As the MegaFlex solar array is scaled for power demands greater than 50kW over the next 20 years and deployed load requirements remain high or increase, advanced MegaFlex blanket support spar designs will be desired. The spars are the structural members that support the MegaFlex solar array deployed blanket. When the solar array experiences a deployed load, the structural load path starts in the spars which carry the load to the hub assembly that then pass it on to the latched panel assemblies that act as the structural back-bone of the deployed array and carry the load to the solar array to spacecraft interface. Therefore as the MegaFlex blanket areas increase the spar loading increases which causes higher stress levels in the spars, unless they are appropriately scaled in size. However directly scaling the spars in size from their current design state is not the most optimized design for strength and mass. This is why AD proposes to develop a hierarchical set of MegaFlex spar designs with ATK. Successful performance of this proposed strategic plan has far reaching benefits which start with the scaling risk reduction of larger future MegaFlex solar arrays to support power demands beyond 50kW with high deployed loading requirements. The benefits continue with mass savings for these arrays obtained by the mass optimized future spars which will enable more payload for future HEOMD or other missions and or launch cost savings. Finally, development costs for future flight qualification of a MegaFlex solar array >50kW in size with high deployed loading requirements will be saved because this work will already have been completed. All of these benefits support future HEOMD missions and others, which therefore further validates the merit of the proposed innovation and work to be completed on this SBIR.

We expect direct commercialization after leveraging the demonstrated MegaFlex scale-up technology capabilities through building and end-to-end testing a 20m diameter 100kW class MegaFlex Technology Development wing. Following this Phase III or earlier work, we expect applications should be in the form of purchase contracts with our subcontractor and commercialization partner, ATK. We expect that after a successful 20m diameter 100kW class MegaFlex Technology Development effort that the community will see this technology as low risk.NASA programs involving large solar arrayswould be particularly interested in this technology advancement, as it directly supports the future very high power SEP mission requirements. The proposed Phase I and II work will reduce developmentcosts andrisksand provide an accelerated extensibility path to build and test testing a 20m diameter 100kW class MegaFlex Technology Development wing. This will enable the desired goal of commercial infusion and significantly expand the acceptance and potential applications of MegaFlex.

Department of Defense, foreign government programs and the commercial sector all have an interest in high power, low-risk, low-cost solar arrays. Risk associated with the MegaFlex design is being retired though ATK internal and NASA sponsored development work. However, MegaFlex's use of flight qualified UltraFlex components minimizes the risk present in this design as-is. The proposed spar development only further advances the TRLof MegaFlex andreducesscaling costs and risks for >50kW of power. This will therefore increase its future application potential. The ViviSat SEP platform is a current MegaFlex opportunity that looks promising.