meetings - Space Flight Mechanics Committee

This paper introduces novel analytical guidance solutions for spacecraft relative motion
considering continuous, on-off thrust, and using Relative Orbit Elements. The relative state
vector can be obtained at any given time, accommodating any thrust magnitude, as well as
generic activation times and durations. Relative Orbit Elements geometrically interpret key
aspects of the relative motion, including, for example, the relative ellipse size, and its center
evolution in time. The analytical solutions are tested using a sample guidance thrust profile
based on input-shaping. The use of Relative Orbit Elements shows substantial benefits and
added simplicity with respect to Cartesian Coordinates.
14:50 AAS Multiple Sliding Surface Guidance for Planetary Landing: Tuning and
13-328 Optimization via Reinforcement Learning
Daniel Wibben, The University of Arizona; Brian Gaudet, University of Arizona;
Roberto Furfaro, The University of Arizona; Jules Simo, University of Strathclyde
15:10 Break
A novel non-linear guidance algorithm for planetary landing is proposed and analyzed.
Based on Higher-Order Sliding Control Theory, the Multiple Sliding Surface Guidance
algorithm has been specifically designed to take advantage of the ability to reach the sliding
surface in a finite time. However, after initial analysis, it has been seen that the performance
of MSSG is very sensitive to the choice in guidance gains and is generally sub-optimal.
Reinforcement learning has been used to tune and investigate the behavior of the MSSG
algorithm to find an optimal set of gains for both performance and fuel efficiency.
15:35 AAS Optimal Lunar Landing and Retargeting using a Hybrid Control Strategy
13-329 Daniel Wibben, The University of Arizona; Roberto Furfaro, The University of
Arizona; Ricardo Sanfelice, The University of Arizona
A novel non-linear spacecraft guidance scheme utilizing a hybrid controller for pinpoint
lunar landing and retargeting is presented. The hybrid system approach utilizes the fact that
the logic and behavior of switching guidance laws is inherent in the definition of the
system, thus autonomous retargeting is possible. The presented case utilizes a combination
of a global controller to bring the lander to a predefined reference trajectory, and a local
controller to bring it to the desired point on the lunar surface. The behavior and
performance of the hybrid system is analyzed, with emphasis on the case of autonomous
retargeting.
15:55 AAS Navigating a Crewed Lunar Vehicle Using LiAISON
13-330 Jeff Parker, University of Colorado at Boulder; Jason Leonard, University of
Colorado at Boulder; Rodney Anderson, NASA / Caltech JPL; Ryan McGranaghan,
University of Colorado at Boulder; Kohei Fujimoto, University of Colorado at
Boulder; George Born, University of Colorado at Boulder
This paper examines the benefits of navigating a crewed vehicle between the Earth and the
Moon using both ground tracking and satellite-to-satellite tracking. Linked Autonomous
Interplanetary Satellite Orbit Navigation (LiAISON) is a new technique that has been
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23 rd AAS / AIAA Space Flight Mechanics Meeting