Full-shell replicated x-ray optics modules for REDSoX and FOXSI-5

The NASA Marshall Space Flight Center (MSFC) has a decades long history of successfully designing, building, and testing full-shell replicated mirror module assemblies (MMAs) for sub-orbital missions. In this work we present the status of MMA development for two recent sounding rocket projects: REDSoX and FOXSI-5. The Rocket Experiment Demonstration of a Soft X-ray (REDSoX) polarimeter is a NASA-funded sounding rocket experiment, led by the Massachusetts Institute of Technology, that is currently developing a novel instrument to measure the polarization of an astrophysical source in the soft x-ray band (0.2-0.4 keV). NASA MSFC is responsible for the design, fabrication, test, and integration of the primary mirror assembly, with delivery expected in March 2026. The Focusing Optics for X-ray Solar Imager (FOXSI) sounding rocket experiment is currently preparing for its fifth flight. For the FOXSI-5 payload, MSFC rebuilt, vibration tested, and X-ray calibrated two high-resolution mirror module assemblies. The MMAs were delivered in July 2025.