Comparison of starshade designs


Bellisario C., Soummer R.




External occulters (starshades) are considered to enable direct imaging and spectroscopy of terrestrial exoplanets to study their atmospheres and search for biomarkers. Starshades have to be deployed and aligned between the star and the telescope, and very long slews of the starshade are required to move from target to target. Therefore, the mission would be facilitated by a smaller, lighter and closer starshade. We study the scaling properties of the optimization of starshades using two methods (analytical hypergaussian, and numerical optimization). We present the results for a parameter space including telescope diameter and shadow size, petal length and occulter diameter, inner working angle, starshade distance, and starlight suppression level. These results provide scaling relationships to help with the design of a starshade mission.