Delfi-C3 control system development and verification

Abstract

Delfi-C3 is a nano satellite, currently under development by primarily Msc. students from Delft University of Technology in the Netherlands. As the satellite is carried into space as a piggyback payload and deployed from a P-POD or T-POD canister, orbital parameters and initial and angular velocity can not be chosen, but are the consequence of the launcher’s primary mission and uncontrolled deployment velocities respectively. Delfi-C3 is to fly two payloads: Thin Film Solar Cells (TFSC) and an Autonomous Wireless Sun Sensor (AWSS). Both the Thin Film Solar Cells and the Autonomous Wireless Sun Sensor are best tested under gradually changing light conditions. None of the payloads require a fixed or stable attitude. Therefore, the satellite is designed to gently tumble about all three axes in its orbit. Two concepts for a passive magnetic attitude control system are being designed: one with a permanent magnet and hystersis rods on both other axes and one using only hysteresis rods on all three axes. Although hysteresis based control mechanisms in combination with a permanent magnet have been used in many missions before, Delfi-C3 would be the first to fly with hysteresis rods on all three axes. At the faculty a Helmholtz cage is being build to verify the design.