CREAM - ESA's Proposal for Collision Risk Estimation and Automated Mitigation Benjamin Bastida Virgili (1) , Tim Flohrer (2) , Holger Krag (2) , Klaus Merz (2) , Stijn Lemmens (2) (1) IMS Space Consultancy @ ESA Space Debris Office, Robert-Bosch-Str. 5, 64293 Darmstadt, Germany, benjamin.bastida.virgili@esa.int (2) ESA Space Debris Office, Robert-Bosch-Str. 5, 64293 Darmstadt, Germany, tim.flohrer@esa.int, holger.krag@esa.int, klaus.merz@esa.int, stijn.lemmens@esa.int ABSTRACT Today, active collision avoidance has become a routine task in space operations, relying on validated, accurate and timely space surveillance data. For a typical satellite in LEO, hundreds of conjunction alerts can be expected every week. Processing and filtering these still leaves about two actionable alerts per spacecraft and week requiring detailed follow-up by an analyst. At ESA, more than one collision avoidance maneuver can be expected per satellite and year. It is clear that such an approach requiring 24/7 expert availability to analyze more than 20 parameters and constraints generates high operational costs. The future with an accelerating launch rate and deployments of smaller satellites and constellations, as well as improved space surveillance networks delivering catalogues of up to 200k objects will render efforts by any operator following this approach an unmanageable task. ESA's proposal for a Space Safety Programme to start in 2020 includes also a cornerstone "Collision Risk Estimation and Automated Mitigation (CREAM)". CREAM entails the development of technologies for automating collision avoidance and its demonstration with a suitable newly developed or existing flying platform. We discuss the status of the CREAM proposal focusing on three central objectives: (a) reducing manpower efforts in particular for large constellations, (b) reducing the number of false alerts, (c) reducing the time between maneuver decision and close approach. We will present ideas for machine learning techniques to replicate expert decisions, for which a competition will run from October to December 2019 as a preparatory activity. We discuss their application to automatic handling and analysis of the reliability of collision risk estimates, as well as implications from emerging trends in spacecraft operations, such as low-thrust maneuvering or attitude changes to control the effective drag towards a “continuous” collision avoidance process in replacement of the classical impulsive maneuvering. An efficient way to coordinate and command maneuvers is needed for the success of the CREAM concept. We will introduce first conceptual ideas how, e.g., adapting an IoT scenario could be implemented to enable late decisions on collision avoidance actions, also considering onboard trajectory estimation based on GNSS and ground-based orbit refinements. We conclude with an outlook to possible demonstration scenarios for the key technology developments, either with newly developed platform, or by using existing missions. 1. INTRODUCTION Today, operating spacecraft faces radical and fundamental changes. Not only the amount of tracked space debris makes active collision avoidance a routine task in space operations [1,2], furthermore the accelerating commercial exploitation of space brings pressing challenges. As access to space becomes more affordable the number of players in space increases rapidly. Further, the accelerated commercialization of space utilization needs to ensure the return of the enormous investments. Guidelines, standards and legal frameworks are undergoing adaptation driven by recent findings on space debris mitigation effectiveness and predictions of the space object population [3,4]. In parallel to the economical, societal and policy changes we will soon see a rapid increase of validated, accurate and timely space surveillance data. Overall, there can be no doubt that the way we operate spacecraft has to adapt and evolve quickly too! In this work, we present an ESA proposal to contribute to the evolution of spacecraft operations, by addressing the development and demonstration of technologies for automating collision avoidance. The ESA proposal is made as part of the proposal for a Space Safety Programme at ESA. Preparatory activities, such as a competition for machine learning supporting the decision process in collision avoidance have already started. 6031.pdf First Int'l. Orbital Debris Conf. (2019)