Before the balloon is launched, the pilot knows which way the wind is blowing. This means that she has a general idea about which way the balloon will go. But, sometimes the pilot can actually control the direction that the balloon flies while in flight. This is because the air above the ground is sectioned into layers in which the direction of the wind may be different. So even though the pilot can't steer the balloon, she can fly or higher or lower into a different layer of air. Some days the difference between the direction of the wind between layers is negligible. But other days the difference is so strong that it can actually push the balloon in a completely different direction!