Pneumatic Membrane Structures for Space and Terrestrial Applications

Pneumatic, pliable membrane structures have found a variety of useful applications on Earth and in space to provide rapidly and easily deployable large volume enclosures that can be transported in compact forms. These characteristics offer particularly important advantages for habitats destined for remote and inhospitable sites where erection times are critical and construction equipment and labor resources are minimal. Such conditions characterize locations where housing shelters are needed following natural and man-made disaster events as well as orbital and lunar/planetary surface facilities. This paper will discuss fundamental differences and similarities between design requirements for terrestrial and extraterrestrial pneumatic structures and will offer illustrative examples of both. An obvious and defining characteristic of any space habitat is a need to retain large internal pressures in an external vacuum environment without significant atmospheric leakage. Means to provide radiation, meteorite/debris and thermal protection in harsh space environments also present vital design priorities. All of these requirements add complexities and weight that distinguish them from much simpler alternatives on Earth. Terrestrial membrane structures can rely upon very small internal pressure differentials between inside and outside atmosphere for support, or alternatively, can incorporate rigidizing structural air tubes into the envelope. The second option eliminates a need to continually add air into the structure, can eliminate the requirement for an air trap at the entrance, and affords structural redundancy in the event of localized damage to the envelope or an air supply failure. The relative volumetric spatial advantages of all pneumatic membrane structures increase with size, and particularly as a function of diameter (in space) or floor span (on Earth). This makes them particularly well suited for large-scale applications to accommodate long-term, crew-intensive space missions or multi-family, community-sized disaster victim populations. Representative design concepts for both types of circumstances will be presented along with general planning considerations.