Research balloons are balloon

Balloon

A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig...

s that are used for scientific research. They are usually (though not always) unmanned, filled with a lighter-than-air gas like helium

Helium

Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...

, and fly at high altitudes

High altitude balloon

High-altitude balloons are unmanned balloons, usually filled with helium or hydrogen that are released into the stratosphere, generally reaching between ....

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Meteorology, atmospheric research, astronomy, and military research may be conducted from a research balloon.
Weather balloon

Weather balloon

A weather or sounding balloon is a balloon which carries instruments aloft to send back information on atmospheric pressure, temperature, humidity and wind speed by means of a small, expendable measuring device called a radiosonde...

s are a type of research balloon. Research balloons usually study a single aspect of science, such as air pollution, air temperature, or wind currents, although sometimes several experiments or equipment are flown together.

Other than weather balloons, few research balloons are launched every year. This is driven by the large cost of the balloon, the instrument, which is usually custom made, and the cost of the launch. Because of the altitude reached by most research balloons, the air is too thin and too cold for humans to survive, therefore most research balloons are unmanned and operated remotely. There have been some balloons equipped with pressurized cabins, beginning with professor Auguste Piccard

Auguste Piccard

Auguste Antoine Piccard was a Swiss physicist, inventor and explorer.-Biography:Piccard and his twin brother Jean Felix were born in Basel, Switzerland...

 in the 1930s.

Research balloons are not only used on earth. With the help of a research balloon, the upper atmosphere of Venus was examined by the Vega program

Vega program

The Vega program was a series of Venus missions which also took advantage of the appearance of Comet Halley in 1986. Vega 1 and Vega 2 were unmanned spacecraft launched in a cooperative effort among the Soviet Union and Austria, Bulgaria, Hungary, the German Democratic Republic, Poland,...

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