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Centaur (rocket Stage)
The Centaur is a family of rocket propelled upper stages that has been in use since 1962. It is currently produced by U.S. launch service provider United Launch Alliance, with one main active version and one version under development. The diameter Common Centaur/Centaur III flies as the upper stage of the Atlas V launch vehicle, and the diameter Centaur V has been developed as the upper stage of ULA's new Vulcan rocket. Centaur was the first rocket stage to use liquid hydrogen (LH2) and liquid oxygen (LOX) propellants, a high-energy combination that is ideal for upper stages but has significant handling difficulties. Characteristics Common Centaur is built around stainless steel pressure stabilized balloon propellant tanks with thick walls. It can lift payloads of up to . The thin walls minimize the mass of the tanks, maximizing the stage's overall performance. A common bulkhead separates the LOX and LH2 tanks, further reducing the tank mass. It is made of two stainless ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlas V
Atlas V is an expendable launch system and the fifth major version in the Atlas (rocket family), Atlas launch vehicle family. It was developed by Lockheed Martin and has been operated by United Launch Alliance (ULA) since 2006. Primarily used to launch payloads for the United States Department of Defense, NASA, and commercial customers, Atlas V is the longest-serving active rocket in the United States. Each Atlas V vehicle consists of two main stages. The First stage (rocketry), first stage is powered by a single Russian-made RD-180 engine that burns kerosene and liquid oxygen. The Centaur (rocket stage), Centaur upper stage uses one or two American-made Aerojet Rocketdyne RL10 engines that burn liquid hydrogen and liquid oxygen. Strap-on booster, Strap-on Solid rocket booster, solid rocket boosters (SRBs) are used in several configurations. Originally equipped with AJ-60A SRBs, the vehicle switched to Graphite-Epoxy Motor (GEM 63) boosters beginning in November 2020, except for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Propellant
Rocket propellant is used as reaction mass ejected 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 chemistry, more specifically combustion. As such, both an oxidizing agen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Cryogenic Second Stage
The Delta Cryogenic Second Stage (DCSS) is a family of cryogenic-fuelled rocket stages used on the Delta III, Delta IV, and on the Space Launch System Block 1 launch vehicles. The DCSS employs a unique two-tank architecture where the cylindrical liquid hydrogen (LH2) tank carries payload launch loads and forms the upper section. An oblate spheroid tank filled with liquid oxygen (LOX) and the engine are suspended from the LH2 tank and covered by the interstage during initial launch. The DCSS is powered by a single RL10B-2 engine built by Aerojet Rocketdyne, which features an extendable carbon–carbon nozzle to improve specific impulse. The DCSS was designed by the National Space Development Agency of Japan, based on the second stage it developed for the H-IIA rocket. The initial versions for the Delta III were built by Mitsubishi Heavy Industries in Japan. For the Delta IV, production was transferred to Boeing Integrated Defense Systems and later to United Launch Allian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centaur Upper Stage Being Lifted
A centaur ( ; ; ), occasionally hippocentaur, also called Ixionidae (), is a creature from Greek mythology with the upper body of a human and the lower body and legs of a horse that was said to live in the mountains of Thessaly. In one version of the myth, the centaurs were named after Centaurus (Greek mythology), Centaurus, and, through his brother Lapithes (hero), Lapithes, were kin to the legendary tribe of the Lapiths. Centaurs are thought of in many Greek myths as being as wild as untamed horses, and were said to have inhabited the region of Magnesia (regional unit), Magnesia and Mount Pelion in Thessaly, the Foloi oak forest in Ancient Elis, Elis, and the Malean peninsula in southern Laconia. Centaurs are subsequently featured in Roman mythology, and were familiar figures in the medieval bestiary. They remain a staple of modern fantastic literature. Etymology The Greek word ''kentauros'' is generally regarded as being of obscure origin. The etymology from ''ken'' + ''tau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Impulse
Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine, such as a rocket engine, rocket using propellant or a jet engine using fuel, generates thrust. In general, this is a ratio of the ''Impulse (physics), impulse'', i.e. change in momentum, ''per mass'' of propellant. This is equivalent to "thrust per massflow". The resulting unit is equivalent to velocity. If the engine expels mass at a constant exhaust velocity v_e then the thrust will be \mathbf = v_e \frac . If we integrate over time to get the total change in momentum, and then divide by the mass, we see that the specific impulse is equal to the exhaust velocity v_e . In practice, the specific impulse is usually lower than the actual physical exhaust velocity inefficiencies in the rocket, and thus corresponds to an "effective" exhaust velocity. That is, the specific impulse I_ in units of velocity *is defined by* : \mathbf = I_ \frac , where \mathbf is the average thrust. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space
Space is a three-dimensional continuum containing positions and directions. In classical physics, physical space is often conceived in three linear dimensions. Modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum known as '' spacetime''. The concept of space is considered to be of fundamental importance to an understanding of the physical universe. However, disagreement continues between philosophers over whether it is itself an entity, a relationship between entities, or part of a conceptual framework. In the 19th and 20th centuries mathematicians began to examine geometries that are non-Euclidean, in which space is conceived as '' curved'', rather than '' flat'', as in the Euclidean space. According to Albert Einstein's theory of general relativity, space around gravitational fields deviates from Euclidean space. Experimental tests of general relativity have confirmed that non-Euclidean geometries provide a bet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helium
Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is the lowest among all the Chemical element, elements, and it does not have a melting point at standard pressures. It is the second-lightest and second-most Abundance of the chemical elements, abundant element in the observable universe, after hydrogen. It is present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this in both the Sun and Jupiter, because of the very high nuclear binding energy (per nucleon) of helium-4 with respect to the next three elements after helium. This helium-4 binding energy also accounts for why it is a product of both nuclear fusion and radioactive decay. The most common isotope of helium in the universe is helium-4, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monopropellant Rocket
A monopropellant rocket (or "monochemical rocket") is a rocket that uses a single chemical as its propellant. Monopropellant rockets are commonly used as small attitude and trajectory control rockets in satellites, rocket upper stages, crewed spacecraft, and spaceplanes. Chemical-reaction based monopropellant rockets The simplest monopropellant rockets depend on the chemical decomposition of a storable propellant after passing it over a catalyst bed. The power for the thruster comes from the high pressure gas created during the decomposition reaction that allows a Rocket engine nozzle, rocket nozzle to speed up the gas to create thrust. The most commonly used monopropellant is hydrazine (), a compound unstable in the presence of a Catalysis, catalyst and which is also a strong reducing agent. The most common catalyst is granular alumina (aluminum oxide, ) coated with iridium. These coated granules are usually under the commercial labels Aerojet S-405 (previously made by Shell plc, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly hazardous unless handled in solution as, for example, hydrazine hydrate (). Hydrazine is mainly used as a foaming agent in preparing Polymeric foam, polymer foams, but applications also include its uses as a precursor (chemistry), precursor to pharmaceuticals and agrochemicals, as well as a long-term storable propellant for in-outer space, space spacecraft propulsion. Additionally, hydrazine is used in various rocket propellant, rocket fuels and to prepare the gas precursors used in airbags. Hydrazine is used within both nuclear and conventional electrical power plant steam cycles as an oxygen scavenger to control concentrations of dissolved oxygen in an effort to reduce corrosion. , approximately 120,000 tons of hydrazine hydrate (corresponding to a 64% solution of hydrazine in water by weight) we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ullage
Ullage or headspace is the unfilled space in a container, particularly with a liquid. Etymology The word ''ullage'' comes from the Latin word ''oculus'', used by the Romans to refer to a barrel cork hole. This word was, in turn, taken in medieval French as ''oeil'', from which a verb ''ouiller'' was created, meaning to fill a barrel to full capacity. Around 1300, the word ''ouillage'' was created by the Normans to refer to the amount of liquid needed to fill a barrel to capacity. Alcoholic beverages In winemaking, ''ullage'' came to refer to any amount by which a barrel is unfilled, perhaps because some of the contents have been used. It is also applied to the unfilled air space at the top of a bottle of wine, which in this case is essential to allow for expansion of the contents as the temperature changes. By further extension, in brewing and beer retail, ''ullage'' is the residue of beer left in a barrel that has been emptied. When calculating tax returns and the like, licens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Control System
A reaction control system (RCS) is a spacecraft system that uses Thrusters (spacecraft), thrusters to provide Spacecraft attitude control, attitude control and translation (physics), translation. Alternatively, reaction wheels can be used for attitude control, rather than RCS. Use of diverted engine thrust to provide stable attitude control of a V/STOL, short-or-vertical takeoff and landing aircraft below conventional winged flight speeds, such as with the Hawker Siddeley Harrier#Controls and handling, Harrier "jump jet", may also be referred to as a reaction control system. Reaction control systems are capable of providing small amounts of thrust in any desired direction or combination of directions. An RCS is also capable of providing torque to allow control of rotation (aircraft principal axes, roll, pitch, and yaw). Reaction control systems often use combinations of large and small (vernier thruster, vernier) thrusters, to allow different levels of response. Uses Spacecr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerojet Rocketdyne
Aerojet Rocketdyne is a subsidiary of American Arms industry, defense company L3Harris that manufactures rocket, Hypersonic flight, hypersonic, and electric propulsive systems for space, defense, civil and commercial applications. Aerojet traces its origins to the General Tire and Rubber Company (later renamed GenCorp, Inc. as it diversified) established in 1915, while Rocketdyne was created as a division of North American Aviation in 1955. Aerojet Rocketdyne was formed in 2013 when Aerojet and Pratt & Whitney Rocketdyne were merged, following the latter's acquisition by GenCorp, Inc. from Pratt & Whitney. Aerojet Rocketdyne was acquired by L3Harris in July 2023 for $4.7 billion. History Background: Aerojet Several decades after it began manufacturing rubber products, General Tire & Rubber diversified into broadcasting and aeronautics. In the 1940s, the Aerojet company began experimenting with various rocket designs. For a solid-fuel rocket, they needed binders, and tur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
