Up, Up and Away
Try to imagine how it would feel to float on a cloud. That’s how it feels to ride in the basket of a hot air balloon!
In the United States, hot air ballooning is becoming a popular sport. There are about 7,500 hot air balloons operating in the country. The Mini Page talked with an expert about hot air ballooning. How does it work?
A hot air balloon flies because the air inside the envelope, or balloon, is hotter than the air outside. Hot air is lighter than cold air, so it rises and lifts the balloon and its gondola, or basket, off the ground.
The air is heated with a burner that runs on a fuel called propane.
The pilot uses the burner and opens and closes a vent in the envelope to control how warm the air is inside the envelope. That way he or she can control how high or low the balloon flies. Into the wild blue yonder
Hot air balloons usually fly about 1,000 feet off the ground. A balloon can go much higher, but above about 12,000 feet there is not enough oxygen in the air for the passengers in the gondola to breathe.
The speed of the balloon depends on the wind speed. Pilots try to fly when the wind is very calm, usually either around sunrise or just before sunset. If the wind speed on the ground is more than about 7 miles per hour, pilots will not fly because they have less control of the balloon while it’s on the ground.
Balloons generally fly around 10 miles per hour (the wind speed is faster at a higher altitude). Hot air balloon flights usually last one to two hours. Balloon pioneers
Most modern hot air balloons are made of rip-stop nylon fabric, similar to a kite or tent material. The gondola is made of wicker and has an aluminum or stainless steel frame.
But hot air balloons weren’t always made of materials like these. Two
French papermakers, the
Montgolfier brothers, made the first balloon to carry human passengers.
It was made of layers of paper and fabric and beautifully painted. It flew about 5 miles in 25 minutes.
The fuel for that flight was made of straw. Two passengers used pitchforks to put the fuel into a container for holding burning coals. The event was very exciting to Parisians — about half the city came to watch.