Uncrewed aerostats can carry instruments and sensors for long durations that are impractical for humans and other aircraft.

The term "aerostat" has two meanings. In the first, broader sense, it includes all lighter than air aircraft. The USGS blimp. ... The USGS blimp. ... The expression lighter than air refers to objects, usually aircraft, that are buoyant in air because they have an average density that is less than that of air (usually because they contain gases that have a density that is lower than that of air). ...

The term "aerostat" comes from the fact that buoyancy is technically said to provide aerostatic lift in that the force upwards arises without movement through the surrounding air mass. This contrasts with aerodynamic lift which requires the movement of at least some part of the aircraft through the surrounding air mass. In physics, buoyancy is an upward force on an object immersed in a fluid (i. ... Aerodynamics is a branch of fluid dynamics concerned with the study of gas flows, first analysed by George Cayley in the 1800s. ... Lift consists of the sum of all the fluid dynamic forces on a body perpendicular to the direction of the external flow around that body. ...

The second, narrower and more techical usage refers only to moored balloons. This article focuses on the narrower use of the term. For a discussion of the other types of bouyant aircraft, see balloon (aircraft), airship, and lighter than air. Balloons are a type of lighter than air aircraft that remain aloft due to their buoyancy. ... USS Akron (ZRS-4) in flight, 2 November 1931 An airship is a buoyant aircraft that can be steered and propelled through the air. ... The expression lighter than air refers to objects, usually aircraft, that are buoyant in air because they have an average density that is less than that of air (usually because they contain gases that have a density that is lower than that of air). ...

Thus, in the narrower sense, an aerostat is a tethered or moored balloon often shaped like an airship and usually filled with helium. Aerostats differ from airships and balloons in that airships and balloons are both free flying whereas aerostats are tied to the ground. Balloons are given for special occasions, like greeting cards or flowers. ... USS Akron (ZRS-4) in flight, 2 November 1931 An airship is a buoyant aircraft that can be steered and propelled through the air. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Atomic mass 4. ... Balloons are a type of lighter than air aircraft that remain aloft due to their buoyancy. ...

The barrage balloons of World War I and World War II were examples of aerostats. Today, Aerostats are used primarily as long duration sensor platforms. US Marine Corps barrage balloon, Parris Island, May 1942 A barrage balloon is a large balloon used as a defence against aircraft. ... World War I was primarily a European conflict with many facets: immense human sacrifice, stalemate trench warfare, and the use of new, devastating weapons - tanks, aircraft, machine guns, and poison gas. ... World War II was a truly global conflict with many facets: immense human suffering, fierce indoctrination, and the use of new, extremely devastating weapons such as the atom bomb. ...

Surveillance aerostats have also been used in the 2004 American occupation of Iraq. Utilizing a high-tech optics system to detect and observe enemies from miles away and have been used accompanying foot patrols in Baghdad. The 2003 Invasion of Iraq began on March 20 comprising United States and United Kingdom forces (98%), and several other nations. ... Related topic: List of optical topics Optics (appearance or look in ancient Greek) is a branch of physics that describes the behavior and properties of light and the interaction of light with matter. ... Average temperature (red) and precipitations (blue) in Baghdad Baghdad (Arabic: ) is the capital of Iraq and of Baghdad Province. ...

Aerostats in Science Fiction

Aerostats are commonly used in science fiction, though they are often envisioned as having a vacuum based displacement rather than helium; doing such appears to require the construction of a very large craft or the use of super-strong rigid materials. Aerostats of fiction are typically not tied to the ground, but rather remain stationary through the use of propulsion systems and internal sensors and controls. Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... For other uses, see vacuum cleaner and Vacuum (musical group). ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Atomic mass 4. ... The Three Graces, here in a painting by Sandro Botticelli, were the goddesses of charm, beauty, nature, human creativity and fertility in Greek mythology. ...

External Links

TCOM - A leading producer of modern aerostat systems