With 500+ balloons taking off in a 2 – 3 hour window, I wondered how it all happened so seamlessly. We asked a pilot when were they taking off. He said “When they tell us to”. And he pointed at the Zebra people! There are at least 2 zebra people per row of balloons and they are on headsets to coordinate with each other and launch control. They also move spectators out of the way. If you hear a whistle, look around you may be in the way of a balloon!