Development of an Electrostatic Precipitator to Remove Martian Atmospheric Dust from ISRU Gas Intakes During Planetary Exploration Missions

Manned exploration missions to Mars will need dependable in situ resource utilization (ISRU) for the production of oxygen and other commodities. One of these resources is the Martian atmosphere itself, which is composed of carbon dioxide (95.3%), nitrogen (2.7%), argon (1.6%), oxygen (0.13%), carbon monoxide (0.07%), and water vapor (0.03%), as well as other trace gases. However, the Martian atmosphere also contains relatively large amounts of dust, uploaded by frequent dust devils and high Winds. To make this gas usable for oxygen extraction in specialized chambers requires the removal of most of the dust. An electrostatic precipitator (ESP) system is an obvious choice. But with an atmospheric pressure just one-hundredth of Earth's, electrical breakdown at low voltages makes the implementation of the electrostatic precipitator technology very challenging. Ion mobility, drag forces, dust particle charging, and migration velocity are also affected because the low gas pressure results in molecular mean free paths that are approximately one hundred times longer than those at Earth .atmospheric pressure. We report here on our efforts to develop this technology at the Kennedy Space Center, using gases with approximately the same composition as the Martian atmosphere in a vacuum chamber at 9 mbars, the atmospheric pressure on Mars. We also present I-V curves and large particle charging data for various versions of wire-cylinder and rod-cylinder geometry ESPs. Preliminary results suggest that use of an ESP for dust collection on Mars may be feasible, but further testing with Martian dust simulant is required

Exploring sustainable urbanism in masterplanned developments: : a collective case study of slippage between principles, policies, and practices

© 2020 Taylor & Francis. This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Urbanism: International Research on Placemaking and Urban Sustainability on 22nd July 2020, available online: https://doi.org/10.1080/17549175.2020.1793802.This article is concerned with masterplan implementation and with exploring, via recourse to case studies, slippages between masterplanning principles, policies, and practices. Framed by a growing body of sustainable urbanism literature we analyse evidence from five masterplanned communities in the UK and Australia to comparatively explore how some key theoretical principles are translated into placemaking in inner urban, suburban, outer urban and semi-rural contexts. We observe varying degrees of disjuncture between masterplanning principles and the urban form envisioned by, and realized through, actual masterplanning proposals and implementation. We postulate that various degrees of slippage at each stage from proposals to practices have occurred which can affect capacity to meet principles of sustainable urbanism. Analysis of the five cases demonstrates where some potential “tripping-up” points lie in the masterplanning process, hinting at broader impediments to delivering masterplanning that is more closely aligned to sustainable urbanism principles in future.Peer reviewedFinal Accepted Versio