Evaluation of the Share of the Space Capacity Share Used by a Mission

In the context of space sustainability and space traffic coordination and management, it is important to define an internationally recognised and accepted approach to measure the Space capacity, defined as the quantity and type of missions/objects that the Space environment can sustain. In parallel to the study on how the capacity can be measured, it is important to define an acceptable threshold of the space capacity and to link such measure to the contribution that each new and already flying mission apport to it, in order to better drive the definition of mitigation guidelines. The THEMIS tool is being developed along these lines: to Track the Health of the Environment and Missions in Space. The software, that will be opened to the whole Space community (i.e., satellite operators, regulators, space debris experts, and general public) through a Web user Interface, is being developed by Politecnico di Milano and Deimos UK within a project funded by the European Space Agency. The space debris mode of the THEMIS tool allows the computation of the space debris index given the profile of a mission, the spacecraft characteristics, orbit characterisation and operational aspects such as collision avoidance manoeuvre efficacy and post mission disposal capabilities and reliability. Then the space capacity mode of the THEMIS tool, currently under development, is described. As part of this task, we perform a literature review of proposed approaches to measure the carrying capacity of other ecosystems to inspire the discussion ongoing in the Space community.