The lightcraft hull design is similar to the zeppelins of the early 20th century. It is a pressure vessel which supports itself on an exterior tube which surrounds the entire craft.. The interior of the craft is filled with a helium-oxygen mixture (Heliox), effectievly making it bouyant in the atmosphere. The outer hull is actually composed of two layers. The two layer system serve to protect the lightcraft from the extreme temperatures generated when leaving and entering the atmosphere. Because the lightcraft is a pressure vessel filled with Heliox, if a crash landing were to occur, the struture of the lightcraft would permit it to act as a gas-bag, protecting interior passengers.