SBIR-STTR Award

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. Potential NASA Applications (Limit 1500 characters, approximately 150 words): 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. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): 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. Duration: 6

This Phase II SBIR project addresses a Strategic Knowledge Gap by developing a lander-mounted system to determine particle size distribution in lander plumes. Plume-Surface-Interactions (PSI) in supersonic, highly rarefied, low gravity environments remain poorly understood. Temporally and spatially variable particle size distributions in lunar ejecta have never been measured accurately. Estimates depend heavily on assumptions and modeling, for which accurate empirical input data from landers is critically needed to predict and prevent damage. Knowledge of particle size distributions in lander plumes will be vital to the coming Gateway and Moon to Mars missions. Hence, our instrument and method represent a Game Changing Development. The method determines laser beam propagation decay constants at multiple wavelengths from imaged light scatter. Phase I showed that various relevant distributions could be determined from knowledge of beam decay constants at as few as four wavelengths. We will develop and test the theory and calculation methods to obtain particle size distributions from beam propagation decay, determine accuracy of the calculation results and effects of uncertainty, and develop on-board automated image and data processing. We will perform experiments on laboratory scattering standards to confirm methods for acquiring beam propagation decay constants and transformation into particle distributions, including relevant particle sizes, mineral mixtures, spatial inhomogeneities, and dynamic particle clouds in vacuum with Lunar simulant. System engineering will select and acquire lasers and cameras for a system prototype, design and fabricate low SWaP system packaging, and design a system mount that simulates a lander platform for lab and field tests. Preparation for flight testing will specify a system configuration, complete a Payload Flight Request, and fabricate the system prototype for Phase II E flight tests. Potential NASA Applications (Limit 1500 characters, approximately 150 words): EjectaBLAST directly addresses a NASA Strategic Knowledge Gap and will provide much-needed information for mitigating the hazards of lunar dust ejected from the surface by the engines of landing vehicles. The proposed PSI sensing instrument is a Game Changing Development. Data from the sensors will inform predictive modelling of debris to inform mitigation procedures. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): Department of Defense and private flight providers have an interest in better understanding PSI from landers. Terrestrial industrial and environmental applications exist, including quantifying dusty environments such as occur in mining, volcanic and fire ash clouds, and aerosols related to smog. Duration: 24