This SBIR Phase I addresses the NASA need expressed in solicitation topic Z7.04, Landing System Technologies, Plume-Surface Interaction (PSI) Instrumentation, Ground Testing, and Analysis. In particular, it addresses “PSI-specific flight instrumentation, with particular emphasis on in situ measurements of particle size and particle velocity during the landing phase.” We will develop a sensor that measures the particle size distribution in PSI ejecta clouds plus the particle concentration (the ejecta cloud’s solid mass density), both with fine spatial and temporal resolution. The Phase I effort will demonstrate high quality lidar backscatter (sidescatter) measurements from visible to long-wave infrared wavelengths over concentration and length scales relevant to measuring ejecta particle size distributions. It will develop the mathematical framework to invert these backscatter measurements to obtain the particle size distribution at each location in the lunar plume ejecta cloud. It will demonstrate that this method may be packaged as a practical instrument for small lunar payloads. The sensor will be combined in Phase II with a particle velocimeter developed by our team under other NASA funding. The work will lead to improved understanding of lunar lander plume ejecta transport. Improvements are sought in the science of soil erosion under extreme conditions, such as supersonic flow, transitionally rarefied gas, low gravity, and unweathered unrounded particulates. The instrument will enable the acquisition by actual landers of empirical data to guide the models and eventually to solve the soil erosion physics. These data will inform NASA’s highly advanced flow codes for predicting these phenomena via empirical correlations.
The sensor will enable NASA to measure particle-scale ejecta transport physics to calibrate its high-fidelity plume/regolith flow code, the Gas Granular Flow Solver. This will enable NASA to predict blast ejecta effects for any size or configuration of lunar lander and to develop mitigation technologies and strategies.
Commercial space companies need sensors to document compliance with international law regarding blast ejecta. The sensor can also be used to quantify volcanic ash clouds and other dust plume affecting airline transport and Earth-monitoring for climate change.