Basic Information
A rocket is a projectile driven by a high speed jet formed from its reacted propellant (a rocket engine). This page is only about the projectile kind - for the vehicle see Rocket (Vehicle).
Rocket projectiles have been used for entertainment and military purposes since at least the 13th century AD, but reached their apogee (literally in most cases) in the mid to late twentieth century.
Early examples used gunpowder as a propellant and were steered - if at all - by firing them from a launching tube with a stick trailing behind them to reduce their ability to turn. Still, rockets could prove alarming unpredictable in flight and would typically cause chaos in target units as they arrived - and in some cases continued to leap about after impact, scattering burning propellant in their wake. This remained more or less the state of the art until the 1920s, although there were limited forays into the use of fins and spin stabilisation to improve accuracy.
From that point on, liquid fuelled rockets became available, as did purpose built rocket nozzles to improve the efficiency with which the gases produced by the propellant were converted into thrust.
Later additions included inertial guidance and adjustable stabiliser fins to allow the rocket to make in-course corrections to its flight path.
In terms of modern weaponry, a rocket is a self-propelled, airborne projectile without significant guidance or course correction (which would tend to make it a guided missile) - with the usual exception of laser guidance.
Early rockets carried a solid metal head much like an arrow plus any residual propellant, but it was not much of a leap to upgrade to explosive or incendiary warheads and from there to many other kinds of payload.
