<p>Space habitats will involve a complex and tightly coupled combination of hardware, software, and humans, while operating in challenging environments that pose many risks, both known and unknown. It will not be possible to design habitats that are immune to failure, nor will it be possible to foresee all possible failures. Rather than aiming for designs where “failure is not an option”, habitats must be resilient to disruptions. We propose a control-theoretic approach to resilient design for space habitats based on the concept of safety controls from system safety engineering. We model disruptions using a state and trigger model, where the space habitat is in one of three distinct states at each time instance: nominal, hazardous, or accident. The habitat transitions from a nominal state to hazardous states via disruptions, and further to hazardous and accident states via triggers. We develop an approach for identifying safety controls that considers these disruptions, hazardous states, and identifies control principles and their possible control flaws. We use safety controls as ways of preventing a system from entering or remaining in a hazardous or accident state. We develop a safety control option space for the habitat, from which designers can select the set of safety controls that best meet resilience, performance, and other system goals. We show how our approach for identifying safety controls drives our control-theoretic approach for resilient design, and how that fits into the larger system safety engineering process. To identify and assess hazards, we use a database and create a network format that stores the relationships between different disruptions and hazardous states for an example space habitat. We use this database in combination with traditional hazard assessment techniques to prioritize control of possible disruptions and hazardous states. To mitigate hazards, we develop a safety control option space that contains safety controls that either prevent transition to hazardous states or return the habitat to a nominal state. We use generic safety controls, or the principle of control, to generate new safety controls as our set of disruptions and hazardous states grows, and store these in the database. Lastly, we evaluate our mitigation techniques using our control effectiveness metric, a metric intended to assess how well a safety control addresses the hazardous state or disruption that it is designed for. Our control-theoretic approach is one way in which we can complete the system safety engineering process for a space habitat system and can provide design guidance for the development of resilient space habitats.</p>

<p>Extra-terrestrial habitats will be embedded in challenging environments and involve complex and tightly coupled combinations of hardware, software, and humans. Such systems will be exposed to many risks, both known and unknown, and anticipating all failures and environmental impacts will not be possible. In addition, complexity and tight coupling in these systems means space habitats are likely to experience system accidents, which arise not only from the failure of individual components but also from the interactions among components. Therefore, we propose a control-theoretic approach to resilient space habitat design, which is grounded in system safety engineering and goes beyond event and component-centric failure models underlying conventional risk-based design. We model the system from a state-based perspective where the habitat is in one of four distinct types of states at a given time: nominal, hazardous, safe, or accident. The habitat transitions from a nominal state to a hazardous state via disruptions, and further to safe and accident states via triggers. We use safety controls to prevent the system from entering or remaining in a hazardous or accident state, or to transition the system into a temporary safe state or back to a nominal state. We develop a safety control option space, from which designers choose the best control strategy to meet resilience, performance, cost, and other system goals. We show the development of a control effectiveness metric, which is defined to assess how well safety controls address the hazardous state or disruption for which they are designed. The control effectiveness metric is one dimension of the overall hazard mitigation evaluation, which should also include aspects like cost and launch mass. We validate this approach by assessing individual safety controls in the Modular-Coupled Virtual Testbed (MCVT). This physics-based habitat simulation models complex disruption scenarios which include unique combinations of hazardous states and safety controls. The MCVT allows for the activation of individual (and sets of) safety controls of varying control effectiveness values to evaluate habitat resilience under different control architectures. Using this simulation, we evaluate the control effectiveness metric to determine whether the definition is appropriate to select safety controls that lead to desired habitat resilience. Completing the validation of this metric is the first step towards the validation of the overall control-theoretic approach to resilient space habitat design. </p>

This thesis confronts the ultimate limits of perceiving the constructed world and the limits of our ability to experience architecture. The imperative of architecture is poetic: to and project encounters between matter and energy that shape the existing and bring forth the as yet unimagined to form a continuing human world. This is explored through the imagining of a habitat and vessel that projects the human endeavor of architecture into the formless depth of space. In drawing the physical from the void, the page becomes a way to move architecture from non-existence into the real by means of the imagination. An imagined wold is drawn from the void in search of the center for a universal and humanist architecture. The thesis is conceived as a vehicle for drawing the limits of perception when we attempt to imagine that which is greater than ourselves. / Master of Architecture

In-situ resource utilization and in-situ manufacturing are being actively pursued as ways to enhance the development of human activities in space. However, the re-purpose of space systems through processes like recycling, re-manufacturing, and re-use, has not received the attention it deserves given its potential to reduce the waste generated by human activities in space, improve the sustainability of space habitats, and reduce the environmental impact on Earth of human activities in space.  This dissertation explores the available life cycle analysis methodologies in order to understand how the industry treats and measures re-purposability, and what re-purposing enabling technologies are available or under development, and proposes the use of the embodied energy and derived metrics to: quantify the waste generated by a space system when reaches its end of life, how re-purposable a space system is, and how valuable the outputs of the re-purposing process are for the habitat were the system is being processed. This data can then used to provide feedback regarding manufacturing process and material selection for the design, enabling a systems architect to optimize it with re-purposability in mind.  This Design to Re-purpose methodology (DTR) is tested through the analysis of selected components of an Lunar Habitat design from Hassell Studios, to the extend possible given the early state of the design, and with some assumptions regarding the expected repurposing technologies available. It demonstrated that performs as expected for the scenario provided, and yielded useful material selection feedback, including how the value of the re-purposing output material can infuence the design to optimize its re-purposability and the subsequent value it provides to the habitat.  Further development of this methodology is necessary, as well as additional testing especially considering scenarios where the initial system is not built on Earth, for which a preliminary road map was laid down.