Testbed Multi-star Wavefront Control Experiement Modeling Analysis

Astro2020 Decadal Survey calls for a mission yield goal of 25 or more habitable zone planets detection and characterization in its recommendation of next NASA flagship mission, the Habitable World Observatory (HWO). Multi-star wavefront control (MSWC) is a technique that enables simultaneous star light suppression of a binary or more star system. It has the potential to help achieve the goal by substantially increasing viable target samples to beyond single star systems. Technology development for MSWC has been ongoing for a number of years. Recently a better than 1e-7 contrast was demonstrated at JPL’s high contrast imaging testbed (HCIT) with a true binary source for the first time mimicking the Alpha Centauri star system. Here we present (high order) wavefront sensing and control (HOWFSC) modeling analysis of the testbed experiments. Our model is a modified extension of the HOWFSC engineering model that has proven to be a valuable tool for Roman Coronagraph Instrument (CGI) and was validated on HCIT. It includes crucial engineering features and factors relevant to testbed (while omitting CGI specific elements) such as probing and sensing with detector noise and finite bandwidth used. The analysis provides important insight into and understanding of MSWC and identifies potential performance-limiting factors that were not previously considered. Adjustments in both hardware and WFSC strategy and algorithm are discussed for next round testbed experiments to improve performance necessary for both Roman and HWO. This work was performed at the Jet Propulsion Laboratory / California Institute of Technology under contract to NASA.