rocketry
A rocket (from Italian: rocchetto, lit. 'bobbin/spool') is a vehicle that uses jet propulsion to accelerate without using the surrounding air.
The Rocketry Portal
A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely from propellant carried within the vehicle; therefore a rocket can fly in the vacuum of space. Rockets work more efficiently in a vacuum and incur a loss of thrust due to the opposing pressure of the atmosphere.
Multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Compared with airbreathing engines, rockets are lightweight and powerful and capable of generating large accelerations. To control their flight, rockets rely on momentum, airfoils, auxiliary reaction engines, gimballed thrust, momentum wheels, deflection of the exhaust stream, propellant flow, spin, or gravity.
Rockets for military and recreational uses date back to at least 13th-century China. Significant scientific, interplanetary and industrial use did not occur until the 20th century, when rocketry was the enabling technology for the Space Age, including setting foot on the Moon. Rockets are now used for fireworks, missiles and other weaponry, ejection seats, launch vehicles for artificial satellites, human spaceflight, and space exploration.
Chemical rockets are the most common type of high power rocket, typically creating a high speed exhaust by the combustion of fuel with an oxidizer. The stored propellant can be a simple pressurized gas or a single liquid fuel that disassociates in the presence of a catalyst (monopropellant), two liquids that spontaneously react on contact (hypergolic propellants), two liquids that must be ignited to react (like kerosene (RP1) and liquid oxygen, used in most liquid-propellant rockets), a solid combination of fuel with oxidizer (solid fuel), or solid fuel with liquid or gaseous oxidizer (hybrid propellant system). Chemical rockets store a large amount of energy in an easily released form, and can be very dangerous. However, careful design, testing, construction and use minimizes risks. (Full article...)
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A jet pack, rocket belt, rocket pack or flight pack is a device worn as a backpack which uses jets to propel the wearer through the air. The concept has been present in science fiction for almost a century and the first working experimental devices were demonstrated in the 1960s.
Jet packs have been developed using a variety of mechanisms, but their uses are limited because of factors including the Earth's atmosphere, gravity, the low energy density of extreme fuels, and the human body not being suited to flight, and they are principally used for stunts. (Full article...)In the news
- 12 April 2024 – Israel–Hezbollah conflict
- Hezbollah forces launch dozens of rockets into northern Israel. The militant group says that the missile barrage targeted IDF artillery positions. No casualties are reported. (Al Arabiya)
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General images -
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Simplified diagram of a solid-fuel rocket:(from Rocket engine)- Solid fuel–oxidiser mixture (propellant) packed into casing
- Igniter initiates propellant combustion.
- Central hole in propellant acts as the combustion chamber.
- Exhaust nozzle expands and accelerates the gas jet to produce thrust.
- Exhaust exits nozzle.
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The four expansion regimes of a de Laval nozzle:• under-expanded• perfectly expanded• over-expanded• grossly over-expanded (from Rocket engine) -
Layout of a V-2 rocket. (from History of rockets) -
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A battery of Katyusha launchers fires at German forces during the Battle of Stalingrad, 6 October 1942 (from History of rockets) -
A German V-2 rocket on a Meillerwagen. (from History of rockets) -
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Robert Goddard (from History of rockets) -
Von Braun's rocket team in 1961 (from History of rockets) -
- A simplified diagram of a solid-fuel rocket.(from Missile)
- A propellant is packed with a hole in the middle
- An igniter combusts the propellant
- The hole acts as a combustion chamber
- The hot exhaust is choked at the throat
- Exhaust exits the rocket
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Robert Esnault-Pelterie (1909). (from History of rockets) -
A "long serpent enemy breaking" fire arrow launcher as depicted in the Wubei Zhi (17th century). It carries 32 medium small poisoned rockets and comes with a sling to carry on the back. (from History of rockets) -
The 'convocation of eagles chasing hare' rocket launcher from the Wubei Zhi (17th century). A double-ended rocket pod that carries 30 small poisoned rockets on each end for a total of 60 rockets. It carries a sling for transport. (from History of rockets) -
Rocket vehicle mechanical efficiency as a function of vehicle instantaneous speed divided by effective exhaust speed. These percentages need to be multiplied by internal engine efficiency to get overall efficiency. (from Rocket engine) -
Armadillo Aerospace's quad vehicle showing visible banding (shock diamonds) in the exhaust jet (from Rocket engine) -
A V-1 flying bomb, amongst the first guided missiles (from Missile) -
Robert Anderson suggests using metal for rocket casing (from History of rockets) -
The Congreve rocket (from History of rockets) -
French Diamant rocket, the second French rocket program, developed from 1961 (from History of rockets) -
Robert Goddard and the first liquid-fueled rocket. (from History of rockets) -
Opel RAK.1 - World's first public manned flight of a rocket plane on September 30, 1929. (from History of rockets) -
Simplified diagram of a liquid-fuel rocket:(from Rocket engine)- Liquid fuel tank
- Liquid oxidiser tank
- Pumps feed fuel and oxidiser under high pressure.
- Combustion chamber mixes and burns the propellants.
- Exhaust nozzle expands and accelerates the gas jet to produce thrust.
- Exhaust exits nozzle.
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Rocket carts from the Wubei Zhi (17th century) (from History of rockets) -
An illustration of fire arrow launchers as depicted in the Wubei Zhi (17th century). The launcher is constructed using basketry. (from History of rockets) -
Typical ballistic missile sequence:(from Missile)- 1. Launches by firing motor1(A)
- 2. Stage1 drops, motor2(B) ignites & shroud(E) ejects
- 3. Motor3(C) ignites and separates
- 4. Stage3 terminates and post-boost vehicle(D) separates
- 5. Vehicle maneuvers itself and prepares re-entry vehicle (RV)
- 6. RV with decoys and chaffs deploys
- 7. RV re-enters the atmosphere
- 8. Warhead(s) detonate on target
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A Tomahawk cruise missile in flight (from Missile) -
Rocket thrust is caused by pressures acting in the combustion chamber and nozzle. From Newton's third law, equal and opposite pressures act on the exhaust, and this accelerates it to high speeds. (from Rocket engine)
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