8 August 2005
Mission success
The Casolba* flight was a complete success, with no less than 47 measurement-gathering sessions. All measurements were highly satisfactory. The mission objective was to use a stratospheric balloon flight to calibrate solar cells.

After 2 hours 30 minutes of data gathering at an altitude of around 35 kilometres and in varying temperature conditions, the balloon gondola was recovered by helicopter. The solar cells were found to be in excellent condition.
Once analysis of the flight data is complete, the measurements and solar cells will serve as a reference to adjust solar simulators on the ground.
They will also be used to model the behaviour of new-generation solar cells and to size satellite solar arrays more precisely.
A unique service
Solar cells are under constant development, so there is a regular need for calibration services from customers all over the world.
Industrial contractors and space agencies — from Alcatel to Spectrolab, and Esa to the Japanese Aerospace Exploration Agency Jaxa — need precise data on how photovoltaic components behave beyond Earth’s atmosphere in near-space solar radiation conditions.
Industrial contractors and space agencies — from Alcatel to Spectrolab, and Esa to the Japanese Aerospace Exploration Agency Jaxa — need precise data on how photovoltaic components behave beyond Earth’s atmosphere in near-space solar radiation conditions.

CNES is the only European organization and one of only 2 in the world to offer this type of service (Nasa is the other).
CNES has offered solar cell calibration services using stratospheric balloon flights since 1975. This activity is important in both commercial and strategic terms.
The use of stratospheric balloons is one of CNES’s unique strengths. For the last 4 decades, CNES has made balloons available to the scientific community at a rate of around 30 to 40 launches per year.
Balloons provide a cheap and effective way to conduct space experiments, study the atmosphere and validate satellite data.
* Casolba: CAlibration of SOLar cells using a BAlloon flight