Design and Guidance of a Multi-Active Debris Removal Mission

Space debris have been becoming exceedingly dangerous over the years as the number of objects in orbit continues to rise. Active debris removal (ADR) missions have garnered significant attention as an effective way to mitigate this collision risk. This research focuses on developing a multi-ADR mission that utilizes controlled reentry and deorbiting. The mission comprises two spacecraft: a Servicer that brings debris down to a low altitude and a Shepherd that rendezvous with the debris to later perform a controlled reentry. A preliminary mission design tool (PMDT) is developed to obtain time or fuel optimal trajectories for the proposed mission while taking the effect of $J_2$, drag, eclipses, and duty ratio into account. The PMDT can perform such trajectory optimizations within computational times that are under a minute. Three guidance schemes are also studied, taking the PMDT solution as a reference, to validate the design methodology and provide guidance solutions for this complex mission profile.