: Rely entirely on internal gas pressure to maintain their shape.
: Powered, steerable aerostats equipped with engines and control surfaces like rudders and elevators for navigation. lighter-than-air craft
: Feature an internal structural framework that holds the gas cells and maintains the ship's shape regardless of gas pressure. : Rely entirely on internal gas pressure to
: Unpowered aerostats that drift with the wind or are tethered in place. Pilots primarily control altitude by adjusting the gas temperature or releasing ballast. lighter-than-air craft
LTA vehicles are broadly categorized into unpowered and powered versions: