Types of balloon aircraft
There are three main types of balloon aircraft:
* Hot air balloons obtain their buoyancy by heating the air inside the balloon. They are the most common type of balloon aircraft.
* Gas balloons are inflated with a gas of lower molecular weight than the ambient atmosphere. Most gas balloons operate with the internal pressure of the gas being the same as the pressure of the surrounding atmosphere. There is a special type of gas balloon, called a superpressure balloon, that can operate with the lifting gas at pressure that exceeds the pressure of the surrounding air, with the objective of limiting or eliminating the loss of gas from day-time heating. Gas balloons are filled with gases such as:
o hydrogen - not widely used for aircraft since the Hindenburg disaster because of high flammability (except for some sport balloons as well as nearly all unmanned scientific and weather balloons).
o helium - the gas used today for all airships and most manned balloons.
o ammonia - used infrequently due to its caustic qualities and limited lift.
o coal gas - used in the early days of ballooning; it is highly flammable.
* Roziere balloons use both heated and unheated lifting gases. The most common modern use of this type of balloon is for long-distance record flights such as the recent circumnavigations.
History:
The hot air balloon Kongming lantern was developed for military communication service around the 2nd or 3rd century AD in China. Later, this kind of hot air balloon was very popular among children and at carnivals.
It has been proposed that some ancient civilizations developed manned hot air balloon flight. For example, it has been proposed that the Nazca lines (which are best seen from the air) presuppose some form of manned flight, and that a balloon was the only possible available technology that could have achieved this.
In 1709 in Lisbon, Bartolomeu de Gusmão made a balloon filled with heated air rise inside a room. He also made a balloon named Passarola (Portuguese: Big bird) and attempted to lift himself from Saint George Castle in Lisbon, but only managed to harmlessly fall about one kilometre away. This was the first man ever to fly in human history.
Following Henry Cavendish's 1766 work on hydrogen, Joseph Black proposed that a balloon filled with hydrogen would be able to rise in the air.
The first recorded manned balloon flight was made in a hot air balloon built by the Montgolfier brothers on November 21, 1783. The flight started in Paris and reached a height of 500 feet or so. The pilots, Jean-François Pilâtre de Rozier and Francois Laurent (the Marquis of d'Arlanders), covered about 5 1/2 miles in 25 minutes.
Only a few days later, on December 1, 1783, Professor Jacques Charles and Nicholas Louis Robert made the first gas balloon flight. Like the first hot air balloon flight, this flight left from Paris. The hydrogen filled balloon flew to almost 2,000 feet (600 m), stayed aloft for over 2 hours and covered a distance of 27 miles (43 km), landing in the small town of Nesle.
Once flight was shown to be possible, the next great challenge was to fly across the English Channel. The feat was accomplished on January 7, 1785 by Jean-Pierre Blanchard, a Frenchman, and American John Jeffries, who sponsored the flight.
The first aircraft disaster occurred in May 1785 when the town of Tullamore, County Offaly, Ireland was seriously damaged when the crash of a balloon resulted in a fire that burned down about 100 houses, giving the town the unusual distinction of being home to the world's first aviation disaster. To this day, the town shield depicts a phoenix rising from the ashes.
Blanchard went on to make the first manned flight of a balloon in America on January 9, 1793. His hydrogen filled balloon took off from a prison yard in Philadelphia, Pennsylvania. The flight reached 5,800 feet (1,770 m) and landed in Gloucester County, New Jersey. President George Washington was among the guests observing the takeoff.
Gas balloons became the most common type from the 1790s until the 1960s.
The first steerable balloon (also known as a dirigible) was attempted by Henri Giffard in 1852. Powered by a steam engine, it was too slow to be effective. Like heavier than air flight, the internal combustion engine made dirigibles – especially blimps – practical, starting in the late 19th century. Alberto Santos Dumont made the first application of an internal combustion motor in aviation's history. He produced and flew in a dirigible using a gas engine.
Ed Yost reinvented the design of hot air balloons in the late 1950s using rip-stop nylon fabrics and high-powered propane burners to create the modern hot air balloon. His first flight of such a balloon, lasting 25 minutes and covering 3 miles (5 km), occurred on October 22, 1960 in Bruning, Nebraska.
Yost's improved design for hot air balloons triggered the modern sport balloon movement. Today, hot air balloons are much more common than gas balloons.
Balloons as flying machines:
A balloon is conceptually the simplest of all flying machines. The balloon is a fabric envelope filled with a gas that is lighter than the surrounding atmosphere. As the entire balloon is less dense than its surroundings, it rises, taking along with it a basket, attached underneath, that carries passengers or payload. Although a balloon has no propulsion system, a degree of directional control is possible through making the balloon rise or sink in altitude to find favorable wind directions.
The first balloons capable of carrying passengers used hot air to obtain buoyancy and were built by the brothers Josef and Etienne Montgolfier in Annonay, France.
Balloons using the light gas hydrogen for buoyancy were flown less than a month later. They were invented by Professor Jacques Charles and first flown on December 1, 1783. Gas balloons have greater lift and can be flown much longer than hot air, so gas balloons dominated ballooning for the next 200 years. In the 19th century, it was common to use town gas to fill balloons; it was not as light as pure hydrogen gas, but was much cheaper and readily available.
The third balloon type was invented by Pilâtre de Rozier and is a hybrid of a hot air and a gas balloon. Gas balloons have an advantage of being able to fly for a long time, and hot air balloons have an advantage of being able to easily change altitude, so the Rozier balloon was a hydrogen balloon with a separate hot air balloon attached. In 1785, Pilâtre de Rozier took off in an attempt to fly across the English Channel, but the balloon exploded a half-hour into the flight. This accident earned de Rozier the title "The First to Fly and the First to Die". It wasn't until the 1980s that technology once again allowed the Rozier balloons to become feasible.
Jean-Pierre Blanchard made the first piloted balloon flight in North America on January 9, 1793.
Both the hot air, or Montgolfière, balloon and the gas balloon are still in common use. Montgolfière balloons are relatively inexpensive as they do not require high-grade materials for their envelopes, and they are popular for balloonist sport activity.
Light gas balloons are predominant in scientific applications, as they are capable of reaching much higher altitudes for much longer periods of time. They are generally filled with helium. Although hydrogen has more lifting power, it is explosive in an atmosphere full of oxygen. With a few exceptions, scientific balloon missions are unmanned.
There are two types of light-gas balloons: zero-pressure and superpressure. Zero-pressure balloons are the traditional form of light-gas balloon. They are partially inflated with the light gas before launch, with the gas pressure the same both inside and outside the balloon. As the zero-pressure balloon rises, its gas expands to maintain the zero pressure difference, and the balloon's envelope swells.
At night, the gas in a zero-pressure balloon cools and contracts, causing the balloon to sink. A zero-pressure balloon can only maintain altitude by releasing gas when it goes too high, where the expanding gas can threaten to rupture the envelope, or releasing ballast when it sinks too low. Loss of gas and ballast limits the endurance of zero-pressure balloons to a few days.
A superpressure balloon, in contrast, has a tough and inelastic envelope that is filled with light gas to pressure higher than that of the external atmosphere, and then sealed. The superpressure balloon cannot change size greatly, and so maintains a generally constant volume. The superpressure balloon maintains an altitude of constant density in the atmosphere, and can maintain flight until gas leakage gradually brings it down.
Superpressure balloons offer flight endurance of months, rather than days. In fact, in typical operation an Earth-based superpressure balloon mission is ended by a command from ground control to open the envelope, rather than by natural leakage of gas.
For air transport balloons must contain a gas lighter than the surrounding air. There are two types:
* Hot air balloons: filled with hot air, which by heating becomes lighter than the surrounding air; they have been used to carry human passengers since the 1790s;
* Balloons filled with:
o hydrogen - highly flammable
o helium - safe if used properly, but very expensive.
Large helium balloons are used as high flying vessels to carry scientific instruments (as do weather balloons), or even human passengers.
Cluster ballooning uses many smaller gas-filled balloons for flight.
Hot air balloon festivals are held annually in many places throughout the year, and give a chance for balloonists to participate in balloon races and display their balloons during evening balloon glows, and for the public to participate in the spectacle of many balloons gathered in one spot and to learn about the sport.
Following are the name of most famous Balloon Festivals
Novotel Balloon Fiesta Australia
US National Hot Air Balloon Championship Anderson, South Carolina
National Balloon Classic Indianola, Iowa
Albuquerque International Balloon Fiesta Albuquerque, New Mexico
National Balloon Rally Statesville, North Carolina
World Hot Air Balloon Championship Tochigi, Japan
Adirondack Hot Air Balloon Festival Glens Falls, New York
Great Forest Park Balloon Race Saint Louis, Missouri
Helen to the Atlantic Balloon Race Helen, Georgia
