Jack Gale

Multi-point design optimisation of microwave electrothermal thruster nozzles for robust in-space operation

Authors: Jack Gale, Madeline Farrugia, Keisuke Suenaga, Suk Hyun Yeo, Gail N. Iles, Hideaki Ogawa

Published in: Aerospace Science & Technology, 2026

Multi-Point Design Optimisation of Microwave Electrothermal Thruster Nozzles for Robust In-Space Operation

Authors: Madeline Farrugia, Keisuke Suenaga, Suk Hyun Yeo, Jack Gale, Gail Iles, Hideaki Ogawa

Published in: IAC, 2025

Microwave electrothermal thrusters (METs), characterised by their considerably high thrust and a broad specific impulse range, offer advantages over other electric propulsion systems in terms of operational lifetime, thruster efficiency, and propellant selection. However, the complex phenomena associated with the multi-physics behaviour of MET operation pose challenges in optimising system components. One notable challenge arises with miniaturised nozzles, caused by significant boundary layer effects, necessitating meticulous consideration in the design process. Multi-objective design optimisation is performed for MET nozzles by incorporating computational fluid dynamics simulations coupled with evolutionary algorithms supported by surrogate model predictions based on machine learning for multiple operating conditions. This approach enables global design optimisation of MET nozzles to maximise performance with respect to flow velocity, thereby enhancing thrust and specific impulse for robust operation against variations in MET chamber conditions. The flowfields within the nozzle and their effects on performance are scrutinised for selected optimal geometries, offering valuable insights into the underlying physical phenomena. Covariance-based sensitivity analysis is performed to identify key design variables and understand their interactions and interdependencies in the physical characterisation and modelling of miniaturised nozzles. Significant effects of the nozzle divergent angle and throat radius on performance have been identified, as they play crucial roles in shaping the flowfield at the nozzle exit, consequently influencing thrust generation.

LithoSpace: A Democratised Spatial Data Platform for Extraterrestrial Geoscience and Geochemical Mapping

Authors: Wayne Noble, Fabian Kohlmann, Jack Gale, Ben Dib, Gail Iles, Brandon Mahan, Moritz Theile

Published in: EGU General Assembly, 2025

This study showcases how LithoSpace's unique cloud-based geochemistry tools can visualise slight variations in geochemical composition using existing, standardised, and cleaned lunar and martian geochemical data. The analysis confirms previously known findings, such as the basaltic geochemical composition of Apollo 11 samples and the wide range of geochemical composition of rocks on Mars as analysed by the Curiosity rover. However, it more importantly highlights how LithoSpace facilitates improved, user-friendly analytics, enabling “on-the-fly” calculation, interpretations and rock classifications. As more data is collected, LithoSpace will enhance our ability to develop new theories about planetary formation and assist with improved geological mapping of extra-terrestrial bodies.