The Recycler: an Innovative Approach to On-Orbit Servicing and Repurposing

Due to its unique properties, the Geostationary Orbit (GEO) hosts one of the most relevant sectors of the satellite indus- \ntry, with hundreds of satellites providing telecommunications, meteorology, military, and many other similarly crucial \nservices. GEO satellites can be very expensive to build, launch and operate: they are hence expected to work seamlessly \nthroughout their lifetime, and a malfunction can represent a major economic loss. Instead of replacing the satellite or \naccepting reduced performances, a malfunctioning satellite could be repaired on site by replacing the faulty component \nwith a functional one, harvested from non-operational satellites and later repurposed. This paper presents the concept \nof the “Recycler”, a spacecraft used to procure replacements for operational GEO satellites by harvesting intact com- \nponents from non-operational spacecraft in the GEO graveyard (the region with altitude approximately GEO ±250 km) \nand surrounding areas. By recovering and repurposing existing hardware, the Recycler would be accessing a previously \nnon-existent second-hand satellite market. The preliminary mission design and analysis for the Recycler are described, \ntogether with a system-level assessment of required components. Given a database of potential targets and a set of client \nsatellites, the Recycler performs multiple missions between several target satellites and a Space Factory, where parts are \nstored to be later repurposed or recycled for raw materials. Methods to find the optimal sequence of multi-target trans- \nfers are investigated, including several phasing strategies and methods to simulate low-thrust trajectories, evaluating the \nmission times and ∆V ’s. Moreover, the target approach procedure, and the technologies and processes to assess the \nsatellite’s non-collaborative target’s attitude and state are reported. The full rendezvous sequence, including a closed- \nloop approach to the target and station keeping manoeuvres, is simulated to evaluate times and ∆V ’s required. Finally, \nthe possibility of using a swarm of scanner satellites to perform inspections of unknown targets is discussed, with the \nfinal aim of characterising the GEO debris environment.