The general station-keeping problem is a focal topic when considering any spacecraft mission application. Recent missions are increasingly requiring complex trajectories to satisfy mission requirements, necessitating the need for accurate station-keeping controllers. An ideal controller reliably corrects for spacecraft state error, minimizes the required propellant, and is computationally efficient. To that end, this investigation assesses the effectiveness of several controller formulations in the circular restricted three-body model. Particularly, a spacecraft is positioned in a L₁ southern halo orbit within the Sun-Earth Moon Barycenter system. To prevent the spacecraft from departing the vicinity of this reference halo orbit, the Floquet mode station-keeping approach is introduced and evaluated. While this control strategy generally succeeds in the station-keeping objective, a breakdown in performance is observed proportional to increases in state error. Therefore, a new hybrid controller is developed which leverages Floquet mode and reinforcement learning. The hybrid controller is observed to efficiently determine corrective maneuvers that consistently recover the reference orbit for all evaluated scenarios. A comparative analysis of the performance metrics of both control strategies is conducted, highlighting differences in the rates of success and the expected propellant costs. The performance comparison demonstrates a relative improvement in the ability of the hybrid controller to meet the mission objectives, and suggests the applicability of reinforcement learning to the station-keeping problem.

With the growth of human interest in the Lunar region, methods of enabling Lunar access including surface and Low Lunar Orbit (LLO) from periodic orbit in the Lunar region is becoming more important. The current investigation explores the Lunar access capabilities of these periodic orbits. Impact trajectories originating from the 9:2 Lunar Synodic Resonant (LSR) Near Rectilinear Halo Orbit (NRHO) are determined through explicit propagation and mapping of initial conditions formed by applying small maneuvers at locations across the orbit. These trajectories yielding desirable Lunar impact final conditions are then used to converge impacting transfers from the NRHO to Shackleton crater near the Lunar south pole. The stability of periodic orbits in the Lunar region is analyzed through application of a stability index and time constant. The Lunar access capabilities of the Lunar region periodic orbits found to be sufficiently unstable are then analyzed through impact and periapse maps. Using the impact data, candidate periodic orbits are incorporated in the the NRHO to Shackleton crater mission design to control mission geometry. Finally, the periapse map data is used to determine periodic orbits with desirable apse conditions that are then used to design NRHO to LLO transfer trajectories.

<div>Experiments were performed on a sharp-nosed 7° half-angle cone at a 6° angle of attack in the Boeing/AFOSR Mach-6 Quiet Tunnel (BAM6QT) to study the stationary crossflow instability and its receptivity to small surface roughness. Heat transfer measurements were obtained using temperature sensitive paint (TSP) and Schmidt Boelter (SB) heat transfer gauges. Great care was taken to obtain repeatable, quantitative measurements from TSP.</div><div></div><div>Consecutive runs were performed at a 0° angle of attack, and the heat transfer measured by the SB was found to drop as the initial model temperature increased, while other initial conditions such as stagnation pressure were held constant. This agreed with calculations done using a similarity solution. It was found that repeatable measurements at a 6° angle of attack could be made if the initial model temperature was controlled and the patch location that was used to calibrate the TSP was picked in a reasonable and consistent manner.</div><div></div><div>The Rod Insertion Method (RIM) roughness, which was used to excite the stationary crossflow instability, was found to be responsible for the appearance of the streaks that were analyzed. The signal-to-noise ratio in the TSP was too low to properly measure the streaks directly downstream of the roughness insert. The heat transfer along the streak experienced linear growth, peaked, and then slightly decayed. It is possible this peak was saturation. The general trend was that the growth of the streaks moved farther upstream as the roughness element height increased, which agreed with past computations and low speed experiments. The growth of the streak also moved farther upstream as the freestream Reynolds number increased. The amplitude of the streaks was calculated by non-dimensionalizing the heat transfer using the laminar theoretical mean-flow solution for a 7° half-angle cone at a 6° angle of attack. The relationship between the amplitude and the non-dimensional roughness height was approximately linear in the growth region of the streaks.</div>

MYCELIUM MILLENNIUM imagines a new era in which biological resources, specifically Fungi and Mycelium, are used to grow a collection of objects for everyday domestic rituals, merging biofabrication and traditional craft. The project is an effort to demystify the transformation of an organism to a biomaterial and at the same time raise questions of aesthetics and cultural acceptance. The fungal mycelium material qualities –  antibacterial, fire-resistant, heat isolating and water-resistant – are incorporated in the function of each design.  The objects adopt antique symbols embedding them in a longer material history, as well as a scale and form that introduces the fungal material to the context of the home. While the collection attempts to stress longevity and resilience, it is integrated into a circular vision, where the material is sourced from nature and returns to nature.   MYCELIUM MILLENNIUM is an invitation to raise awareness for a material revolution, an opportunity to learn from nature and its potential, where products and objects could match the planet's needs.

A ubiquitous household appliance, the washing machine currently sees a fall in its usage life to a mere 7 years, with valuable and finite resources getting lost to the landfill faster than ever. The reason?  Mechanical obsolescence and barriers in repair that make helpless users as far removed from the process as possible. The goal of my degree project is to create long lasting product and service experiences through easier channels of repair and to design deeper partnerships between humans and the appliances that surround them. I want to be part of a rising sustainability movement that aims for a seismic shift in thinking by creating resilient product experiences.  Can the key to a sustainable future be appliances that last for generations?

In the last three decades, the increased use of plastics is rapidly becoming a global environmental issue, resulting in growing landfills and pollution of air and water. The automotive industry, as a major demander of plastic materials, is starting to take responsibility with promised sustainability actions. One action relates to the concept of circular economy and closed loop thinking through the implementation of recycled plastics. However, the barriers of such implementations are still undiscovered, with research missing out on the challenges of strategic and business perspectives. The aim of this thesis is to asses and understand the challenges connected to implementing recycled plastics in the automotive industry, and to provide strategic recommendations. In order to identify the challenges, an empirical case study was carried out collecting data through 10 interviews with suppliers throughout the plastics refining chain. A cost calculation was also included, to highlight the economic potentials of recycled plastics. The findings address 6 themes as barriers for implementing recycled plastics in the automotive industry: economic, organizational, infrastructural, interactional, design and technical barriers. The barriers shed light on the challenges connected to the implementation of recycled plastics and concludes that the rate of recycled plastics in a car can be increased, which also increases sustainability and circular thinking. However, the rates could be further improved if managers were to consider the existing barriers when implementing higher rates of recycled plastics in their components.

In a world which is highly reliant on international trade and at the same time is facing what has been described as among the greatest challenges planet Earth ever seen, climate change. The connection the two have to each other becomes increasingly essential to understand. This study was put in the context of a developing country, Malaysia, due to the increased amount of businesses located in developing countries which are choosing to internationalise and export products. The 17 Global Goals created by the United Nations, which has been adopted by all member states are aimed to be reached in 2030. The Global Goals are built upon trust and responsibility for the planet which creates a scenario where the behaviour of both businesses and consumers is changed. The purpose of the study was to gain knowledge of how the aspect of environmental sustainability impacts export and what motivates the Malaysian businesses to change for the better. The outcome of this study indicates that the customers have a significant role for both motivation of businesses and the implementation of new strategies. The study has also seen an indication of a connection between the speed of internationalisation and export related to how businesses are motivated by customers in terms of environmental sustainability. Moreover, the study has shown that there is little connection between the business’s selection of export mode and environmental sustainability.

Background As of today the textile and fashion industry mainly relies on a linear production model, also referred to as the take-make-waste system. This economy depends solely on the single use of raw materials leaving space for an open-ended production and no intention of salvaging or recovering resources. Such a system cannot be supported by the environment in the future; therefore, several stakeholders are starting to embrace circular production systems and a closed-loop economy. One example of these efforts is take-back schemes (TBS) which strive to make the fashion industry more regenerative and restorative by narrowing, slowing, and closing the resource loops. Nonetheless, practitioners and academia have found adversities during the implementation stage which instead require competent knowledge, skills, and unique capabilities to achieve a successful performance. Purpose To achieve a successful implementation of a TBS, companies require unique capabilities that allow them to adapt and adopt a sustainable innovation. Therefore, this study investigates the dynamic capabilities (DCs) needed to implement a TBS in order to provide practitioners and academia with a guide that eases the application, overcomes the known adversities as well as explores the relationship between these and the relevant DCs. Methodology The research was based on a multiple case study method embracing abductive reasoning by extending the theory of DCs for circular business model implementation to TBS within the fashion industry. Semi-structured interviews were conducted with three companies applying different types of take-back schemes; the primary data was strengthened by document research and a validation round of interviews. The data was analyzed through qualitative thematic content analysis. Further, the characteristics of the study lend themselves well to be represented through a qualitative causal loop diagram appropriate for developing novel solution strategies such as the DCs. Findings The results show, through the use of two maps, that several DCs have to be developed when implementing a TBS in order to reach a substantial competitive advantage in the form of a cost leadership, differentiation or focus strategy. Further, the causal loop maps also shed light on the different relationships between DCs and how these can be exploited to overcome the difficulties or utilizing the possibilities in implementing a TBS. Practical implications and research limitations - The thesis creates new insights on TBS implementation through the use of DCs by presenting two causal loop maps. Thus, aiding practitioners and allowing them to quickly recognize their current situation against the maps as well as what changes need to be made following the suggested capabilities. The study is limited by the choice of interviewed companies, which represent only retailers with TBS in Sweden.

Background: The circular economy model is an essential theme in sustainable development research and a promising chance for companies to combine environmental and economic benefits. Nevertheless, a CE implementation was not realised in most companies to date. Purpose: The purpose of the study is to understand what hinders companies from becoming more circular and what measures need to be taken to initiate a CE implementation. Method: An embedded single case study methodology serves to explore the process of initiating a CE implementation, based on a firm within the manufacturing industry. Conclusion: Our research reveals the necessity of a pre-implementation phase before the CE implementation. The readiness of a company can be evaluated through a scoresheet that assesses the status quo. This scoresheet helps to estimate a potential urgency to achieve CE readiness. A pre-implementation sheet provides insights for firms to understand measures that need to be taken to reach readiness.

Aim: The aim of this thesis is to describe possible steps of how circular partnerships can be formed, and how they can connect the different steps of a material loop, such as design and recycling. The focus of the empirical study within this thesis is the reconnection of recycling, design and production within the household goods industry. By this we will answer the following research question:“What are the rationales and circumstances needed for separate organizations to develop a sustainability-oriented innovative partnership in the context of the Circular Economy?” The Case: This research project is based on a case study of a collaboration between Stena Recycling AB, a Swedish recycling company, and Electrolux AB, a global appliances producer. Together those two companies formed a pilot project, called the “Infinity Project”, whose goal is to produce a vacuum cleaner which is made out of 100% post-consumer recycled materials, and is 100% recyclable. Methodology: The researchers participated in the meetings of the Infinity Project, and interviewed the people who were involved in the beginning of the collaboration. The research is done in an abductive process, as literature was analyzed that explained the findings made in our observations. From the theory and our findings we created a model, which helps explain the what, why, and how of Stena Recycling AB and Electrolux AB reconnecting recycling with design and production processes. Key findings: Through industrial symbiotic lenses and a corporate social innovation mindset the two companies recognized the enormous amount of waste as a problem of linear business models. With a mindset driven by corporate social innovation, they saw the potential of a collaboration in order to achieve a shared competitive advantage. By selecting each other as a partner for this circular economic collaboration, they identified how they could combine their respective knowledge and resources to reach their mutual goals. Through a long term strategic approach with a clear and shared vision, clear targets from the directing management, and a team with complementary skills, many program synergies have been realized, with potentially outsized successes for each organization. This setting also created an environment of trust and a common identity within the project, which was fundamental to create social innovation and to find successful ways to reconnect recycling with design and production. Additionally, the existence of the project within each organization seemed to function as a talent magnet, attracting like-minded sustainability-motivated talent who would best perform towards the goals of the project.