Govt. Girls Higher Secondary School , Pattom , Trivandrum. ROCKET Done by, ARDHRA P.B. & RAMYA D. Standard : X Govt. Girls Higher Secondary School , Pattom , Trivandrum.

INTRODUCTION A rocket is a vehicle, missile or aircraft which obtains thrust by the reaction to the ejection of fast moving exhaust gas from within a rocket engine. Often the term rocket is also used to mean a rocket engine.

PARTS OF ROCKET Engine Mount Fins Launch Lug Nose Cone Parachute Recovery Wadding

MAJOR ROCKET COMPONENTS

DESCRIPTION OF PARTS 1. Engine Mount The engine is used only once, and then is replaced with a new engine for the next flight. Engines come in a variety of sizes and can be purchased at hobby stores and at some toy stores. The thrust of the engine is transmitted to the body of the rocket through the engine mount.

2. Fins Beginning at the far right, the body of the rocket is a green cardboard tube with black fins attached at the rear. The fins can be made of either plastic or balsa wood and are used to provide stability during flight.

3. Launch Lug The launch lugs are small tubes (straws) which are attached to the body tube. The launch rail is inserted through these tubes to provide stability to the rocket during launch.

4. Nose Cone The nose cone can be made of balsa wood, or plastic, and may be either solid or hollow. The nose cone is inserted into the body tube before flight.

5. Parachute The recovery system consists of a parachute (or a streamer) and some lines to connect the parachute to the nose cone. Parachutes and streamers are made of thin sheets of plastic.

6. Recovery Wadding Recovery wadding is inserted between the engine mount and the recovery system to prevent the hot gas of the ejection charge from damaging the recovery system. The recovery wadding is sold with the engine.

How Rocket Works? A . Action and Reaction Rockets produce the force that moves them forward by burning their fuel inside a chamber in the rocket and then expelling the hot exhaust that results. Rockets carry their own fuel and the oxygen used for burning their fuel. In liquid-fueled rockets, the fuel and oxygen-bearing substance (called the oxidizer) are in separate compartments. The fuel is mixed with the oxygen and ignited inside a combustion chamber. The nozzle directs the rocket exhaust and causes it to come out faster, increasing the thrust and efficiency of the rocket.

B . Thrust and Efficiency Thrust is a measurement of the force of a rocket, or the amount of “push” exerted backward to move a rocket forward. Thrusts vary greatly from rocket to rocket. Exhaust velocity, or the speed at which exhaust leaves the rocket, is another way to measure rocket performance. The higher the exhaust velocity, the greater the thrust. Propellants with higher exhaust velocities also have higher specific impulses. Exhaust velocities can range from 600 to 900 m/sec for gunpowder, 2,000 m/sec for a mixture of liquid oxygen and gasoline, to 4,000 m/sec or more for a mixture of liquid oxygen and liquid hydrogen.

C . Staging In rockets that use stages, the stages are stacked on top of each other. The stage on the bottom of the stack is the first one to fire. The first and most powerful stage lifts the launch vehicle into the upper atmosphere. The first stage then separates from the rest of the rocket and falls toward Earth. The second stage carries less weight than the first stage, because the first stage has dropped off of the rocket. When the second stage takes over, the vehicle reaches a much higher speed; the second stage, however, also uses up its fuel and drops off. The third stage fires and places the spacecraft into orbit . On deep space missions, the third stage allows the spacecraft to reach escape velocity and head away from Earth. The rocket then fires and carries its cargo into orbit.

The Uses of Rockets 1. About 770 years ago in China, rockets were used in wars. 2. Rockets are used for many peaceful purposes. 3. They are used to carry payloads for commercial or scientific purposes into space. 4. Scientists use rockets to carry space probes into outer space to study other planets and objects in space. 5. Sounding rockets carry scientific instruments into the upper atmosphere.

ACKNOWLEDGEMENT We collected information from the following websites: www.wikipedia.org www.msn.com www.nasa.org And from Books.

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