| 61. |
- Israel Nazarious, Miracle, et al.
(författare)
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Calibration and preliminary tests of the Brine Observation Transition To Liquid Experiment on HABIT/ExoMars 2020 for demonstration of liquid water stability on Mars
- 2019
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Ingår i: Acta Astronautica. - : Elsevier. - 0094-5765 .- 1879-2030. ; 162, s. 497-510
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Tidskriftsartikel (refereegranskat)abstract
- The search for unequivocal proofs of liquid water on present day Mars is a prominent domain of research with implications on habitability and future Mars exploration. The HABIT (Habitability: Brines, Irradiation, and Temperature) instrument that will be on-board the ExoMars 2020 Surface Platform (ESA-IKI Roscosmos) will investigate the habitability of present day Mars, monitoring temperature, winds, dust conductivity, ultraviolet radiation and liquid water formation. One of the components of HABIT is the experiment BOTTLE (Brine Observation Transition To Liquid Experiment). The purposes of BOTTLE are to: (1) quantify the formation of transient liquid brines; (2) observe their stability over time under non-equilibrium conditions; and (3) serve as an In-Situ Resource Utilization (ISRU) technology demonstrator for water moisture capture. In this manuscript, we describe the calibration procedure of BOTTLE with standard concentrations of brines, the calibration function and the coefficients needed to interpret the observations on Mars.BOTTLE consists of six containers: four of them are filled with different deliquescent salts that have been found on Mars (calcium-perchlorate, magnesium-perchlorate, calcium-chloride, and sodium-perchlorate); and two containers that are open to the air, to collect atmospheric dust. The salts are exposed to the Martian environment through a high efficiency particulate air (HEPA) filter (to comply with planetary protection protocols). The deliquescence process will be monitored by observing the changes in electrical conductivity (EC) in each container: dehydrated salts show low EC, hydrated salts show medium EC and, liquid brines show high EC values. We report and interpret the preliminary test results using the BOTTLE engineering model in representative conditions; and we discuss how this concept can be adapted to other exploration missions.Our laboratory observations show that 1.2 g of anhydrous calcium-chloride captures about 3.7 g of liquid water as brine passing through various possible hydrate forms. This ISRU technology could potentially be the first attempt to understand the formation of transient liquid water on Mars and to develop self-sustaining in-situ water harvesting on Mars for future human and robotic missions.
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| 62. |
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| 63. |
- Israel Nazarious, Miracle, et al.
(författare)
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Measuring Electrical Conductivity to Study the Formation of Brines Under Martian Conditions
- 2021
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Ingår i: Journal of Visualized Experiments. - : JoVE. - 1940-087X. ; 173
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes a protocol to design experiments to study the formation of brines under Martian conditions and monitor the process with electrical conductivity measurements. We used the Engineering Qualification Model (EQM) of Habitability: Brines, Irradiation, and Temperature (HABIT)/ExoMars 2022 instrument for the experiment setup but we provide a brief account of constructing a simple and inexpensive electrical conductivity measurement setup. The protocol serves to calibrate the electrical conductivity measurements of the salt deliquescence into brine in a simulated Martian environment. The Martian conditions of temperature (-70 °C to 20 °C), relative humidity (0% to 100%) and pressure (7 - 8 mbar) with carbon-dioxide atmosphere were simulated in the SpaceQ Mars simulation chamber, a facility at the Luleå University of Technology, Sweden. The hydrate form of the known amount of salt accommodated between a pair of electrodes and thus the electrical conductivity measured depends predominantly on its water content and the temperature and relative humidity of the system. Electrical conductivity measurements were carried out at 1 Hz while exposing salts to a continuously increasing relative humidity (to force transitioning through various hydrates) at different Martian temperatures. For demonstration, a day-night cycle at Oxia Planum, Mars (the landing site of ExoMars 2022 mission) was recreated.
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| 64. |
- Israel Nazarious, Miracle, et al.
(författare)
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Metabolt : An In-Situ Instrument to Characterize the Metabolic Activity of Microbial Soil Ecosystems Using Electrochemical and Gaseous Signatures
- 2020
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Ingår i: Sensors. - : MDPI. - 1424-8220. ; 20:16
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Tidskriftsartikel (refereegranskat)abstract
- Metabolt is a portable soil incubator to characterize the metabolic activity of microbial ecosystems in soils. It measures the electrical conductivity, the redox potential, and the concentration of certain metabolism-related gases in the headspace just above a given sample of regolith. In its current design, the overall weight of Metabolt, including the soils (250 g), is 1.9 kg with a maximum power consumption of 1.5 W. Metabolt has been designed to monitor the activity of the soil microbiome for Earth and space applications. In particular, it can be used to monitor the health of soils, the atmospheric-regolith fixation, and release of gaseous species such as N2, H2O, CO2, O2, N2O, NH3, etc., that affect the Earth climate and atmospheric chemistry. It may be used to detect and monitor life signatures in soils, treated or untreated, as well as in controlled environments like greenhouse facilities in space, laboratory research environments like anaerobic chambers, or simulating facilities with different atmospheres and pressures. To illustrate its operation, we tested the instrument with sub-arctic soil samples at Earth environmental conditions under three different conditions: (i) no treatment (unperturbed); (ii) sterilized soil: after heating at 125 °C for 35.4 h (thermal stress); (iii) stressed soil: after adding 25% CaCl2 brine (osmotic stress); with and without addition of 0.5% glucose solution (for control). All the samples showed some distinguishable metabolic response, however there was a time delay on its appearance which depends on the treatment applied to the samples: 80 h for thermal stress without glucose, 59 h with glucose; 36 h for osmotic stress with glucose and no significant reactivation in the pure water case. This instrument shows that, over time, there is a clear observable footprint of the electrochemical signatures in the redox profile which is complementary to the gaseous footprint of the metabolic activity through respiration.
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| 65. |
- Israel Nazarious, Miracle, et al.
(författare)
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Pressure Optimized PowEred Respirator (PROPER) : A miniaturized wearable cleanroom and biosafety system for aerially transmitted viral infections such as COVID-19
- 2020
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Ingår i: HardwareX. - : Elsevier. - 2468-0672. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The supply of Personal Protective Equipment (PPE) in hospitals to keep the Health Care Professionals (HCP) safe taking care of patients may be limited, especially during the outbreak of a new disease. In particular, the face and body protective equipment is critical to prevent the wearer from exposure to pathogenic biological airborne particulates. This situation has been now observed worldwide during the onset of the COVID-19 pandemic. As concern over shortages of PPE at hospitals grows, we share with the public and makers’ community the Pressure Optimized PowEred Respirator (PROPER) equipment, made out of COTS components. It is functionally equivalent to a Powered Air Purifying Respirator (PAPR). PROPER, a hood-based system which uses open source and easily accessible components is low-cost, relatively passive in terms of energy consumption and mechanisms, and easy and fast to 3D print, build and assemble. We have adapted our experience on building clean room environments and qualifying the bioburden of space instruments to this solution, which is in essence a miniaturized, personal, wearable cleanroom. PROPER would be able to offer better protection than an N95 respirator mask, mainly because it is insensitive to seal fit and it shields the eyes as well. The PROPER SMS fabric is designed for single-use and not intended for reuse, as they may start to tear and fail but the rest of the parts can be disinfected and reused. We provide a set of guidelines to build a low-cost 3D printed solution for an effective PAPR system and describe the procedures to validate it to comply with the biosafety level 3 requirements. We have validated the prototype of PROPER unit for air flow, ISO class cleanliness level, oxygen and carbon-dioxide gas concentrations during exhalation, and present here these results for illustration. We demonstrate that the area inside the hood is more than 200 times cleaner than the external ambient without the operator and more than 175 times with the operator and in an aerosol exposed environment. We also include the procedure to clean and disinfect the equipment for reuse. PROPER may be a useful addition to provide protection to HCPs against the SARS-CoV-2 virus or other potential future viral diseases that are transmitted aerially.
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| 66. |
- Kahanpää, Henrik, et al.
(författare)
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Convective vortices and dust devils at the MSL landing site : annual variability
- 2016
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Ingår i: Journal of Geophysical Research - Planets. - 2169-9097 .- 2169-9100. ; 121:8, s. 1514-1549
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Tidskriftsartikel (refereegranskat)abstract
- Two hundred fifty-two transient drops in atmospheric pressure, likely caused by passing convective vortices, were detected by the Rover Environmental Monitoring Station instrument during the first Martian year of the Mars Science Laboratory (MSL) landed mission. These events resembled the vortex signatures detected by the previous Mars landers Pathfinder and Phoenix; however, the MSL observations contained fewer pressure drops greater than 1.5 Pa and none greater than 3.0 Pa. Apparently, these vortices were generally not lifting dust as only one probable dust devil has been observed visually by MSL. The obvious explanation for this is the smaller number of strong vortices with large central pressure drops since according to Arvidson et al. [2014] ample dust seems to be present on the surface. The annual variation in the number of detected convective vortices followed approximately the variation in Dust Devil Activity (DDA) predicted by the MarsWRF numerical climate model. This result does not prove, however, that the amount of dust lifted by dust devils would depend linearly on DDA, as is assumed in several numerical models of the Martian atmosphere, since dust devils are only the most intense fraction of all convective vortices on Mars, and the amount of dust that can be lifted by a dust devil depends on its central pressure drop. Sol-to-sol variations in the number of vortices were usually small. However, on 1 Martian solar day a sudden increase in vortex activity, related to a dust storm front, was detected.
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| 67. |
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| 68. |
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| 69. |
- Kloos, Jacob L., et al.
(författare)
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The First Martian Year of Cloud Activity from Mars Science Laboratory (Sol 0 - 800)
- 2016
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Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 57:5, s. 1223-1240
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Tidskriftsartikel (refereegranskat)abstract
- Using images from the Navigation Cameras onboard the Mars Science Laboratory rover Curiosity, atmospheric movies were created to monitor the cloud activity over Gale Crater. Over the course of the first 800 sols of the mission, 133 Zenith Movies and 152 Supra-Horizon Movies were acquired which use a mean frame subtraction technique to observe tenuous cloud movement. Moores et al. (2015a) reported on the first 360 sols of observations, representing LS = 150° to 5°, and found that movies up to LS = 184° showed visible cloud features with good contrast while subsequent movies were relatively featureless. With the extension of the observations to a full Martian year, more pronounced seasonal changes were observed. Within the Zenith Movie data set, clouds are observed primarily during LS = 3° - 170°, when the solar flux is diminished and the aphelion cloud belt is present at equatorial latitudes. Clouds observed in the Supra-Horizon Movie data set also exhibit seasonality, with clouds predominantly observed during LS = 72° - 108°. The seasonal occurrence of clouds detected in the atmospheric movies is well correlated with orbital observations of water-ice clouds at similar times from the MCS and MARCI instruments on the MRO spacecraft. The observed clouds are tenuous and on average only make up a few-hundredths of an optical depth, although more opaque clouds are observed in some of the movies. Additionally, estimates of the phase function calculated using water-ice opacity retrievals from MCS are provided to show how Martian clouds scatter sunlight, and thus provide insight into the types of ice crystals that comprise the clouds.
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| 70. |
- Konatham, Samuel, et al.
(författare)
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Atmospheric composition of exoplanets based on the thermal escape of gases and implications for habitability
- 2020
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Ingår i: Proceedings of the Royal Society. Mathematical, Physical and Engineering Sciences. - : Royal Society. - 1364-5021 .- 1471-2946. ; 476:2241
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Tidskriftsartikel (refereegranskat)abstract
- The detection of habitable exoplanets is an exciting scientific and technical challenge. Owing to the current and most likely long-lasting impossibility of performing in situ exploration of exoplanets, their study and hypotheses regarding their capability to host life will be based on the restricted low-resolution spatial and spectral information of their atmospheres. On the other hand, with the advent of the upcoming exoplanet survey missions and technological improvements, there is a need for preliminary discrimination that can prioritize potential candidates within the fast-growing list of exoplanets. Here we estimate, for the first time and using the kinetic theory of gases, a list of the possible atmospheric species that can be retained in the atmospheres of the known exoplanets. We conclude that, based on our current knowledge of the detected exoplanets, 45 of them are good candidates for habitability studies. These exoplanets could have Earth-like atmospheres and should be able to maintain stable liquid water. Our results suggest that the current definition of a habitable zone around a star should be revisited and that the capacity of the planet to host an Earth-like atmosphere to support the stability of liquid water should be added.
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