On the threshold of the 21st century...

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The technology Improving the systems efficiency

MORE RELIABLE TECHNOLOGICAL FOUNDATIONS The design principle behind Rozier balloons has proved its worth. Apart from meteorological factors, the remaining problems are essentially due to an imprecise evaluation of the interdependence between fuel consumption and the thermal differences on the helium cell.

The Breitling Orbiter 3 is a mixed balloon, or Rozier balloon, meaning a combination of a hot-air balloon and a gas balloon, characterized by a helium cell placed within the hot-air envelope.

Initially, the helium cell is filled to only 47% of its maximal capacity. During the ascension, the drop in atmospheric pressure and the expansion of gas due to the effect of the sun make the helium increase in volume and the balloon can thus gain altitude. If the expansion effect is too strong, some gas must be freed in order to curb the ascension and avoid the balloon exploding. Consequently, for such a long trip, the quantity of helium on arrival is reduced to a fraction of the initial quantity.

When night falls, the drop in temperature leads to a contraction of helium and a progressive drop in altitude. Lighting the burners makes it possible to heat up the helium and thus to stabilize the altitude of the balloon.

On the threshold of the 21st century...

Contents

Improving the systems efficiency The technology