Autonomous guidance and control for planetary surface relocations

Autonomous guidance and control (G&C) is vital for planetary surface exploration missions. The challenge of space applications is to find computational efficient algorithms that can be employed on-board while giving optimal and feasible solutions. Addressing this issue, this article presents a G&C solution for planetary surface relocations using thrust steering based on analytical suboptimal algorithms. The proposed solution is an alternative to on-board optimization using feedback linearization, time-optimal trajectories for each individual axis and a novel snap-based control, which considers the limits of the spacecraft design. The robustness of the G&C solution to model uncertainties is demonstrated using Monte Carlo simulations on the nonlinear surface dynamics of 67P/Churyumov–Gerasimenko (67P). Compared to other G&C approaches, the algorithms can easily be implemented on-board, reduce verification & validation costs, and minimize computational effort.