ABSTRACT: Powered descent is a critical phase of planetary landing missions, requiring precise guidance to autonomously steer the lander to a safe and accurate touchdown. This presentation will begin with a revisit of the legendary Apollo Lunar Descent Guidance (ALDG) law, which successfully guided all Apollo lunar landings and remains a benchmark in powered descent guidance technology even six decades later. However, the landscape of powered descent guidance methods has evolved significantly in recent years. We will introduce the intriguing theory of Fractional-Polynomial Powered Descent Guidance (FP2DG) and share the interesting findings that the well-known Apollo-era guidance laws, the ALDG and E-guidance laws, are special cases within the broader FP2DG family. But the FP2DG laws provide much greater flexibility and a wider range of guidance options to accommodate diverse mission scenarios and requirements than the ALDG law. From there we will branch into recent advances in propellant-optimal powered descent guidance research and discuss some of the latest developments that could render propellant-optimal powered descent guidance a viable option for human-scale lunar and Mars landings.

BIOSKETCH: Ping Lu received his Ph.D. in Aerospace Engineering from the University of Michigan and has 35 years of experience in aerospace research and education. His expertise lies in computational guidance and control, and he has authored or co-authored over 200 journal and conference papers. Previously a professor of Aerospace Engineering at Iowa State University, he joined San Diego State University in 2016, where he is a Distinguished Professor and the Chair of the Aerospace Engineering Department. Professor Lu is a Fellow of the American Institute of Aeronautics and Astronautics, and the Editor-in-Chief of the Journal of Guidance, Control, and Dynamics, the premier international journal in aerospace guidance, control, and flight dynamics/astrodynamics.