HARDWARE-IN-THE-LOOP VALIDATION OF SENSING AND ALGORITHMS FOR AUTONOMOUS DESCENT AND LANDING

The current state of the practice for autonomous descent and landing consists of pre-orchestrated trajectories touching down within a pre-selected landing ellipse, as demonstrated with the Mars Science Laboratory, the Rosetta Philae Lander, and the planned OSIRTS-REx mission. Future missions designed with more specific scientific objectives or with the aim of in-situ resource extraction will require significantly more precise autonomous descent and landing capabilities. The Texas A&M Land, Air, and Space Robotics Lab (LASR) has developed a candidate system to provide real time autonomous Guidance, Navigation, and Control (GN&C) during descent and landing based on computational vision. As ground based intervention is impossible during landing situations, any potential method must be extensively tested and validated prior to flight. This paper describes a hardware-in-the-loop implementation of the candidate landing and navigation system in a characteristic small body landing scenario using the Holonomic Omnidirectional Motion Emulation Robot (HOMER) as a simulation platform. A detailed description of the landing GN&C system and the experimental test case is provided, along with results for the performance of each system compared to "truth" data from laboratory sensing systems.