The hot air balloon is the oldest successful human-carrying flight technology, dating back to its
invention by the Montgolfier brothers in Annonay, France in 1783. The first flight carrying humans
was made on November 21, 1783, in Paris by Jean-François Pilâtre de Rozier and
François Laurent d'Arlandes.
Hot air balloons that can be propelled through the air rather than just being pushed along by the wind
are known as airships or, more commonly, thermal airships.
A hot air balloon consists of a bag called the envelope that is capable of containing heated air.
Suspended beneath is the gondola or wicker basket (in some long-distance or high-altitude balloons,
a capsule) which carries the passengers and a source of heat. The heated air inside the envelope
makes it buoyant since it has a lower density than the relatively cold air outside the envelope.
Unlike gas balloons, the envelope does not have to be sealed at the bottom since the rising hot air
only exerts pressure on the upper hemisphere of the balloon to provide lift. In today's sport balloons
the envelope is generally made from nylon fabric and the mouth of the balloon (closest to the burner
flame) is made from fire resistant material such as Nomex.
Recently, balloon envelopes have been made in fantastic shapes, such as hot dogs, rocket ships,
and the shapes of commercial products.