James Captain

The Use of Tribocharging in the Electrostatic Beneficiation of Lunar Simulant

The use of tribocharging as a potential method to provide sufficient charge to several different lunar simulants for electrostatic beneficiation was investigated. The objective was to determine whether specific minerals of interest (e.g., ilmenite) that are present in lunar regolith could be enriched in concentration by beneficiation that would therefore allow for more efficient extraction for in situ resource utilization use. The production of oxygen, water, and other resources on the Moon from raw materials is vital for future missions to the Moon. Successful separation of ilmenite was achieved for a prepared simulant (KSC-1), which is a mixture of pure commercially supplied pyroxene, olivine, feldspar, and ilmenite, in a 4 : 4 : 1 : 1 ratio, showing proof of concept when tribocharged against three different charging materials, namely, Al, Cu, and PTFE. Separation by chemical composition was also observed for existing lunar simulants JSC-1 and JSC-1A; however, the interpretation of the separation was difficult due to the complex mineralogy of the simulants compared to the simple prepared mixture.

Trash-to-Gas: Using Waste Products to Minimize Logistical Mass During Long Duration Space Missions

Just as waste-to-energy processes utilizing municipal landftll and biomass wastes are finding increased terrestrial uses, the Trash-to-Gas (TtG) project seeks to convert waste generated during spaceflight into high value commodities. These include methane for propulsion and water for life support in addition to a variety of other gasses. TtG is part of the Logistic Reduction and Repurposing (LRR) project under the NASA Advanced Exploration Systems Program. The LRR project will enable a largely mission-independent approach to minimize logistics contributions to total mission architecture mass. LRR includes technologies that reduce the amount of consumables that need to be sent to space, repurpose items sent to space, or convert wastes to commodities. Currently, waste generated on the International Space Station is stored inside a logistic module which is de-orbited into Earths atmosphere for destruction. The waste consists of food packaging, food, clothing and other items. This paper will discuss current results on incineration as a waste processing method. Incineration is part of a two step process to produce methane from waste: first the waste is converted to carbon oxides; second, the carbon oxides are fed to a Sabatier reactor where they are converted to methane. The quantities of carbon dioxide, carbon monoxide, methane and water were measured under the different thermal degradation conditions. The overall carbon conversion efficiency and water recovery are discussed.

Quantification of Efficiency of Beneficiation of Lunar Regolith

Electrostatic beneficiation of lunar regolith is being researched at Kennedy Space Center to enhance the ilmenite concentration of the regolith for the production of oxygen in in-situ resource utilization on the lunar surface. Ilmenite enrichment of up to 200% was achieved using lunar simulants. For the most accurate quanitification of the regolith particles, standard petrographic methods are typically followed, but in order to optimize the process, many hundreds of samples were generated in this study that made the standard analysis methods time prohibitive. In the current studies, x-ray photoelectron spectroscopy (XPS) and secondary electron microscopy/energy dispersive spectroscopy (SEM/EDS) were used that could automatically, and quickly, analyze many separated fractions of lunar simulant. In order to test the accuracy of the quantification, test mixture samples of known quantities of ilmenite (2, 5, 10, and 20 wt%) in silica (pure quartz powder), were analyzed by XPS and EDS. The results showed that quantification for low concentrations of ilmenite in silica could be accurately achieved by both XPS and EDS, knowing the limitations of the techniques.

Electrostatic Beneficiation of Lunar Regolith: Applications in In-Situ Resource Utilization

AbstractReturning to the Moon, or going further afield such as to Mars, presents enormous challenges in sustaining life for extended periods of time far beyond the few days the astronauts experienced on the Moon during the Apollo missions. A stay on Mars is envisioned to last several months, and it would be cost prohibitive to take all the requirements for such a stay from Earth. Therefore, future exploration missions will be required to be self-sufficient and use the resources available at the mission site to sustain human occupation. Such an exercise is currently the focus of intense research at National Aeronautics and Space Administration under the in situ resource utilization program. As well as the oxygen and water necessary for human life, resources for providing building materials for habitats, radiation protection, and landing/launch pads are required. All these materials can be provided by the regolith present on the surface because it contains sufficient minerals and metals oxides to meet the r...

Mars Atmospheric Capture and Gas Separation

The Mars atmospheric capture and gas separation project is selecting, developing, and demonstrating techniques to capture and purify Martian atmospheric gases for their utilization for the production of hydrocarbons, oxygen, and water in ISRU systems. Trace gases will be required to be separated from Martian atmospheric gases to provide pure C02 to processing elements. In addition, other Martian gases, such as nitrogen and argon, occur in concentrations high enough to be useful as buffer gas and should be captured as welL To achieve these goals, highly efficient gas separation processes will be required. These gas separation techniques are also required across various areas within the ISRU project to support various consumable production processes. The development of innovative gas separation techniques will evaluate the current state-of-the-art for the gas separation required, with the objective to demonstrate and develop light-weight, low-power methods for gas separation. Gas separation requirements include, but are not limited to the selective separation of: (1) methane and water from un-reacted carbon oxides (C02- CO) and hydrogen typical of a Sabatier-type process, (2) carbon oxides and water from unreacted hydrogen from a Reverse Water-Gas Shift process, (3) carbon oxides from oxygen from a trash/waste processing reaction, and (4) helium from hydrogen or oxygen from a propellant scavenging process. Potential technologies for the separations include freezers, selective membranes, selective solvents, polymeric sorbents, zeolites, and new technologies. This paper and presentation will summarize the results of an extensive literature review and laboratory evaluations of candidate technologies for the capture and separation of C02 and other relevant gases.

Testing and Modeling of the Mars Atmospheric Processing Module

Here we report further progress in the development of the MARCO POLO/Mars ISRU Pathfinder Atmospheric Processing Module (APM). The APM is designed to demonstrate in situ resource utilization (ISRU) of the Martian atmosphere, which primarily consists of carbon dioxide (CO2). The APM is part of a larger project with the overall goal of collecting and utilizing CO2 found in the atmosphere and water in the regolith of Mars to produce methane and oxygen to be used as rocket propellant, eliminating the need to import those to Mars for human missions, thus significantly reducing costs. The initial focus of NASA’s new ISRU Project is modeling of key ISRU components, such as the CO2 Freezers and the Sabatier reactor of the APM. We have designed models of those components and verified the models with the APM by gathering additional data for the CO2 Freezer and the Sabatier reactor. Future efforts will be focused on simultaneous operations of the APM and other MARCO POLO/Mars ISRU Pathfinder modules.