Since 1977, the french CNES (Centre National d'Études Spatiales - sort of French
N.A.S.A) developed the MIR balloon for the stratospheric long duration scientific
During the day, the MIR balloon flies at an altitude of about 28 km to 32 km and during night between 18 et 22 km depending on the infrared flux radiating from the over flown area and the temperature of the air at the flight altitude. They can carry a payload of about 50 kg. The route follow the stratospheric wind. Enough for more than on turn around the world...
The MIR is a hot air balloon "open at the bottom" with an helium complement
at takeoff. With their reflective cover, those balloons from 35 000 m3
to 45 000 m3 are heated only by the heat from the sun during the day or
the infrared radiation from the earth during the night. The "passive"
heater heat the air within the balloon, giving some lift to the vehicle
made by ZODIAC INTERNATIONAL, the MIR is made of 2 different made in a
material presenting a good compromise between optic-thermal properties
- The top part is made of aluminized Mylar 12 µm thick making a cavity for absorbing ascendants infrared and block any re emission toward the sky.
- The bottom part is made of linear polyethylene 15µm thick ,an infrared transparent material and tough at cold (temperature inferior to -80°C) during the flight.
The sketch shows the radiation of the MIR balloon :
For more about MIR balloons (in french) :
- consultez un communiqué du CNES du 11 Mai 2001
- consultez un communiqué du CNES du 24 mars 2004
- consultez le site du CNES