Safeguarding outer space
Constantly increasing, the amount of orbital debris in space is starting to reach dangerous levels. Nearly 20 000 objects larger than 10 cm are known to orbit Earth while the number of smaller natural (meteoroid) and artificial (man-made) particles greatly exceeds this. This number is not only concerning but also has the potential to result in catastrophic losses of space assets. At the same time, the capability of both industry and policymakers to apply debris mitigation measures is hampered by technological, financial and political constraints. With EU financial support, the 'Alignment of capability and capacity for the objective of reducing debris' (ACCORD) project surveyed international debris mitigation strategies. Specifically, the mitigation practices investigated were drawn from the Inter-Agency Space Debris Coordination Committee's (IADC) guidelines and included passivation of spacecraft at the end of their mission and post-mission disposal. Assessment of their effectiveness in low, medium and geosynchronous orbit regions resulted in a clearer ranking of the existing measures. Moreover, the results of this comprehensive analysis were used together with those from a survey of the European space industry's capability to implement them to develop an environmental impact rating system (EIRS). The prototype system uses indicators of the effectiveness of mitigation measures to limit the growth of space debris as well as metrics of the industry's capability to implement them. Together with other key parameters, the EIRS calculates a rating for the environmental impact of break-ups of rocket bodies, collisions of spacecraft with untracked objects and abandoned satellites. A public version of the spacecraft rating calculator is presented on a dedicated ACCORD project web page. The EIRS can help decrease risks for spacecraft, encourage investments in the European space industry to manage the challenges, and lead to more effective debris standards for future space activities.
Keywords
Orbital debris, space debris, spacecraft, geosynchronous orbit, low Earth orbit, mitigation measures, post-mission disposal, collision avoidance
