Abstract

Status of the CLIMB CubeSat mission of FHWN

W. Treberspurg¹, C. Obertscheider¹, A. Stren¹, E. Eizinger²

¹ FHWN, University of Applied Sciences Wiener Neustadt
² FOTEC, Forschungs- und Technologietransfer GmbH

 

Abstract

New space missions make extensive use of commercial off-the-shelf (COTS) components, which provide a state-of-the-art performance but require extensive environmental testing to mitigate risks due to the non-specified reliability. This especially applies to CubeSat space crafts, which continue to establish as a powerful tool for professional missions in science and industry. In accordance with this trend, the university of applied sciences Wiener Neustadt (FHWN) is developing the CLIMB  3U CubeSat mission. The satellite provides a high-power density to operate a Field Emission Electric Propulsion (FEEP) system and change its initial circular orbit of about 500 km altitude to a slightly elliptical one with an apogee at around 1000 km – well inside the inner Van Allen belt [1]. During this about 1.5 years mission, the space environment and its impact on the satellite is monitored by a radiation monitor, developed by Seibersdorf Laboratories and a COTS based magnetometer instrument, developed by FHWN. In order to address the harsh radiation exposure – accumulating to about 20 krad at an average shielding equivalent to 1 mm of aluminum – the CLIMB mission extensively employs established structures from the precursor mission PEGASUS and started to conduct radiation tests of critical, sensitive and modified components. The 2U PEGASUS satellite launched in 2017 as Austrians contribution of QB50 and recorded and provided data until its re-entry 01/2024. 

We will present the environmental testing effort of the CLIMB mission, including thermal vacuum and irradiation studies. The integration of the FEEP system into a CubeSat introduces several challenges on the thermal concept due to the required high electrical power and correlated heat dissipation. For this reason, a specialized propulsion test chamber has been developed and thermal simulation studies were done. 

After exposing the On-Board-Computer of CLIMB to a total ionizing dose (TID) or 50 krad with a 60Co source, single event effect (SEE) tests were conducted with the proton beam at MedAustron [2]. Within this board level test, the beam mimicked a homogenous exposure by mapping the area with a pencil beam in a predefined pattern.

To account for radiation effects at the hardly shielded boom structure of the magnetometer instrument an Anisotropic Magneto Resistance (AMR) device with flight heritage is used as primary sensor (HMC1022). In addition, the latest generation of highly integrated AMR ICs (MMC5983MA) serve as secondary sensors and provide differential measurements along the boom [3]. Those secondary sensors have been TID tested to 30 krad and SEE tested on a component level with high MeV protons.

The presentation concludes with a summary of the results and the triggered modifications in the design, which will mitigate expected effects.  
 

References

[1] Verena Eschelmüller, et al., „Development of a CubeSat CLIMBing to the Van-Allen belt”. 4th Symposium on Space Educational Activities. Universitat Politècnica de Catalunya, 2022

[2] Felix Ulrich-Pur, et al., “Commissioning of low particle flux for proton beams at MedAustron”, NIMA Volume 1010, 2021, https://doi.org/10.1016/j.nima.2021.165570
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[3] Wolfgang Treberspurg, et al., „Magnetic properties of a 3U CubeSat with electric propulsion”, Advances in Space Research, Volume 72, Issue 8, 2023, https://doi.org/10.1016/j.asr.2023.07.002​​​​​​​.