The last few years have seen considerable levels of Satcom sector activity aimed at developing systems for deployment into Low Earth Orbit. There is continued progress in the emerging communications constellations sector, with the launch of proof-of-concept' or mission validation' spacecraft by two projects in the last year, the formation of further strategic partnerships with the established GEO satellite operator community, further steps in establishing relationships with industrial (manufacturing) companies, and a number of projects now having secured US market access via the FCC. In addition, more than a dozen companies have declared plans to serve M2M/IoT applications via small satellite deployments to LEO, e.g. Kepler, Fleet, Lacuna Space, and Hiber. As well as new system designs, there are already established communications systems operating from LEO, e.g. Iridium, GlobalStar, and ORBCOMM, as well as many operational and planned spacecraft serving other application areas, principally Earth Observation, but also Navigation, and Science.
Given the anticipated proliferation of spacecraft operating from LEO, a cornerstone requirement for each of these planned andoperational systems must be to ensure that the space environment is used responsibly and sustainably. De-commissioning strategies and associated technologies from LEO are very different to the long-established and proven operational practices of GEO missions, andwith such large numbers of diverse spacecraft planned to be deployed over the coming decade, a mitigation strategy in the event of future anomalies and failures seems essential.
The proposed activity is therefore a Phase A feasibility study that will investigatethe requirements, design, and operation of an Active Debris Removal (ADR) system/mission to support LEO satellite communications missions. It is expected that the planned de-commissioning of spacecraft at the end of their life cycle will be a robust and validatedfeature of all future systems, and as such, the envisaged ADR system would not constitute a routine or nominal part of spacecraft operations. As anomalies should therefore be relatively rare, the activity shall consider the performance, technology, and economic trade-offs between an ADR system specific to one project/constellation/user, versus an independent capability able to service multiple users (or a hybrid, for example with different elements for controlled and uncontrolled re-entry), considering such factors as thenumber of spacecraft deployed, their design and expected reliability, and the type and number of different orbits used.
The need for features built into target spacecraft to facilitate capture shall be investigated, both in terms of technical and programmatic implications, as well as the implications of both cooperative and uncooperative capture and methods for subsequent passivation and de-orbiting. Considerations shall also include whether such system(s) should be placed into orbit in anticipation of future needs, or deployed based on realised needs.
The activity will exploit the knowledge gained through other ESA preparatory activities conducted under the TRP and GSP programmes that have studied technologies for debris removal, constellation operation, and design for demisability. The outcomes are expected to be an understanding of the possible need for (a) future ADR system(s), including identification of themission(s) and spacecraft types that could be targeted, a feasible system design and operational concept, and an identification of the key technology developments needed to realise its deployment.
In addition, an understanding of the most viable business models for such a system/service (e.g. public venture, private venture or public-private partnership) will be developed in order to inform next steps, as well as an understanding of the likely demand for such a capability and analysis of implications (such as e.g. liability). Based on the results, consequent steps may include technology developments through the ARTES AT and CG lines, outreach topotential partners for a future commercial ADR service development, and knowledge for both national licensing authorities and system operators to help future LEO communication projects become a reality.