There are generally two main types of aerostats - fixed balloons and airships. Fixed balloons have a gondola suspended below the main gas bag but lack a propulsion system, requiring them to remain relatively stationary. Airships, on the other hand, have onboard propulsion that allows limited maneuverability and mobility while airborne. https://www.coherentmarketinsights.com/market-insight/aerostat-system-market-4831