An ASDL paper focused on CFD for simulations of a human-scale Mars lander concept vehicle has received the 2025 best paper award from the Fluid Dynamics Technical Committee of the American Institute of Aeronautics and Astronautics (AIAA). “Closed-Loop Simulations of Human-Scale Mars Lander Descent Trajectories on Frontier” (AIAA 2024-3535) was presented at the 2024 AIAA ASCEND event. The co-authors on the paper included ASDL alumni Zachary Ernst (PhD 2022) and Alexandra Hickey (PhD 2023), recent graduate Hayden Dean (PhD 2025), Bradford Robertson and Dimitri Mavris. The paper was written in collaboration with researchers at NASA Langley Research Center and NASA Ames Research Center.

The paper describes a computational campaign that was performed to run high-fidelity, free-flight simulations of a human-scale Mars lander concept vehicle decelerating under retropropulsion with closed-loop flight control through the Martian atmosphere. A novel approach was used to couple computational fluid dynamics (CFD) software with a mature flight mechanics package, where the two applications communicated in real-time across two geographically dispersed computational facilities.

The CFD was performed on the Frontier exascale system located at Oak Ridge National Laboratory, and the flight mechanics were executed on a system located at NASA Langley Research Center. In the campaign, CFD was performed using finite-rate chemistry to account for the interactions between the LOX/CH4 engines and the CO2 Martian atmosphere. A simulation of a closed-loop main engine throttling and RCS actuation was presented, demonstrating that the vehicle and model are able to maintain stability in a long-duration CFD-in-the-loop flight simulation. Comparisons were made to a reduced order model ignoring aero-propulsive interactions.