The Space Coronagraph Optical Bench (SCoOB): 1. Design and Assembly of a Vacuum-compatible Coronagraph Testbed for Spaceborne High-Contrast Imaging Technology

TL;DR

This paper presents the design, assembly, and initial validation of a vacuum-compatible high-contrast imaging testbed for spaceborne coronagraph technology, aiming to enable exoplanet detection in space environments.

Contribution

It introduces a novel vacuum-compatible testbed with advanced wavefront control and coronagraph modes for space applications, validated in a thermal vacuum chamber.

Findings

Achieved initial optical surface quality and alignment.

Demonstrated operation of vector vortex and Lyot coronagraphs.

Validated vacuum chamber integration and testbed readiness.

Abstract

The development of spaceborne coronagraphic technology is of paramount importance to the detection of habitable exoplanets in visible light. In space, coronagraphs are able to bypass the limitations imposed by the atmosphere to reach deeper contrasts and detect faint companions close to their host star. To effectively test this technology in a flight-like environment, a high-contrast imaging testbed must be designed for operation in a thermal vacuum (TVAC) chamber. A TVAC-compatible high-contrast imaging testbed is undergoing development at the University of Arizona inspired by a previous mission concept: The Coronagraphic Debris and Exoplanet Exploring Payload (CDEEP). The testbed currently operates at visible wavelengths and features a Boston Micromachines Kilo-C DM for wavefront control. Both a vector vortex coronagraph and a knife-edge Lyot coronagraph operating mode are under test. The optics will be mounted to a 1 x 2 meter pneumatically isolated optical bench designed to operate at 10^-8 torr and achieve raw contrasts of 10^-8 or better. The validation of our optical surface quality, alignment procedure, and first light results are presented. We also report on the status of the testbed's integration in the vaccum chamber.