A launch pad
is a structure or platform from which a rocket
is ignited and lifts off. Originally, in the early days of rocketeering, rockets were launched from the ground. As the power of rocket engine
s increased, it became desirable to utilize a flameproof surface to avoid fires, as well as to lift the rocket from the ground so that its own reflected blast and thrown up debris
would be less likely to damage it while firing.
The Merriam-Webster Online Dictionary claims the term dates to 1958; I suspect that means its date of inclusion in the dictionary. During World War II, German rocket experiments were conducted from concrete surfaces for this very reason, sometimes with structures atop them. Concrete and ceramic remain popular options for launch pads due to their strength and ability to resist heat.
As time went on, the term came to mean any dedicated facility used for launching rockets or spacecraft. NASA's Launch Complex 39A and 39B, used originally for Apollo missions and presently to launch the Space Shuttle, are referred to as 'launch pads' despite being enormous complexes of structures below, on and above the ground.