From 1783 when the first human flew in a balloon propelled by hot air rising an open fire, innovations in hot-air balloons have been revolutionary. Hot air was quickly replaced by hydrogen, which was easier to control. Hot-air ballooning has become a popular sport with more than 5000 hot-air balloon pilots in the United States. Chemistry has contributed the durable, inexpensive and heat-resistant nylon fabric and the liquid propane technology used for propulsion. During the 1960s, hot-air balloons attracted less interest, but later they became a popular means of sport and recreation, for instance in the United States. Chemistry contributed to the success of this special kind of sport by developing light-weight and strong synthetic fabrics. The burner unit of today's balloons gasifies liquid propaneto produce hot air.
Flying in a hot-air balloon is fundamentally different from every other kind of flight. Having an undisturbed view of 360 degrees from the basket, balloons provide us with an undeniable feeling of liberty.