OCEAN: a space telescope for Orbit Characterization of near-by Exoplanets by Astrometric determinatioN on a cubesat enviroment

The paper presents the current status and technological advancements of OCEAN (Orbit Characterization of near-by exoplanetary systems by Astrometric determinatioN) mission. The mission is conceived as a 36 U Cubesat, aiming at rapid implementation with a compact telescope designed for high stability and low sensitivity to perturbations, ensuring 1-μas systematic floor. The payload relies on a single-aperture, highly-stable space telescope enforcing circular symmetry on the whole optical system, down to the detector populating an annular region of uniform diffraction limited imaging. The payload is compact, light, and cheap. OCEAN represents a transformative step toward democratizing space-based based astrometry and exoplanet discovery. The mission combines scientific ambition with engineering pragmatism. It builds on existing CubeSat heritage while pushing the limits of precision and stability, potentially unlocking a new class of affordable, targeted astronomical observatories.