What are Lighter-Than-Air Craft or Aerostats?
An aircraft is anything that flies. A lighter-than-air craft is any vehicle that flies because it is lighter than air. This includes (a) balloons and (b) airships, also known as dirigibles. Lighter-than-air craft are also known as aerostats, a term which is derived from the ancient greek words “aer” and “statos”, i.e. standing or staying in the air. What makes a vehicle lighter than air, is the fact that it uses a lifting gas (i.e. helium or hot air) in order to be lighter than the surrounding air. The difference between airships and balloons are the following: Balloons simply follow the direction of the winds. In contrast, airships are powered and have some means of controlling their direction, usually with rudders.
