Initial Trajectory Assessment of the RAMSES Mission to (99942) Apophis

TL;DR

This paper analyzes feasible trajectories for ESA's RAMSES mission to reach asteroid Apophis before its 2029 close approach, using advanced optimization methods to inform mission planning.

Contribution

It introduces a combined optimization approach for rapid trajectory assessment to enable timely mission design for Apophis.

Findings

Multiple feasible launch windows identified.

Trajectory optimization methods proved effective.

Provides critical data for mission planning.

Abstract

(99942) Apophis is a potentially hazardous asteroid that will closely approach the Earth on April 13, 2029. Although the likelihood of an impact has been ruled out, this close encounter represents a unique opportunity for planetary science and defense. By investigating the physical and dynamical changes induced by this interaction, valuable insights into asteroid cohesion, strength, and internal structure can be obtained. In light of these circumstances, a fast mission to Apophis holds great scientific importance and potential for understanding potentially hazardous asteroids. To this aim, ESA proposed the mission RAMSES (Rapid Apophis Mission for SEcurity and Safety) to reach Apophis before its close encounter. In this context, the paper focuses on the reachability analysis of (99942) Apophis, examining thousands of trajectories departing from Earth and reaching the asteroid before the fly-by, using a low-thrust spacecraft. A two-layer approach combining direct sequential convex programming and an indirect method is employed for fast and reliable trajectory optimization. The results reveal multiple feasible launch windows and provide essential information for mission planning and system design.