**ROCKET SCIENCE(How a rocket engine works)**

Hello Steemians, have you ever looked up in the sky and see a small tiny object moving relatively fast and ejects a whitish jet that leaves a trail behind it and then ask yourself....What is this?and how does it works?

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Very well steemians you will get all your answer in this post. What you saw was a,space shuttle or a rocket and we are here to talk about its working principle of the rocket engine.

ROCKET ENGINE
The Rocket engine is a type of reaction engine that produces thrust by issuing out high velocity of jet(combustion products) from the back of the engine this high velocity of jet is produced from the combustion of the on board fuel and oxidizer.

It should be noted that the Rocket engines are of 4 different types

1)Solid fuel Rocket: This type of chemical rocket uses fuel in the solid state in which the oxider and the fuel are both embedded homogenously in the solid propellant early rocket engine uses gun powder as their propellant which consist of carbon(charcoal or coke),sulphur and potassium trioxonitrate(v)(KNO3)...The carbon acts as the fuel while the KNO3 act as the oxider because it decomposes to give out oxygen.

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The solid propellant is used as booster rocket in the space shuttle and as missiles for ballistics the they are used to launch satelite into space

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One advantage of a solid propellant rocket is the ease of its storage and doesn't requires a pump as other contemporaries

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The disadvantage of a solid propellant rocket is that it has a low specific impulse when compared to liquid propellant rocket(where specific impulse is the total impulse (i.e change in momentum) delivered per unit of propellant consumed and is dimensionally equivalent to the generated thrust divided by the propellant mass or weight flow rate. If mass (kilogram or slug) is used as the unit of propellant, then specific impulse has units of speed/velocity.
Solid propellant rocket are also used to launch satelite into orbit.

1. liquid propellant rocket This is type of rocket engine that produces thrust by combusting fuel(which is stored in its liquid state) and oxygen gas at high pressure to produce a high temperature high pressure gases which are then channelled to a de laval nozzel to accelerate the gas to a supersonic velocity
   
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   Liquid propellant rocket has higher specific impulse when compared to solid fuel rocket. Liquid propellant liquid are of 3 types..(monopropellant,bipropellant and tripropellant rocket) liquid propellant rocket are used in space shuttle here, liquid hydrogen is used as fuel while liquid oxygen is used as the oxider this engine have a turbopump which is responsible for pumping both propellant to a pressure higher than that of the combustion chamber.
   

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1. Hybrid Rocket: This type of rocket combine both Solid fuel rocket and liquid fuel rocket incoporating it into one set up.
   The hybrid rocket engine avoid the disadvantage of propellant handling and the disadvantage of mechanical complexity in liquid propellant rocket.

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The hybrid rocket has a disadvantage of effective combustion as it is diffcult for the two phase(solid phase fuel & liquid phase oxidizer) to mix homogeneously.

(4)Monopropellant rocket: This type of rocket engine has just one propellant and its depends on chemical reaction. The propulsive power is provided by the chemical itselt. That is, the energy to propel the engine is provided from the chemical energy stored in the propellant.
A very good example of a compound that can be used as a monopropellant is the " HYDRAZINE"..N2H4 which decomposes in the presence of aluminium catalyst at high temperature(1000°C)

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The rocket engine is very distint from othe internal combustion engine because it doesnt depends on the atomospheric air(oxygen), rather it carries both its fuel and oxidizer that is why the rocket engine is capable of operating in space where there is virtually no air.
The rocket engine is capable of propelling space craft up to mach11, that is 11 times the speed of sound making the space craft/rocket the fastest vehicle in the planet.
Research is still on going on the development of rocket engines which wont be using fossil fuel i hope to write on that very soon. Thanks for stopping by to read this post. I remain John Philip

Reference
http://www.businessinsider.com/juno-is-officially-the-fastest-spacecraft-ever-2016-7?IR=T
http://www.yuzhnoye.com/en/technique/rocket-engines/unicomponent/
https://en.m.wikipedia.org/wiki/Hybrid-propellant_rocket