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Rocket Self Propelled Device As a FireWork

Rocket Self Propelled Device As a FireWork

Rocket, self-propelled device that carries its own fuel, as well as the oxygen, or other chemical agent,

A rocket can be as simple and small as a firework, which has a small amount of thrust, or as complex and powerful as the Saturn V rocket, which took humans to the Moon. British Congreve war rockets, which were used in the War of 1812, are referred to in a line of the United States national anthem: “And the rockets red glare…” Rockets have many applications both on Earth and in space. The most common and well-known use of rockets is for missiles—weapons that deliver explosive warheads through the air to specified targets (see Guided Missile). Rockets also have numerous peaceful purposes. Upper atmospheric research rockets, or sounding rockets, carry scientific instruments to high altitudes, helping scientists carry out astronomical research and learn more about the nature of the atmosphere. Jet-Assisted-Take-Off (JATO) rockets help lift heavily loaded planes from runways. Lifesaving rockets carry lifeline ropes to ships stranded offshore. Ships in distress can launch signal rockets to signal for help. Rocket ejection seats safely boost pilots out of jet planes during emergencies. Fireworks have provided entertainment for centuries, and model rockets form the basis of a popular hobby.

II  ROCKET USES,

People use all kinds of rockets for the same basic purpose: to carry objects through air and space. Missiles carry explosive devices to targets, while sounding rockets carry scientific instruments into the upper atmosphere. Launch vehicles boost satellites and other spacecraft into space, and smaller thruster rockets steer or stabilize spacecraft in space.

A  Missiles,

The term missile actually means any object thrown at an enemy and includes arrows, bullets, and other weapons. In modern military usage, however, missile usually means an explosive device propelled through the air by a rocket or an air-breathing engine. (Air-breathing engines differ from rockets in that rockets carry their own oxygen, while air-breathing engines get their oxygen from the air as they fly through it.)

Missiles can be launched from the ground, from airplanes, and even from submarines. Some missiles are designed to hit targets in the air, while others are built to hit targets on the ground. Some missiles, called guided missiles, have steering systems that guide them to their target.

B  Sounding Rockets,

Scientists use sounding rockets to carry scientific instruments into the upper atmosphere to take measurements of air quality, radiation from space, and other data. Many countries use sounding rockets to monitor weather and pollution. Engineers enable a rocket to reach its target altitude by shutting down the rocket at a specific height. The rocket then coasts upward until air friction and gravity stop its upward movement and cause it to fall back to Earth. The instruments usually include a radio transmitter that sends measurements back to Earth. Some sounding rockets carry parachutes that allow their controllers to recover the rocket and the instruments, but some fall back to Earth without a parachute. Engineers design a sounding rocket’s flight path so that the rocket will fall into the ocean or into an uninhabited area in order to avoid damaging property or hurting people.

C  Launch Vehicles,

Launch vehicles send satellites and other spacecraft into space. These vehicles must be far more powerful than other types of rockets, because they carry more cargo farther and faster than other rockets. To place an object into orbit around Earth, the launch vehicle must reach a velocity of about 30,000 km/h (about 18,500 mph). To escape Earth’s gravitational pull entirely and head into deep space, these rockets must attain a velocity, called an escape velocity, of about 40,000 km/h (about 25,000 mph). Engineers have found that the most efficient way for launch vehicles to reach these speeds is to use staged rockets, or rockets divided into different stages, one atop another.

D  Thrusters,

Many spacecraft use small rockets called thrusters to move around in space. Thrusters can change the speed and direction of a spacecraft. They allow a spacecraft to steer in space, to jump to a higher orbit, or to fall back to Earth.

III  HOW ROCKETS WORK,

All rockets—whether small or large, simple or complex—work by the basic principle of action and reaction, which was formulated by English scientist Sir Isaac Newton in 1687. Newton’s third law of motion states, “For every action there is an equal and opposite reaction.” In the case of the rocket, the expulsion of exhaust gases from the rear is the action, and the forward movement of the rocket is the reaction.



needed to burn its fuel. Most rockets move by burning their fuel and expelling the hot exhaust gases that result. The force of these hot gases shooting out in one direction causes the rocket to move in the opposite direction. A rocket engine is the most powerful engine for its weight. Other forms of propulsion, such as jet-powered and propeller-driven engines, cannot match its power. Rockets can operate in space, because they carry their own oxygen for burning their fuel. Rockets are presently the only vehicles that can launch into and move around in space.

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