Aerostat
Overview
 
An aerostat (From Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 ἀήρ aer (air) + στατός statos (standing) through French) is a craft that remains aloft primarily through the use of buoyant
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...

 lighter than air
Lighter than air
Lighter than air refers to gases that are buoyant in air because they have densities lower than that of air .Some of these gases are used as lifting gases in lighter-than-air aircraft, which include free balloons, moored balloons, and airships, to make the whole craft, on average, lighter than air...

 gases, which impart lift to a vehicle with nearly the same overall density as air. Aerostats include free balloons
Balloon (aircraft)
A balloon is a type of aircraft that remains aloft due to its buoyancy. A balloon travels by moving with the wind. It is distinct from an airship, which is a buoyant aircraft that can be propelled through the air in a controlled manner....

, airship
Airship
An airship or dirigible is a type of aerostat or "lighter-than-air aircraft" that can be steered and propelled through the air using rudders and propellers or other thrust mechanisms...

s, and moored balloon
Moored balloon
A moored balloon is an inflated fabric structure, often shaped like an airship and usually filled with helium, that is restrained by a cable attached to the ground or a vehicle. Moored balloons differ from airships and free balloons in that it is not free-flying.Moored balloons are sometimes...

s. An aerostat's main structural component is its envelope, a lightweight skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...

 containing a lifting gas
Lifting gas
Because of the Archimedes' principle, a lifting gas is required for aerostats to create buoyancy. Its density is lower than that of air . Only certain lighter than air gases are suitable as lifting gases.- Hot Air :...

 to provide buoyancy
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...

, to which other components are attached.
 
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