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Dong Fang Hong 2
Dong Fang Hong 2 (also romanised as Dongfanghong 2) was the primary television satellite used by China during the later part of the 20th century. It was developed at the Chinese Academy of Space Technology (CAST) and had a design life 4.5 years. The first operational satellite in this group was launched into a geosynchronous orbit on 8 April 1984. Three satellites orbited in geosynchronous orbits at 87.5°, 110.5°, and 98.0° east. A fourth satellite failed to achieve a stable orbit due to a problem with the third stage. Background Operating under the name Dong Fang Hong 2, the Shiyong Tongbu Tongxing Weixing (STTW, , literally Operational Geostationary Communications Satellite) was the designation of a family of indigenous Chinese communications satellites developed under the Project 331 initiative of the late 1970s and early 1980s. Being able to provide both civilian and military long distance telephony, in addition to satellite television, the initiative was promoted by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television 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 satellit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Earth Orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never more than about one-third of the radius of Earth. The term ''LEO region'' is also used for the area of space below an altitude of (about one-third of Earth's radius). Objects in orbits that pass through this zone, even if they have an apogee further out or are sub-orbital, are carefully tracked since they present a collision risk to the many LEO satellites. All crewed space stations to date have been within LEO. From 1968 to 1972, the Apollo program's lunar missions sent humans beyond LEO. Since the end of the Apollo program, no human spaceflights have been beyond LEO. Defining characteristics A wide variety of sources define LEO in terms of altitude. The altitude of an object in an elliptic orbit can vary significantly along the orbit. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellites Of China
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope thermoelectric generators (RTGs). Most satellites also have a method of communication to ground stations, called transponders. Many satellites use a standardized bus to save cost and work, the most popular of which is small CubeSats. Similar satellites can work together as a group, forming constellations. Because of the high launch cost to space, satellites are designed to be as lightweight and robust as possible. Most communication satellites are radio relay stations in orbit and carry dozens of transponders, each with a bandwidth of tens of megahertz. Satellites are placed from the surface to orbit by launch vehicles, high enough to avoid orbital decay by the atmosphere. Satellites can then change or maintain the orbit by pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ren Xinmin
Ren or REN may refer to: Abbreviations * Orenburg Tsentralny Airport, IATA code REN, civil airport in Russia * Redes Energéticas Nacionais (REN), Portuguese company * Renanthera, abbreviated as Ren, orchid genus * Ringer equivalence number (REN), a number which denotes the loading effect of a telephone ringer on a telephone line Geography * Ren County, in Hebei, China * Ren, Iran, a village in Kerman Province, Iran * Ren (building), a high-rise residential building in Seattle, Washington, United States Science, technology and medicine * REN (gene) * Ren, in anatomy, a kidney * Ren (command), a shell command in computing People * A diminutive of the given name Renée * Ren (surname) (任), Chinese surname * MC Ren, rapper from the group NWA * Ren (singer), member of South Korean boy band NU'EST * Renforshort, Canadian singer formerly known as Ren * , Japanese traditional calligrapher * , Japanese businessman * , Japanese actor * , Japanese politician * , Japanese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dong Fang Hong I
''Dong Fang Hong 1'' (), in the western world also known as China 1 or PRC 1, was the first space satellite of the People's Republic of China (PRC), launched successfully on 24 April 1970 as part of the PRC's Dongfanghong space satellite program. It was a part of the "Two Bombs, One Satellite" program. At , it was heavier than the first satellites of other countries. The satellite carried a radio transmitter which broadcast the ''de facto'' national anthem of the same name. The broadcast lasted for 20 days while in orbit. It was developed under the direction of Qian Xuesen, dean of the China Academy of Space Technology (CAST). At the time, a total of five identical satellites were created. The first satellite launched successfully. The academy formulated a "Three-Satellite Plan" consisting of ''Dongfanghong 1'', re-entry satellites, and geosynchronous orbit communications satellites. Sun Jiadong was responsible for the ''Dongfanghong 1'' technology. In 1967, Dang Hongxin chos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photovoltaic System
A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and convert sunlight into electricity, a solar inverter to convert the output from direct current, direct to alternating current, as well as photovoltaic mounting system, mounting, solar cable, cabling, and other electrical accessories to set up a working system. It may also use a solar tracking system to improve the system's overall performance and include an rechargeable battery, integrated battery. PV systems convert light directly into electricity, and are not to be confused with other solar technologies, such as concentrated solar power or Solar thermal energy, solar thermal, used for heating and cooling. A solar array only encompasses the ensemble of solar panels, the visible part of the PV system, and does not include all the other hardw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Cell
A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.Solar Cells chemistryexplained.com It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as , , or resistance, vary when exposed to light. Individual solar cell devices are often the electrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ChinaSat
ChinaSat () is the brand name of communications satellites operated by China Satellite Communications. History In 2007, a joint venture China Direct Broadcast Satellite was formed to run the brand ChinaSat. It was a joint venture of state-owned companies China Satellite Communications, China Orient Telecommunications Satellite and Sino Satellite Communications. The latter was controlled by China Aerospace Science and Technology Corporation (CASC). However, China Satellite Communications was changed from a direct subsidiary of the State-owned Assets Supervision and Administration Commission of the State Council (SASAC) to a direct subsidiary of CASC in 2009, the joint venture was dissolved and Sino Satellite Communications became a subsidiary of China Satellite Communications. The brand ChinaSat was previously operated by China Telecommunications Broadcast Satellite Corporation, which was owned by China's Ministry of Posts and Telecommunications. China Telecommunications B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dongfanghong Program
Dongfanghong () was a satellite program of the People's Republic of China. The program started in August 1965 as Project 651—a less ambitious successor to the earlier Project 581—with the goal of launching a satellite heavier than both Sputnik 1 and Explorer 1 into space, and developing all the necessary technologies to do so. History In 1958, the Chinese Academy of Science proposed Project 581 which included a plan to launch a satellite into space before 1 October 1959. The project was troubled due to the country's lack of expertise in the field of rocketry. On 21 January 1959, Zhang Jingfu, who was in charge in the satellite research program, postponed the project to allow effort to be put into developing more basic technologies, such as sounding rocketry. In December 1964, during the 3rd National People's Congress, Zhao Jiuzhang suggested that the work on satellites be resumed. In August 1968, the Central Special Committee approved Chinese Academy of Science's plan ... [...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 d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western China
Western China (, or rarely ) is the west of China. In the definition of the Chinese government, Western China covers one municipality (Chongqing), six provinces (Sichuan Sichuan (; zh, c=, labels=no, ; zh, p=Sìchuān; alternatively romanized as Szechuan or Szechwan; formerly also referred to as "West China" or "Western China" by Protestant missions) is a province in Southwest China occupying most of the ..., Guizhou, Yunnan, Shaanxi, Gansu, and Qinghai), and three autonomous regions of China, autonomous regions (Tibet Autonomous Region, Tibet, Ningxia, and Xinjiang). Administrative divisions Cities with urban area over one million in population Provincial capitals in bold. See also * China Western Development * Northwest China * Southwest China * Sichuan University, West China Union College * West China Union University ;Other regions * East China * North China * Northeast China * Northern and southern China * South Central China References External li ... [...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] |
