This is a postprint version of the following published document: Sánchez-Arriaga, G., et al. The E.T.PACK Project: towards a fully passive and consumable-less deorbit kit based on low work-function tether technology, In: Acta astronautica, 177 (Special Section on SI: Tethers in Space 2019), Dec. 2020, Pp. 821-827. DOI: https://doi.org/10.1016/j.actaastro.2020.03.036 © 2020 IAA. Published by Elsevier Ltd. All rights reserved. This work is licensed under a Creative Commons Attribution- NonCommercial-NoDerivatives 4.0 International License.