Demonstration of Roman Coronagraph Instrument Star Acquisition in Thermal Vacuum

Abstract: NASA's Nancy Grace Roman Space Telescope is a flagship astrophysics mission planned for launch no later than May 2027. The Coronagraph Instrument (CGI) aboard Roman will demonstrate the technology for direct imaging and spectroscopy of exoplanets around nearby stars and starlight suppression that surpass previous space-based and ground-based coronagraphs. This is accomplished using active wavefront control in space with deformable mirrors. CGI requires a star acquisition system capable of acquiring reference and target stars to achieve this goal. This paper describes two CGI star acquisition system methods: EXCAM and Raster Scan. Furthermore, it will detail the results of the CGI thermal vacuum (TVAC) tests conducted to evaluate system-level star acquisition and verify its performance requirements.