Preliminary AOCS Design for Pointing Budget Assessment of the BIOMASS Candidate Earth Explorer Core Mission

This paper presents the preliminary assessment of the attitude control design and performance for a baseline concept of the Biomass mission, a candidate for ESA's next Earth Explorer Core Missions. This satellite concept, as conceived at the end of the Phase 0 studies, has a 20-meter P-band antenna, for which the impact of high flexibility and uncertainty must be assessed. As a result, a rapid prototyping procedure has been established to assess the feasibility of various performance and robustness requirements at an early stage of the satellite's development. This has been done by incorporating a covering uncertainty model to reflect the structural dynamics with associated tolerances. This allows the use of a control design solely based on rigid dynamics, resulting in a low-order control solution, for which coverage is demonstrated by means of multivariable robust performance and stability margins expressed in the structured singular value metrics. Using non-linear simulations, we demonstrate the suitability of the robust design approach to the selected satellite concept.