Magnetic properties of a 3U CubeSat with electric propulsion

Abstract

Nano-satellites, which are following the CubeSat standard are increasingly utilized for demanding industrial and astronomical applications with critical requirements on pointing and stability. Due to their small moment of inertia, even a small disturbance torque - caused by the residual magnetic moment - can result in a significant effect on the attitude. In order to study the magnetic moment of a 3 U CubeSat, an electrical model with a representative set of subsystems has been developed. A simulation tool was developed to calculate the magnetic field generated by the current flow inside the satellite. The simulation tool served to study the CubeSat mission so-called CLIMB, which employs a Field-emission electric propulsion electric propulsion system to rise its orbit by 500 km with a power consumption of 40 W at operation. In this context, the magnetic fields of this high energy density nano-satellite were measured for different operation modes inside the magnetic test facility of IABG. The data were correlated to the simulation results of the automatized model. It demonstrates, that the magnetic dipole moment is dominated by soft and hard magnetic materials like Li-ion batteries, especially at the discharging modes. This results in magnetic dipole moments of 14 mAm2 to 18 mAm2 for discharging and in between 4 mAm2 and 6 mAm2 for charging modes. The simulation tool was verified by a comparison with multi dipole models of the satellite and by modeling the impact of the solar panels only.