Processes and materials for flexible PV arrays

Electrical power is a major driver for nearly all classes of space missions and, consequently, the maximization of available power is an on-going challenge. Advanced missions within the Air Force are investigating the use of flexible PV array systems. The rapidly-evolving technology of flexible thin film PV cells lends itself particularly well to a flexible array concept. A parallel incentive for development of flexible PV arrays are the possibilities of synergistic advantages for certain types of spacecraft, in particular the solar thermal propulsion (STP) vehicle. The large sun-tracking solar concentrators of an STP vehicle present a highly-efficient support and pointing system for a large flexible PV array mounted on the deployed support torus, or the concentrator. The work performed focused on advancing the technologies that will improve and extend the application of solar arrays in a variety of space and aerospace environments. SRS Technologies performed analyses and demonstrated the feasibility of combining thin film PV array technology with methods to manufacture deployable membrane concentrators for solar thermal propulsion. Significant issues addressed were: the interconnection of the newly developed cells, proper thermal control, and electrostatic charge control of the complete system in the space environment. SRS demonstrated a self-metallizing polyimide concept for electrical interconnection of the backplane, and printing PV array interconnect circuitry directly on the thin film prior to lamination to the array. The actions accomplished indicated the feasibility and desirability of a flexible, high specific power, PV array concept and have established a firm foundation and roadmap for development of an operational concept.