Rocket Factory Augsburg (RFA) a German New Space Startup is developing a three-stage rocket launcher aiming at LEO/SSO orbits. A fundamental responsibility of the GNC team is the development of the rocket navigation algorithm to estimate the attitude, position, and velocity allowing the guidance and control loops to autonomously steer the rocket. This thesis focuses on the analysis and design of a Hybrid Navigation system able to satisfy the various necessities of a launch vehicle, such as delay compensation and GNSS outages. The navigation architecture was chosen to be a Closed Loop, Loosely Coupled, Delayed Error State Kalman Filter thanks to the proven capability of COTS receivers to autonomously provide a consistent PVT solution throughout the flight. A preliminary analysis used a reference trajectory to evaluate the effect of the sensor grade on inertial performances and choose an appropriate integration scheme. The filter’s system model was explored using approximate analytical results on observability. The developed navigation module was then tested within a Monte Carlo simulation environment by perturbating the sensor parameter in accordance with the sensor datasheet. As a further verification, the modeled IMU output was compared to the engineering model, to assure that the simulation result would yield conservative errors. Due to concern over the visibility of GNSS satellites during flight, a simplified Almanac-based GPS model has been developed, proving that enough satellite visibility is available along the trajectory. The estimation error was compared with the filter’s estimated covariance and found well within the bounds. Through the study of the covariance evolution, it was determined that given the reference dynamics, the sensor misalignments are the least observable states. Realistic signal outages were introduced in the most critical flight intervals. The filter was indeed found to be robust and the tuning proved to be adequate to capture the dead reckoning drift. Finally, the entire navigation module was deployed onto the avionics engineering model, including the flight computer, IMU, GNSS, and antennas, in a configuration equivalent to flight. The navigation module was then tested to ensure that the execution was in performance under severe multipath errors and prolonged GNSS outages with the covariance estimates correctly covering the uncertainty. / Rocket Factory Augsburg (RFA), ett tyskt nystartat rymdföretag, utvecklar en trestegsraket som siktar på LEO/SSO-banor. Ett grundläggande ansvar för GNC-teamet är utvecklingen av raketnavigationsalgoritmen för att uppskatta attityd, position och hastighet så att styr- och kontrollslingorna kan styra raketen autonomt. Avhandlingen fokuserar på analys och design av ett hybridnavigeringssystem som kan uppfylla de olika krav som ställs på en bärraket, såsom kompensation för fördröjningar och GNSS-avbrott. Navigationsarkitekturen valdes att vara ett Closed Loop, Loosely Coupled, Delayed Error State Kalman Filter tack vare den bevisade förmågan hos COTS-mottagare att autonomt tillhandahålla en konsekvent PVT-lösning under hela flygningen. En preliminär analys använde en referensbana för att utvärdera effekten av sensorkvaliteten på tröghetsprestanda och välja ett lämpligt integrationsschema. Filtrets systemmodell undersöktes med hjälp av approximativa analytiska resultat om observerbarhet. Den utvecklade navigeringsmodulen testades sedan i en Monte Carlo-simuleringsmiljö genom att störa sensorparametern i enlighet med sensorns datablad. Som en ytterligare verifiering jämfördes den modellerade IMU-utgången med den tekniska modellen, för att säkerställa att simuleringsresultatet skulle ge konservativa fel. På grund av oro över GNSS-satelliternas synlighet under flygning har en förenklad Almanac-baserad GPS-modell utvecklats, som bevisar att tillräcklig satellitsikt finns tillgänglig längs banan. Uppskattningsfelet jämfördes med filtrets uppskattade kovarians och låg väl inom gränserna. Genom att studera kovariansutvecklingen fastställdes det att givet referensdynamiken är sensorernas feljusteringar de minst observerbara tillstånden. Realistiska signalavbrott infördes i de mest kritiska flygintervallen. Filtret visade sig verkligen vara robust och inställningen visade sig vara tillräcklig för att fånga upp dödberäkningens drift. Slutligen installerades hela navigeringsmodulen på den flygtekniska modellen, inklusive flygdator, IMU, GNSS och antenner, i en konfiguration som motsvarar en flygning. Navigationsmodulen testades sedan för att säkerställa att utförandet var i prestanda under allvarliga multipath-fel och långvariga GNSS-avbrott med kovariansuppskattningarna som korrekt täcker osäkerheten.

Concurrent Design studies have become of great importance in the space industry reducing the time and costs associated to the feasibility assessments for future space missions. This has also helped companies and space agencies to be at the forefront of this fast-developing sector. These collaborative sessions are carried out by an interdisciplinary group of engineers, experts and customers who are capable of achieving an optimal design solution within a short period of time, typically a few weeks. They make use of dedicated tools, like COMET® which is developed by RHEA Group, to store and share the data within the team, as well as with other partners or stakeholders. As new software tools are developed for Model-Based Systems Engineering (MBSE) applications, parallel improvements are needed for Concurrent Engineering teams, since this can be one of the first steps for a model-based approach. One of the main constraints during Concurrent Design studies is the limited number of analysed options, since evaluating the entire design space would require longer sessions and increased time availability from the experts, and would consequently result in more expensive projects. One solution for this problem can be the application of generative engineering technologies to Concurrent Design studies. This method would allow to explore the entire design space by first defining the study model together with the system constraints, and then using a software to automatically generate all the possible architecture variants for that specific model. An example of state-of-the-art technologies for generative design is Simcenter™ Studio, a recently released tool from Siemens Digital Industries Software. The complexity of space missions requires a very detailed definition and evaluation of the system architecture, even at the early stages of the design process. Therefore, research is needed on the use and implementation of new methodologies that will tackle the challenges related to Concurrent Design. The context of the research presented in this thesis is the new project proposed by RHEA Group, Siemens and OHB, called Generative Concurrent Design (GCD). It aims to combine their software tools COMET® and Simcenter Studio, bringing generative engineering to Concurrent Design. One of the main advantages is achieving more optimised solutions in shorter times, reducing the number of necessary iterations on the system architecture during the entire project lifecycle. An enhanced feature of this tool is the possibility for the users to explore the solutions trade space with the support of an Artificial Intelligence (AI) based system. This thesis presents and demonstrates the application of the GCD methodology to a use case at system level, focused on the evaluation of configuration and assembly options in the design of a spacecraft. Using the mission EnVision, selected in 2021 by ESA’s Science Programme Committee, as the design baseline, the GCD methodology has been implemented in this use case study making use of both software tools and showing potential future features and applications. / Les études de conception concourante ont pris une grande importance dans l'industrie spatiale, en réduisant le temps et les coûts associés aux évaluations de faisabilité des futures missions spatiales. Cela a également permis aux entreprises et aux agences spatiales d'être à l'avant-garde de ce secteur en plein essor. Ces sessions de collaboration sont menées par un groupe interdisciplinaire d'ingénieurs, d'experts et de clients qui sont capables d'obtenir une solution de conception optimale dans un délai court, généralement quelques semaines. Ils utilisent des outils dédiés, comme COMET® qui est développé par RHEA Group, pour stocker et partager les données au sein de l'équipe, ainsi qu'avec d'autres partenaires ou parties prenantes. Au fur et à mesure que de nouveaux outils logiciels sont développés pour les applications d'ingénierie des systèmes basés sur les modèles (MBSE), des améliorations parallèles sont nécessaires pour les équipes d'ingénierie concourante, car cela peut constituer l'une des premières étapes d'une approche basée sur les modèles. L'une des principales contraintes lors des études de conception concourante est le nombre limité d'options analysées, car l'évaluation de l'ensemble de l'espace de conception nécessiterait des sessions plus longues et une plus grande disponibilité des experts, ce qui se traduirait par des projets plus coûteux.  Une solution à ce problème pourrait être l'application des technologies d'ingénierie générative aux études de conception concourante. Cette méthode permettrait d'explorer l'ensemble de l'espace de conception en définissant d'abord le modèle d'étude ainsi que les contraintes du système, puis en utilisant un logiciel pour générer automatiquement toutes les variantes possibles du système pour ce modèle spécifique. Un exemple de technologies de pointe pour la conception générative est Simcenter™ Studio, un outil récemment publié par Siemens Digital Industries Software.  La complexité des missions spatiales exige une définition et une évaluation très détaillées de l'architecture du système, même aux premiers stades du processus de conception. Par conséquent, des recherches sont nécessaires sur l'utilisation et la mise en œuvre de nouvelles méthodologies qui permettront de relever les défis liés à la conception concourante. Le contexte de la recherche présentée dans cette thèse est le nouveau projet proposé par RHEA Group, Siemens et OHB, appelé Conception Concurrente Générative (Generative Concurrent Design ou GCD en anglais). Il vise à combiner leurs outils logiciels COMET® et Simcenter Studio, en apportant l'ingénierie générative à la conception concourante. L'un des principaux avantages est de parvenir à des solutions plus optimisées dans des délais plus courts, en réduisant le nombre d'itérations nécessaires sur l'architecture du système pendant tout le cycle de vie du projet. Une caractéristique améliorée de cet outil est la possibilité, pour les utilisateurs, d'explorer l'espace commercial des solutions avec le soutien d'un système basé sur l'intelligence artificielle (IA). Cette thèse présente et démontre l'application de la méthodologie GCD à un cas d'utilisation au niveau système, centré sur l'évaluation des options de configuration et d'assemblage dans la conception d'un vaisseau spatial. En utilisant la mission EnVision, sélectionnée en 2021 par le Comité du Programme Scientifique de l'ESA, comme base de conception, la méthodologie GCD a été mise en œuvre dans cette étude de cas d'utilisation, en employant les deux outils logiciels et en montrant les fonctionnalités et applications potentielles futures.

This thesis describes the development of an autonomous recovery system for stratospheric balloons, focusing on the novel pressurised balloon prototype BALMAN of CNES. Stratospheric balloons, reaching altitudes of up to 40 km, are utilised for scientific experiments, with recovery of payloads being a critical aspect. While traditional recovery methods involve separating the balloon envelope and deploying a parachute, BALMAN's parachute will be deployed in free fall. The proposed autonomous system comprises decision-making and electronics components. The decision-making segment employs microcontrollers and environmental sensors to recognise the balloon's descent, triggering the release decision. The electronics section, responsible for providing energy to a pyro cutter, is designed with electrical switches and capacitors. Thermal simulations guide the placement of heaters, maintaining system temperature within operational limits. The final prototype, tested for functionality on-ground, exhibits a measured energy release of 24 mJ, double the requirement for pyro cutter activation. However, environmental and flight testing remain pending. The system's potential applications extend beyond BALMAN, offering a standardised autonomous recovery solution for various balloons. This innovation promises enhanced landing accuracy, obviates the need for telecommunication in recovery, and facilitates payload descent deceleration. Future endeavors involve comprehensive testing and potential integration into BALMAN missions, showcasing the system's adaptability and operational simplicity across diverse stratospheric endeavors.

The probability of satellite collisions and disintegrations cluttering the near-Earth orbital environmentis ever-growing. This is especially true for the congested Low Earth Orbit (LEO) regime; once a critical density of objects is reached, a collisional cascading is projected to generate runaway growth of theorbital population. Comprehensive tracking of Resident Space Objects (RSO) is a requisite precursor to conjunction forecasting and avoidance; a strategy for active debris mitigation. Conducted at Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR) Andøya Space, this work presents a means through which a passive optical observation station can be established using only an off-the shelf Canon EOS-1300 camera for uncued detection. A custom processing pipelinewas developed to perform data reduction on the retrieved images and initialisation of the object orbit was accomplished via implementations of the classic Initial Orbit Determination (IOD) algorithms of Laplace and Gauss. RSO identification was performed by reconstruction of the overpass and comparison against objects in a Two Line Elements (TLE) database. The complete script initiates the tracking process, and requires no inputs other than the image, and the geodetic coordinates of the ground station. The processing pipeline was demonstrated to perform robustly on the collected images and the algorithms were tested for different orbital regimes using precision angular data extracted from literature, with the retrieved results corresponding closely to the available reference values for all orbital regimes. Their performance as predictors of satellite position was compared for a variety of test cases, withthe Gauss algorithm producing more consistent results. However, orbits could not be initialised from the images, due to insufficient angular and timing precision. Various adaptations and extensions are suggested in order to achieve the requisite accuracy in the optical data and improve the data collection.

This thesis explores the potential of utilizing metal-based plasma sources as a sustainable solution for high-powered electric propulsion and its implications for future interplanetary travel. Focusing on the Vacuum Arc Thruster and the Variable Specific Impulse Magnetoplasma Rocket engine, the study encompasses numerical simulations, analytical comparisons, and performance analyses to assess the feasibility of metal plasma fuels in space missions.The numerical analysis employs COMSOL Multiphysics to delve into the magnetohydrodynamics behavior within the VAT. Such simulation setup could provide valuable insights. Although the numerical results are disappointing for this paper, there exist possibilities within future work. The main hurdle is the simulation of vacuum. There are workarounds in COMSOL's Vacuum System Modeling tool which was not available for this thesis. Also, the used material properties were not suited for this high temperature plasma environment. The lack of material properties is a consequence of the insufficient research in the metal plasma field.Performance analysis is conducted on both the VAT and VASIMR engine, exploring efficiency, thrust capabilities, and feasibility for interplanetary missions. The results demonstrate the potential of metal-based plasma sources to reduce dependence on Earth for refueling and decrease mission costs. It is found that aluminum and magnesium have similar performance as the argon gas used in the VASIMR.Although challenges exist, such as integration problems and availability of material properties for metals in plasma states, the study underscores the promise of metal plasma fuels for sustainable space exploration. By advancing high-powered electric propulsion technologies, we move closer to realizing humanity's ambitious journey to distant celestial bodies. This research paves the way for future innovations, enabling a more self-sustaining space economy and unlocking new horizons of interplanetary travel.

With growing space market and entry of more private companies into the industry, there arecompanies and stakeholders who would like to have a high order of accuracy mission outputrequirements. These requirements vary from mission to mission. This simply means that if acompany wants an Earth observation mission, the main requirement to be fulfilled would be tohave the highest resolution of image possible. In order to achieve this, the satellite carrying the camera payload would be required to bepointed in the right direction with utmost accuracy. For a satellite to be pointed in the rightdirection, the noise generated by the sensors and actuators on-board, which determines theattitude of the satellite and helps in changing it, should be minimized. The aim of this thesisis to design a method which could help in determining the right components to be procuredso that the pointing requirements of the satellite are fulfilled. This objective is achieved bydesigning algorithms in python and MATLAB. The values generated by these algorithms, ultimately describe the type of sensor or actuator to be procured. Finally, the noise generated bysuch individual components act as pointing error source and then PEET is used to translatethese error sources to platform error, to generate a pointing budget and ensure that all pointingrequirements are satisfied.

Satellite power management systems play a crucial role in ensuring the operational success andlongevity of satellite missions. As satellites operate in the harsh environment of space, efficient powermanagement is essential to maximize energy utilization, maintain stability, and extend mission lifespans.Within the framework of the Avionics department, CNES has acquired the Power Conditioning andDistribution Unit (PCDU) GOMSPACE P60, in order to demonstrate the reliability of Commercial Offthe Shelf (COTS) products and viability of a low-cost satellite architecture. In this thesis, the integrationand characterization of the GOMSPACE P60 PCDU is presented. This internship consisted of mainlythree objectives. The development of the software needed to control the equipment, the development ofa graphics unit interface (GUI) for housekeeping data visualisation and the preparation, carrying out andreporting of different performance tests. Some of the main characteristics of the system assessed, includethe high adaptability that it has based on the mission requirements. The equipment appeared to notprovide easy access to the design after delivery, but it functions nominally upon delivery. It is robust inlow or high temperatures as well as in harsh (electromagnetic interference) EMI perturbations. Thiselectrical power system (EPS) allows for high control of its board parameters and observability of thetelemetry data. However, this command control is hard to integrate based on the supplied C libraries andthere were occasional unexpected behaviours from the system. Based on the assessment done duringthis internship, it could replace previously used PCDUs that have lesser performance and higher cost infuture nanosatellites low cost missions such as student or proof of concept missions. However, thelimited information and details provided in the data package by the distributor, makes the equipmentinsufficient for larger missions. Higher level of analysis and qualification is required for this scope,based on the common requirements and standards followed by the agency.

The design of a liquid rocket propulsion system, unlike that of a standalone system, is intertwined with the overall development of a number of associated systems and is influenced by a multitude of conditions and considerations: from the requirements needed to accomplish the mission to the rationalizations involved behind the development of each rocket system and/or component. In my thesis, the preliminary design of a “new generation” 30 kN rocket engine driven by an electric pump feed system and running on liquid methane and liquid oxygen is performed. The propulsion system would be employed on a hypothetical small-lift orbital-class twin-stage rocket to deliver a light payload of about 200 kg into a circular 500 km LEO. Such topics as the selection of bipropellant combinations, the feasibility of electric pump feed systems, design methodologies for thrust chambers, for nozzles in particular, management of the high thermal energy and the selection of compatible wall materials, as well as the design of an injector have been looked comprehensively into. It is realized that methalox is indeed better than both hydrolox (with regard to density impulse) and kerolox (in terms of specific impulse). Besides, a suite of attractive characteristics makes the bipropellant a combination of choice to power rockets of the future. Yet more notably, an electric-pump-fed engine cycle is, under the right circumstances of engine operation, established to outperform both the pressure feed system and the turbopump feed system. With constant advancement in battery technologies, improvement of both power density and energy density to achieve much higher performance is but a matter of time. The adoption of a propulsion system such as ours for a mission objective as outlined above, therefore, is not just viable but unquestionably realistic. Two thrust chamber versions—a sea-level variant for the booster stage and a vacuum-optimized variant for the upper stage—are developed for our rocket. And both the nozzles employ a TOP “thrust optimised parabolic” contour; also, the booster stage comprises a cluster of 9 engines in a parallel burn arrangement. Concerning thermal management, the entirety of the booster-stage thrust chamber implements regenerative cooling (using Inconel 625), whereas the aft of the upper-stage nozzle section implements radiative cooling (with Niobium C-103). Further, the injector faceplate (also of Inconel 625) comprises two concentric patterns of unlike impingement doublet sets: with 80 pairs on the outer ring and 40 pairs on the inner ring. With rational assumptions, our hypothetical launch vehicle is deemed to have a mass of roughly 17200 kg (200 kg of which is the payload) and a delta-v of approximately 9600 m/s—quite within the desirable range of specifications for small-lift orbital-class twin-stage rockets of today.

The Comet Interceptor is a joint mission by European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) which seeks to perform a flyby over a Long Period Comet using a multi-element spacecraft. The Comet Interceptor comprises three spacecrafts- A, B1 and B2. All three spacecrafts will observe and map the comet at three different points on the coma of the comet, thereby making this mission the first ever multipoint mission dedicated to study a Long Period Comet. Out of the eleven instruments aboard the Comet Interceptor, the work done for this thesis aims to help the team designing the instrument-Optical Periscope Imager forComets (OPIC). The team designing OPIC uses the imaging simulation software Space Imaging Simulator for Proximity Operations (SISPO) to render images of theoretically modelled dust and gas densities of the coma of a comet to obtain prerequisite knowledge of the images which is to be taken by OPIC during its flyby. Using the theoretical model of the coma, a 3D model was created as part of the thesis which shall be later implemented in SISPO. The structure of the coma was made with the help of a sparse volumetric data manipulation tool OpenVDB, which was coded and run in Python. The generated data was imported in Blender to visualise the volumetric data with the help of Blender’s rendering engine-Cycles. To visualise the 3D model with utmost physical realism as the software Blender allows, a study on the scattering properties of the dust and gas model was done. Also, a motion blur was implemented in Blender to simulate the high relative velocity between the instrument and comet. Multiple approaches of varying complexities and time consumption were considered for importing and visualising the volumetric data. The final render images were brightness-matched with reference to images from previous cometary missions. Finally, a qualitative analysis was done by visually comparing the render images to the images from previous missions. With the help of this qualitative analysis, several features and characteristics were identified which were analogous to the real life images, thus establishing the correctness of the renders produced.

The constant growth of space debris and the associated risks force the space community to find solutions to mitigate them. Today the most advanced solutions to dispose of satellites and rocket stages after the end of mission consists of moving them either into a graveyard orbit or towards an atmospheric re-entry ending in the demise of both spacecraft and its materials. Alternative solutions should be considered, such as providing a sustainable solution by reusing materials in space. However, it is crucial to understand better the ageing process of the materials present in currently active spacecraft and space debris. The space environment causes degradation and damage over time, making the state of those materials uncertain for potential re-use. Degradation effects have been studied as a source mechanism to result in paint flakes, ejecta particles, or delaminated insulation foils released into the space environment and sustaining a positive feedback loop through potential impacts into spacecraft. A better understanding of degradation effects would also help to better characterize the small debris environment and its evolution. The current materials databases used by the space industry could be useful tools to select materials for satellite missions with respect to their reusability, but they often do not include the evolution of material properties in space after the end of mission.This study will investigate the impact of the damage effects of radiation and meteoroid impact on solar panels. During this research, the methodology used to analyse these effects was explained. The results showed that radiation caused the most damage and could cause solar panels to lose more than a third of their performance over a period of 50 years. It was therefore possible to estimate the quantity of solar panels available for re-use. It was concluded that the results were valid, but that to obtain more accurate data, all the different types of deterioration would also have to be considered. / Creaternity