The Gordon Bennett race (https://en.wikipedia.org/wiki/Gordon_Bennett_Cup_(ballooning)) is the oldest and the most popular gas balloon race.
We have developped a model that captures the trajectory of a gas balloon. With some sensors installed in the gondola we can anticipate potential instable atmospheric situations and predict the sand and gas consumption.
Moreover, we have developped tools to predict the trajectory of a balloon.
See Fribourg Freiburg Challenge for some nice pictures and videos.