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YZ-32
Yuanzheng () is a restartable upper stage developed by the China Academy of Launch Vehicle Technology (CALT) for the Long March rocket family. The Yuanzheng stage enables the Chinese launch vehicles to deploy payloads directly to high-energy orbits such as medium Earth orbit (MEO) and geosynchronous orbit (GSO). Since the Long March third stage cannot restart, it cannot circularize a GSO or GEO orbit from a geosyncronous transfer orbit ( GTO). With its restart capability, Yuanzheng has enabled the deployment of satellite pairs for the BeiDou Navigation Satellite System in MEO and communications satellites in GSO. This eliminates the need for the spacecraft to include a liquid apogee engine or an apogee kick motor. Yuanzheng has a thrust of with a specific impulse of 315.5 seconds. It uses the storable hypergolic propellants unsymmetrical dimethylhydrazine (UDMH) and dinitrogen tetroxide (), and can perform at least two burns within its rated life of 6.5 hours, sufficient to r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China Academy Of Launch Vehicle Technology
The China Academy of Launch Vehicle Technology (CALT) is a major state-owned civilian and military space launch vehicle manufacturer in China and one of the major launch service providers in the world. CALT is a subsidiary of the larger China Aerospace Science and Technology Corporation (CASC). It was established in 1957 by Dr. Xue-Sen Qian and is headquartered in Fengtai District, Beijing. Its major contribution to China's civilian and military launch capability has been the manufacture of the Long March family of rockets. CALT has 31,600 employees and at least 13 research facilities. The current Chief Designer is Long Lehao (). CALT is also planning two spaceplanes. They would both be single-stage to space sub-orbital rocketplanes. One would be a 10-ton 4-passenger plane that would fly to 100 km at Mach 6. The other would be a 100-ton 20-passenger plane that would fly to 130 km at Mach 8. They would be equipped with liquid methane/liquid oxygen rocket engines. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geostationary Orbit
A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitude above Earth's equator ( in radius from Earth's center) and following the direction of Earth's rotation. An object in such an orbit has an orbital period equal to Earth's rotational period, one sidereal day, and so to ground observers it appears motionless, in a fixed position in the sky. The concept of a geostationary orbit was popularised by the science fiction writer Arthur C. Clarke in the 1940s as a way to revolutionise telecommunications, and the first satellite to be placed in this kind of orbit was launched in 1963. Communications satellites are often placed in a geostationary orbit so that Earth-based satellite antennas do not have to rotate to track them but can be pointed permanently at the position in the sky where the sat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jiuquan Satellite Launch Center
Jiuquan Satellite Launch Center (JSLC; also known as Shuangchengzi Missile Test Center; Launch Complex B2; formally Northwest Comprehensive Missile Testing Facility (); Base 20; 63600 Unit) is a Chinese space vehicle launch facility (spaceport) located in the Gobi Desert, Inner Mongolia. It is part of the Dongfeng Aerospace City (Base 10). Although the facility is geographically located within Ejin Banner of Inner Mongolia's Alxa League, it is named after the nearest city, Jiuquan in Gansu Province. The launch center straddles both sides of the Ruo Shui river. History It was founded in 1958, the first of China's four spaceports. As with all Chinese launch facilities, it is remote and generally closed to foreigners. The Satellite Launch Center is a part of Dongfeng Space City (), also known as ''Base 10'' () or ''Dongfeng base'' (). The Dongfeng site also includes People's Liberation Army Air Force (PLAAF) test flight facilities, a space museum and a so-called marty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of BeiDou Satellites
This is a list of past and present satellites of the BeiDou/Compass navigation satellite system. , 44 satellites are operational: 7 in geostationary orbits (GEO), 10 in 55° inclined geosynchronous orbits (IGSO) and 27 in Medium Earth orbits (MEO). Furthermore, 5 satellites (2 in Medium Earth orbit, 1 in geostationary orbit and 2 in inclined geosynchronous orbit) are undergoing testing or commissioning. The full constellation consists of 35 satellites and was completed on 23 June 2020. Satellites Summary table Full list Medium Earth Orbit Satellites Orbital slots See also * List of Galileo satellites * List of GLONASS satellites * List of GPS satellites * List of NAVIC satellites References {{reflist External links BeiDou Constellation Status (Test and Assessment Research Center of China Satellite Navigation Office) BeiDou The BeiDou Navigation Satellite System (BDS; ) is a Chinese satellite navigation system. It consists of two separate satell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wenchang Satellite Launch Center
The Wenchang Space Launch Site ( zh, 文昌航天发射场, links=no), located in Wenchang, Hainan, China, is a rocket launch site — one of the two spacecraft launch sites of Xichang Satellite Launch Center (the other site is in Xichang, Sichuan). It is a former suborbital test center. It is China's fourth and southernmost space vehicle launch facility (spaceport). It has been specially selected for its low latitude, which is only 19° north of the equator, allowing for the increase in payload necessary for launching China's future space station. It is capable of launching the Long March 5, currently the most powerful Chinese rocket. Unlike the space centers on the mainland, whose rail tracks are too narrow to transport the new five meter core boosters, Wenchang uses its sea port for deliveries. Initial launches of the CZ-5 booster from Wenchang were expected to start in 2014, one year after the intended commissioning of the Wenchang Launch Site. However, the first laun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xichang Satellite Launch Center
The Xichang Satellite Launch Center (XSLC), also known as the Xichang Space Center, is a spaceport of China. It is located in Zeyuan Town (), approximately northwest of Xichang, Liangshan Yi Autonomous Prefecture in Sichuan. The facility became operational in 1984 and is used to launch numerous civil, scientific, and military payloads annually. It is notable as the site of Sino-European space cooperation, with the launch of the first of two Double Star scientific satellites in December 2003. Chinese officials have indicated interest in conducting additional international satellite launches from XSLC. In 1996, a fatal accident occurred when the rocket carrying the Intelsat 708 satellite failed on launch from the Xichang Satellite Launch Center. Also, a 2007 test of an anti-satellite missile was launched from the center. History China's first crewed space program In order to support the Chinese Project 714 crewed space program in the 1960s, the construction of a new space ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yuanzheng Upper Stages
Yuanzheng () is a restartable upper stage developed by the China Academy of Launch Vehicle Technology (CALT) for the Long March rocket family. The Yuanzheng stage enables the Chinese launch vehicles to deploy payloads directly to high-energy orbits such as medium Earth orbit (MEO) and geosynchronous orbit (GSO). Since the Long March third stage cannot restart, it cannot circularize a GSO or GEO orbit from a geosyncronous transfer orbit ( GTO). With its restart capability, Yuanzheng has enabled the deployment of satellite pairs for the BeiDou Navigation Satellite System in MEO and communications satellites in GSO. This eliminates the need for the spacecraft to include a liquid apogee engine or an apogee kick motor. Yuanzheng has a thrust of with a specific impulse of 315.5 seconds. It uses the storable hypergolic propellants unsymmetrical dimethylhydrazine (UDMH) and dinitrogen tetroxide (), and can perform at least two burns within its rated life of 6.5 hours, sufficient to r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinitrogen Tetroxide
Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russia rocket engineers) as amyl, is the chemical compound N2O4. It is a useful reagent in chemical synthesis. It forms an equilibrium mixture with nitrogen dioxide. Its molar mass is 92.011 g/mol. Dinitrogen tetroxide is a powerful oxidizer that is hypergolic (spontaneously reacts) upon contact with various forms of hydrazine, which has made the pair a common bipropellant for rockets. Structure and properties Dinitrogen tetroxide could be regarded as two nitro groups (-NO2) bonded together. It forms an equilibrium mixture with nitrogen dioxide. The molecule is planar with an N-N bond distance of 1.78Å and N-O distances of 1.19Å. The N-N distance corresponds to a weak bond, since it is significantly longer than the average N-N single bond length of 1.45Å. This exceptionally weak σ bond (amounting to overlapping of the ''sp''2 hybrid orbitals of the two NO2 units) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unsymmetrical Dimethylhydrazine
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypergolic
A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. The main advantages of hypergolic propellants are that they can be stored as liquids at room temperature and that engines which are powered by them are easy to ignite reliably and repeatedly. Common hypergolic propellants are difficult to handle due to their extreme toxicity and/or corrosiveness. In contemporary usage, the terms "hypergol" and "hypergolic propellant" usually mean the most common such propellant combination: dinitrogen tetroxide plus hydrazine and/or its relatives monomethylhydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH). History In 1935, Hellmuth Walter discovered that hydrazine hydrate was hypergolic with high-test peroxide of 80-83%. He was probably the first to discover this phenomenon, and set to work devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Impulse
Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse is exactly proportional to the effective exhaust gas velocity. A propulsion system with a higher specific impulse uses the mass of the propellant more efficiently. In the case of a rocket, this means less propellant needed for a given delta-v, so that the vehicle attached to the engine can more efficiently gain altitude and velocity. In an atmospheric context, specific impulse can include the contribution to impulse provided by the mass of external air that is accelerated by the engine in some way, such as by an internal turbofan or heating by fuel combustion participation then thrust expansion or by external propeller. Jet engines breathe external air for both combustion and by-pass, and therefore have a much higher specific impulse than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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