Hot Air Balloons
1Have you ever seen a giant, colorful bubble drifting across the morning sky? It may have been a hot air balloon. In this report, you will learn about the parts of a hot air balloon, how it goes up and down, and how it travels from place to place.
2A hot air balloon has three main parts. The big cloth bag at the top is called the envelope. It is made of strong, light fabric. A basket hangs below the envelope, and the pilot and riders stand inside it. Just above the basket is the burner, which can make a huge flame.
3A hot air balloon can fly because hot air rises above cooler air. When the pilot turns on the burner, the air inside the envelope gets hotter, and the balloon floats up. When the air inside cools down, the balloon slowly sinks. The basket is often woven from wicker.
4A hot air balloon has no steering wheel. It floats wherever the wind carries it. The wind can blow in different directions at different heights, so the pilot moves the balloon up or down to find a wind going the right way. Many flights take place early in the morning, when the air is often calm. A team on the ground follows the balloon in a truck and picks up the riders after it lands.
5Hot air balloons are amazing machines. The next time you see one in the sky, you will know how it works.