10-Year Anniversary of the European Proximity Operations Simulator 2.0—Looking Back at Test Campaigns, Rendezvous Research and Facility Improvements

Completed in 2009, the European Proximity Operations Simulator 2.0 (EPOS 2.0) succeeded its predecessor EPOS 1.0 at the German Space Operations Center (GSOC) in Oberpfaffenhofen, near Munich. One of the many contributions the old EPOS 1.0 facility made to spaceflight rendezvous is the verification of the Jena-Optronik LiDAR sensors that fed the Automated Transfer Vehicle's safety monitoring system with distance and direction estimates. While EPOS 2.0 builds upon its heritage, it is a completely new design aiming at considerably more complex rendezvous scenarios for in-space assembly, on orbit servicing and space debris removal. During the last ten years, GSOC's On-Orbit-Servicing \& Autonomy group, who operates, maintains and evolves EPOS 2.0, has made numerous contributions to the field of uncooperative rendezvous, using EPOS as its primary tool. After general research in optical navigation and familiarization with the facility's capabilities in the early 2010s, the OOS group took a leading role in the DLR project "On-Orbit-Servicing End-to-End (E2E) Simulation" in 2014, with three DLR institutes working together. EPOS 2.0 served as the hardware in the loop simulator of the rendezvous phase and contributed substantially to the project's remarkable success. Over the years, E2E (and follow-up project RICADOS) have revealed demanding requirements, leading to numerous facility improvements and extensions. Besides the OOS group's research work, the numerous and diverse open-loop test campaigns for industry and internal (DLR) customers have shaped the capabilities of EPOS 2.0. These campaigns aimed at verifying optical rendezvous sensors and associated algorithms in an open-loop manner. This paper looks back at 10 years of intense EPOS 2.0 operations. It illustrates how the OOS group's own research and development work has driven the various enhancements of the facility. It outlines the numerous test campaigns for industry and internal customers. And it looks ahead towards challenges and opportunities in the near future.