A boat will float on water because its weight is less than the weight of the water it displaces. The same happens with a hot air balloon, the pilot will heat the air in the balloon lighter than the cold air outside the balloon. The whole balloon becomes lighter than the air outside it which will cause it to float like a boat on the water.
Hot air is lighter than cold air
Make a really large ballon with space for people and fuel on the bottom
Burn the fuel in some sort of burner to heat the air and make the balloon lighter and go up, pull cables that releases some of the hot air to come down
Now that you can control height you can use different winds at different height to control sideways motion
Latest Answers