Integrating life cycle assessment of space systems into the concurrent design process

Recent commitments by national and international bodies towards environmental problems has allowed a range of mitigation measures and key sustainability issues to filter down and become embedded in a growing number of industrial and commercial sectors. Notwithstanding this, space operations have often been overlooked in key legislation or regulatory requirements, with the result that the environmental impact of such activities were often disregarded or ignored. Over the last few years things have begun to change as interest has intensified in the transparency and accountability needed from the space industry in order to fully understand and articulate its effects on the environment. This has led to the development of an environmental management tool called Life Cycle Assessment (LCA) which is increasingly being adopted by the space industry to assess the full environmental impact of their products and practices over their entire life cycle. The European Space Agency (ESA) began work on this topic in 2009 by employing an internal concurrent design study called ECOSAT to consider the life cycle impact of the design, manufacturing, launch and operations of a satellite. One of the key findings of this study revealed that existing terrestrial focussed LCA databases lacked the scope and capacity to conduct such advanced assessments due to the unique and specialist nature of space sector operations. To overcome this, ESA has continued to develop LCA methodology within the space sector to the point where it is now looking at introducing it into the design of future spacecraft and space systems. This indicates the manner in which the design and execution of European space missions will likely proceed. Running alongside this green movement, the New Space trend is predicted to introduce large numbers of small satellites into the space environment which will substantially alter environmental and societal impacts. This paper presents an open-source LCA platform currently under development at the University of Strathclyde, outlining its integration into the concurrent design process of next generation green space systems. The LCA platform includes extreme scale systems from large constellations of nanosats to solar power satellites. Both extremes have in common the need of massive production cycles. The integration of LCA into the design process allows one to minimise the environmental impact and define new optimality criteria for the space system

An Intelligent Fuse-box for use with Renewable Energy Sources integrated within a Domestic Environment

This paper outlines a proposal for an intelligent fuse-box that can replace existing fuse-boxes in a domestic context such that a number of renewable energy sources can easily be integrated into the domestic power supply network, without the necessity for complex islanding and network protection. The approach allows intelligent control of both the generation of power and its supply to single or groups of electrical appliances. Energy storage can be implemented in such a scheme to even out the power supplied and simplify the control scheme required, and environmental monitoring and load analysis can help in automatically controlling the supply and demand profiles for optimum electrical and economic efficiency. Simulations of typical scenarios are carried out to illustrate the concept in operation

Concurrent engineering and social distancing 101 : lessons learned during a global pandemic

Social distancing measures introduced in the wake of COVID-19 greatly impacted the concurrent engineering process. This paper addresses methodological adaptation measures which are required to ensure the continuity of this activity. Two CubeSat feasibility studies run at the University of Strathclyde, one physical and one virtual, are compared to quantify the impact of the adaptation. Three evaluation criteria are used: the fulfilment of requirements & customer satisfaction, server data flow rate and participant perceptions. The results indicate that although adaptation was successful, it failed to lift all communication barriers introduced by virtual exchanges

Optimizing the Jiles-Atherton Model of Hysteresis by a genetic algorithm

Modeling magnetic components for simulation in electric circuits requires an accurate model of the hysteresis loop of the core material used. It is important that the parameters extracted for the hysteresis model be optimized across the range of operating conditions that may occur in circuit simulation. This paper shows how to extract optimal parameters for the Jiles-Atherton model of hysteresis by the genetic algorithm approach. It compares performance with the well-known simulated annealing method and demonstrates that improved results may be obtained with the genetic algorithm. It also shows that a combination of the genetic algorithm and the simulated annealing method can provide an even more accurate solution that either method on its own. A statistical analysis shows that the optimization obtained by the genetic algorithm is better on average, not just on a one-off test basis. The paper introduces and applies the concept of simultaneous optimization for major and minor hysteresis loops to ensure accurate model optimization over a wide variety of operating conditions. It proposes a modification to the Jiles-Atherton model to allow improved accuracy in the modeling of the major loop

A resilience approach to the design of future moon base power systems

This paper proposes a novel approach to the design of complex engineering systems which maximise performance, and global system resilience. The approach is applied to the system level design of the power system for future Moon bases. The power system is modelled as a network, where each node represents a specific power unit: energy storage, power distribution, power generation, power regulation. The performance and resilience of each power unit is defined by a mathematical model that depends on a set of design (control) and uncertain variables. The interrelationship among nodes is defined by functional links. The combination of multiple interconnected nodes defines the performance and resilience of the whole system. An optimisation procedure is then used to find the optimal values of the design parameters. The optimal solution maximises global system resilience where an optimal resilient solution is either robust, i.e. it is not subject to disruptive failures, or recovers from failures to achieve a functioning state, albeit different from the starting one, after a contingency occurs. The power system supports a Lunar base developed within the ESA-lab initiative, IGLUNA, led by the Swiss Space Centre. The power system, developed at the University of Strathclyde as part of the PowerHab project, is composed of nine interconnected elements: a hydrogen fuel cell energy storage system, a thermal mass storage system, a lithium-ion battery storage system, a constellation of solar power satellites (SPS) working in conjunction with a microwave wireless power transmission system, a reflecting satellite constellation and a ground-based solar power array. Distinct space and ground segments are identifiable, with orbit, AOCS and reflecting satellite nodes cooperating to provide optimal performance of the SPS constellation. The ground segment encompasses the ground-based solar array, energy storage systems, Lunar habitation module and the power transmission lines connecting these elements. Power generation is predominantly supplied by the ground-based array, with the SPS constellation and energy storage systems complementing this source; as well as providing redundancy and a reliable power supply during the Lunar night period

STRATHcube : The design of a student CubeSat using concurrent engineering methods

With the role of concurrent engineering (CE) becoming more important to the success of companies, it is vital that engineering students are able to understand and apply this concept. In this regard, the University of Strathclyde regularly offers its students opportunities to learn about this process through practical-based CE workshops. The results from a student-based CE study of a CubeSat are therefore outlined, including the effectiveness of the session as a learning experience for students. Through collaboration and teamwork, the student team produced a feasible design concept which achieved most of the prespecified objectives. Additionally, it was determined that the learning outcomes of the study were widely met, despite it taking place virtually due to COVID-19

The Strathclyde concurrent and collaborative design studio : past, present and future

Since opening in October 2015, the Concurrent & Collaborative Design Studio (CCDS) at the University of Strathclyde has been used to foster and promote innovation in the field of aerospace engineering across a wide variety of educational and industrial projects. This paper will describe the development process of the CCDS to now, including a discussion on how it currently operates. In so doing, the paper will go on to present the successes and failures of hosting a concurrent design facility (CDF) in an academic environment, focussing on the provision of teaching and learning as well as industrial engagement. Based on this, a development plan has been proposed to optimise the use of the facility in the future