Inflatable structures are in practice not that common because they are challenging to design with sufficient rigidness and durability. In the case of proper design can such structures have many advantages. Usually they are lighter and cheaper, in the application of radome however it also important that they do not disturb any of the incoming electromagnetic signals. Since radomes are placed in the environment they are exposed to natural elements. Here we present the theory necessary to mechanically evaluate inflatable shell structures, analytical and experimental validation cases and numerical model to analyse radome. Specifics of spherical geometry cause interesting deformational shapes when under compression. Such structure, when exposed to a load that is beyond critical, loses a lot of its load-bearing capabilities. Due to this we also present a method to determine critical load.