The CubeSpec mission: high resolution spectroscopy from a CubeSat

CubeSpec is an in-orbit demonstration CubeSat mission in the ESA GSTP programme, developed and funded by the Belgian federal space policy BELSPO. The goal of the mission is to demonstrate high-spectral-resolution astronomical spectroscopy from a 12-unit CubeSat. The technological challenges are numerous. The optical payload, consisting of an off-axis Cassegrain telescope and a compact Echelle spectrometer have been designed to fit in the bigger half of a 12U CubeSat (12x20x30cm). The telescope is built entirely from a ceramic material to limit defocusing when the spacecraft thermal environment changes. The payload radiator is shielded from the Sun via a deploying Sun shade, allowing pointing to a large part of the sky without illuminating the radiator panel. The high resolution spectrograph requires arcsecond-level pointing stability. This is achieved using a performant 3-axis wheel stabilised attitude control system with two star trackers augmented with a piezo-actuated 3-axis fine beam steering mechanism in the payload. CubeSpec is now starting the implementation phase, with a planned launch in 2026. A qualification and a flight model are being constructed and tested. We give an overview of the mission, its technologies and qualification status.