The emergence of Low Earth Orbit Positioning, Navigation, and Timing (LEO-PNT) systems represents a promising evolution of global navigation, offering faster convergence, improved geometric diversity, and stronger resilience against jamming and spoofing. This thesis investigates the design of a fully independent LEO-PNT constellation capable of delivering GNSS-comparable performance while remaining feasible for real-world implementation.

While most studies have focused solely on performance, this work incorporates system-level factors such as cost, deployment strategy and timeline, robustness, and debris considerations into the design process. Using a multi-objective optimisation framework based on NSGA-III, the analysis reveals that the most balanced constellation solutions typically feature single-shell polar Walker Star configurations with repeating orbits, altitudes around 1450 km, and roughly 120–150 satellites. This approach provides a realistic and adaptable foundation for future LEO navigation missions and emphasises the importance of integrating system-level constraints early in constellation design. ... Read more

In the last few decades, a large increase in interest in space and particularly the Moon has taken place. The Moon is seen as a gateway to the rest of the Solar System. Missions to the Moon will inevitably lead to technological and scientific advancements. These would help in humanity’s mission to explore and develop habitats in the Solar System. Companies see economic opportunities in these places for activities such as the acquisition of rare Earth materials, as well as commercialising space travel. Furthermore, countries see these accomplishments
as a sort of international competition while also collaborating with other nations. The mission design presented here aims to facilitate these objectives by providing the necessary navigation support to any future mission on or around the Moon... ... Read more