SBIR-STTR Award

Proposed is an architecture for large (>200 m2 surface area) photovoltaic (PV) arrays, deployable from compact stowage with one single, continuously smooth sweep of motion and directly scalable to sizes at least an order of magnitude larger to provide surface areas beyond 4000 m2 -- the area associated with 1 MW power production, the upper limit of projected solar electric propulsion (SEP) needs in 10-20 years. In particular, examined is the integration of a version of the "spiral fold" (an origami-like surface mechanism to wrap without stretching a tessellated sheet on a hub) and wrap rib technology (supporting ribs that also wrap around the hub when stowed) with some additional concept elements to increase stiffness when deployed and the robustness of deployment. Kinematic conflicts between components with geometric mismatch in a real-life hardware context re resolved, metrics for stowage and structural performance are assessed, and a streadmlined concept design is defined to satisfy all targeted specifications. TRL level is advanced from 1 to 3.

Proposed is the development and validation in a laboratory environment of a photovoltaic (PV) array design of unique and enabling characteristics. Namely, smoothly deployed from compact stowage with one single, continuous sweep of motion, a total PV surface area up to and beyond 4000~m2 (the area associated with 1~MW power) is provided by two wings, with mechanical performance objectives also met. The PV cells are mounted on flexible strups that, assembled, constitute array disk pie segments between straight ribs and smoothly wrap between the latter on the central hub for stowage. The surface shears in stowage effected by this kinematics are absorbed by shear compliant hinge strips between the strips, and the PV cells are mounted on the latter ro precisely align in the roll. Deployed, the surface segments between the ribs are pretensioned with catenaries on the outer perimeter, supported by the rib tips which extend outward. A full mechanical design is developed to complete concept validation for a pair of wings 2000 m2 each, fabrication and operational issues are explored and addressed, and a working prototype wing is built to complete concept validation.