ADReS-A: Mission architecture for the removal of SL-8 rocket bodies

The awareness of space debris as a threat for the safe operation of satellites in Earth´s orbit increased rapidly over the last few years. Attempts such as improving trajectory predictions of non-functional objects in space, guidelines for safer launches nowadays, and post-mission disposal maneuver, however, will not stop the growth in debris numbers, as simulations predict. Mitigation needs therefore the realization of removal missions. This paper introduces an exemplary removal mission for 5 Russian SL-8 rocket bodies at an inclination of 83° orbiting at an altitude of 970 km - an area crowded with space debris and thus involving a high collision risk. By removing large objects, the potential for the creation of smaller fragments due to collisions shall be reduced. The mission itself consists of a main satellite (Autonomous Debris Removal satellite - ADReS-A) and smaller De-orbit Kits being launched together into an orbit close to the targets position. While the De-orbit Kits are equipped with a de-orbit thruster, the task of ADReS-A is, to approach the uncooperative target, perform berthing operations, stabilize the compound system and attach one De-orbit Kit onto the rocket body. The main satellite will take each De-orbit Kit separately to the individual targets, shuttling between the parking orbit and the target orbits. Future investigations concentrate on autonomy for highly critical situations resulting from the interaction with an uncooperative target. A prospect is given towards the end of the paper with a preliminary design for a decision process for autonomy.