A hot air balloon is a flying craft with a large balloon-shaped upper part and a basket-like lower part.

Hot air balloons use hot air as the lifting gas. A large opening at the bottom of the balloon allows for inflating with hot air and letting cold air enter. When air is heated, its density decreases.

Modern hot air balloons are equipped with basic flight instruments, fuel tanks, and burners in the basket. To ascend from the ground, the burner is ignited, heating the air which is then directed into the balloon through the opening at the bottom. During flight, the pilot controls the ascent or descent by regulating the amount of fuel fed to the burner.

The hot air balloon's sole source of propulsion is the wind. For hot air balloons attempting global flights, it is crucial to select high-altitude wind currents with suitable speed and direction and move with them to efficiently complete the journey.

Just as one would need to change planes continuously during a round-the-world trip, hot air balloons must hitch rides on different air currents. When "changing currents," the pilot's task is to adjust the altitude. Hot air balloons typically need to reach heights of tens of kilometers.

In the 18th century, the Montgolfier brothers, French paper manufacturers, invented the hot air balloon. Inspired by the constant rising of paper scraps in a fire, they conducted experiments using paper bags to gather hot air, enabling the bags to ascend with the airflow. On June 4, 1783, the Montgolfier brothers publicly demonstrated a simulated balloon with a circumference of 110 feet in Lyon's Annonay Square, which flew gracefully for 1.5 miles.

On September 19 of the same year, in front of the Palace of Versailles in Paris, they performed a hot air balloon ascent for the king, queen, court ministers, and 130,000 Parisians.

On the afternoon of November 21 of the same year, the Montgolfier brothers conducted the world's first manned hot air balloon flight at the Muette Castle in Paris, flying for 25 minutes and crossing half of Paris before landing near the Place des Victoires. This flight predates the Wright brothers' airplane flight by a full 120 years. Regarding gas-filled balloons, the Robert brothers of France were the first to ascend into the sky aboard a balloon filled with hydrogen.

After 1945, advancements in technology popularized materials for balloon envelopes and heating fuels, making hot air balloons a convenient and simple public recreational activity unrestricted by location. From August 11 to 17, 1978, "Double Eagle III" successfully crossed the Atlantic Ocean, and in 1981, it successfully crossed the Pacific Ocean.

The International Aeronautical Federation once ranked hot air balloons as the safest aircraft. Looking at the data alone, hot air balloons indeed have a high safety coefficient. It is estimated that there are around 20,000 hot air balloons worldwide. In developed countries such as Europe and America, hot air ballooning is a popular sport, with balloon races or events almost every day.

With the development of hot air ballooning, technological elements continue to be integrated into the sport, reflected in the equipment used and the theoretical and practical training of pilots, among other aspects, achieving qualitative leaps.

The history of hot air balloons is like a brilliant chapter, from the Montgolfier brothers' initial attempts to the present high-tech era. Hot air balloons have always carried the dreams and pursuits of humanity for flight. They are not only a means of transportation but also a charming sport, attracting countless enthusiasts. While pursuing safety, convenience, and enjoyment, hot air ballooning continues to evolve and improve.

Technological advancements inject new vitality and possibilities into the sport. Whether challenging the limits with global flights or enjoying leisurely excursions, hot air balloons, with their unique charm, continue to lead humanity toward the dream of soaring freely in the sky.