1 The Cyber-ASAT: On the Impact of Cyber Weapons in Outer Space Abstract: Satellites have revolutionized military strategy and the dynamics of national power. However, satellites themselves are fragile and can be destroyed by even miniscule projectiles. Anti-Satellite Weapons (ASATs) which exploit this weakness have long been prophesied as the Achilles heel of space power; yet orbit has remained relatively peaceful for more than sixty years. As the threat of cyber attacks against space assets looms, the impact that cyberspace will have on stability in outer space is not well understood. This paper presents a strategic analysis of the impact of cyber weapons on three key stabilizing factors which have thus far contributed to peace in space. Based on this analysis, it contends that cyber-ASATs threaten the foundations of space’s longstanding stability due to their high accessibility, low attributability, and low risk of collateral damage. This conjecture is tested experimentally though the development of a simulated cyber-ASAT capability targeting one small component of satellite operations: space situational awareness data. By leveraging orbital simulations and genetic algorithms, we demonstrate the ability to artifcially alter debris collision forecasts and cause direct harm to critical space systems without fring a single rocket. The attack method is tested in realistic simulations and shown to have a high success rate against real- world satellites of vital strategic importance. Our interdisciplinary approach unifes strategic analysis with technical experimentation James Pavur DPhil Researcher Cybersecurity Centre for Doctoral Training Oxford University Oxford, United Kingdom james.pavur@cybersecurity.ox.ac.uk Ivan Martinovic Professor of Computer Science Department of Computer Science Oxford University Oxford, United Kingdom ivan.martinovic@cs.ox.ac.uk 2019 11th International Conference on Cyber Confict: Silent Battle T. Minárik, S. Alatalu, S. Biondi, M. Signoretti, I. Tolga, G. Visky (Eds.) 2019 © NATO CCD COE Publications, Tallinn Permission to make digital or hard copies of this publication for internal use within NATO and for personal or educational use when for non-proft or non-commercial purposes is granted providing that copies bear this notice and a full citation on the frst page. Any other reproduction or transmission requires prior written permission by NATO CCD COE.