last changed : 01/10/2003

The thunder cell, the stratospheric balloon

Jean-Paul Domen has invented a revolutionary hot air balloon.
"At the beginning, I wanted to make a solar balloon. I didn't know it was already made and even distributed by the kid magazine Pif Gadget : some plastic trash bags to build a black screen, adhesive tape to put together the envelope. Build it in my kitchen ... Launch... and a ridiculous result : my toy got into a tangle at the top of the TV antenna of my neighbor ... any way, it flew for a short while. From this time, I have extrapolated to build a solar balloon able to lift a human to a high altitude. Computing all that I noticed that the needed energy increase faster with the balloon size than the energy actually intercepted. To sum-up the bigger the balloon the slower it rise. So we need an energy proportional to the volume.
It is into the huge quantity of energy available in the thunder storms that Jean-Paul DOMEN found the solution : into a cumulonimbus cloud vertical velocity can reach 100m/s because of the heat generated by the condensing water vapor.
The rest is easy to guess : "and what if we'd do the same into the balloon enclosing a small cloud?".
The thunder cell balloon was born.
The water vapor is stored into the envelope. During the ascent the sun heat up the air and when the "point de rosée" (dew point altitude) is reached (during a sunny summer day around 2000m altitude), it is mainly the condensing of the water vapor that provide the needed energy to continue the ascent.
Jean-Paul DOMEN, independent engineer, docteur-ingénieur Sup'Aéro, has made a vapor generator adapted to this project then performed some flight with the balloon "Bulle d'Orage" (thunder cell) during the years 1992 to 1996.
Most of those test have been realized under the control of CNES (Centre National d'études Spatiales) (sort of French N.A.S.A) and the goal was to lift a heavy load into the stratosphere :

• 15 May 1992, a load 1 kg under a balloon 30m3 rise up to an altitude of 18000m,
• 6 May 1993, a balloon 600m3 lift a load of 40 kg to 12200m,
• February 1996, a balloon 8000m3, 25m diameter lift a load of 270 kg at an altitude of 12000m

For more information about the "Bulle d'Orage" balloon ...
- 1994-1995 article
- Jean-Paul DOMEN patent (in french)

The leisure solar hot air balloon

Summer 1996, Jean-Paul DOMEN performs the first free flight of a solar balloon on a distance of 300m the balloon was 16m diameter inflated with ambient air (without adding vapor ).. It is a simple envelope made of black polyethylene thickness : 15 microns. A valve 2,5m diameter is fitted at the top. The bottom opening is about 2m wide ; a propeller driven by an electric motor permit to inflate / deflate the balloon to control the altitude.
For more information about the "la montgolfière solaire de loisir" balloon :
- Jean-Paul DOMEN patent (in french) - Acrobat Reader - 330Ko - "save it to disc" then decompress it with Winzip.

Jean-Paul DOMEN didn't found the funds to continue on this project so he switched to more profitable research about sea water desalinization.