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Long March 4C
The Long March 4C, also known as the Chang Zheng 4C, CZ-4C and LM-4C, previously designated Long March 4B-II, is a Chinese orbital launch vehicle. It is launched from the Jiuquan, Taiyuan, and Xichang Satellite Launch Centers, and consists of 3 stages. Long March 4C vehicles have been used to launch the Yaogan-1, Yaogan-3 synthetic-aperture radar (SAR) satellites and the Fengyun-3A polar orbiting meteorological satellite. On 15 December 2009, a Long March 4C was used to launch Yaogan-8. Because it was still designated as Long March 4B-II at the time of its maiden flight, the first launch is often mistaken for a Long March 4B. The Long March 4C is derived from the Long March 4B, but features a restartable upper stage, and a larger payload fairing. On 1 September 2016, the Long March 4C failed for reasons not yet known. A Long March 4C rocket blasted off from the Taiyuan Satellite Launch Center in Shanxi but failed to insert its payload, the Gaofen 10 satellite, into its desi ...
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CZ-4C
The Long March 4C, also known as the Chang Zheng 4C, CZ-4C and LM-4C, previously designated Long March 4B-II, is a Chinese orbital launch vehicle. It is launched from the Jiuquan, Taiyuan, and Xichang Satellite Launch Centers, and consists of 3 stages. Long March 4C vehicles have been used to launch the Yaogan-1, Yaogan-3 synthetic-aperture radar (SAR) satellites and the Fengyun-3A polar orbiting meteorological satellite. On 15 December 2009, a Long March 4C was used to launch Yaogan-8. Because it was still designated as Long March 4B-II at the time of its maiden flight, the first launch is often mistaken for a Long March 4B. The Long March 4C is derived from the Long March 4B, but features a restartable upper stage, and a larger payload fairing. On 1 September 2016, the Long March 4C failed for reasons not yet known. A Long March 4C rocket blasted off from the Taiyuan Satellite Launch Center in Shanxi but failed to insert its payload, the Gaofen 10 satellite, into its desi ...
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UDMH
Unsymmetrical dimethylhydrazine (UDMH; 1,1-dimethylhydrazine, НДМГ or codenamed Geptil) is a chemical compound with the formula H2NN(CH3)2 that is used as a rocket propellant. It is a colorless liquid, with a sharp, fishy, ammonia-like smell typical for organic amines. Samples turn yellowish on exposure to air and absorb oxygen and carbon dioxide. It is miscible with water, ethanol, and kerosene. In concentration between 2.5% and 95% in air, its vapors are flammable. It is not sensitive to shock. Symmetrical dimethylhydrazine, 1,2-dimethylhydrazine is also known but is not as useful. Production UDMH is produced industrially by two routes. Based on the Olin Raschig process, one method involves reaction of monochloramine with dimethylamine giving 1,1-dimethylhydrazinium chloride: :(CH3)2NH + NH2Cl → (CH3)2NNH2 ⋅ HCl In the presence of suitable catalysts, acetylhydrazine can be N-dimethylated using formaldehyde and hydrogen to give the N,N-dimethyl-N'-acetylhydrazine, w ...
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Sun-synchronous Orbit
A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is an orbit arranged so that it precesses through one complete revolution each year, so it always maintains the same relationship with the Sun. Applications A Sun-synchronous orbit is useful for imaging, reconnaissance, and weather satellites, because every time that the satellite is overhead, the surface illumination angle on the planet underneath it is nearly the same. This consistent lighting is a useful characteristic for satellites that image the Earth's surface in visible or infrared wavelengths, such as weather and spy satellites, and for other remote-sensing satellites, such as those carrying ocean and atmospheric remote-sensing instruments that require sunlight. For example, a satellite in Sun-synchronous orbit might ascend acros ...
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Coordinated Universal Time
Coordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about one second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently used prime meridian) and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT). The coordination of time and frequency transmissions around the world began on 1 January 1960. UTC was first officially adopted as CCIR Recommendation 374, ''Standard-Frequency and Time-Signal Emissions'', in 1963, but the official abbreviation of UTC and the official English name of Coordinated Universal Time (along with the French equivalent) were not adopted until 1967. The system has been adjusted several times, including a brief period during which the time-coordination radio signals broadcast both UTC and "Stepped Atomic Time (SAT)" before a new UTC was adopted in 1970 and implemented in 1972. This change also a ...
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Gaofen (satellite)
Gaofen () is a series of Chinese high-resolution Earth imaging satellites launched as part of the China High-resolution Earth Observation System (CHEOS) program. CHEOS is a state-sponsored, civilian Earth-observation program used for agricultural, disaster, resource, and environmental monitoring. Proposed in 2006 and approved in 2010, the CHEOS program consists of the Gaofen series of space-based satellites, near-space and airborne systems such as airships and UAVs, ground systems that conduct data receipt, processing, calibration, and taskings, and a system of applications that fuse observation data with other sources to produce usable information and knowledge. Although the first seven Gaofen satellites and their payloads have been heavily detailed, little to no details on Gaofen 8 and later satellites have been revealed prompting suggestions that Gaofen satellites may be dual purpose supporting both civilian and military missions. In 2003, the China National Space Admin ...
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Shanxi
Shanxi (; ; formerly romanised as Shansi) is a landlocked province of the People's Republic of China and is part of the North China region. The capital and largest city of the province is Taiyuan, while its next most populated prefecture-level cities are Changzhi and Datong. Its one-character abbreviation is "" (), after the state of Jin that existed there during the Spring and Autumn period. The name ''Shanxi'' means "West of the Mountains", a reference to the province's location west of the Taihang Mountains. Shanxi borders Hebei to the east, Henan to the south, Shaanxi to the west and Inner Mongolia to the north. Shanxi's terrain is characterised by a plateau bounded partly by mountain ranges. Shanxi's culture is largely dominated by the ethnic Han majority, who make up over 99% of its population. Jin Chinese is considered by some linguists to be a distinct language from Mandarin and its geographical range covers most of Shanxi. Both Jin and Mandarin are spoken in Shanx ...
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Multistage Rocket
A multistage rocket or step rocket is a launch vehicle that uses two or more rocket ''stages'', each of which contains its own engines and propellant. A ''tandem'' or ''serial'' stage is mounted on top of another stage; a ''parallel'' stage is attached alongside another stage. The result is effectively two or more rockets stacked on top of or attached next to each other. Two-stage rockets are quite common, but rockets with as many as five separate stages have been successfully launched. By jettisoning stages when they run out of propellant, the mass of the remaining rocket is decreased. Each successive stage can also be optimized for its specific operating conditions, such as decreased atmospheric pressure at higher altitudes. This ''staging'' allows the thrust of the remaining stages to more easily accelerate the rocket to its final speed and height. In serial or tandem staging schemes, the first stage is at the bottom and is usually the largest, the second stage and subseq ...
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Long March 4B
The Long March 4B (), also known as the Chang Zheng 4B, CZ-4B and LM-4B is a Chinese expendable orbital Launch vehicle. Launched from Launch Complex 1 at the Taiyuan Satellite Launch Center, it is a 3-stage launch vehicle, used mostly to place satellites into low Earth orbit and Sun-synchronous orbits. It was first launched on 10 May 1999, with the FY-1C weather satellite, which would later be used in the 2007 Chinese anti-satellite missile test. The Chang Zheng 4B experienced its only launch failure on 9 December 2013, with the loss of the CBERS-3 satellite. Launch Statistics List of launches See also * Long March 4C * Long March (rocket family) * Medium-lift launch vehicle A medium-lift launch vehicle (MLV) is a rocket launch vehicle that is capable of lifting between by NASA classification or between by Russian classification of payload into low Earth orbit (LEO).50t payloads" An MLV is between small-lift laun ... References {{Long March rockets ...
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Weather Satellite
A weather satellite or meteorological satellite is a type of Earth observation satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be polar orbiting (covering the entire Earth asynchronously), or geostationary (hovering over the same spot on the equator). While primarily used to detect the development and movement of storm systems and other cloud patterns, meteorological satellites can also detect other phenomena such as city lights, fires, effects of pollution, auroras, sand and dust storms, snow cover, ice mapping, boundaries of ocean currents, and energy flows. Other types of environmental information are collected using weather satellites. Weather satellite images helped in monitoring the volcanic ash cloud from Mount St. Helens and activity from other volcanoes such as Mount Etna. Smoke from fires in the western United States such as Colorado and Utah have also been monitored. El Niño and its effects on weather are monitored ...
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Fengyun
Fēngyún (FY, ) are China's meteorological satellites. Launched since 1988 into polar sun-synchronous and geosynchronous orbit, each three-axis stabilized Fengyun satellite is built by the Shanghai Academy of Spaceflight Technology (SAST) and operated by the China Meteorological Administration ( CMA). To date, China has launched nineteen Fengyun satellites in four classes (FY-1 through FY-4). Fengyun 1 and Fengyun 3 satellites are in polar sun-synchronous orbit while Fengyun 2 and 4 are geosynchronous orbit. On 11 January 2007 China destroyed one of these satellites (FY-1C, COSPAR 1999-025A) in a test of an anti-satellite missile. According to NASA, the intentional destruction of FY-1C created 2,841 high-velocity debris items, a larger amount of dangerous space junk than any other space mission in history. Classes Fengyun 1 The four satellites of the Fengyun 1 (or FY-1) class were China's first meteorological satellites placed in polar, sun-synchronous orbit. In this orbi ...
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Synthetic-aperture Radar
Synthetic-aperture radar (SAR) is a form of radar that is used to create two-dimensional images or three-dimensional reconstructions of objects, such as landscapes. SAR uses the motion of the radar antenna over a target region to provide finer spatial resolution than conventional stationary beam-scanning radars. SAR is typically mounted on a moving platform, such as an aircraft or spacecraft, and has its origins in an advanced form of side looking airborne radar (SLAR). The distance the SAR device travels over a target during the period when the target scene is illuminated creates the large ''synthetic'' antenna aperture (the ''size'' of the antenna). Typically, the larger the aperture, the higher the image resolution will be, regardless of whether the aperture is physical (a large antenna) or synthetic (a moving antenna) – this allows SAR to create high-resolution images with comparatively small physical antennas. For a fixed antenna size and orientation, objects which are ...
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Yaogan
Yaogan () is the cover name used by the People's Republic of China to refer to its military reconnaissance satellites. Yaogan satellites are largely known to primarily support the People's Liberation Army's Strategic Support Force (PLASSF), formerly the Aerospace Reconnaissance Bureau of the Second Department of the General Staff. Yaogan satellites are the successor program to the Fanhui Shi Weixing ( FSW) recoverable reconnaissance satellite program but, unlike its predecessor, includes a variety of classes utilizing various means of remote sensing such as optical reconnaissance, synthetic-aperture radar (SAR), and electronic intelligence (ELINT) for maritime surveillance. Yaogan satellites have been launched from the Taiyuan Satellite Launch Center (TSLC) in Shanxi province, the Jiuquan Satellite Launch Center (JSLC) in Inner Mongolia Autonomous Region, and the Xichang Satellite Launch Center (XSLC) in Sichuan province. Although individual Yaogan satellites are often refe ...
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