It is generally accepted that gunpodwer (the primary fuel of rockets until the early 20^th century) were invented around the ninth century in China and was first used in rockets around the 13^th century, but were mainly used as weapons and for cerimonial purposes (fireworks). Sometime around the 14^th century it is believed that the arab people broght gunpowder and rockets to Spain and from there it made it�s way to the other countries of Europe, where the fomula of gunpowder was documented and improved upon by Robert Bacon to make it a more effective explosive. (which also made a more efficent rocket fuel.) Because Europeans didn�t commonly use rocket for weapons, rockets didn�t really advance after that for another six hundred years.

But in 1909 Dr. Robert H Goddard, a New England Physics Professor and a pioneer in rocket technology had an idea to make a rocket that did not use solid fuel but fuel that was in a liquid form. He came to the conclusion that a rocket that used a liquid fuel would be burn faster and hotter than a solid fueled rocket. It took him seventeen years of theoretical and experimental work, but on March 16 1926 Dr. Goddard�s idea became a reality when he launched the first liquid fueled rocket. And from that time on rocket fuel technology grew in leaps and bounds with new and even more efficient fuels being discovered. Because it used a liquid fuel instead of a solid fuel it was much more efficient and rockets became noticed as a from of weaponry and was quickly developed further. By the 1960 rockets had grown to be hundreds of feet high and could travel more than half way around the world and even into space.

Along with the increase in size and the increase in range, new types of fuel were also developed. The fuel changed to more combustible types of fuel, from the gasoline that was used to power Dr. Goddard�s rocket to Kerosene used in the Saturn V rocket that Carried people to the moon, and later even hydrogen was used to power the Space Shuttles. Now Conventional rockets have almost reached their limits, an the space programs are desperately searching for more efficient was to move something in space. And so in 1998 the first ion drive rocket engine was put into the �Deep Space I� probe, other sources of power are also being considered, such as fission powered rockets and fusion powered rockets.