Dust Removal Technolgy for a Mars In Situ Resource Utilization System

Several In Situ Resource Utilization (lSRU) systems being considered to enable future manned exploration of Mars require capture of Martian atmospheric gas to extract oxygen and other commodities. However, the Martian atmosphere contains relatively large amounts of dust which must be removed in tbe collection systems of the ISRU chambers. The amount of atmospheric dust varies largely with the presence of daily dust devils and the less frequent but much more powerful global dust storms. A common and mature dust removal technology for terrestrial systems is the electrostatic precipitator. With this technology, dust particles being captured are imparted an electrostatic charge by means of a corona discharge. Charged dust particles are then driven to a region of high electric field which forces the particles onto a collector for capture. Several difficulties appear when this technology is adapted to the Martian atmospheric environment At the low atmospheric pressure of Mars, electrical breakdown occurs at much lower voltages than on Earth and corona discharge is difficult to sustain. In this paper, we report on our efforts to obtain a steady corona/glow discharge in a simulated Martian atmosphere of carbon dioxide at 9 millibars of pressure. We also present results on the design of a dust capture system under these atmospheric conditions

Far-Infrared Blocked Impurity Band Detector Development

DRS Sensors & Targeting Systems, supported by detector materials supplier Lawrence Semiconductor Research Laboratory, is developing far-infrared detectors jointly with NASA Langley under the Far-IR Detector Technology Advancement Partnership (FIDTAP). The detectors are intended for spectral characterization of the Earth's energy budget from space. During the first year of this effort we have designed, fabricated, and evaluated pilot Blocked Impurity Band (BIB) detectors in both silicon and germanium, utilizing pre-existing customized detector materials and photolithographic masks. A second-year effort has prepared improved silicon materials, fabricated custom photolithographic masks for detector process, and begun detector processing. We report the characterization results from the pilot detectors and other progress

Mitigation of Electrostatic Hazards on Spacecraft

Spacecraft are complex systems operating in challenging environments that require customized testing procedures designed to mitigate the unique hazards of a space launch environment. As an example of those testing procedures, we describe the test methodology and recommendations developed to mitigate electrostatic discharges that could have triggered an explosion of the Space Shuttle during launch, return to launch site, abort after one orbit, or during normal landing

An Electrostatic Precipitator System for the Martian Environment

Human exploration missions to Mars will require the development of technologies for the utilization of the planet's own resources for the production of commodities. However, the Martian atmosphere contains large amounts of dust. The extraction of commodities from this atmosphere requires prior removal of this dust. We report on our development of an electrostatic precipitator able to collect Martian simulated dust particles in atmospheric conditions approaching those of Mars. Extensive experiments with an initial prototype in a simulated Martian atmosphere showed efficiencies of 99%. The design of a second prototype with aerosolized Martian simulated dust in a flow-through is described. Keywords: Space applications, electrostatic precipitator, particle control, particle chargin

A New Large-Well 1024x1024 Si:As Detector for the Mid-Infrare

We present a description of a new 1024x1024 Si:As array designed for ground-based use from 5 - 28 microns. With a maximum well depth of 5e6 electrons, this device brings large-format array technology to bear on ground-based mid-infrared programs, allowing entry to the megapixel realm previously only accessible to the near-IR. The multiplexer design features switchable gain, a 256x256 windowing mode for extremely bright sources, and it is two-edge buttable. The device is currently in its final design phase at DRS in Cypress, CA. We anticipate completion of the foundry run in the beginning of 2006. This new array will enable wide field, high angular resolution ground-based follow up of targets found by space-based missions such as the Spitzer Space Telescope and the Widefield Infrared Survey Explorer (WISE).Comment: 8 pages, 9 figures, 2005 San Diego SPI

Integration of the Electrodynamic Dust Shield on a Lunar Habitat Demonstration Unit

NASA is developing a Habitat Demonstration Unit (HDU) to investigate the feasibility of lunar surface technologies and lunar ground operations. The HDU will define and validate lunar scenario architecture through field analog testing. It will contain a four-port vertical habitat module with docking demonstration capabilities. The Electrodynamic Oust Shield (EDS) is being incorporated into the HDU to demonstrate dust removal from a viewport and from a door prior to docking procedures. In this paper, we will describe our efforts to scale up the EDS to protect a viewport 20 cm in diameter. We will also describe the development of several 20 cm x 25 cm EDS patches to demonstrate dust removal from one of the HDU doors

Dust Removal Technology Demonstration for a Lunar Habitat

We have developed an Electrodynamic Dust Shield (EDS), an active dust mitigation technology with applications to solar panels, thermal radiators, optical systems, visors, seals and connectors. This active technology is capable of removing dust and granular material with diameters as large as several hundred microns. In this paper, we report on the development of three types of EDS systems for NASA's Habitat Demonstration Unit (HDU). A transparent EDS 20 cm in diameter with indium tin oxide electrodes on a 0.1 mm-thick polyethylene terephtalate (PET) film was constructed for viewport dust protection. Two opaque EDS systems with copper electrodes on 0.1 mm-thick Kapton were also built to demonstrate dust removal on the doors of the HDU. A lotus coating that minimizes dust adhesion was added to one of the last two EDS systems to demonstrate the effectiveness of the combined systems

An evaluation of the relative efficacy of an open airway, an oxygen reservoir and continuous positive airway pressure 5 cmH2O on the non-ventilated lung

Publisher's copy made available with the permission of the publisher © Australian Society of AnaesthetistsThe aim of this study, during one-lung ventilation, was to evaluate if oxygenation could be improved by use of a simple oxygen reservoir or application of 5 cmH2O continuous positive airway pressure (CPAP) to the non-ventilated lung compared with an open airway. Twenty-three patients with lung malignancy, undergoing thoracotomy requiring at least 60 minutes of one-lung ventilation before lung lobe excision, were studied. After routine induction and establishment of one-lung ventilation, the three treatments were applied in turn to the same patient in a sequence selected randomly. The first treatment was repeated as a fourth treatment and these results of the repeated treatment averaged to minimize the effect of slow changes. Arterial oxygenation was measured by an arterial blood gas 15 minutes after the application of each treatment. Twenty patients completed the study. Mean PaO2 (in mmHg) was 210.3 (SD 105.5) in the 'OPEN' treatment, 186.0 (SD 109.2) in the 'RESERVOIR' treatment, and 240.5 (SD 116.0) in the 'CPAP' treatment. This overall difference was not quite significant (P=0.058, paired ANOVA), but comparison of the pairs showed that there was a significant better oxygenation only with the CPAP compared to the reservoir treatments (t=2.52, P=0.021). While the effect on the surgical field was not apparent in most patients, in one patient surgery was impeded during CPAP. Our results show that the use of a reservoir does not give oxygenation better than an open tube, and is less effective than the use of CPAP 5 cmH2O on the non-ventilated lung during one-lung ventilation.J. Slimani, W. J. Russell, C. Jurisevichttp://www.aaic.net.au/Article.asp?D=200404