Effect of Space Telescope Primary Mirror Segment Errors on Coronagraph Instrument Performance

Direct imaging of potentially habitable planets is challenging because of the relative proximity of the planet to the star and the low flux ratio (typically well under 1e-9 in the visible) of the planet relative to the star. Future exoplanet direct imaging telescopes like the Habitable Exoplanet Imaging Mission (HabEx) or the Large UV/Optical/Infrared Surveyor (LUVOIR) will hence require large collecting apertures with very low wavefront errors. The feasibility of these missions is in a large part dependent on the sensitivity of the achieved contrast at small working angles to imperfections and motions of the telescope optics. In past studies, we explored the effect of applying specific modes to segmented and monolith telescopes on the contrast leakage of a coronagraph. Here we present a revised analysis which, though not substantially different from the previous results, includes a mode careful theoretical examination of the issues involved. We conclude by highlighting the importance of the temporal characteristics of the errors.