Science and Hot Air Balloons
Since the 1890s scientists have been using balloons for meteorological research.
Research balloons
In the 1930's, a device called the radiosonde (a very small radio transmitter) was invented. This enabled scientists to gather data without having to retrieve the balloon once it had landed.
These days, small balloons containing sensitive instruments are regularly launched and followed using tracking instruments to gather information from Earth's atmosphere.
Astronomers and physicists also use large balloons made from an extremely tough material called Astrofilm E. These balloons are sometimes several hundred metres tall and float right to the edge of Earth's protective atmosphere, to collect information about cosmic and gamma rays. Their reusable instrument packages are released by remote control so the package can float down to Earth attached to a parachute. These are not hot air balloons, but sealed balloons filled with lighter than air helium or hydrogen gas.