Sequential Convex Programming for Multimode Spacecraft Trajectory Optimization

TL;DR

This paper introduces a sequential convex programming method for optimizing spacecraft trajectories with multiple propulsion modes, improving efficiency and flexibility in mission design.

Contribution

The paper extends SCP with automatic differentiation and new constraints to handle multi-mode propulsion, enabling efficient trajectory optimization for complex spacecraft configurations.

Findings

Successfully optimized trajectories for Earth-67P rendezvous and Earth-Mars transfer.

Demonstrated computational efficiency in handling multiple propulsion modes.

Validated the approach with realistic spacecraft propulsion scenarios.

Abstract

Spacecraft equipped with multiple propulsion modes or systems can offer enhanced performance and mission flexibility compared with traditional configurations. Despite these benefits, the trajectory optimization of spacecraft utilizing such configurations remains a complex challenge. This paper presents a sequential convex programming (SCP) approach for the optimal design of multi-mode and multi-propulsion spacecraft trajectories. The method extends the dynamical linearization within SCP using sparse automatic differentiation, enabling efficient inclusion of multiple propulsion modes or systems without complex manual reformulation while maintaining comparable computational efficiency. New constraint formulations are introduced to ensure selection of a single propulsion mode at each time step and limit the total number of modes used. The approach is demonstrated for (i) a low-thrust Earth-67P rendezvous using the SPT-140 thruster with 20 discrete modes, and (ii) an Earth-Mars transfer employing both a low-thrust engine and a solar sail. Results confirm that the proposed method can efficiently compute optimal trajectories for these scenarios.