Faculty of Science, Technology and Medicine
Faculty of Law, Economics and Finance
Faculty of Humanities, Education and Social Sciences
Interdisciplinary Centre for Security, Reliability and Trust
Luxembourg Centre for Systems Biomedicine
Luxembourg Centre for Contemporary and Digital History
Luxembourg Centre for European Law
Luxembourg Centre for Socio-Environmental Systems
The Doctoral School in Science and Engineering is happy to invite you to Konstantinos KANAVOURAS’s defence entitled
Systems Engineering for Sub-CubeSat Spacecraft
Supervisor: Assoc. Prof Andreas HEIN
As of 2026, 549 satellites weighing less than 1 kg have been launched into Earth orbit. Compared to their larger counterparts, CubeSats, these “Sub-CubeSat Spacecraft (SCS)” provide benefits in terms of size, cost and mass, at the expense of reduced functionality and performance. However, despite their reduced complexity compared to CubeSats, Sub-CubeSat Spacecraft still experience a high failure rate in orbit, and a median development time of 2 years, which is higher than the typical 1 to 1.5 year turnaround for SCS launch opportunities. Scholars have linked these observations to inadequate systems engineering practices and insufficient project planning. Currently, the majority of SCS developers either use ad-hoc processes or adapt existing methodologies from larger spacecraft. These methodologies are deemed unsuitable for the different technical and environmental characteristics of SCS projects, either because of the significant overhead they introduce, or because of their incapability to integrate past lessons learned from similarly-sized missions. This thesis presents a tailored systems engineering methodology for the development of Sub-CubeSat Spacecraft, which covers the aspects of Technical Management, System Description, and System Realisation for these systems. The goal of this methodology is to reduce the development duration between development start and qualification, with an aim of consistently achieving 1 to 1.5 year-missions, without an adverse effect on technical risk. The proposed methodology incorporates the practices of agile software engineering, aided by the considerably low manufacturing difficulty and cost of an SCS system. The methodology is founded on an iterative lifecycle process model, which revolves around rapid prototyping, short iterations, and continuous system-level verification. Based on this model, more methods suited for SCS are proposed, targeting requirements management, technical planning and engineering data management. Additionally, the methodology covers technical aspects of the development process, by providing a set of guidelines for defining a design solution and for verification. It is found that the concepts of modularity and reuse have more limited benefits compared to larger spacecraft, while verification via reduced, automated testing instead of analysis can decrease development duration without reducing confidence in the system design. Furthermore, the use of different software development practices is evaluated, showing that an appropriate selection of programming language can generally increase software reliability, based on a case study comparison between different On-Board Computer frameworks. The methodology is validated through its implementation on four internal case studies, which returned successful results from testing, qualification or flight: 1. a hosted ChipSat to demonstrate Visible Light Communication, 2. a hosted PCB payload to demonstrate AI edge computing, 3. a 1p PocketQube with 2 technology demonstration payloads, and 4. an independent ChipSat with a lens-less camera. By performing counter-factual analysis on the programmatic data generated in these missions, it is estimated that the proposed methodology can reduce development duration by an average of 40% compared to waterfall-style approaches. The biggest influences towards a short development time are found to be the reduced analysis/testing approach (average 29% reduction) and the multi-step iterative process (average 25% reduction), with other factors showing a less significant correlation. Perceived technical risk and cost are found to be correlated, either negatively or positively, with some of the individual treatments of the methodology. From the presented analysis, it can be concluded that the methodology can be applied to Sub-CubeSat systems to reduce development duration, but requires specific tailoring to reach a desired optimal point, or to individually control for cost and risk. A goal of approximately 1 year-long development time was reached for the participating case studies, which can be generalised across similar missions. As future work, the proposed methodology can be expanded with more SCS-specific mission data to aid tailoring decisions, or extended to apply to larger spacecraft domains.