Plume-surface Interaction Physics Focused Ground Test 1: Diagnostics and Preliminary Results

View Video Presentation: https://doi.org/10.2514/6.2022-1810.vid The powered descent of any spacecraft will create complex plume-surface dynamics which will erode the granular surface. This inevitability in the retro-propulsion of a lander introduces a host of phenomena such as the liberation of particles from the granular surface, which could damage the lander and surrounding infrastructure, and the production of a crater with an evolution that depends on several parameters. Studies in the past have been relegated to small scale setups and have not been able to resolve the full complexity of this issue. Therefore, to understand this problem, a new experimental campaign was conducted at NASA Marshall Space Flight Center in a large 15' vacuum chamber that was modified to study erosion under near-Lunar and Martian conditions. The vacuum chamber is essential since the ambient pressure affects the expansion angle of the rocket exhaust plume, further influencing the soil erosion behavior and the associated cratering dynamics. An optical diagnostic system and synchronization of this system was developed to simultaneously capture the complex cratering and ejecta dynamics in a vacuum environment. This study is the second in a series that is devoted to the effort of synchronizing all the data acquisition systems operating at timescales spanning from O(1 kHz) to O(1 MHz) to capture these complex dynamics.