A hot-air balloon is a lighter-than-air aircraft consisting of a bag, called an envelope, which contains heated air. Suspended beneath is a gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule), which carries passengers and a source of heat, in most cases an open flame caused by burning liquid propane.
The working of a hot air balloon is simple. It is made up of a balloon-shaped envelope in which you fill hot air. The balloon itself is made up of a nylon material with a heat resistant material at the mouth where the burner is.
The liquid propane fuel is stored in cylinders in the wicker basket below.Hot air balloons cannot navigate on their own. They must rely on the wind to push them in any particular direction.
The heated air inside the envelope makes it buoyant, since it has a lower density than the colder air outside the envelope. As with all aircraft, hot-air balloons cannot fly beyond the atmosphere.The hot-air balloon is the first successful human-carrying flight technology.