An MPC Strategy for Low-Thrust Space Debris Rendezvous

The removal of orbital debris by means of dedicated space missions has been recently identified as a priority for the sustainability of the space environment. Electrically propelled spacecraft, in particular, are seen as a cost-effective solution for such type of missions. This paper develops an MPC strategy for space debris rendezvous, which is able to account for mission-specific performance and safety requirements, while satisfying on-off constraints inherent to the electric propulsion technology. The proposed design requires to solve a mixed integer linear program at each time step. In order to limit the computational burden, a linear programming relaxation tailored to a realistic thrusting configuration is devised. A rendezvous case study demonstrates the effectiveness of the proposed solution.