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.

The ongoing worldwide pandemic of coronavirus disease 2019 (COVID-19), has been one of the most significant challenges to humankind in centuries. The extremely contagious nature of the SARS-CoV-2 virus has put forth an immense pressure on the health sector. In order to mitigate the stress on the healthcare systems especially to battle the crisis of mechanical ventilators, we have designed a modular, and robust DIY ventilator, ATMO-Vent (Atmospheric Mixture Optimization Ventilator) which can be fully mounted within two days by two operators. The ATMO-Vent has been designed using low-cost, robust, Commercial Off The Shelf (COTS) components, with many features comparable to a full-fledged ventilator. ATMO-Vent has been designed based on the United Kingdom Medicines & Healthcare products Regulatory Agency (UK-MHRA) guidelines for Rapidly Manufactured Ventilator System (RMVS), yet scalable to the specific requirements of different countries. ATMO-Vent is capable of adjusting the Fraction of Inspiratory Oxygen (FiO2) levels, Tidal Volume (TV), frequency of breaths, Inspiratory/Expiratory ratio (I/E), Peak Inspiratory Pressure (PIP) and Positive End-Expiratory Pressure (PEEP). ATMO-Vent can operate in two modes - Continuous Mandatory Ventilation (CMV) using Volume-Controlled Ventilation (VCV) and in Assisted Control (AC) mode with pressure triggered by the patient. ATMO-Vent has undergone rigorous testing and qualifies under Class B Electric and Magnetic Compatibility (EMC) requirements of EN 55011 CISPR 11 standards.

The HabitAbility: Brines, Irradiation and Temperature (HABIT) instrument will be part of the ExoMars 2020 mission (ESA/Roscosmos) and will be the first European In-situ Resource Utilization (ISRU) instrument capable of producing liquid water on Mars. HABIT is composed by two modules: Environmental Package (EnvPack) and Brine Observation Transition To Liquid Experiment (BOTTLE). EnvPack will help to study the current habitability conditions on Mars investigating the air and surface thermal ranges and Ultraviolet (UV) irradiance; and BOTTLE is a container with four independent vessels housing deliquescent salts, which are known to be present on Mars, where the liquid water will be produced after deliquescence. In order to prevent capillarity of deliquescent or hydrated salts, a mixture of deliquescent salts with Super Absorbent Polymer (SAP) based on polyacrylamide is utilized. This mixture has deliquescent and hydrogel properties and can be reused by applying a thermal cycle, complying thus with the purpose of the instrument. A High Efficiency Particulate Air (HEPA) grade filter made of polytetrafluroethylene (PTFE) porous membrane sandwiched between spunbounded non-woven fabric stands as a physical barrier allowing interaction between the gaseous molecules of the Martian atmosphere and the salt mixtures, and at the same time preventing the passage of any potential biological contamination from the cells to the outside or vice-versa. In addition to the physical barrier, a strict bioburden reduction and analysis procedure is applied to the hardware and the contained salt mixtures adhering to the European Cooperation for Space Standardization protocol of microbial examination of flight hardware (ECSS-Q-ST-70-55C). The deliquescent salts and the SAP products need to be properly treated independently to adhere to the planetary protection protocols. In this manuscript, we describe the bioburden reduction process utilized to sterilize the salt mixtures in BOTTLE and the assays adopted to validate the sterilization. We also describe the construction of a low-cost, portable ISO 7 cleanroom tent, exclusively designed for planetary protection tests. The sterilization process involves Dry Heat Microbial Reduction (DHMR) of the deliquescent salts and the SAP mixtures. The performance of SAP after DHMR is validated to ensure its working efficiency after sterilization. A slightly modified version of the standard swab assay is used in the validation process and a comparison is made between samples exposed to a thermal shock treatment and those without thermal shock, to determine the best assay to be applied for future space hardware utilizing such salt mixtures for planetary investigation and In-Situ Resource Utilization (ISRU). The demonstration of the compatibility of these products with the processes commonly required for space applications has implications for the future exploration of Mars.

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.

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.

This PhD thesis describes, from an engineering perspective, some of the preliminary steps that need to be implemented to facilitate the human exploration of Mars. It focuses on the development of a set of novel scientific or technology demonstrator instruments. The engineering problem starts with a conceptual idea and the definition of individual functional requirements, that may be related to scientific or technological objectives. To solve this problem, an unique approach adapted during this thesis, allowed for designing and building efficiently, testing and refining the instruments in multiple iterations using simple techniques like 3-D printing, breadboard prototyping and low-cost commercial off the shelf (COTS) components. This approach reduces the cost and facilitates the accessibility of space instrument design and testing to a broader community. The steps include demonstrating the operability of the concept with prototypes, calibrating the responses and validating their operation in representative environments, thereby raising the technology readiness level (TRL) of the instrument with a lower investment in time and resources than traditional approaches that use specialized components and fabrica-tion techniques.

The thesis provides a detailed description of the design and development process, and discusses the calibration and validation results of four different instruments, namely: 1) Brine Observation Transition To Liquid Experiment (BOTTLE) as a part of HabitAbil-ity: Brines, Irradiation and Temperature (HABIT) instrument onboard the ESA/IKI’s ExoMars 2022 Surface Platform Kazachok, for investigating the surface environmen-tal conditions and demonstrating the capability of salts to absorb water on Mars, 2) Metabolt, a small-sized portable incubator to monitor the behaviour of the microbiome in soils, which will be a critical element of future greenhouses on Mars or the Moon, 3) Methanox, an in-situ resource utilization demonstrator for converting local resources on Mars and producing methane and ammonia as space fuel, and 4) PRessure Optimized PowEred Respirator (PROPER), a wearable cleanroom developed for protecting the hu-mans against biological pathogens, showing the direct applicability of this research to solve Earth-based problems. During the final phase of the PhD thesis, the world suffered the COVID-19 pandemic. This challenge provided an opportunity to test the approach presented in this thesis and inspired the development of this equipment, and may also be of relevance to protect from biological cross-contamination in planetary habitats and laboratories while handling local regolith materials and samples on Mars.

This work also highlights the calibration of the HABIT Flight Model (FM) in the cleanroom of Omnisys Instruments AB, Sweden, defines the retrieval models that will be used during ExoMars 2022 mission operations and data archiving in the Planetary Science Archive (PSA). Parts of this thesis were already published in the form of peer-reviewed journal articles and conference abstracts.

We describe a versatile simulation chamber that operates under representative space conditions (pressures from < 10⁻⁵ mbar to ambient and temperatures from 163 to 423 K), the SpaceQ chamber. This chamber allows to test instrumentation, procedures, and materials and evaluate their performance when exposed to outgassing, thermal vacuum, low temperatures, baking, dry heat microbial reduction (DHMR) sterilization protocols, and water. The SpaceQ is a cubical stainless-steel chamber of 27,000 cm³ with a door of aluminum. The chamber has a table which can be cooled using liquid nitrogen. The chamber walls can be heated (for outgassing, thermal vacuum, or dry heat applications) using an outer jacket. The chamber walls include two viewports and 12 utility ports (KF, CF, and Swagelok connectors). It has sensors for temperature, relative humidity, and pressure, a UV–VIS–NIR spectrometer, a UV irradiation lamp that operates within the chamber as well as a stainless-steel syringe for water vapor injection, and USB, DB-25 ports to read the data from the instruments while being tested inside. This facility has been specifically designed for investigating the effect of water on the Martian surface. The core novelties of this chamber are: (1) its ability to simulate the Martian near-surface water cycle by injecting water multiple times into the chamber through a syringe which allows to control and monitor precisely the initial relative humidity inside with a sensor that can operate from vacuum to Martian pressures and (2) the availability of a high-intensity UV lamp, operating from vacuum to Martian pressures, within the chamber, which can be used to test material curation, the role of the production of atmospheric radicals, and the degradation of certain products like polymers and organics. For illustration, here we present some applications of the SpaceQ chamber at simulated Martian conditions with and without atmospheric water to (i) calibrate the ground temperature sensor of the Engineering Qualification Model of HABIT (HabitAbility: Brines, Irradiation and Temperature) instrument, which is a part of ExoMars 2022 mission. These tests demonstrate that the overall accuracy of the temperature retrieval at a temperature between −50 and 10 °C is within 1.3 °C and (ii) investigate the curation of composite materials of Martian soil simulant and binders, with added water, under Martian surface conditions under dry and humid conditions. Our studies have demonstrated that the regolith, when mixed with super absorbent polymer (SAP), water, and binders exposed to Martian conditions, can form a solid block and retain more than 80% of the added water, which may be of interest to screen radiation while maintaining a low weight. 

The HABIT (HabitAbility: Brine Irradiation and Temperature) instrument is a European payload of the ExoMars 2022 Surface Platform Kazachok that will characterize the present-day habitability at its landing place in Oxia Planum, Mars. HABIT consists of two modules: (i) EnvPack (Environmental Package) that monitors the thermal environment (air and ground), the incident ultraviolet radiation, the near surface winds and the atmospheric dust cycle; and (ii) BOTTLE (Brine Observation Transition To Liquid Experiment), an In-situ Resource Utilization instrument to produce liquid water for future Mars exploration. BOTTLE will be used also to investigate the electrical conductivity properties of the martian atmosphere, the present-day atmospheric-ground water cycle and to evaluate if liquid water can exist on Mars in the form of brines, and for how long. These variables measured by HABIT are critical to determine the present and future habitability of the martian surface. In this paper, we describe in detail the HABIT instrument and sensors, together with the calibration of its Flight Model (FM) and the Engineering Qualification Model (EQM) versions. The EnvPack module has heritage from previous missions operating on the surface of Mars, and the environmental observations of its sensors will be directly comparable to those delivered by those missions. HABIT can provide information of the local temperature with ±0.2 °C accuracy, local winds with ±0.3 m/s, surface brightness temperature with ±0.8 °C, incident UV irradiance with 10% error of its absolute value in the UV-A, UV-B, UV-C ranges, as well as in the total UV-ABC range, and two additional wavebands, dedicated to ozone absorption. The UV observations can be used to derive the total opacity column and thus monitor the dust and ozone cycles. BOTTLE can demonstrate the hydration state of a set of four deliquescent salts, which have been found on Mars (calcium chloride, ferric sulphate, magnesium perchlorate and sodium perchlorate) by monitoring their electric conductivity (EC). The EC of the air and the dry salts under Earth ambient, clean room conditions is of the order of 0.1 μScm−1. We have simulated HABIT operations, within an environmental chamber, under martian conditions similar to those expected at Oxia Planum. For dry, CO2 atmospheric conditions at martian pressures, the air EC can be as low as 10−8 μScm−1, however it increases with the relative humidity (RH) percentage. The laboratory experiments show that after an increase from 0 to 60% RH within a few hours, the EC of the air increased up to 10−1 μScm−1, magnesium perchlorate hydrated and reached values of 10 μScm-1, whereas calcium chloride deliquesced forming a liquid state with EC of 102 μScm−1. HABIT will operate with a regular cadence, through day and night. The Electronic Unit (EU) is protected with a heater that is activated when its temperature is below −33 °C and disabled if the temperature of the surface platform rises above −30 °C. Additionally, the heaters of the BOTTLE unit can be activated to dehydrate the salts and reset the experiment. HABIT weighs only 918 g. Its power consumption depends on the operation mode and internal temperature, and it varies between 0.7 W, for nominal operation, and 13.1 W (when heaters are turned on at full intensity). HABIT has a baseline data rate of 1.5 MB/sol. In addition to providing critical environmental observations, this light and robust instrument, will be the first demonstrator of a water capturing system on the surface of Mars, and the first European In-Situ Resource Utilization in the surface of another planet.

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.

The HABIT (HabitAbility, Brines, Irradiation and Temperature) instrument, will be the first Swedish Instrument that will land on the surface of Mars as a part of the ExoMars 2020 mission (ESA/IKI). It is also the first European ISRU (In-situ Resource Utilization) instrument capable of producing liquid water on Mars extracting atmospheric water vapor using salt deliquescence to form a stable liquid brine. HABIT also will study current habitability conditions on Mars investigating the air and surface thermal ranges and UV (Ultra-Violet) irradiance. The BOTTLE (Brine Observation Transition To Liquid Experiment) is the container element of HABIT with four independent cells housing deliquescent salts, which have been found on Mars, exposing them to the Martian atmosphere. In order to prevent capillarity of deliquescent or hydrated salts a mixture of deliquescent salts with Super Absorbent Polymer (SAP) based on polyacrylamide is utilized. This mixture has deliquescent and hydrogel properties that can be reused by applying a thermal cycle, complying thus with the purpose of the instrument. A Poly-Tetra Fluro Ethylene (PTFE) coated nylon HEPA (High Efficiency Particulate Air) filter stands as a physical barrier allowing interaction between the gaseous molecules of the Martian atmosphere and the salt mixtures, and at the same time prevents the passage of any biological contamination from the cells to the outside or vice-versa. In addition to the physical barrier, a strict bioburden reduction and analysis is made on the contained salt mixtures adhering to the European Cooperation for Space Standardization protocol of Microbial examination of flight hardware (ECSS-Q-ST-70-55C). The deliquescent salts and the SAP products need to be properly treated independently to adhere to the planetary protection protocols. In this paper, we have described the bioburden reduction process utilized to sterilize the salt mixtures in BOTTLE and the assays adopted to validate the sterilization. The sterilization process adopted involves ultra-fine filtration and Dry Heat Microbial Reduction (DHMR) of the deliquescent salts and the SAP respectively. The performance of SAP after DHMR is validated to ensure its working efficiency after sterilization. A standard swab assay and a pour-plate assay are adopted in the validation process and a comparison is made between them to determine the best assay to be applied for future space hardware utilizing such salt mixtures for planetary investigation and ISRU. The demonstrating of the compatibility of these products with the processes commonly required for space applications has implications for the future explorationof Mars.