| 1. |
- Mathanlal, Thasshwin
(författare)
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Development of robotic instruments and techniques for space and astrobiological exploration and research
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Astrobiology is the study of life in the universe. The search for life beyond the Earth requires an understanding of the signatures of life, and of the nature of the environments that support it. Space exploration is a crucial factor to achieve these goals. The PhD thesis focusses on developing novel techniques for astrobiological and Earth exploration. It includes instrument prototyping, validation and calibration of a flight-ready space in-strument.This thesis explains the development of four instruments namely 1) KORE – a robotic exploration rover designed for subsurface analogue planetary explorations; 2) InXSpace3D – a 3D mapping payload for biogeomorphological analysis based on a com-mercial RGB-D camera and an open-source algorithm; 3) S3ME2 – a self-sustainable environmental monitoring station capable of withstanding harsh environments on Earth; and 4) PACKMAN – a space weather monitoring instrument. The instruments are devoted to: 1) the spatial exploration and characterization (KORE and InXSpace3D) of a potentially habitable environment and 2) the monitorization of the rapidly vary-ing environmental variables that may affect life (S3ME2 and PACKMAN), its evolution and preservation. The instruments are developed according to the Technology Readiness Level (TRL) Ladder and a cost and time effective methodology which maximizes the use of Commercial Off-The-Shelf (COTS) components and Open source software.The thesis also discusses the bioburden sterilization and control procedure of some of the sensors on the flight-ready space Instrument HABIT (HabitAbility: Brines, Irradi-ation and Temperature), that will be part of the ExoMars 2022 mission. Again, a COTS and an open source software-based approach has been used in these higher TRL level procedures. This demonstrates the fact that such an engineering approach can benefit the scientific community by developing instruments with a minimal investment of time and resources without compromising the scientific quality of the instrument. The thesis concludes with the adaptation of the research methodology to adapt space technologies that are applicable in space for human support systems to address an emerging problem on Earth: ATMO-Vent, a low-cost COTS-based ventilator that produces an adapted breathable atmosphere for COVID-19 patients.During the PhD thesis, the author has published five peer-reviewed journal papers, two peer-reviewed conference abstracts and two co-authored peer-reviewed journal pa-pers. The first authored papers and conference abstracts have been appended to the Part-II of the thesis.
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| 2. |
- Nazarious, Miracle Israel, 1992-
(författare)
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Scientific Instruments to Facilitate the Human Exploration of Mars
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 3. |
- Konatham, Samuel, 1992-
(författare)
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Atmospheric Species and Spectral Radiation in Terrestrial Exoplanets : Implications for Astrobiology
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The physical properties of the planets and their parent stars are fundamental in the composition of atmospheres and radiative environments, which fundamentally determine their surface temperature and habitability. The atmospheric composition and radiation play a vital role in the emergence of life. This doctoral thesis presents two main results: 1. A method that uses the physical properties of the planets and their parent stars to infer the potential atmospheric compositions of the known exoplanets. For that, fundamental physics concepts and the basics of the kinetic theory of gases are used. Additionally, a new list of potentially habitable exoplanets is presented based on the resulting atmospheric compositions and the criteria that Earth-like atmospheres that can host liquid water should be considered habitable. The presented method also provides a preliminary classification of exoplanets similar to Earth (in terms of atmosphere) and their potential habitability. 2. A study of the impact of the radiation environment on the development and evolution of the human visual system towards optimal use of the available radiation. Human vision's possible evolutionary directions are presented while overcoming the shortcomings in the existing studies. The human visual system is hypothesised to have evolved in conjugation with the prevailing spectral radiation environment for photopic (daytime) and scotopic (night-time). One of the main novelties of this study is the comparison of the human vision bandwidth with the Full Width at half-maximum (FWHM) of the radiation reaching the shallow depths of the ocean, which may suggest that this is optimized for the development of animal sight during the formation of the early proto-visual system. Moreover, the observed maximum absorption wavelength during photopic vision (555nm) correlates with the maximum total energy for a 300 nm vision bandwidth. Furthermore, the analysis of the radiation environment at different solar zenith angles (SZA) during dusk suggests that the scotopic vision evolved to optimize information retrieval during these hours. The work presented in this thesis contributes to perform screening of Earth-like exoplanets and the study of astrobiological or space exploration aspects such as potential habitability, human-like vision, photosynthesis efficiency and evolution of life systems on exoplanets.
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| 4. |
- Nyberg, Erik, 1986-
(författare)
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Ionic Liquid Lubricants for Space Applications
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lubrication is critical to the efficient and reliable operation of machine elements such as gears, bearings, or any other moving mechanical assembly (MMA). On Earth, machine designers are accustomed to the access of a wide range of liquid lubricants that enable predictable and reliable long-term operations of high performance MMA. In space applications on the other hand, engineers are constrained to a comparatively limited choice of lubricant candidates that can meet the stringent demands of tribosystems operating in a space environment. At the same time, repair or maintenance are seldom options that are possible in space, and consequently lubricant failures are potentially critical. As international space agencies are converging on the goal of establishing a permanently crewed lunar Gateway for human presence on the Moon and eventually onwards to Mars, there is a need for radical improvements in many aspects of space exploration technology, including space tribology and space grade lubricants. Liquid lubricants are enablers of high performance. A thin fluid film – even in the submicron scale – is often sufficient to separate opposing surface boundaries from direct contact, and thereby prevent excessive friction and wear. Liquid lubricants are therefore attractive for use in space mechanisms. Unfortunately, liquid lubricants must overcome several issues in order to be effective in the space environment. Vacuum, microgravity, and low temperatures are all factors that oppose the effective supply of liquid lubricants into the tribological contact of MMA. If the tribological contact becomes starved of oil, the surfaces enter the boundary lubrication regime where seizure is an ever-present threat. There are very few types of fluids available that meet the stringent space grade lubricant requirements. Perfluoropolyalkylethers (PFPE), or multiply alkylated cyclopentanes (MAC) are two fluids with significant heritage in space applications. These fluids are currently employed as lubricants in a wide range of space applications, as they are rare examples of fluids that meet the high demands on resistance to vacuum outgassing. Unfortunately, these compounds are susceptible to degradation under boundary lubrication conditions, and unlike conventional lubricants employed on Earth, these fluids have poor compatibility with the boundary lubrication additives that are commonly employed in conventional oils. Ionic liquids (ILs) have emerged as potential liquid lubricant candidates in space. These synthetic fluids are composed of anions and cations. The resulting ionic interaction enables the substance to have low vapor pressure with relatively low molecular weight. For this reason, ILs have been advocated as one of the candidate lubricants for space applications. When employing ILs as lubricants, the ionic charge provides Coulombic interaction with surfaces to enable the formation of a boundary lubricating film. This is an important part of the IL lubricating mechanism, but successful lubricant performance requires integrating the lubricant candidate into the tribosystem, taking into account operating conditions and environment. Therefore, the boundary film formation should be tunable to the application at hand. Ionic liquids are designable fluids, with properties dependent on the combination of anion and cation as well as incorporated functional groups. Based on this background, this work focused on evaluating the feasibility of employing ionic liquid lubricants for space applications. In this thesis, the molecular design of an IL lubricant was described Paper [1], and the resulting hydrocarbon-mimicking ionic liquid (P-SiSO) was evaluated in tribological experiments in boundary lubricated conditions. Boundary film formation by neat P-SiSO was studied in Paper [2], and in Paper [3] we describe the use of P-SiSO as a multipurpose performance ingredient in MAC. A test methodology was devised in Paper [4] in order to evaluate the lubrication performance under component scale experiments in space relevant conditions. The designed ionic liquid lubricant was evaluated in Paper [5] by the specific methodology. Advanced surface analysis was employed to understand the tribo-mechanism of P-SiSO in both the model scale experiments as well as the component scale. The lubricated surfaces were analyzed in terms of surface topography- and chemistry, and mechanisms of lubrication are discussed. A highly effective boundary film based on ionic adsorption and formation of silicate was observed by these ionic liquids. This thesis demonstrates the feasibility of employing ionic liquids for lubrication of moving mechanical assemblies in space applications.
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| 5. |
- Vakkada Ramachandran, Abhilash
(författare)
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A planetary chamber to investigate the thermal and water cycle on Mars
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The water processes that affect the upper layers of the surface of Mars are not yet fully understood. Describing the processes that may induce changes in the water content ofthe surface is critical to determine the present-day habitability of the Martian surface,understand the atmospheric water cycle, and estimate the efficiency of future water extraction procedures from the regolith for In-Situ-Resource-Utilization (ISRU). This PhD thesis describes the design, development, and plausible uses of a Martian environmental facility ‘SpaceQ chamber’ which allows to simulate the near surface water cycle.This facility has been specifically designed to investigate the effect of water on the Martian surface. SpaceQ has been used to investigate the material curation and has 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 thesis also includes the testing of HABIT operation, of theESA/IKI ExoMars 2022 robotic mission to Mars, within the SpaceQ chamber, underMartian conditions similar to those expected at Oxia Planum. The tests monitor the performance of the brine compartment, when deliquescent salts are exposed to atmospheric water.In this thesis, a computational model of the SpaceQ using COMSOL Multiphysics has been implemented to study the thermal gradients and the near surface water cycle under Martian temperature and pressure experimental conditions. The model shows good agreement with experiments on the thermal equilibration time scales and gradients. The model is used to extrapolate the one-point relative humidity measurement of the experimental to each grid points in the simulation. This gives an understanding ofthe gradient in atmospheric water relative humidity to which the experimental samples such as deliquescent salts and Martian regolith simulants are exposed at different time intervals. The comparison of the thermal simulation and the experimental behavior of HABIT instrument tests, shows an extra internal heating source of about 1 W which can be attributed to the hydration and deliquescence of the salts exposed to Martian conditions when in contact with atmospheric moisture.Finally, this thesis experimentally demonstrates that pure liquid water can persist for 3.5 to 4.5 hours at Mars surface conditions. The simulated ground captured 53% of the atmospheric water either as pure liquid water, hydrate, or brine. The result concludes that the relative humidity values at night-time on Mars may allow for significant water absorption by the ground, which is released at sunrise. The water cycle dynamics near the surface is therefore always out of equilibrium. After frost formation, thin films of water may survive for a few hours. The results of this thesis about the water cycle on Mars, and about the interaction of atmospheric water with regolith and salts, have implications for the present-day habitability of the Martian surface and planetary protection policies.
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