High spatio-temporal resolution particle sizer for plume-induced ejecta clouds

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.nbsp; In particular, it addresses ldquo;PSI-specific flight instrumentation, with particular emphasis on in situ measurements of particle size and particle velocity during the landing phase.rdquo;nbsp; We will develop a sensor that measures the particle size distribution in PSI ejecta clouds plus the particle concentration (the ejecta cloudrsquo;s solid mass density), both with fine spatial and temporal resolution. nbsp;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.nbsp; 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.nbsp; It will demonstrate that this method may be packaged as a practical instrument for small lunar payloads.nbsp; The sensor will be combined in Phase II with a particle velocimeter developed by our team under other NASA funding.nbsp; The work will lead to improved understanding of lunar lander plume ejecta transport.nbsp; 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. nbsp;The instrument will enable the acquisition by actual landers of empirical data to guide the models and eventually to solve the soil erosion physics. nbsp;These data will inform NASArsquo;s highly advanced flow codes for predicting these phenomena via empirical correlations.