“A safe and secure space environment is a requirement for all current and future space activities. Analyses performed by ESA and NASA indicate that the only means of sustaining the orbital environment at a safe level for space operations in future will be by carrying out both active debris removal and end-of-life de-orbiting or re-orbiting of future space assets. ESA, through its Clean Space (CS) initiative, is devoting an increasing amount of attention to the environmental impact of its activities.
To contribute to space sustainability, some agencies and governments have established or adopted policies to mitigate space debris creation. For instance, the ESA Policy on Space Debris states that satellites must remove themselves from the protected regions, less than 25 years for LEO and less than two months for GEO after operations are complete.
Nevertheless, even if spacecraft are designed to achieve an End-of-Life (EOL) compliance with these Space Debris Mitigation (SDM) requirements, a failure of the spacecraft, or other unforeseen events, may lead to the satellite becoming non-operational in the protected regions (this is even reflected in the SDM requirement, which calls for a reliability of 90%). Therefore, such a failed satellite may require ...