Lesson learnt from the first 18 months of ESA’s new Space Debris Mitigation Policy

In response to the significant change in the use of space and the increasing concern related to the space debris issues and space sustainability topics at large, ESA has decided to introduce the so-called “Zero Debris” approach. The goal is to significantly limit the production of debris in Earth and Lunar orbits by 2030 for all future missions, programmes and activities.
As part of said initiative, in 2023, ESA updated two fundamental documents that regulate how all the Agency's space missions are designed, built, operated and disposed: ESA’s Space Debris Mitigation Policy and Space Debris Mitigation Requirements. This process took place through two working groups where more than 50 experts from all-over ESA were involved, with dedicated workshops organised in parallel with industry stakeholders to gather their feedback.
The new ESA Space Debris Mitigation Requirements (ESSB-ST-U-007) is built upon an existing European framework, which has been in effect since 2008 with the first ESA Space Debris Mitigation Policy and Requirements, enforced in 2014 by applying the ECSS-U-AS-10C standard adoption notice of ISO 24113, and eventually evolved through a series of additional requirements that cover several aspects of a mission. These aspects include more stringent conditions for orbital clearance, the adoption of design-for-removal features for missions with high-risk scenarios of space debris generation, the formalisation of best practices for collision avoidance and space traffic coordination, and, finally, the request for assessment of the impact of space missions on astronomy.
The more stringent technical requirements, combined with the policy’s scope and its immediate applicability to any mission have requested some practical implementation measures, ranging from the definition of a phased approach in the application of the requirements, the organisation of extensive training sessions, the preparation of example cases that could be used as references for other missions, together with the update of ESA’s Space Debris Mitigation Compliance Verification Guidelines (ESSB-HB-U-002).
The current paper will provide an overview of the first 18 months of application of the policy, considering not only the level of compliance, but also the identified critical points, together with the lessons learned during this transition period, especially in view of the planned update of ESA’s Space Debris Mitigation Requirements by 2030 to fully align with the goal of ESA’s Zero Debris Approach.