Survey of the operational state of the art in conjunction analysis

In the last two decades all major space agencies have established processes for operational conjunction analysis (CA) and collision avoidance (COLA). This work highlights the approaches of ESA, DLR, JAXA, NASA, CNES, and CSA. It is found that commercial satellite operators (Inmarsat, Intelsat, SES, and Eutelsat) do not primarily rely on the same sources of data as the major space agencies; however, a common operational process could be identified. Beside comparing the current operational state of the art, the models and methods used by the Combined Space Operations Center (CSpOC) to compute Conjunction Data Messages were studied. The space situational awareness (SSA) community still heavily depends on data provided by CSpOC; however, alternatives are maturing. Last but not least the operational state of the art is compared to theoretical developments of the SSA community. It is shown that while operational tools and processes meet the current needs, the gap is widening with respect to new high-fidelity methods available in literature (e.g., non-Gaussian uncertainty representations). This gap needs to be reduced for the systems to maintain compatibility to future requirements and expected perimeter changes, as for instance a heavily increased number of conjunction messages due to new sensor systems, such as the space fence radar and mega-constellation operations.