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Vikas Engine
The Vikas (a portmanteau from initials of ''VIK''ram ''A''mbalal ''S''arabhai ) is a family of liquid fuelled rocket engines conceptualized and designed by the Liquid Propulsion Systems Centre in the 1970s. The design was based on the licensed version of the Viking engine with the chemical pressurisation system. The early production Vikas engines used some imported French components which were later replaced by domestically produced equivalents. It is used in the Polar Satellite Launch Vehicle (PSLV) and the Geosynchronous Satellite Launch Vehicle (GSLV) series of expendable launch vehicles for space launch use. Vikas engine is used to power the second stage of PSLV, boosters and second stage of GSLV Mark I and II and also the core stage of GSLV Mark III. The propellant loading for Vikas engine in PSLV, GSLV Mark I and II is 40 tons, while in GSLV Mark III is 55 tons. History In 1974, Societe Europeenne de Propulsion agreed to transfer Viking engine technology in return for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast, it shares land borders with Pakistan to the west; China, Nepal, and Bhutan to the north; and Bangladesh and Myanmar to the east. In the Indian Ocean, India is in the vicinity of Sri Lanka and the Maldives; its Andaman and Nicobar Islands share a maritime border with Thailand, Myanmar, and Indonesia. Modern humans arrived on the Indian subcontinent from Africa no later than 55,000 years ago., "Y-Chromosome and Mt-DNA data support the colonization of South Asia by modern humans originating in Africa. ... Coalescence dates for most non-European populations average to between 73–55 ka.", "Modern human beings—''Homo sapiens''—originated in Africa. Then, interm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Hindu
''The Hindu'' is an Indian English-language daily newspaper owned by The Hindu Group, headquartered in Chennai, Tamil Nadu. It began as a weekly in 1878 and became a daily in 1889. It is one of the Indian newspapers of record and the second most circulated English-language newspaper in India, after '' The Times of India''. , ''The Hindu'' is published from 21 locations across 11 states of India. ''The Hindu'' has been a family-owned newspaper since 1905, when it was purchased by S. Kasturi Ranga Iyengar from the original founders. It is now jointly owned by Iyengar's descendants, referred to as the "Kasturi family", who serve as the directors of the holding company. The current chairperson of the group is Malini Parthasarathy, a great-granddaughter of Iyengar. Except for a period of about two years, when Siddharth Varadarajan, S. Varadarajan held the editorship of the newspaper, the editorial positions of the paper were always held by members of the family or held under t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UH 25
UH 25 is a fuel mixture for rockets. It was developed for the European Ariane 2–4 launch vehicles. UH 25 was developed after a disaster during flight 2 of the Ariane 1 rocket. During launch, one of the four Viking engines on the first stage developed a combustion instability which led to an engine fire, subsequent explosion and destruction of the vehicle. Following this event and starting with Ariane 2, the fuel was changed from pure UDMH to the mixture UH 25. UH 25 was used in Ariane rocket versions 2 through 4, and in the Indian GSLV Mk III UH 25 is a mixture of 75% UDMH and 25% hydrazine hydrate.Tim Furniss: ''Ingenieure bei der Arbeit, Raumschiffe und Raketen'', Tessloff Verlag, Nürnberg (1989), Seite: 31 (German) It is hypergolic with dinitrogen tetroxide as oxidizer, and both can be stored as liquids at room temperature. Danger Like its components, UH 25 is flammable, toxic (carcinogenic) and corrosive. Safety labels See also * Aerozine 50 - a 50:50 mix of hydra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSLV
Geosynchronous Satellite Launch Vehicle (GSLV) is an expendable launch system operated by the Indian Space Research Organisation (ISRO). GSLV was used in fourteen launches from 2001 to 2021. Even though GSLV Mark III shares the name, it is an entirely different launch vehicle. History The Geosynchronous Satellite Launch Vehicle (GSLV) project was initiated in 1990 with the objective of acquiring an Indian launch capability for geosynchronous satellites. GSLV uses major components that are already proven in the Polar Satellite Launch Vehicle (PSLV) launch vehicles in the form of the S125/S139 solid rocket booster and the liquid-fueled Vikas engine. Due to the thrust required for injecting the satellite in a geostationary transfer orbit (GTO) the third stage was to be powered by a LOX/ LH2 Cryogenic engine which at that time India did not possess or have the technological expertise to build. The first development flight of the GSLV (Mk I configuration) was launched on 18 ... [...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] |
Thrust
Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that system. The force applied on a surface in a direction perpendicular or normal to the surface is also called thrust. Force, and thus thrust, is measured using the International System of Units (SI) in newtons (symbol: N), and represents the amount needed to accelerate 1 kilogram of mass at the rate of 1 meter per second per second. In mechanical engineering, force orthogonal to the main load (such as in parallel helical gears) is referred to as static thrust. Examples A fixed-wing aircraft propulsion system generates forward thrust when air is pushed in the direction opposite to flight. This can be done by different means such as the spinning blades of a propeller, the propelling jet of a jet engine, or by ejecting hot gases from a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Propellant
Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical rocket, or from an external source, as with ion engines. Overview Rockets create thrust by expelling mass rear-ward, at high velocity. The thrust produced can be calculated by multiplying the mass flow rate of the propellants by their exhaust velocity relative to the rocket ( specific impulse). A rocket can be thought of as being accelerated by the pressure of the combusting gases against the combustion chamber and nozzle, not by "pushing" against the air behind or below it. Rocket engines perform best in outer space because of the lack of air pressure on the outside of the engine. In space it is also possible to fit a longer nozzle without suffering from flow separation. Most chemical propellants release energy through redox ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSAT 6A
GSAT-6A was a communication satellite launched by the Indian Space Research Organisation (ISRO) It featured a unfurlable S-band antenna similar to the one used on GSAT-6. Around 17 minutes after lift-off, the three stage GSLV Mk.II rocket flying on GSLV F08 mission successfully injected the satellite into a geosynchronous transfer orbit. Due to power failure during its orbit raising burns the communication was lost with GSAT-6A before it could reach its final circular geostationary orbit (GSO). History GSAT-6A was launched to complement GSAT-6 satellite which was launched in August 2015 by ISRO. The cost of building GSAT-6A was around ₹270 crore. GSAT-6A was to provide mobile communication services to the Indian Armed Forces. Launch GSLV-F08 carrying GSAT-6A spacecraft was launched from Second Launch Pad of Satish Dhawan Space Centre on 29 March 2018, 11:26 UTC and after flight of 17 minutes 45 seconds, placed GSAT-6A into its planned geostationary transfer orbit with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gimbal
A gimbal is a pivoted support that permits rotation of an object about an axis. A set of three gimbals, one mounted on the other with orthogonal pivot axes, may be used to allow an object mounted on the innermost gimbal to remain independent of the rotation of its support (e.g. vertical in the first animation). For example, on a ship, the gyroscopes, shipboard compasses, stoves, and even drink holders typically use gimbals to keep them upright with respect to the horizon despite the ship's pitching and rolling. The gimbal suspension used for mounting compasses and the like is sometimes called a Cardan suspension after Italian mathematician and physicist Gerolamo Cardano (1501–1576) who described it in detail. However, Cardano did not invent the gimbal, nor did he claim to. The device has been known since antiquity, first described in the 3rd c. BC by Philo of Byzantium, although some modern authors support the view that it may not have a single identifiable inventor. Histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen 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] |
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, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSLV C50 Second Stage With Vikas Engine
The Polar Satellite Launch Vehicle (PSLV) is an expendable medium-lift launch vehicle designed and operated by the Indian Space Research Organisation (ISRO). It was developed to allow India to launch its Indian Remote Sensing (IRS) satellites into sun-synchronous orbits, a service that was, until the advent of the PSLV in 1993, only commercially available from Russia. PSLV can also launch small size satellites into Geostationary Transfer Orbit (GTO). Some notable payloads launched by PSLV include India's first lunar probe Chandrayaan-1, India's first interplanetary mission, Mars Orbiter Mission (Mangalyaan) and India's first space observatory, Astrosat. PSLV has gained credibility as a leading provider of rideshare services for small satellites, owing to its numerous multi-satellite deployment campaigns with auxiliary payloads, usually ride-sharing along with an Indian primary payload. As of June 2022, PSLV has launched 345 foreign satellites from 36 countries. Most no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
