last changed : 04.04.2004
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last changed : 04.04.2004
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The black balloon pickup the thermal energy from the sun. The air within it will heat up and become "lighter than ambient". The balloon is then able to lift a payload around 2 kg (with - 8°C outside temperature, the 4m balloon of Bastien had lifted more than 3 kg !). the envelope is about 1 kg. Loaded with 500 gr, it can go up to more than 18000m (test from Gérard Auvray the 6 July 1997). The balloon is a hot air balloon, meaning it is opened at the bottom. It doesn't explode at altitude. It will stays aloft as long as there is enough sun to heat the air inside the balloon.
Example : Balloon with 1/2 angle at bottom 40 °, no valve. Difference of temperatures more than 20°C and so a lift of around 90 g/m3. PE 20 microns.
| Dia- meter m |
Area square meter |
Volume cubic meter |
Nb of pieces |
Length of one piece meter |
Plastic length meter |
Lift kg |
Thick weight kg |
Adhesive weight kg |
Payload max. kg |
| D | S | V | F | L | FxL | Vx0,090 90g/m3 |
Sx20gr/m2 | FxLx2,5gr/m | Lift - PE - adhesive - basket |
| 4,00 | 52,32 | 35,14 | 6 | 6,55 | 39,33 | 3,16 | 1,05 | 0,10 | 1,92 |
More the outside air is cold and dense heavier will be the load lifted.
The best results will be on
the snow (high albedo)
during high pressure (anticyclonic).
To learn more ,
Solar balloon Theory (in french)