This innovation uses photochemical cyclopolymerization of polyimides to manufacture ultraviolet rigidizable composites for use in RIS (ridgidizing inflatable) structures. Sunlight initiated polymerization (UV polymerization) has been identified as a promising method for ridgidizing composites for inflatable space structures. The use of in-situ polymerized polyimides will provide superior dimensional and dynamic properties to enhance the performance characteristics of RIS deployed space based structures such as antennas, solar arrays and sunshields. As a class, polyimide polymers are known to possess excellent physical and chemical properties superior to conventional thermoset resins. But polyimides are typically produced at very high temperatures, making their use as RIS materials impractical. By utilizing a unique chemistry and polymerizing in-situ with sunlight, a new ridgidizable composite will be fabricated. The resulting polyimide impregnated composite can be rigidized in space and provide mechanical properties superior to those achieved with previous radiation cured composites. Stability of the polyimide precursors will permit long term storage of RIS prior to deployment. When produced in scale the composite will provide a cost competitive method of fabricating RIS and meet the growing demand for this type of space architecture. Terrestrial applications also exist in the homeland security and disaster response sectors.