Christine Gregg
NASA Ames Research Center
The discovery of exoplanets in the habitable zone is one of the highest priorities in astrophysics. However, direct imaging would benefit immensely from much larger telescopes apertures than the James Webb Space Telescope, which already pushed the limit of deployable technologies and programmatic/budgetary capabilities. Starshade-based methods, both for in-space observatories like the Habitable Worlds Observer or ground-based observatories, have the potential to increase our observational capability without launching ever increasing telescope apertures. Construction of these starshades with the necessary low mass, stability, precision, launch volume, and size (>100m for some missions) remains a challenge, since loading can be significant for ultra-light structures during slewing and station keeping during observations. Large-scale space structure designs are often driven by dynamic stability requirements that are linked to precision requirements. Traditional materials inherently trade-off between stiffness and damping, which limits the operational capabilities and dynamic precision of resultant space structures. Recent advances in dissipative metamaterial and phononic crystals present an opportunity to disrupt this trade-off, creating high-stiffness and high-damping structures, as well as structures with phononic band gaps (i.e., the forbidden frequency range for the propagation of mechanical waves) for mode suppression. This study will design a starshade structure that utilizes novel dissipative and phononic metamaterials to design ultra-stable occulter structures at a fraction of the mass of traditional deployable designs. By enabling lower mass starshades with lower fuel requirements, this technology can transform our ability to discover exoplanets.