TUI proposes to develop and demonstrate a process for fabricating high-performance composite truss structures on-orbit and integrating them with thin film solar cell assemblies to enable the deployment of very large solar arrays with lower cost and increased power-per-mass than SOA array technologies. On-orbit fabrication enables order-of-magnitude improvements in packing efficiency compared to state of the art deployables technologies such as coilable booms, deployable masts, and inflatable structures, and also enables geometric optimizations to provide order-of-magnitude improvements in structural performance. The proposed effort will build upon an existing TRL-3 truss-fabrication mechanism design, called the "Trusselator", which adapts techniques used in 3D printing and automated fiber placement to fabricate arbitrarily-long composite trusses using compactly-wound spools of textile materials as a feedstock. The Phase I SBIR effort will evolve this design to enable fabrication of high-performance truss structures using space-worthy materials, and develop methods for integrating these truss structures with solar cell blankets and the necessary wiring. The Phase II effort will prepare an advanced prototype and mature it to TRL-5 through environmental testing in the lab, preparing it for orbital validation testing in follow-on efforts.