Advances in Starshade Technology Readiness for an Exoplanet Characterizing Science Mission in the 2020's

This paper presents an overview of the work to date on the mechanical system for Starshade to TRL5 (S5) Technology Development Plan(14), with emphasis on the technical status compared to the upcoming technology milestones with an overview of how that work fits into the overall technology plan. The conclusion of the NASA trade study in 2018 for the starshade mechanical architecture resulted in a consolidated and focused approach, which was the baseline design used for the technology plan. Recent progress has included the production of multiple prototypes including a full-scale Petal Launch Restraint & Unfurl Subsystem prototype (14m tip to tip deployed), and has included demonstrations of the design from fully stowed to deployed. A10m (full-scale) inner disk subsystem including perimeter truss and optical shield was designed, analyzed, built and tested for deployment functionality and accuracy. Lastly, a 4m long x 1.5m wide (1/2 scale x 3/4 scale) petal prototype along with shape critical components of the perimeter truss have been built and tested for thermal stability. The culmination of this work, both in the design side and the prototype side, has led to greatly improved design fidelity, and most importantly, validation of the design against the performance requirements. This provides much greater confidence in the viability of the design, and much lower risk moving forward toward technology readiness level 5, and eventually a flight mission.