Balloon (aeronautics)

A balloon is a flying machine.

It uses a big bag to float. Some bags use hot air to rise.

Others use a very light gas. A basket hangs below the bag. People or tools sit in the basket. This helps them fly high in the sky. The wind moves the balloon along. Some balloons stay tied to the ground. It is a simple way to fly!

A balloon is a very simple flying machine.

It is a large fabric bag filled with gas. This gas must be lighter than the air around it. This helps the balloon float or rise. Most balloons have a basket or capsule hanging below. This part carries people or tools like cameras.

There are three main ways to make a balloon fly. The first is a hot air balloon. It uses a burner to heat the air inside. As air gets hot, it expands and becomes lighter. This type is very popular for sport today.

The second type is a gas balloon. These use gases like helium or hydrogen. Helium is safe to use. Hydrogen can be explosive, so it is used less often now. Gas balloons can stay up for a long time. Some science balloons fly very high. They can even reach near-space.

The third type is a Rozière balloon. This uses two bags. One bag holds hot air. The other bag holds gas. This helps the pilot control the height. It is good for very long trips.

A balloon is a very simple flying machine.

It is a large fabric bag called an envelope. This bag is filled with gas that is lighter than the air around it. This creates buoyancy, which is the force that helps it float. Most balloons have a basket or a capsule hanging underneath. This part carries people or heavy equipment like cameras and telescopes.

Because they have no engines, balloons move with the wind. Pilots can control their height by rising or sinking to find different wind directions.

There are a few different ways these machines work. A hot air balloon, or Montgolfière, uses a burner to heat the air inside. When air is heated, it expands and becomes less dense. This makes the balloon lighter than the air outside, so it rises.

A gas balloon, or Charlière, uses gases like helium or hydrogen instead of heat. Helium is very common today because it is safe. Hydrogen provides even more lift, but it is highly flammable. Some special balloons, called Rozière balloons, use both hot air and gas to stay up longer.

People have been interested in flying for a very long time. In China, Zhuge Liang used airborne lanterns for military signals during the Three Kingdoms era. In 1709, Bartolomeu de Gusmão made a small paper balloon rise in Lisbon. The most famous early flights happened in France in 1783. The Montgolfier brothers built the first hot air balloon to carry passengers. Their first flight carried a sheep, a duck, and a rooster.

Shortly after, Professor Jacques Charles flew the first gas balloon in December 1783.

Balloons come in many sizes and types for different jobs.

Scientific gas balloons can fly over 100,000 feet into the air. Some are zero-pressure balloons that swell as they rise. Others are superpressure balloons that stay the same size and can fly for months. In the 19th century, people often used coal gas because it was cheap. Today, helium is the main gas used for most manned trips. Some balloons are even tethered to the ground with a rope for safety.

You can think of a balloon like a floating bubble in a pool. Just as a bubble rises through water, a balloon rises through the air.

It is much different from an airship, which has an engine to move itself. While an airship can steer, a balloon must follow the wind's path. This makes ballooning a unique way to see the world from above. Whether for sport or science, they help us reach the sky.

A balloon is an unpowered aerostat that stays aloft through buoyancy.

Buoyancy is the force that allows an object to float in a fluid, like air or water. A balloon consists of a large fabric envelope filled with a lifting gas. This gas must be lighter than the surrounding atmosphere. Because the entire balloon is less dense than the air around it, it rises. Most balloons feature a basket, gondola, or capsule suspended underneath. This structure carries passengers or a payload, such as telescopes or cameras.

Unlike an airship, a balloon has no propulsion system to move itself. It moves entirely with the wind. However, pilots can achieve a degree of directional control. They do this by changing altitude to find wind currents moving in different directions.

There are three primary types of balloons based on how they achieve lift. The first is the hot air balloon, also known as a Montgolfière. This type obtains buoyancy by heating the air inside the envelope. As air is heated, it expands, meaning a specific volume contains less air and becomes lighter. The second type is the gas balloon, or Charlière. These are inflated with gases that have a lower molecular weight than the ambient atmosphere.

The third type is the Rozière balloon. This combination type uses two separate gasbags. One bag holds a heated gas, while the other holds an unheated lifting gas. This design allows for better altitude control during long-distance flights.

Gas balloons function using specific lifting gases. Historically, hydrogen was used extensively because it provides great lift. However, hydrogen is highly flammable, so it is seldom used today after the Hindenburg disaster. In the nineteenth and early twentieth centuries, many used coal gas. Coal gas was cheaper and more available, though it provided only about half the lift of hydrogen. Today, helium is the standard for most manned gas balloons and airships because it is safe. Other gases like ammonia or methane have been tested, but they have poor lifting capacity.

Scientific missions often use unmanned gas balloons to reach much higher altitudes.

Scientists use two distinct sub-types of light-gas balloons. Zero-pressure balloons are the traditional version. They are partially inflated so the internal gas pressure matches the external atmospheric pressure. As the balloon rises, the gas expands and the envelope swells. At night, the gas cools and contracts, causing the balloon to sink. To manage this, pilots must release gas when too high or drop ballast weights when too low. This process limits their flight to a few days. In contrast, superpressure balloons use a tough, inelastic envelope. They are filled to a pressure higher than the outside air. This allows them to maintain a constant volume and altitude. Superpressure balloons can stay aloft for months, often lasting until ground control commands them to open the envelope.

High-altitude balloons serve critical roles in science and observation. Some can fly over 100,000 feet, which is about 30.5 kilometers, into the air. These are often designed to burst at a specific altitude. When they burst, a parachute deploys to bring the payload safely back to Earth. Other specialized versions include cluster ballooning, which uses many small gas-filled balloons for flight.

Some balloons are also tethered to a fixed point on the ground. Tethered balloons are used for military observation, meteorology, or commercial purposes. In windy conditions, these are often shaped aerodynamically and called kite balloons to keep them stable.

Ballooning has a long and fascinating history. Unmanned versions, like Kongming lanterns, were used in China for military signaling during the Three Kingdoms era. In 1709, Bartolomeu de Gusmão demonstrated a small hot air balloon in Lisbon. The modern era of ballooning began in France in 1783. Joseph and Etienne Montgolfier built the first hot air balloon to carry passengers. Their first flight on September 19, 1783, carried a sheep, a duck, and a rooster.

Later that year, on December 1, Professor Jacques Charles flew the first gas balloon. His hydrogen flight covered 27 miles and lasted over two hours. These early pioneers paved the way for all modern aeronautics.

One notable figure in balloon history was Pilâtre de Rozier. He realized that long-distance flight required better altitude control. He developed the Rozière design to use both hot air and gas. However, his attempt to cross the English Channel in 1785 ended in tragedy when his hydrogen bag caught fire. He became known as "The First to Fly and the First to Die." It took until the 1980s for technology to make the Rozière type safe by using non-flammable helium. Today, balloons connect to many fields, from weather tracking to recreational sport, continuing to help us explore the atmosphere.