Optimal Science-time Reorientation Policy for the Comet Interceptor Flyby via Sequential Convex Programming

TL;DR

This paper presents a sequential convex programming algorithm for optimal spacecraft reorientation during high-speed flybys, maximizing scientific instrument exposure while handling nonlinear dynamics and actuator constraints.

Contribution

It introduces a novel convex reformulation of the reorientation problem, enabling efficient trajectory optimization even with actuator faults and limited hardware.

Findings

Successfully maximized science time in simulated Comet Interceptor scenarios.

Handled actuator faults and dust impacts effectively in trajectory planning.

Achieved efficient solutions using convex programming on limited hardware.

Abstract

This paper introduces an algorithm to perform optimal reorientation of a spacecraft during a high speed flyby mission that maximizes the time a certain target is kept within the field of view of scientific instruments. The method directly handles the nonlinear dynamics of the spacecraft, sun exclusion constraint, torque and momentum limits on the reaction wheels as well as potential faults in these actuators. A sequential convex programming approach was used to reformulate non-convex pointing objectives and other constraints in terms of a series of novel convex cardinality minimization problems. These subproblems were then efficiently solved even on limited hardware resources using convex programming solvers implementing second-order conic constraints. The proposed method was applied to a scenario that involved maximizing the science time for the upcoming Comet Interceptor flyby mission developed by the European Space Agency. Extensive simulation results demonstrate the capability of the approach to generate viable trajectories even in the presence of reaction wheel failures or prior dust particle impacts.