Status of the radiation environment simulations for CLIMB
Wolfgang Treberspurg1, Carlo Girardello1, Robert Kralovsky2, Christof Obertscheider1, Andreas Sinn3, Carsten Scharlemann1
1 University of Applied Sciences Wiener Neustadt
2 RKOS IT Consulting
The main objective of the CLIMB 3-U CubeSat mission of the FHWN is to reach the inner Van-Allen-Belt by increasing the apogee height of its orbit from 500 km to about 1000 km, by performing maneuvers with a FEEP  thruster. Beside of challenges concerning the thermal loads, the available energy budget and the required attitude control of the satellite, this mission demands special precautions with regard to the radiation hardness of the satellite. In order to take those environmental impacts into account during the development of the mission, several simulations and tests were performed. The effect of the propulsive maneuvers is numerically simulated with the system tool kit  allowing to determine the various orbit options. Those orbits are then used to estimate the total and time dependent radiation dose e.g. with the omere package . The environmental specifications are further coupled via the FastRad software  with the CAD design files of the satellite to consider and optimize shielding effects for the specification of the total dose at sensitive components inside the structure. The microprocessor of the on-board computer (OBC) is a typical example for a sensitive and mission critical component. To ensure its radiation hardness up to the preliminary estimated worst case of 50 krad, irradiation tests have been performed with the 60Co source at the Seibersdorf Laboratories. The analysis of these results shows that the microprocessor itself could withstand the irradiated dose, although some components like temperature sensors and dosimeter are more likely to fail under the radiation effects of the harsh environment CLIMB will face.
 Krejci, David. “Demonstration of the IFM nano FEEP thruster in low Earth orbit”. ResearchGate (Report). Retrieved 27 March 2019