Nonintrusive Diagnosis of Ejecta Cloud from Plume Surface Interactions using High-Speed Digital Holography

The main objective of the proposed Phase II effort is to build a deliverable high-speed digital holography (DH) instrument that can be adapted to a NASA ground test facility to perform diagnosis of plume-surface interaction (PSI) events of interests to NASA scientists, and further, build a PSI facility at MetroLaser that can replicate similar PSI events and can deploy MetroLaser’s DH and other advanced diagnostics, such as focusing schlieren and photogrammetry, to interrogate and obtain 3D ejecta particle trajectories, velocities and size distributions and crater profiles that will help NASA scientists understand the physics of the PSI problem, and provide benchmark-worthy datasets for validation of modeling and simulation (M&S) tools. The understanding obtained from these studies will be used by MetroLaser to develop and build another prototype DH instrument that can provide preliminary information for a future onboard space lander deployment that can perform measurements on ingested ejecta particles. Further this prototype will be tested at these PSI facilities to characterize its capabilities in real-life applications scenarios as a pathway towards onboard deployment in future NASA lander missions. The Phase II funding will be used to build a state-of-the-art PSI facility at MetroLaser with custom-built optical access ports to perform large scale physics focused ground tests akin to those performed at NASA’s Marshall Space Flight Center. Further, we will deploy DH and other diagnostics in a systematic manner at different radial and longitudinal locations from the regolith bed and obtain a map of 3D particle velocities, trajectories and sizes around the jet impingement site. This parametric study will consist of different regolith simulants, jet velocities, mass flow rates, ambient pressures, and different jet heights. The findings will be used to build a deliverable DH instrument for NASA’s ground test facility and another onboard DH sensor for lander deployment.