Solar Glint From Uncoated Starshade Optical Edges

The perimeter of a sunflower-like starshade has hundreds of meters of sharp edges that are directly exposed to sunlight. The sunlight diffracts and reflects from the edge resulting in a dual-lobed glint pattern that can be brighter than an exoplanet. We present estimates of the glint brightness distribution for the Starshade Rendezvous Mission and the HabEx Starshade Mission concepts based on measurements of flight-like, environmentally tested, uncoated metallic edges using custom-built scatterometers. A companion paper addresses the performance for edges coated with a thin anti-reflection coating. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License.