Print Email Facebook Twitter A cutting edge 6U CubeSat ADCS design for Earth observation with sub-meter spatial resolution at 230–380 km altitude Title A cutting edge 6U CubeSat ADCS design for Earth observation with sub-meter spatial resolution at 230–380 km altitude Author Kuiper, J.M. (TU Delft Space Systems Egineering) Dolkens, D. (TU Delft Space Systems Egineering) Date 2020-12 Abstract A 6U CubeSat for Earth observation in 230–350 km orbits with sub-meter resolution is presented. The proposed Stable and Highly Accurate Pointing Earth-Imager (SHAPE) system’s attitude determination and control system (ADCS) is composed of a single momentum bias wheel with magnetic bearings at rotational speeds of 6000–7000 rpm and refined magnetorquers. Reaction wheels as instability source are absent. The ADCS stabilizes the spacecraft attitude by counteracting the torques from external disturbances in the thermosphere down to < 1° pointing accuracy and < 0.1° instability. The momentum wheel was sized to an angular momentum of 1 Nms based on the worst-case atmospheric density of the next solar cycle. The 0.5 Am2 magnetorquer dipole moment provides with low power consumption, mass and cost, high reliability and sufficient torque. The ADCS initialisation study revealed three stable start-up modes, while the all-spun state is achieved using a set of thrusters. De-tumbling analysis show that the magnetorquers reduce the tumbling rates with magnitudes of up to 35°/s to mean motion values in less than an orbit using a static gain B-dot controller. A 3U camera design capable of sub-meter spatial resolution at 230 km altitude is presented which complies with the SHAPE spacecraft system design. The instrument has a single deployable primary mirror enabled by a deployment hinge design with hysteresis < 0.5 μ. This payload combined with air-breathing electric propulsion technology at 230 km nominal altitude boosts the SHAPE system Earth observation potential down to sub-meter spatial resolution and enables tuning of the mission lifetime by orbit keeping. Subject 6U CubeSatCutting-edge ADCSMagnetic bias momentum wheelSub-meter spatial resolution To reference this document use: http://resolver.tudelft.nl/uuid:c90c8c9c-75cb-4684-8034-ad3139b9a414 DOI https://doi.org/10.1007/s12567-020-00323-7 ISSN 1868-2502 Source CEAS Space Journal, 12 (4), 613-621 Part of collection Institutional Repository Document type journal article Rights © 2020 J.M. Kuiper, D. Dolkens Files PDF Kuiper_Dolkens2020_Articl ... SDesig.pdf 1.22 MB Close viewer /islandora/object/uuid:c90c8c9c-75cb-4684-8034-ad3139b9a414/datastream/OBJ/view