In the quest to answer the question “Are we alone in the universe?”, one of the biggest breakthroughs promises to come from detailed atmospheric characterisation of small, Earth-like exoplanets. To make such observations possible, the Large Interferometer for Exoplanets (LIFE) space mission has been proposed. This mission makes use of the nulling interferometry principle, a concept in which a null is placed on the host star, allowing for the orbiting exoplanets to be observed directly.

To achieve the required angular resolution and observational stability for the interferometric measurements, the LIFE concept would require precise control of a rotating spacecraft formation, over baselines of up to 600 meters. Four collector and one beam combiner spacecraft are arranged into a specific geometry dubbed the Emma X-array and together act as one large telescope.

This thesis, based on LIFE’s scientific requirements, presents a systems-level analysis of a future nulling interferometry formation-flying mission in the Sun-Earth L2 region. To that end, an operational phase mission simulator was developed within the circular restricted three-body problem (CR3BP) framework, with the spacecraft formation employing continuous-thrust propulsion for formation keeping, and higher-thrust impulsive propulsion for formation reconfigurations and orbital maintenance. The results show that, with this setup, a five-year mission is achievable from a ΔV perspective, requiring approximately 20 to 40 kg of propellant per collector and less than 10 kg for the beam combiner, assuming each spacecraft mass would be 1000 kg. In addition, the influence of several system characteristics on mission feasibility and ΔV requirements was quantified, with rotational speed and baseline size identified as the primary drivers of the mission propellant cost. Interestingly, the choice of reference orbit was found to have a negligible effect on the formation design. ... Read more

There is a strong coupling between the interior, surface, atmosphere, and magnetosphere of planetary bodies which contains fundamental information about their evolution and dynamics. However, sparse observations beyond Earth limit the ability to isolate faint signals from background variability. This thesis establishes a scientific and engineering framework to address these limitations with a spatially and temporally distributed sensor array. The study maps mission goals to science and payload instrumentation requirements for Earth and planetary scenarios via a Science Traceability Matrix. The methodology includes performance and cost modeling with multi objective evolutionary algorithms to produce non-dominated constellation architectures. Furthermore, it develops a general model of spacecraft reconfiguration dynamics by exploiting the non-spherical gravity field of the central body, with results on propellant/time trade-offs. This work contributes to the "PULSAR" NASA Innovative Advanced Concepts proposal and was conducted within the NASA JPL Robotics Modeling and Simulation group. ... Read more

Binary near-Earth asteroid systems are key targets for planetary defence, resource prospecting, and small spacecraft missions, yet their coupled orbital and rotational dynamics make trajectory design intrinsically difficult. Most manifold based mission designs have focused on large planetary systems and on connections between a limited subset of libration point orbits, leaving open the question of how far these techniques can be pushed for close proximity tours in small binary systems using SmallSats. This thesis develops an end-to-end methodology in the circular restricted three-body problem to systematically design low-cost planar tours that exploit Lyapunov orbits around the three collinear equilibrium points and their invariant manifolds. Families of periodic orbits are generated about L₁, L₂ and L₃, their stable and unstable manifolds are computed, and a two-dimensional search in phase space is used to build maps of feasible connections as a function of the Jacobi constant at departure and arrival. These maps act as a graphical design tool, allowing the construction of multi-leg tours, equatorial landing trajectories, and imaging arcs by inspection of low-energy corridors and their associated ΔV and time of flight. Two landing concepts are considered, direct collisions along invariant manifolds and ballistic descents constructed by backward propagation from the surface, and their attainable impact speeds and phase windows are characterised. A simplified CubeSat class visible context camera model, representative of current Hera mission payloads, is then used to evaluate surface visibility and ground sampling distance along both stationing and transfer arcs. The methodology is applied to the Didymos, Moshup, and 2000 DP₁₀₇ systems, showing that their scaled geometry and mass distribution shape the density, cost and duration of manifold based transfer corridors, yet still allow tours with centimetre to decimetre per second manoeuvres per leg, flight times of days to weeks, and end of mission landings with sub metre per second impact speeds. The results demonstrate that planar CR3BP manifolds can support operationally relevant tours for small spacecraft at binary asteroids and provide a structured framework that can be extended to three-dimensional motion and higher-fidelity environment models. ... Read more

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

Solar-sailing is a promising propellant-free propulsion method leveraging the momentum of photons to generate a thrust force, making them attractive for long-term missions both in Earth-bound and interplanetary space. In Earth orbit, solar-sails have been envisioned for space debris removal missions aiming to de-orbit multiple defunct satellites. However, their large sail area make them vulnerable to hypervelocity impacts with debris, potentially causing loss of attitude control. Therefore, this thesis presents a study of the long-term effects of tumbling on a sail's orbit and of the capability of a modern vane attitude control system to time-optimally stabilise the attitude motion. The tumbling dynamics result in an orbital eccentricity growth which is independent of the tumbling rate, potentially leading to a re-entry of the sail. The vane system is capable of detumbling rotational velocities up to 26 deg/s. For rotational velocities up to 8 deg/s, this system is capable of detumbling the sailcraft at a linear rate of 2 deg/s per day. For larger rotational velocities, the duration of the detumbling manoeuvre grows non-linearly. These results are considered for the specific case study of hypervelocity impacts and the sensitivity of the results to the sail reflectance model, the orbital regime, and the number of degrees of freedom of the vanes is assessed. ... Read more