Balloon

 Balloon, vehicle that can rise within Earth's atmosphere because its total weight is less than that of the air it displaces. This principle was first enunciated by Greek mathematician and inventor Archimedes.

Balloon Festival
Gatineau hot air balloon festival/ Festival de montgolfi\u00e8res de Gatineau (panorama by Denis Tremblay, Labtex).

Balloon

Balloon, vehicle that can rise within Earth's atmosphere because its total weight is less than that of the air it displaces. This principle was first enunciated by Greek mathematician and inventor Archimedes. The necessary lift or buoyancy is obtained by filling an envelope with a gas lighter than air (eg, hydrogen, helium, heated air).

The dream of flying was realized in 1783, when a duck, a sheep and a rooster were sent aloft in a basket hanging under a balloon constructed of paper and fabric. On 15 October of that year, a few months after the duck's historic flight, scientist François Pilâtre de Rozier rose 250 ft beneath his tethered balloon, "Aerostat Reveillon." It stayed aloft for 15 minutes and then landed safely nearby.

The first manned balloon flight was made over Paris on 21 November 1783 by François Pilâtre de Rozier and the Marquis d'Arlandes in a gondola beneath a cloth and paper envelope, inflated by air heated by a fire hung below it. The balloon was constructed by the Montgolfier brothers. Ten days later, French scientist J.A.C. Charles and his assistant flew about 43 km suspended beneath a hydrogen-filled silk-and-rubber balloon, returning safely to Earth.

This balloon incorporated many features of a modern gas-filled balloon, eg, an open-necked envelope allowing for gas expansion, a top-mounted gas-release valve and a supply of ballast for altitude control. Many significant flights followed, as ballooning developed military, sporting and scientific applications.

Within about 10 years of the first manned flights, tethered balloons were being used as military observation posts, while free balloons were used as somewhat unpredictable delivery systems for passengers, bombs and messages during long sieges. In WWI, bombing of civilian and military targets from airships changed the nature of warfare. Tethered barrage balloons protected strategic targets from low-level aircraft attack during WWII.

In the 20th century, powered airships were used extensively for passenger transportation, until the Hindenburg disaster in 1937 demonstrated the danger of using highly flammable and explosive hydrogen as lift gas. Balloons are still used as heavy-lift vehicles in remote, inaccessible areas (eg, logging operations in BC forests). Modern variants of the airship, lifted by the light but inert gas helium, are used as platforms for television cameras at sporting events, spectacular advertising billboards and, more recently, passenger vehicles on tourist flights across major cities.

Balloon-flying has always had a sporting component, with rallies, races and long-duration flights catching the public imagination. In the 1960s, development of the modern hot-air balloon, with a strong, light nylon envelope inflated by hot air from a reliable propane burner, led to a resurgence of interest in the sport and a growth in commercial flights for passengers and for advertising. The first hot-air crossing of the Atlantic was made in 1978 by the Double Eagle II, a helium balloon carrying Ben Abruzzo, Maxie Anderson and Larry Newman. The team set a new balloon flight duration record of 137 hours. In 1981, the 13-storey high Double Eagle V, piloted by Ben Abruzzo, Larry Newman, Ron Clark and Rocky Aoki launched from Nagashimi, Japan on 10 November, landing 84 hrs, 31 mins later in Mendocino National Forest, California. They set a new distance record of 5768 miles.

The first hot-air balloon crossing of the Atlantic was made in 1987 by Per Lindstrand and Richard Branson, who flew 2900 miles in 33 hours to set a new record for hot-air ballooning. The balloon was 2.3 million cubic feet of capacity, the largest ever flown at the time. In 1991, the same team became the first to traverse the Pacific by hot air balloon, reaching speeds in the jet stream of up to 245 mph in their "Otsuka Flyer," travelling 6700 miles in 46 hours. They broke the world distance record with their flight from Japan to the Canadian Arctic.

The challenge of an around-the-world balloon flight was an elusive one until 20 March 1999, when Bertran Piccard of Switzerland and Brian Jones of Britain completed the first circumnavigation of the globe by balloon. The flight had been attempted unsuccessfully 3 times by American multi-millionaire Steve Fossett.

In science, routine meteorological soundings (atmospheric temperature, moisture content, wind speed and direction) by small instrument packages on rubber balloons are an essential part of modern global weather forecasting. The modern scientific balloon is a huge but extremely thin polyethylene envelope, reinforced with nylon tapes and inflated with helium. It can place instruments within the layers of interest for atmospheric studies or above absorbing and turbulent layers for astronomical observations. Balloon-borne instrumentation has led to advances in atmospheric pollution studies, cosmic ray research, X-ray and infrared astronomy and high-resolution photography of astronomical sources, including the sun.

X-ray measurements from smaller balloons during auroral displays have been important in unravelling the complex interactions of the solar wind with Earth's magnetic field, which cause the northern lights. In biology, balloons have often provided silent platforms for the observation of wild animals in their undisturbed habitat.

Support agencies for scientific ballooning in Canada are the Canadian Space Agency and the Atmospheric Environment Service of Environment Canada. Scientists from the latter agency have carried out regular stratospheric monitoring flights since 1974, while the universities of Calgary, Saskatchewan and Toronto and York University have been active in astronomical, aeronomical and atmospheric research from balloons, using launch sites at Churchill and Gimli, Man and Yorkton and Vanscoy, Sask.


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