En 1638, paraît en Angleterre un ouvrage de John Wilkins (1614 - 1672), traitant de la pluralité des Mondes et plus précisément de la découverte d’un nouveau Monde : la Lune. Grâce à une argumentation dialectique, l’auteur tente de montrer la similarité entre la Terre et notre satellite. Il s’appuie pour cela sur le modèle copernicien et sur les observations astronomiques de Galilée. De cette similarité, en résulte, selon lui, l’idée que la Lune est peut-être habitée comme la Terre, par des êtres qu’il nomme Sélénites. Il ajoute qu’il serait possible de s’y rendre, et de commercer avec les habitants. L’objectif de cette thèse est d’étudier la place des sciences du vivant dans les théories sur la pluralité des Mondes, principalement dans l’œuvre de John Wilkins, et les différentes implications littéraires, théologiques et philosophiques qui en découlent. / In 1638, a book is published in England by John Wilkins (1614-1672), dealing with the plurality of Worlds, and more specifically the discovery of a New World: the Moon. With a dialectical reasoning, the author tries to show the similarities between the Earth and the Moon. For this he uses the Copernican model and astronomical observations of Galileo. From these similarities, Wilkins suggests the idea that the moon could be harboring living beings like Earth and then conjecture on the nature of its inhabitants, the Selenites. He writes that it may be possible one day to reach the Moon and trade with its inhabitants. The purpose of our work is to study the living in the discourse on the plurality of worlds, and observe its place in the work of Wilkins.

Les forçages physiques conditionnent la discontinuité dans l'espace et le temps (patchiness) du plancton dans l'océan. La thèse s'est basée sur deux exemples. Le premier concerne le nord-ouest des Sargasses où une série temporelle à du macrozooplankton a été analysée à partir du rétro signal acoustique (Sv) mesuré avec un ADCP 153-KHz. Trois types de tourbillons ont été identifiés: un tourbillon cyclonique productif, la périphérie d'un tourbillon "mode-water", et la périphérie d'un tourbillon anticyclonique. Les valeurs de Sv ont augmenté au cours du passage des tourbillons, avec une hausse plus marquée associée au bord des tourbillons cyclonique et anticyclonique, ce qui suggère une réponse biologique significative aux upwelling localisées dans la zone frontale de ces tourbillons. Dans le deuxième exemple, la distribution spatiale et temporelle du zooplancton a été étudiée au large de la Nouvelle-Calédonie au cours de deux campagnes multidisciplinaires en 2011. La variabilité du zooplancton a été évaluée à l'aide d'échantillonnage au filet ainsi qu'à partir de mesures acoustiques (ADCP embarqué, échosondeur scientifique et TAPS). Des amplitudes plus élevées de la migration verticale nycthémérale (DVM) du zooplancton étaient associées à une plus grande abondance de petit zooplancton et aux eaux froides du sud de la zone d'étude, tandis que des amplitudes de DVM plus faibles dans le nord étaient associés à des eaux plus chaudes et à de plus grande abondance des grands organismes. Ces mesures acoustique ont clairement mis en évidence le rôle des forçage physique, notamment des structures à méso-échelle, sur la répartition spatiale et temporelle du zooplancton. / Physical forcing drives the space and time discontinuity (patchiness) of plankton in the ocean. The thesis was focused on the role of these forcing on the zooplankton, studied using both acoustic and traditional methods with net sampling. The study was based on two examples. The first one concerns the northwestern Sargasso Sea where high resolution time-series data on 0-200m macrozooplankton abundance and distribution off Bermuda was estimated from volume backscattering strength (Sv) measured with a 153-Khz ADCP. Three types of eddies were identified: a productive cyclonic eddy, the periphery of a mode water eddy, and the periphery of an anticyclonic eddy. Sv values increased during passage of theses eddies, with a more pronounced increase associated with the edge of the cyclonic and the anticyclonic eddies, suggesting a significant biological response to localized upwelling in the high velocity boundary of these eddies. In the second example, spatial and temporal distribution of zooplankton off New Caledonia was studied during two multidisciplinary cruises in 2011. Zooplankton variability was assessed using net sampling together with acoustic measurements (shipborne ADCP, scientific echosounder and TAPS). Higher amplitudes of diel vertical migration (DVM) of zooplankton were associated with higher abundance of large zooplankton and cold waters to the south of the study area, while lower DVM amplitudes in the north were associated with warmer waters and higher abundance of small organisms. These acoustic measurements clearly evidenced the role of physical forcing, particularly mesoscale features, in shaping zooplankton space and time distribution.

L’étude du paléomagnétisme des roches extraterrestres fournit des informations sur les champs magnétiques présents dans le système solaire il y a plusieurs milliards d’années. A travers ce travail de thèse nous avons exploré deux grands aspects : un champ de dynamo sur un corps différencié, la Lune, et des champs magnétique dans le système solaire primitif avec l’étude de chondrites (CM et les rumurutites). Notre étude des échantillons lunaires a permis de confirmer l’existence d’un champ de dynamo ancien de forte intensité (~50 µT) entre 3.8 et 3.3 Ga. En utilisant l’anisotropie de susceptibilité magnétique comme indicateur de paléohorizontale et en faisant l’hypothèse d’une géométrie de champ dipolaire, nous avons déterminé que l’axe de cette dynamo était centré sur l’axe de rotation actuel de la Lune. Les chondrites CM et les Rumurutites ont enregistré des champs magnétiques anciens quelques millions d’années après la formation du système solaire. L’aimantation rémanente des chondrites CM constitue probablement le plus ancien enregistrement paléomagnétique jamais mis en évidence. L’estimation de la paléointensité (2 µT) et les contraintes chronologiques dont nous disposons ne permettent pas de trancher entre un champ d’origine externe (solaire ou nébulaire) ou d’origine interne (dynamo). Cette dernière hypothèse laisse entrevoir la possibilité de la formation de corps partiellement différenciés dès les premiers millions d’année du système solaire. Dans les rumurutites, les conclusions sont similaires, avec une paléointensité également estimée à 2 µT. Cependant l’aimantation étant plus jeune, une origine interne est favorisée. / Paleomagnetic studies of extraterrestrials rocks provide information on magnetic fields that prevailed in the solar system several million years ago.Through this work we have explored two main aspects: a field dynamo on a differentiated body, the moon, and magnetic fields in the early solar system with the study of two chondrites classes; CM and rumurutites. Our study of lunar samples confirmed that an old dynamo field of high intensity (~50 µT) existed on the Moon between at least 3.8 and 3.3 Ga. Using the anisotropy of magnetic susceptibility as a proxy for paleohorizontale and assuming a dipole field geometry, we determined that the dynamo axis was centered on the actual rotation axis of the Moon.CM chondrites and Rumurutites recorded old magnetic fields acquired few million years after the formation of the solar system. The remanent magnetization of CM chondrites is probably the oldest paleomagnetic record never evidenced. The estimated paleointensity (2 µT) and time constraints not allowed to discriminate between a field of external (solar or nebular) or internal origin (dynamo). This latter hypothesis suggests that formation of partially differentiated body could occur during the first million years of the solar system history. In rumurutites, conclusions are similar, with a paleointensity also estimated at ~2µT. However, the magnetization is younger and an internal origin is favored.

<p> </p> <p>In the coming decades, numerous missions plan to exploit multi-body orbits for operations. Given the complex nature of multi-body systems, trajectory designers must possess effective tools that leverage aspects of the dynamical environment to streamline the design process and enable these missions. In this investigation, a particular class of dynamical structures, quasi-periodic orbits, are examined. This work summarizes a computational framework to construct quasi-periodic orbits and a design framework to leverage quasi-periodic motion within the path planning process. First, quasi-periodic orbit computation in the Circular Restricted Three-Body Problem (CR3BP) and the Bicircular Restricted Four-Body Problem (BCR4BP) is summarized. The CR3BP and BCR4BP serve as preliminary models to capture fundamental motion that is leveraged for end-to-end designs. Additionally, the relationship between the Earth-Moon CR3BP and the BCR4BP is explored to provide insight into the effect of solar acceleration on multi-body structures in the lunar vicinity. Characterization of families of quasi-periodic orbits in the CR3BP and BCR4BP is also summarized. Families of quasi-periodic orbits prove to be particularly insightful in the BCR4BP, where periodic orbits only exist as isolated solutions. Computation of three-dimensional quasi-periodic tori is also summarized to demonstrate the extensibility of the computational framework to higher-dimensional quasi-periodic orbits. Lastly, a design framework to incorporate quasi-periodic orbits into the trajectory design process is demonstrated through a series of applications. First, several applications were examined for transfer design in the vicinity of the Moon. The first application leverages a single quasi-periodic trajectory arc as an initial guess to transfer between two periodic orbits. Next, several quasi-periodic arcs are leveraged to construct transfer between a planar periodic orbit and a spatial periodic orbit. Lastly, transfers between two quasi-periodic orbits are demonstrated by leveraging heteroclinic connections between orbits at the same energy. These transfer applications are all constructed in the CR3BP and validated in a higher-fidelity ephemeris model to ensure the geometry persists. Applications to ballistic lunar transfers are also constructed by leveraging quasi-periodic motion in the BCR4BP. Stable manifold trajectories of four-body quasi-periodic orbits supply an initial guess to generate families of ballistic lunar transfers to a single quasi-periodic orbit. Poincare mapping techniques are used to isolate transfer solutions that possess a low time of flight or an outbound lunar flyby. Additionally, impulsive maneuvers are introduced to expand the solution space. This strategy is extended to additional orbits in a single family to demonstrate "corridors" of transfers exist to reach a type of destination motion. To ensure these transfers exist in a higher fidelity model, several solutions are transitioned to a Sun-Earth-Moon ephemeris model using a differential corrections process to show that the geometries persist.</p>

For 500 years transient light phenomena (TLP) have been observed on the lunar surface by ground-based observers. The actual physical reason for most of these events is today still unknown. Current plans of NASA and SpaceX to send astronauts back to the Moon and already successful deep-space CubeSat mission will allow in the future research nanosatellite missions to the cislunar space. This thesis presents a new hardware and software concept for a future payload on such a nanosatellite. The main task was to develop and implement a high-performance image processing algorithm which task is to detect short brightening flashes on the lunar surface. Based on a review of historic reported phenomena, possible explanation theories for these phenomena and currently active and planed ground- or space-based observatories possible reference scenarios were analyzed. From the presented scenarios one, the detection of brightening events was chosen and requirements for this scenario stated. Afterwards, possible detectors, processing computers and image processing algorithms were researched and compared regarding the specified requirements. This analysis of available algorithm was used to develop a new high-performance detection algorithm to detect transient brightening events on the Moon. The implementation of this algorithm running on the processor and the internal GPU of a MacMini achieved a framerate of 55 FPS by processing images with a resolution of 4.2 megapixel. Its functionality and performance was verified on the remote telescope operated by the Chair of Space Technology of the University of Würzburg. Furthermore, the developed algorithm was also successfully ported on the Nvidia Jetson Nano and its performance compared with a FPGA based image processing algorithm. The results were used to chose a FPGA as the main processing computer of the payload. This concept uses two backside illuminated CMOS image sensor connected to a single FPGA. On the FPGA the developed image processing algorithm should be implemented. Further work is required to realize the proposed concept in building the actual hardware and porting the developed algorithm onto this platform.

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<p> </p> <p>There are several challenges that occur when creating extraterrestrial structures that are not relevant to terrestrial applications. The Resilient Extra-Terrestrial Habitat Institute is a NASA funded research project focused on developing resilient lunar habitats. In order to develop these deep-space structures, many considerations have to be made to account for scenarios that are not relevant to Earth. Such scenarios include meteorite impacts, moonquakes, radiation, and moon dust accumulation. To observe possible consequences of these disruptions, RETHi established a modular coupled virtual testbed to monitor the effects of different deep-space related situations. MCVT is a computer model of a lunar habitat that uses a system-of-systems approach to examine the impacts of these scenarios. Currently, MCVT is developing methods to confront these extraterrestrial situations by utilizing robotic agents and expanding upon a variety of safety responses to increase resiliency.  RETHi also utilizes a cyber physical testbed to run cyber-physical experiments to validate the approaches used in MCVT. </p> <p><br></p> <p>One of the numerous models in MCVT is the Habitat Interior Environment Model. HIEM monitors the interior environment of the lunar structure using physics-based calculations and inputs from its surroundings. There are three main disturbances that directly affect the interior environment—fire within the dome, meteorite impacts, and airlock failure. Such scenarios either increase or decrease the temperature and pressure. This data is then forwarded to other subsystems for further evaluation. HIEM can be remodeled to fit the pressure box in the cyber physical testbed. By doing so, it is then possible to validate the pressure leakage calculations used in HIEM using experimental data. HIEM is specifically designed to the lunar habitat currently in development; however, the model can be refitted to a variety of applications such as terrestrial, aerospace, space, and marine. </p>

<p dir="ltr">This research explores the potential of AR for lunar missions via the xEMU spacesuit. A market analysis of commercial off-the-shelf AR devices identifies technological trends and constraints that inform the architectural decisions for AR integration with the xEMU. User evaluations in simulated work environments ensure lunar informatics align with crew needs. Drawing insights from human-in-the-loop testing of COTS AR devices, qualitative test results underscore the importance of display optimization, occlusion management, and environmental considerations for enhancing the AR experience during lunar EVAs. Grounded in a task analysis from JETT3 analog testing, crew workflows and communication dynamics are baselined, underscoring the vital role of communication and collaboration. Integrating AR into the EVA work environment holds the potential to streamline decision-making, improve navigation, and enhance overall efficiency, but may come with unintended operational consequences. The human-centered approach prioritizes crew involvement, ensuring that technology remains a facilitator rather than an encumbering element in lunar exploration. The study's significance lies in advancing AR technology for lunar EVAs, guiding hardware design, and enabling seamless integration into the EVA work environment. AR holds promise in reshaping the human-technology relationship, empowering crew members, maximizing science output, and contributing to the next chapter in lunar exploration.</p>

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<p dir="ltr"> With NASA's Artemis program and international collaborations focused on building a sustainable infrastructure for human exploration of the Moon, there is a growing demand for lunar exploration and complex spaceflight operations in cislunar space. However, designing efficient transfer trajectories between the Earth and the Moon remains complex and challenging. This investigation focuses on developing a dynamically informed framework for constructing low-energy transfers in the Earth-Moon-Sun Bicircular Restricted Four-body Problem (BCR4BP). Techniques within dynamical systems theory and numerical methods are exploited to construct transfers to various cislunar orbits. The analysis aims to contribute to a deeper understanding of the dynamical structures governing spacecraft motion. It addresses the characteristics of dynamical structures that facilitate the construction of propellant-efficient pathways between the Earth and the Moon, exploring periodic structures and energy properties from the Circular Restricted Three-body Problem (CR3BP) and BCR4BP. The investigation also focuses on constructing families of low-energy transfers by incorporating electric propulsion, i.e., low thrust, in an effort to reduce the time of flight and offer alternative transfer geometries. Additionally, the investigation introduces a process to transition solutions to the higher fidelity ephemeris force model to accurately model spacecraft motion through the Earth-Moon-Sun system. This research provides insights into constructing families of ballistic lunar transfers (BLTs) and cislunar low-energy flight paths (CLEFs), offering a foundation for future mission design and exploration of the Earth-Moon system.</p>