is a Japanese geostationary communications satellite, which is operated by SKY Perfect JSAT Group. Details It was ordered to replace the JCSAT-11 satellite which was lost in a launch failure on a Proton-M/Briz-M rocket in 2007, and is currently used as an on-orbit spare satellite; a role in which it replaced the older JCSAT-R spacecraft, providing a reserve for if one of the company's other satellites fails. It is a satellite, which was constructed by Lockheed Martin based on the A2100AX satellite bus, with the same configuration as JCSAT-10 and JCSAT-11. The contract to build JCSAT-12 was awarded on 6 September 2007, the day after JCSAT-11 failed to reach orbit. It was launched, along with the Australian Optus D3 satellite, by Arianespace. An Ariane 5ECA rocket was used for the launch, which occurred from ELA-3 at the Guiana Space Centre in Kourou, French Guiana. The launch took place at 22:09 GMT on 21 August 2009, at the start of a 60- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton-M
The Proton-M, (Протон-М) GRAU index 8K82M or , is an expendable Russian heavy-lift launch vehicle derived from the Soviet-developed Proton. It is built by Khrunichev, and launched from sites 81 and 200 at the Baikonur Cosmodrome in Kazakhstan. Commercial launches are marketed by International Launch Services (ILS), and generally use Site 200/39. The first Proton-M launch occurred on 7 April 2001. Proton flew its most recent mission on 13 December 2021, launching two Ekspress communication satellites into geostationary orbit. As of August 2020, a number of Roscosmos and other Russian government missions remain on Proton launch manifest. Vehicle description The Proton-M launch vehicle consists of three stages; all of them powered by liquid rocket engines using the hypergolic propellant combination of dinitrogen tetroxide as the oxidizer, and unsymmetrical dimethylhydrazine for fuel. The first stage is unique in that it consists of a central cylindrical oxidizer tank ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lockheed Martin A2100
The A2100 is a model of communications satellite spacecraft made by Lockheed Martin Space Systems. It is used as the foundation for telecommunications payloads in geosynchronous orbit, as well as GOES-R weather satellites and GPS Block IIIA satellites. Over 40 satellites use the A2100 bus. History The first satellite, AMC-1, was launched September 8, 1996, and has achieved 15-year on-orbit service life. Since 1996 there have been over 45 of the A2100 based satellites launched, with over 400 years of total on-orbit service. Other A2100 spacecraft include JCSAT-13 and VINASAT-2, which were launched May, 2012 on an Ariane 5 rocket, as well as Arabsat-6A and Hellas Sat 4/SaudiGeoSat-1 of Saudi Arabia's Arabsat-6G program. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Briz-M
The Briz-K, Briz-KM and Briz-M (russian: Бриз-К, КM and M meaning ''Breeze-K, KM and M'') are Russian liquid-propellant rocket orbit insertion upper stages manufactured by Khrunichev State Research and Production Space Center and used on the Proton-M and Angara A5. The upper stages were also used on Rokot, one of Russia's smaller launchers, before its retirement in 2019. Characteristics Briz-K and Briz-KM Briz-K, GRAU index 14S12, is a single-piece structure with a conical tank compartment and the engine located in a recess in the fuel tank. Briz-KM (GRAU index 14S45) is an improved version of Briz-K. The Briz-K and Briz-KM were used as a third stage of the Rokot launch vehicles. Briz-M Briz-M, GRAU index 14S43, is designed for injecting large payloads into a low, medium-height or high geosynchronous orbit. Briz-M is a twin upper stage consisting of a core module (using Briz-KM as the baseline) and a jettisonable add-on toroidal tank surrounding the core. It is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JCSAT-3A
JCSAT-3A, known as JCSAT-10 before launch, is a geostationary communications satellite operated by SKY Perfect JSAT Group (JSAT) which was designed and manufactured by Lockheed Martin on the A2100 platform. Satellite description The spacecraft was designed and manufactured by Lockheed Martin on the A2100AX satellite bus. It had a launch mass of and a 15-year design life. It would provide communications services throughout Japan and Asia. As most satellites based on the A2100 platform, it uses a LEROS-1C LAE for orbit raising. Its solar panels span when fully deployed and, with its antennas in fully extended configuration it is wide. Its payload is composed of eighteen 27 MHz and twelve 36 MHz Ku band plus twelve C band transponders, for a total bandwidth of 1,350 MHz. Its high-power amplifiers had an output power of 127 Watts on Ku band and 48 Watts on C band. History On April 20, 2004, JSAT ordered a satellite from Lockheed Martin, JCSAT-10. Bas ... [...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] |
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] |
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] |
High-power Amplifier
In electronics, the figures of merit of an amplifier are numerical measures that characterize its properties and performance. Figures of merit can be given as a list of specifications that include properties such as gain, bandwidth, noise and linearity, among others listed in this article. Figures of merit are important for determining the suitability of a particular amplifier for an intended use. Gain The gain of an amplifier is the ratio of output to input power or amplitude, and is usually measured in decibels. When measured in decibels it is logarithmically related to the power ratio: ''G''(dB)=10 log(''Pout'' /''Pin''). RF amplifiers are often specified in terms of the maximum ''power gain'' obtainable, while the voltage gain of audio amplifiers and instrumentation amplifiers will be more often specified. For example, an audio amplifier with a gain given as 20 dB will have a ''voltage gain'' of ten. The use of voltage gain figure is appropriate when the amplifier's in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
