IAC 2022: On-Orbit SSA: Bespoke and Multi-purpose Optical Sensors to Support In-orbit Servicing

Astroscale is developing capabilities to address and mitigate the risk associated with space debris through a number of In-orbit servicing (IOS) techniques including Active Debris Removal (ADR), Life Extension (LEX) and End-Of-Life (EOL). These activities rely on space situational awareness (SSA) in order to be conducted safely and effectively, but they themselves also facilitate the use of sensors on orbital platforms to conduct novel inspace situational awareness (ISSA) observations. ISSA has potential to enable a range of observations not possible from the ground, with the capability to characterise objects in new ways. This paper provides an overview of Astroscale’s work to understand and develop ISSA capabilities. With a number of IOS missions in development, and one in orbit, Astroscale is uniquely placed to apply these to the maturation of ISSA techniques. Astroscale’s spaceborne platforms offer the opportunity for a number of optical ISSA observations that groundbased sensors cannot achieve. Spaceborne imagers can observe objects from significantly shorter ranges than ground-based telescopes, allowing detailed characterisation of a range of properties. Favourable observation conditions with no atmospheric interference, indifference to weather, and the potential for observation durations exceeding ground-based best-cases can extend the number and type of objects that can be observed and improve the possible analyses. Some ISSA observations can be conducted with rendezvous proximity operations (RPO) sensors – whose primary purpose is to support RPO and IOS activities – effectively extending the utility of essential hardware. Other ISSA observations require dedicated instruments with abilities such as sensitivity to faint objects, or multispectral imaging. Astroscale is therefore working to understand the ISSA capabilities of a range of different sensor setups, in order to develop capabilities to support and enhance future IOS missions. This paper introduces some key areas of ISSA and describes the activities that Astroscale is conducting to understand and develop relevant techniques. The technical requirements that optical cameras must meet to conduct ISSA is discussed, along with physical limits on observation capabilities. Some ISSA experiments being conducted with the ELSA-d spacecraft are described.