The intensification of space activities and the emergence of new actors along with new technological and business concepts (i.e. large constellations, miniaturized systems, etc.) have raised, and continue raising, new challenges to ensure the safety of operations and the long-term sustainability of the space environment.

Taking stock of the ESA-developed Space Environment Capacity Concept, ESPI’s latest report explores policy, regulatory and diplomatic perspectives on threshold-based models for space safety & sustainability, discusses how metric-based approaches to the orbital environment can foster the development of fact-based discussions on sustainability and safety of operations.

The report aims to inform the space community on the considerations, implications and drivers for applying a metric-based approach to the space environment, focusing on:

  • The adequacy of the existing framework for space safety and sustainability;
  • The relevance & effectiveness of threshold-based models for the space environment;
  • The feasibility of threshold-based models for the space environment;
  • The role of public actors with regard to metric-based models;
  • The future evolution and next steps for metric-based approaches to the space environment.

The report recognizes the value of the threshold-based approach in addressing safety and sustainability concerns in outer space, while identifying the need to further mature and elaborate the approach by driving sustained activities through both scientific & technical dimensions and policy & diplomatic dimensions.

To further elaborate on the report and discuss perspectives on the elusive definitions of what “safe” and “sustainable” practices signify, ESPI will be hosting an online event on 20 April 2022. In a panel discussion scientific, industry and policy stakeholders will discuss potential implications capacity approaches in outer space would entail.




ESPI - European Space Policy Institute

Schwarzenbergplatz 6

A-1030 Vienna

(Entrance: Zaunergasse 1)

Phone +43 1 718 11 18 -0

Fax +43 1 718 11 18 -99