THESEUS mission definition and subsystems sizing with Collaborative Engineering approach =

The level of complexity, sophistication and accuracy of space systems has continuously increased over the last years. Especially during the early design phases, a multidisciplinary team and a consistent approach are fundamental, along with appropriate tools and facilities, to reduce costs, to optimize the usage of time in terms of designing processes and increasing project robustness. The most popular approaches are usually sequential and centralized and largely applied because of their proven features. However, a more innovative approach consists in the “Concurrent Engineering” (CE), which is considered an up-and-coming method due to its design process performances and achieved results. A motivated and coordinated team of technical specialists, leveraging on different know-how and backgrounds, is the core of CE approach success. Since the design early phases, team members start sharing data and information, this happens real time and in the same place in order to allow a quasi-parallel execution of each project aspect. The goal of the thesis is to acquire knowledge and practical experience through a real business case and to experience the methodology in person. The work has been carried out in close collaboration with one of the most important aerospace companies in Europe, Thales Alenia Space Italy (TAS-I). I have conducted a phase A study of space mission THESEUS (Transient High Energy and Early Universe Surveyor) as team member, I have closely collaborated with specialists’ part of three relevant European companies: TAS-I was the main contractor, OHB and TAS-F the subcontractors. The mission was classified as a medium-size mission (M5) and selected by the European Space Agency (ESA) as part of the Cosmic Vision Programme. Its main objective is to increase the discovery space of the high energy transient phenomena over the entire cosmic history, launching date planned by 2032. As planned, during the period spent at TAS-I, a new software developed by CNES (Centre National D'études Spatiales) has been explored and observed by myself. The software named IDM-CIC (Integrated Design Model) storages and manages data allowing users to set up mission budgets, applying a “Concurrent Engineering” methodology. As result of the period in TAS-I, an overview about the methodology has been achieved and a strong understanding of system engineer role within CE approach has been reached. To further reinforce the knowledge obtained through IDM-CIC, additional supporting studies have been undertaken in relation to some specific fields and using specific software. In order to carry out those supplementary investigations, STK (System Tool Kit) was utilized. The tool is a “software suite” dedicated to the simulation, modelling and analysis of complex missions and systems. Indeed, the orbit selection represents a key point in a phase A study. The second complementary investigation performed has concerned the sizing of communication and power subsystems through advanced worksheets to meet the system requirements. The thesis shows the need of an integrated and digital model based on a web application, called Digital Integrated System Model (DISM). The latter should be able to exchange information between several software to obtain a faster and efficient design process, to reduce design costs and time, to increase project reliability and to optimize the subsystems sizing.