Hot Air Balloon

A hot air balloon is a lighter-than-air object made up of an envelope-like bag that holds heated air.
A wicker basket, gondola, or capsule suspended below transports people and a heat source, typically an open flame produced by burning liquid propane. A tablet also carries passengers in some long-distance or high-altitude balloons.
Since the warm air inside the envelope has a lower density than the cooler air outside, it is buoyant.
Hot air balloons cannot travel higher than the atmosphere, like all other aircraft types.
Since the air within the envelope is at a similar pressure to the air outside, the bottom of the envelope does not need to be sealed.

Modern sport balloons typically have a nylon fabric envelope, with a fire-resistant material, such as Nomex, near the balloon’s inlet (which is closest to the burner flame).
Although the classic shape is utilized for the majority of non-commercial and many commercial purposes, modern balloons have been created in a variety of designs, including rocket ships and the shapes of numerous commercial objects.