Hold down release mechanisms (HDRMs) are used for tightly attaching segments of bodies together when it is desired to release them rapidly at some point. When transporting sensitive payloads on launch vehicles, the challenge arises of releasing the fastened segments of the spacecraft without risking damage to the costly equipment. Non-explosive HDRMs are favourable from a safety perspective as there is a lower risk of producing potentially destructive shock-waves throughout the structure.  One variant of a non-explosive HDRM uses a so called 'split spool initiator'. This initiator can only be used once in the actuator mechanism and to reuse the HDRM the initiator must be replaced. The purpose of this thesis is to design an improved split spool initiator which can be reusable while conserving the functionality aspects of the existing design. To achieve this, different ideas were considered and ultimately a solution using shape memory alloys (SMAs) was explored. A prototype was constructed to demonstrate the functionality of the design and simulations are done to determine the forces acting on different parts of the mechanism. / Hold down release-mekanismer (HDRM) används för att säkert kunna fästa samman delar av strukturer för att sedan kunna lossa dessa vid rätt tillfälle. När det transporteras känslig last på exempelvis rymdfarkoster uppkommer utmaningen att göra så på ett sätt som inte riskerar att skada den ofta dyra utrustningen. Det finns en mängd olika HDRM, dessa kan delas upp i två typer som är icke explosiva release-mekanismer och pyrotekniska release-mekanismer. Icke explosiva release-mekanismer har en fördel över pyrotekniska som är att de inte producerar potentiellt destruktiva chock-vågor som sprids genom strukturen. En typ av icke-explosiva release-mekanismer är den så kallade split spool-initieraren. Denna kan endast användas en gång när fästelementet är aktiverat och för att kunna använda fästelementet igen måste hela initieraren bytas ut. Syftet med denna studie har varit att att designa en förbättrad split spool-initierare som är återanvändbar, medan funktionaliteten hos den ursprungliga designen är bevarad. För att åstadkomma detta övervägdes olika idéer och slutligen valdes en lösning som använder minnesmetaller eller Shape memory alloys på engelska (SMA). En prototyp konstruerades för att demonstrera funktionaliteten hos designen. Simuleringar gjordes även för att bestämma krafter som agerade på split spool-strukturen och för att få en överblick över spänningsfördelningen genom initieraren.

This study is an empirical case study of the Swedish space- and automation company Unibap AB about how to build trust in the space industry. The space industry is distinctive in the way that space missions are at high stakes because of the high costs and the fact that the technology can not be modified after launch. Reliability and trust are therefore crucial factors of doing business in the space industry. Also, AI-based satellite solutions can bring huge benefits but 60% of the resistance from companies to running AI is linked to lack of trust. The concept of trust has been discussed before in the industrial marketing literature and differentiates between social sources and offer-related sources of trust. However, there appears to be an empirical as well as a theoretical gap when it comes to building trust in the space industry. Because the topic is unexplored, an exploratory methodology is used when interviewing 12 actors in the space- and high-tech industry worldwide. Since one important aspect of offer-related trust seems to be usability, this study also includes a usability evaluation of Unibap's space computer solution SpaceCloud which enables on-board AI applications. Key antecedents of trust in the space industry were found to be transparency, competence, reliability of technology, and exact delivery times. It appears that social- and offer-related trust significantly influence partnerships between companies and that offer-related trust is the most important type of trust to win contracts of tax-funded agencies. Strengths and improvements of the usability of SpaceCloud are also identified, and it is concluded that SpaceCloud has the potential to offer a new way of building satellite applications in the future.

For performance optimisation of modern liquid cryogenic bipropellant rocket combustion chambers, one component which plays an important role in reducing the wall side heat flux, is the behaviour of the cooling film. At the Institute of Space Propulsion of the German Aerospace Center (DLR) in Lampoldshausen, hot test runs have been performed using the experimental combustion chamber BKM, to investigate the wall side heat flux which is -- among other factors -- dependent on cooling film properties. To gain more insight into the film behaviour under real rocket-like conditions, optical diagnostics have been applied. The chosen methods were shadowgraphy and OH* imaging producing optical data sets which are analysed in this study. In this context, a description of the necessary background information is given, concerning rocket combustion chambers, film cooling and optical diagnostics of O2/H2 combustion. The applied methodology for optical analysis is described, followed by a presentation of the results. During the test campaign, it became clear that the optical setup was not optimised for creating meaningful shadowgraphy recordings which is why the shadowgraphy data has to be treated as flame emission imaging. The behaviour of the gas layer adjacent to the chamber wall could be characterised based on qualitative (luminosity, LOx shadow, reflection, recirculation zone and flame shape) and quantitative (layer thickness, layer length, pressure conditions) analysis. The thickness could be identified for each load step and an average length of the layer was found as well. OH* imaging has been used supplementary to support the observations from the flame emission images. An in depth frame by frame analysis was not possible due to time constraints. However, the time averaged images yielded results in accordance to the flame emission and could give a relative figure for the temperature distribution in the combustion volume. An artefact in the data was found, stemming presumably from the image intensifier. This artefact needs to be researched for a future error reduction in the data of this and other campaigns. Additionally, the thickness of the layer suggested a correlation to the models for film cooling efficiency. Such a correlation could not be established. Nevertheless, the film cooling models show the same behaviour as the data obtained from the flame emission imaging. Finally, suggestions are given how the data analysis and the optical setup could be improved for future, similar campaigns.

The cooling systems in a gas turbine are especially important as the turbine blades and vanes are exposed to extreme temperatures. The relatively cool air is extracted from the compressors and fed to the turbines to cool the turbine blades. The manufacturing of these blades and channels used to cool is especially complicated using conventional manufacturing techniques. Additive Manufacturing (AM) gives the designer much more freedom to design core components. The AM technique currently explored is the Selective Laser Melting process (SLM). The surface area is exposed to the cooling airflow by using lattice structures which can be manufactured at relative ease using AM. This thesis will provide some insights into using AM parts for the cooling, by analyzing the pressure drop that could be expected from superalloys that are manufactured using AM. The surface roughness is an inherent property of the AM components therefore it would be interesting to analyze a turbulent flow through AM channels (CM247LC and INCONEL 939). The thesis deals with turbulent flows as the airflow used for cooling in the gas turbine is most likely turbulent.  The friction factor (Darcy–Weisbach friction factor) is used to relate the impact of the surface roughness to the pressure drop. The results from the previous experiments are contrasted as the flow in the previous experiments was assumed to be fully developed but in reality, it was not. And the accuracy of the previous results to the actual fully developed flow will shed some light on the feasibility of the flow analysis techniques used in the previous experiments. It is found that the previous experimental results for the CM247LC TPs have good agreement with current experimental results but INCONEL 939 exhibits significant deviation. The possible reasons for the deviations are directly linked to the assumptions made to calculate the minor losses. The Test Pieces (TP) analyzed in this thesis have varying length to diameter (L/D) ratios and the impact of the variation of different L/D ratios is analyzed along with varying pressure ratios. Where the flow resistance increases with an increase in L/D and pressure ratio. The technique to accommodate the compressibility of the airflow is also explored in this thesis. Finally, reasons for the manifestation of anomalies are discussed. The probability of the compressibility effects of the airflow on the anomalies was found to be quite high, and concluding remarks are provided.

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.

In the aviation industry, safety and robustness are the number one priorities, which is why they use well-tested systems such as hydraulic actuators. However, drawbacks such as high weight and maintenance have pushed the industry toward newer, electrical, actuators that are more efficient and lighter. Electrical actuators, on the other hand, have some reliability issues. In particular, short circuits in the stator windings of Permanent-Magnet SynchronousMotors (PMSMs), referred to as Inter-Turn Short Faults (ITSFs), are the dominating faults, and is the focus of this thesis. ITSFs are usually challenging to detect and often do not become noticeable until the fault has propagated, and the motor is on the verge of being destroyed. This thesis investigates the possibility of detecting ITSFs in a PMSM, at an early stage when only one turn is shorted. The method is limited to finding the faults using ML algorithms. Both an experiential PMSM and a simulated model of the experimental PMSM, with the ability to induce an ITSF, were used to collect the data. Several Machine Learning (ML) models were developed, and then trained and tested with the collected data. The results show that four of the tested ML models, being: Random Forest, Gaussian SVM, KNN, and the CNN, all achieve an accuracy exceeding 95%, and that the fault can be found at an early stage in a PMSM with three coils connected in parallel in each phase. The results also show that the ML models are able to identify the ITSF when the simulated data is downsampled to the same frequency as the experimental data. We conclude that the ML models, provided in this study, can be used to detect an ITSF in a simulated PMSM, at an early stage when only one turn is shorted, and that there is great potential for them to detect ITSFs in a physical motor as well.

The study aimed to identify and analyse methods for establishing external communication between humans and autonomous/teleoperated machines/vehicles using various Human-Machine Interfaces (HMIs). The study was divided into three phases. The purpose of the first phase was to identify and highlight previously tested/researched methods for establishing external communication by conducting a literature review. The findings from the literature review were categorised into six points of interest: machine indications, test delivery methods, HMI technologies/types, symbols, textual/numerical messages, and colours associated with different indications. Based on these findings, four HMIs (projection, display, LED-strip, and auditory) were selected for evaluation in a virtual reality environment for the second phase of the study, which has the purpose of identifying which of the human-machine interfaces can effectively communicate the intentions of autonomous/teleoperated machines to humans. The results of phase two indicate that the participants preferred projection as the most effective individual HMI, and when given the option to combine two HMIs, projection combined with auditory was the most preferred combination. The participants were also asked to pick three HMIs of their choosing, resulting in the projection, display and audible HMI combination being the preferred option. The evaluation of HMIs in a virtual reality environment contributes to improving dependability and identifying usability issues.  The objective of the third and final phase was to gather all the findings from the previous phases and subsequently refine the report until it was considered finalised. Future work includes enhancing the realism of the VR environment, refining machine behaviour and scenarios, enabling multiple participants to simultaneously interact with the environment, and exploring alternative evaluation methods. Addressing these areas will lead to more realistic evaluations and advancements in human-machine interaction research.

The space industry is currently undergoing a significant servitization-shift as space agencies globally are transitioning from the government-led product-oriented procurement approach, that has been the standard for decades, to a more commercial service-oriented procurement approach. The purpose of the thesis is to identify what challenges exists within servitization in European space exploration and translate these into related improvement areas for the service-oriented procurement approach adopted by the European Space Agency (ESA). The thesis adopts a qualitative case-study approach where four different commercial services, developed through a commercial partnership between ESA and private enterprises, are being studied. In total, the study identifies 21 challenges across three different life-cycle stages for the commercial services. First, the study identifies cultural challenges for both the space agency and industry as they struggle in transitioning to a service culture from the existing culture that is strongly linked with the traditional approach. Second, the study also identifies several challenges related to how the processes established within the frame of the commercial partnership are currently inadequate to support the transition to commercial services. In particular, the study highlights knowledge gaps related to business planning and marketing, insufficient processes to ensure a balance in cost and quality incentives and high barriers of entry for SMEs. Finally, the study identifies relational challenges with regards to the collaboration between the space agency and the commercial partner. The results indicate that the collaboration between ESA and the commercial partners currently lack the necessary transparency and efficiency in collaboration needed to succeed with servitization. In order to resolve these challenges, the study proposes 21 different improvement areas for ESA in relation to its commercialisation initiative. In particular, the thesis highlights process improvements related to the choice of procurement approach, development of business plans, evaluation of upfront commitment to utilization and visibility into the service design. The thesis concludes by highlighting the need for continued work with development of improvements. The thesis results serve as a starting point for developing a future approach of planning and managing development of commercial services within space exploration. / Rymdindustrin genomgår för närvarande en betydande tjänstefiering där rymdorganisationer globalt övergår från en statligt styrd produkt-orienterad tjänste-orienterad upphandlingsmetod. Syftet med examensarbetet är att identifiera vilkautmaningar som finns inom tjänstefiering i europeisk rymdutforskning samt vilka relaterade förbättringsområden som följaktligen finns inom den tjänste-orienterade upphandlingsmetod som European Space Agency (ESA) har antagit. Examensarbetet baseras på en fallstudie där fyra olika kommersiella tjänster, utvecklade genom ett kommersiellt partnerskap mellan ESA och privata företag, studeras. Studien identifierar totalt sett 21 utmaningar över tre olika livscykelfaser för de kommersiella tjänsterna. För det första identifierar studien kulturella utmaningar för både rymdorganisationen och industrin upplever svårigheter i att övergå från den befintliga kulturen som starkt är kopplad till den traditionella metoden till en tjänste-orienterad kultur. För det andra identifierar studien även flera utmaningar relaterade till hur processerna som etablerats inom ramen för det kommersiella partnerskapet för närvarande är otillräckliga för att stödja övergången till kommersiella tjänster. Studien lyfter särskilt fram kunskapsluckor inom affärsplanering och marknadsföring, otillräckliga processer för att säkerställa balans mellan kostnads- och kvalitetsincitament samt höga inträdeshinder för små och medelstora företag. Slutligen identifierar studien relationsmässiga utmaningar med avseende på samarbetet mellan rymdorganisationen och den kommersiella partnern. Resultaten indikerar att samarbetet mellan ESA och industrin idag saknar den nödvändiga transparensen och effektiviteten i samarbetet som krävs för att lyckas med tjänstefiering. För att lösa dessa utmaningar föreslår studien 21 olika förbättringsområden för ESA i relation till dess kommersialiseringsinitiativ. Särskilt framhävs processförbättringar relaterade till val av upphandlingsmetod, utveckling av affärsplaner, utvärdering av tidiga åtaganden för utnyttjande och insyn i tjänstedesignen. Examensarbetet avslutas med att betona behovet av fortsatt arbete med utveckling av förbättringar. Resultaten utgör en startpunkt för att utveckla en framtida strategi för planering och hantering av utvecklingen av kommersiella tjänster inom rymdutforskning.

World resources are becoming more and more scarce due to the increasing demand. Hence, the industry is moving towards sustainable development in order to suffice the needs of the future generations. Electricity is one such resources that account for 90% of the daily utility. In Sweden alone 378 TWh of electricity is consumed over a year. The major source of production of electricity is the fossil fuels, but due to development in the renewable resource's the electricity is also produced using solar, wind and geothermal energy. However, no production process is 100% efficient and hence, there is loss of energy in the form of waste. Organic Rankine Cycle Turbine (ORC) is a technology which is under the focus of the researcher and the industry to convert this wasteful energy into useful energy. Designing of these machines is a challenging task which requires careful consideration of every design parameter, i.e. with the change in every parameter the losses in the turbine either increase or decrease. In this study, effect of the parameters such as inlet mach number, stagger angle, inlet angle and pitch to chord is studied to see the effect on the profile loss. Since ANSYS Fluent works with 2D unlike ANSYS CFX which work with pseudo 2D geometry, ANSYS Fluent was used for investigating profile loss. Furthermore, a methodology is defined to investigate the tip leakage loss based on the geometry provided by the Againity AB for future studies. Tip leakage loss simulations were carried out in ANSYS CFX turbo mode due to its user friendly interface for simulating turbo machinery flows. The results of the profile loss investigation suggested a range for parameters where the profile loss is observed to be comparatively lower than elsewhere. The methodology proposed for tip leakage loss investigation paved a pathway for the further improvement with respect to the future studies.

An obstacle to the wide spread use of additive manufacturing (AM) is the difficulty in estimating the effects of process parameters on the mechanical properties of the manufactured part. The complex relationship between the geometry, parameters and mechanical properties makes it impractical to derive an analytical relationship and calls for the use of a numerical model. An approach to formulate a numerical model in developed in this thesis. The AM technique focused in this thesis is fused filament fabrication (FFF). A numerical model is developed by recreating FFF build process in a simulation environment. Machine instructions generated by a slicer to build a part is used to create a numerical model. The model acts as a basis to determine the effects of process parameters on the stiffness and the strength of a part. Determining the stiffness of the part is done by calculating the response of the model to a uniformly distributed load. The strength of the part depends on it's thermal history. The developed numerical model serves as a basis to implement models describing the relation between thermal history and strength. The developed model is suited to optimize FFF parameters as it encompass effects of all FFF parameters. A genetic algorithm is used to optimize the FFF parameters for minimum weight with a minimum stiffness constraint. / Ett hinder för att additiv tillverkning (AT), eller ”3D-printing”, ska få ett bredare genomslag är svårigheten att uppskatta effekterna av processparametrar på den tillverkade produktens mekaniska prestanda. Det komplexa förhållandet mellan geometri och processparametrar gör det opraktiskt och komplicerat att härleda analytiska uttryck för att förutsäga de mekaniska egenskaperna. Alternativet är att istället använda numeriska modeller. Huvudsyftet med denna avhandling har därför varit att utveckla en numerisk modell som kan användas för att förutsäga de mekaniska egenskaperna för detaljer tillverkade genom AT. AT-tekniken som avses är inriktad på Fused Filament Fabrication (FFF). En numerisk modell har utvecklats genom att återskapa FFF-byggprocessen i en simuleringsmiljö. Instruktioner (skriven i GCode) som används för att bygga en detalj genom FFF har här översatts till en numerisk FE-modell. Modellen används sen för att bestämma effekterna av processparametrar på styvheten och styrkan hos den tillverkade detaljen. I detta arbete har strukturstyvheten hos olika detaljer beräknats genom att utvärdera modellens svar för jämnt fördelade belastningsfall. Styrkan, vilket är starkt beroende på den tillverkade detaljens termiska historia, har inte utvärderats. Den utvecklade numeriska modellen kan dock fungera som underlag för implementering av modeller som beskriver relationen mellan termisk historia och styrka. Den utvecklade modellen är anpassad för optimering av FFF-parametrar då den omfattar effekterna av alla FFF-parametrar. En genetisk algoritm har använts i detta arbete för att optimera parametrarna med avseende på vikt för en given strukturstyvhet.