Rocket

                                        Rocket

                                                 The word "rocket" can mean different things. Most people think of a tall, thin, round vehicle. They think of a rocket that launches into space. "Rocket" can mean a type of engine. The word also can mean a vehicle that uses that engine. A rocket (Italian rocchetta‚ "little fuse" is a missile, spacecraft, aircraft or other vehicle that obtains thrust from a rocket engine. Rocket engine exhaust is formed entirely from propellant carried within the rocket before use. Rocket engines work by action and reaction and push rockets forward simply by expelling their exhaust in the opposite direction at high speed, and can therefore work in space.

Indeed, rockets work more efficiently in space than in an atmosphere. Multi-stage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Compared with air-breathing engines, rockets are lightweight and powerful and capable of generating large accelerations. Rockets rely on momentum, airfoils, auxiliary reaction engines, gimballed thrust, momentum wheels, deflection of the exhaust stream, propellant flow, spin, and/or gravity to help control flight.

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, weaponry, ejection seats, and 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 (monopropellants), two liquids that spontaneously react on contact (hypergolic propellants), two liquids that must be ignited to react, a solid combination of one or more fuels with one or more oxidizers (solid fuel), or solid fuel with liquid oxidant (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 minimize risks.

History of Rockets

The availability of black powder (gunpowder) to propel projectiles was a precursor to experiments as weapons such as bombs, cannon, incendiary fire arrows and rocket-propelled fire arrows. The discovery of gunpowder was probably the product of centuries of alchemical experimentation in which Taoist alchemists were trying to create an elixir of immortality that would allow the person ingesting it to become physically immortal. However, anyone with a wood fire might have observed the acceleration of combustion that accidentally-chosen saltpetre-containing rocks would have produced.

Exactly when the first flights of rockets occurred is contested. Merely lighting a centimeter-sized solid lump of gunpowder on one side can cause it to move via reaction (even without a nozzle for efficiency), so confinement in a tube and other design refinements may easily have followed for the experimentally-minded with ready access to saltpetre.

A problem for dating the first rocket flight is that Chinese fire arrows can be either arrows with explosives attached, or arrows propelled by gunpowder. There were reports of fire arrows and 'iron pots' that could be heard for 5 leagues (25 km, or 15 miles) when they exploded, causing devastation for a radius of 600 meters (2,000 feet), apparently due to shrapnel.[8] A common claim is that the first recorded use of a rocket in battle was by the Chinese in 1232 against the Mongol hordes at Kai Feng Fu.[9] However, the lowering of iron pots there may have been a way for a besieged army to blow up invaders. A scholarly reference occurs in the Ko Chieh Ching Yuan (The Mirror of Research), states that in 998 AD a man named Tang Fu invented a fire arrow of a new kind having an iron head.

Less controversially, one of the earliest devices recorded that used internal-combustion rocket propulsion, was the 'ground-rat,' a type of firework recorded in 1264 as having frightened the Empress-Mother Kung Sheng at a feast held in her honor by her son the Emperor Lizong. Subsequently, one of the earliest texts to mention the use of rockets was the Huolongjing, written by the Chinese artillery officer Jiao Yu in the mid-14th century. This text also mentioned the use of the first known multistage rocket, the 'fire-dragon issuing from the water' (huo long chu shui), used mostly by the Chinese navy.

Uses of Rocket

1. Military

2. Science and research

3. Spaceflight

4. Rescue

5. Hobby, sport, and entertainment

Answers and questions about Rocket

 What is Rocket?

 The word "rocket" can mean different things. Most people think of a tall, thin, round vehicle. They think of a rocket that launches into space. "Rocket" can mean a type of engine. The word also can mean a vehicle that uses that engine.

How Does a Rocket Engine Work?

Like most engines, rockets burn fuel. Most rocket engines turn the fuel into hot gas. The engine pushes the gas out its back. The gas makes the rocket move forward. A rocket is different from a jet engine. A jet engine needs air to work. A rocket engine doesn't need air. It carries with it everything it needs. A rocket engine works in space, where there is no air. There are two main types of rocket engines. Some rockets use liquid fuel. The main engines on the space shuttle orbiter use liquid fuel. The Russian Soyuz uses liquid fuels. Other rockets use solid fuels. On the side of the space shuttle are two white solid rocket boosters. They use solid fuels. Fireworks and model rockets also fly using solid fuels.

Why Does a Rocket Work?

In space, an engine has nothing to push against. So how do rockets move there? Rockets work by a scientific rule called Newton's third law of motion. English scientist Sir Isaac Newton listed three Laws of Motion. He did these more than 300 years ago. His third law says that for every action, there is an equal and opposite reaction. The rocket pushes on its exhaust. The exhaust pushes the rocket, too. The rocket pushes the exhaust backward. The exhaust makes the rocket move forward.

This rule can be seen on Earth. Imagine a person standing on a skateboard. Imagine that person throwing a bowling ball. The ball will go forward. The person on the skateboard will move, too. The person will move backward. Because the person is heavier, the bowling ball will move farther.

When Were Rockets Invented?

The first rockets we know about were used in China in the 1200s. These solid rockets were used for fireworks. Armies also used them in wars. In the next 700 years, people made bigger and better solid rockets. Many of these were used for wars too. In 1969, the United States launched the first men to land on the moon using a Saturn V rocket.

How Does NASA Use Rockets?

Early NASA missions used rockets built by the military. Alan Sheppard was the first American in space. He flew on the U.S. Army's Redstone rocket. John Glenn was the first American in orbit. He flew on an Atlas rocket. NASA's Gemini missions used the Titan II rocket. The first rockets NASA built to launch astronauts were the Saturn I, the Saturn IB and the Saturn V. These rockets were used for the Apollo missions. The Apollo missions sent men to the moon. A Saturn V also launched the Skylab space station. The space shuttle uses rocket engines.

NASA uses rockets to launch satellites. It also uses rockets to send probes to other worlds. These rockets include the Atlas V, the Delta II, the Pegasus and Taurus. NASA uses smaller "sounding rockets" for scientific research. These rockets go up and come back down. They do not fly into orbit.

How Will NASA Use Rockets in the Future?

The new rockets will not look like the space shuttle. These rockets will look more like earlier ones. They will be tall and round and thin. These rockets will take astronauts into space. They will take supplies to the International Space Station. NASA also is working on a powerful new rocket called a heavy lift vehicle. This rocket will be able to take big loads into space.

What Is the International Space Station?

The International Space Station is a large spacecraft. It orbits around Earth. It is a home where astronauts live.

The space station is also a science lab. Many countries worked together to build it. They also work together to use it.

The space station is made of many pieces. The pieces were put together in space by astronauts. The space station's orbit is about 220 miles above Earth. NASA uses the station to learn about living and working in space. These lessons will help NASA explore space.

How Old Is the Space Station?

The first piece of the International Space Station was launched in 1998. A Russian rocket launched that piece. After that, more pieces were added. Two years later, the station was ready for people. The first crew arrived on November 2, 2000. People have lived on the space station ever since. Over time more pieces have been added. NASA and its partners around the world finished the space station in 2011.

How Big Is the Space Station?

The space station is as big inside as a house with five bedrooms. It has two bathrooms, a gymnasium and a big bay window. Six people are able to live there. It weighs almost a million pounds. It is big enough to cover a football field including the end zones. It has science labs from the United States, Russia, Japan and Europe.

What Are the Parts of the Space Station?

The space station has many parts. The parts are called modules. The first modules had parts needed to make the space station work. Astronauts also lived in those modules. Modules called "nodes" connect parts of the station to each other. Labs on the space station let astronauts do research.

On the sides of the space station are solar arrays. These arrays collect energy from the sun. They turn sunlight into electricity. Robot arms are attached outside. The robot arms helped to build the space station. They also can move astronauts around outside and control science experiments. Airlocks on the space station are like doors. Astronauts use them to go outside on spacewalks.

Docking ports are like doors, too. The ports allow visiting spacecraft to connect to the space station. New crews and visitors enter the station through the docking ports. Astronauts fly to the space station on the Russian Soyuz. The crew members use the ports to move supplies onto the station.

Why Is the Space Station Important?

The space station is a home in orbit. People have lived in space every day since the year 2000. The space station's labs are where crew members do research. This research could not be done on Earth. Scientists study what happens to people when they live in space. NASA has learned how to keep a spacecraft working for a long time. These lessons will be important in the future.

NASA has a plan to send humans deeper into space than ever before. The space station is one of the first steps. NASA will use lessons from the space station to get astronauts ready for the journey ahead.