Development of a CubeSat CLIMBing to the Van-Allen belt

Abstract

Based on its successful CubeSat mission PEGASUS, the University of Applied Sciences Wiener Neustadt (FHWN) is preparing its new CubeSat mission called CLIMB. CLIMB is a 3U CubeSat that will be launched to a low, circular orbit of about 500 km. Using a Field Emission Electric Propulsion (FEEP) system commercialized by the company ENPULSION, the satellite will be lifted to an elliptical orbit with its apogee around 1000 km – well inside the inner Van Allen belt. During its 1.5 yearlong ascent and its operation in the Van Allen belt, the satellite will continuously monitor the space radiation with a RadFET dosimeter payload and the impact on CLIMB’s subsystems. Comparisons with radiation testing on ground will allow the assessment of the capability of ground tests to predict effects of space radiation on CubeSat subsystems. The operation of the propulsion system will raise the satellite’s apogee on average 16 times a day. A comprehensive analysis has been conducted to assess its collision probability throughout its mission time. Using various tools, provided by ESA (CROC, MASTER and the DRAMA ARES python package), the collision probability for the entire mission duration (~3 years) was calculated to be 3.38 × 10-5, i.e. a magnitude smaller than the requested probability of 10-4. The second payload of CLIMB is an anisotropic magnetoresistance (AMR) magnetometer with a, for CubeSats high, sensitivity of about 10 nT RMS. The first results of measurements with this COTS based magnetometer are presented as well as experimental assessments of the satellite’s magnetic cleanliness. The benign thermal conditions on CubeSats operating close to Earth are complicated by the relatively high-power propulsion system onboard CLIMB. Detailed numerical analysis (ANSYS, ESATAN) and experimental verifications resulted in the identification of possible methods to deal with up to 18 W of dissipated electric power. The main heat sources are the thruster and the battery unit, during thruster operation