Rocket

A rocket or rocket vehicle is a missile, aircraft or other vehicle which obtains thrust by the reaction of the rocket to the ejection of fast moving fluid exhaust from a rocket engine. Chemical rockets create their exhaust by the combustion of rocket propellant. The action of the exhaust against the inside of combustion chambers and expansion nozzles accelerates the gas to extremely high speed and exerts a large reactive thrust on the rocket (since every action has an equal and opposite reaction).
The history of rockets goes back to at least the 13th century, and military and recreational display use dates from that time. Widespread military, scientific, and industrial use did not occur until the 20th century, when rocketry was the enabling technology of the Space Age, with man visiting the moon.
Rockets are used for fireworks and weaponry, ejection seats and launch vehicles for artificial satellites, human spaceflight and exploration of other planets. While inefficient for low speed use, they are, compared to other propulsion systems, very lightweight and powerful, capable of generating large accelerations and of attaining extremely high speeds with reasonable efficiency.
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.

The availability of black powder (gunpowder) to propel projectiles was a precursor to the development of the first solid rocket. Ninth Century Chinese Taoist alchemists discovered black powder while searching for the Elixir of life; this accidental discovery led to experiments in the form of weapons such as bombs, cannon, incendiary fire arrows and rocket-propelled fire arrows.
Exactly when the first flights of rockets occurred is contested. Some say that the first recorded use of a rocket in battle was by the Chinese in 1232 against the Mongol hordes. There were reports of fire arrows and 'iron pots' that could be heard for 5 leagues (25 km, or 15 miles) when they exploded upon impact, causing devastation for a radius of 600 meters (2,000 feet), apparently due to shrapnel. The lowering of the iron pots may have been a way for a besieged army to blow up invaders. The fire arrows were either arrows with explosives attached, or arrows propelled by gunpowder, such as the Korean Hwacha.
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.