Modeling and Control Techniques for Landing on Apophis: An analysis of the mission scenario

Abstract

On April 13 2029, the near-Earth asteroid (99942) Apophis will perform a close flyby within a distance of 32,000 km of Earth’s surface. This event, which is 10 times closer than the Moon and closer than many geostationary communication satellites, offers an unprecedented opportunity to study an asteroid in great detail. To leverage this close encounter, a fast sample return mission, APOSSUM, was designed using ESA’s current RAMSES mission as a use case. This paper presents a detailed analysis of the APOSSUM mission scenario, focusing on feasibility. It covers the separation of the APOSSUM probe, its cruise toward Apophis, and the subsequent landing and return phases. Particular emphasis is placed on the landing scenario, with studies of different density models of Apophis and a comparison of control techniques for precision landing. The findings from this mission will significantly advance understanding of small-body landing maneuvers