ADR MISSION DESIGN AND DE-ORBITING STRATEGIES APPLIED TO HEAVY TARGETS

摘要

In the near future, ADR missions are very likely to become a key objective for international aerospace community. Therefore, joint efforts shall be geared toward enabling technologies, necessary to plan and successfully execute preliminary experimentation. In this context, this paper has the major goal of presenting the status of activities in Aviospace Company and the results achieved so far. Research over the last year has followed two distinct yet complementary strands: the study of systems of capture and de-orbiting, and trajectory optimization strategies for multi-target missions. As regards the capture system trade-off, attention was first focused on the reference target, whose geometry is known and representative of an entire debris family (R/Bs and upper stages), thereby evaluating pros and cons of different capture strategies and the impact they may have on close approach and de-orbiting. On the other hand, in perspective of a future mission with the goal of removing several targets, a strategy of selection of the capture sequence was studied. Thus, an optimizer based on a hybrid evolutionary algorithm was implemented, by modeling each maneuver as a 4-impulses time-fixed rendezvous and exploiting the effect of J_2 perturbation for the compensation of the orbital parameters of Ω and ω. The algorithm logic is driven by a fitness function, which shall be reformulated in order to take into account several mission factors and not only the energy associated with the rendezvous maneuvers. Finally, a new approach is proposed in order to increase the optimization power, whose applicability extends over ADR context. Both strands of research are currently in progress at Aviospace in the frame of R&D activities, and another aim of the paper is ultimately to give directions and guidelines to new developments.