Contrast performance of an 8m off-axis, segmented space telescope equipped with an adaptive optics system

Axel Potier; Garreth Ruane; Kiarash Tajdaran; Chris Stark; Pin Chen; Larry Dewell; Roser Juanola-Parramon; Alison Nordt; Laurent Pueyo; David Redding; A J Eldorado Riggs; Dan Sirbu

arXiv · 2208.08553

Contrast performance of an 8m off-axis, segmented space telescope equipped with an adaptive optics system

Axel Potier·Garreth Ruane·Kiarash Tajdaran·Chris Stark·Pin Chen·Larry Dewell·Roser Juanola-Parramon·Alison Nordt·Laurent Pueyo·David Redding·A J Eldorado Riggs·Dan Sirbu

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Abstract

The Astro2020 decadal survey recommended an infrared, optical, ultra-violet (IR/O/UV) telescope with a $\sim$6~m inscribed diameter and equipped with a coronagraph instrument to directly image exoEarths in the habitable zone of their host star. A telescope of such size may need to be segmented to be folded and then carried by current launch vehicles. However, a segmented primary mirror introduces the potential for additional mid spatial frequency optical wavefront instabilities during the science operations that would degrade the coronagraph performance. A coronagraph instrument with a wavefront sensing and control (WS\&C) system can stabilize the wavefront with a picometer precision at high temporal frequencies ($>$1Hz). In this work, we study a realistic set of aberrations based on a finite element model of a slightly larger (8m circumscribed, 6.7m inscribed diameter) segmented telescope with its payload. We model an adaptive optics (AO) system numerically to compute the post-AO residuals. The residuals then feed an end-to-end model of a vortex coronagraph instrument. We report the long exposure contrast and discuss the overall benefits of the adaptive optics system in the flagship mission success.

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Axel Potier, Garreth Ruane, Kiarash Tajdaran, Chris Stark, Pin Chen, Larry Dewell, Roser Juanola-Parramon, Alison Nordt, Laurent Pueyo, David Redding, A J Eldorado Riggs, Dan Sirbu. 2022-08-17. Contrast performance of an 8m off-axis, segmented space telescope equipped with an adaptive optics system. https://arxiv.org/abs/2208.08553

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