caa a22 4500 606245154 CHVBK 20210128101334.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s12567-015-0084-2 doi (NATIONALLICENCE)springer-10.1007/s12567-015-0084-2 The Euclid AOCS science mode design [Elektronische Daten] [A. Bacchetta, M. Saponara, A. Torasso, G. Saavedra Criado, B. Girouart] Euclid is a Medium-Class mission of the ESA Cosmic Vision 2015-2025 plan. Thales Alenia Space Italy has been selected as prime contractor for the Euclid design and implementation. The spacecraft will be launched in 2020 on a Soyuz launch vehicle from Kourou, to a large-amplitude orbit around the sun-earth libration point L2. The objective of Euclid is to understand the origin of the Universe's accelerating expansion, by mapping large-scale structure over a cosmic time covering the last 10 billion years. The mission requires the ability to survey a large fraction of the extragalactic sky (i.e. portion of sky with latitude higher than 30deg with respect to galactic plane) over its lifetime, with very high system stability (telescope, focal plane, spacecraft pointing) to minimize systematic effects. The AOCS is a key element to meet the scientific requirements. The AOCS design drivers are pointing performance and image quality (Relative Pointing Error over 700s less than 25m as, 68% confidence level), and minimization of slew time between observation fields to meet the goal of completing the Wide Extragalactic Survey in 6years. The first driver demands a Fine Guidance Sensor in the telescope focal plane for accurate attitude measurement and actuators with low noise and fine command resolution. The second driver requires high-torque actuators and an extended attitude control bandwidth. In the design, reaction wheels (RWL) and cold-gas micro-propulsion (MPS) are used in a synergetic and complementary way during different operational phases of the science mode. The RWL are used for performing the field slews, whereas during scientific observation they are stopped not to perturb the pointing by additional mechanical noise. The MPS is used for maintaining the reference attitude with high pointing accuracy during the scientific observation. This unconventional concept achieves the pointing performance with the shortest maneuver times, with significant mass savings with respect to the MPS-only solution. CEAS, 2015 GNC for scientific missions nationallicence High accuracy AOCS nationallicence Fine guidance sensor nationallicence Bacchetta A. Thales Alenia Space Italia, Strada Antica di Collegno 253, 10146, Turin, Italy aut Saponara M. Thales Alenia Space Italia, Strada Antica di Collegno 253, 10146, Turin, Italy aut Torasso A. Thales Alenia Space Italia, Strada Antica di Collegno 253, 10146, Turin, Italy aut Saavedra Criado G. ESA/ESTEC, Keplerlaan 1, 2200 AG, Noordwijk, The Netherlands aut Girouart B. ESA/ESTEC, Keplerlaan 1, 2200 AG, Noordwijk, The Netherlands aut CEAS Space Journal Springer Vienna 7/2(2015-06-01), 71-85 1868-2502 7:2<71 2015 7 12567 https://doi.org/10.1007/s12567-015-0084-2 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s12567-015-0084-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bacchetta A. Thales Alenia Space Italia, Strada Antica di Collegno 253, 10146, Turin, Italy aut NATIONALLICENCE 700 1- Saponara M. Thales Alenia Space Italia, Strada Antica di Collegno 253, 10146, Turin, Italy aut NATIONALLICENCE 700 1- Torasso A. Thales Alenia Space Italia, Strada Antica di Collegno 253, 10146, Turin, Italy aut NATIONALLICENCE 700 1- Saavedra Criado G. ESA/ESTEC, Keplerlaan 1, 2200 AG, Noordwijk, The Netherlands aut NATIONALLICENCE 700 1- Girouart B. ESA/ESTEC, Keplerlaan 1, 2200 AG, Noordwijk, The Netherlands aut NATIONALLICENCE 773 0- CEAS Space Journal Springer Vienna 7/2(2015-06-01), 71-85 1868-2502 7:2<71 2015 7 12567