Hot Air Balloon

flight · buoyancy · adventure

Heated air rises. Hot air balloons work because warm air is lighter and less dense than cold air. When you heat the air inside the big envelope (that's the balloon part), it becomes buoyant and lifts the whole aircraft up into the sky.

Wicker basket below. Passengers and the heat source sit in a gondola, which is usually a wicker basket hanging from the balloon. This basket is suspended safely beneath the enormous envelope that holds all the hot air.

Propane does the heating. Most hot air balloons use an open flame powered by liquid propane to heat the air inside. The pilot controls how hot the air gets to make the balloon go up, stay level, or come down.

Modern materials matter. Today's balloon envelopes are made from nylon fabric, while the bottom opening uses fire-resistant material called Nomex so it won't burn. These special materials make hot air balloons safe and long-lasting.

Wild shapes possible. While traditional balloons are round and simple, modern balloons can be shaped like rocket ships, animals, or even giant bottles for advertising. But most sport balloons stick with the classic round design because it works so well.