Space propulsion has been a critical subsystem for manoeuvring spacecraft since the beginning of the space era. Among various technologies, radio-frequency inductively coupled plasma (RF-ICP) electrothermal micro-thrusters, typically operating with inert gases such as argon, have demonstrated significant potential for small satellite propulsion. However, the search for alternative propellants has led to the exploration of solid hydrocarbons, which are abundant on Earth and offer a storage advantage.

In this talk, I will present the thrust performance of several solid hydrocarbons: naphthalene, adamantane, camphor, borneol, and hexamine, as potential alternative propellants for electrothermal plasma thrusters. I will begin by discussing the experimental characterisation of each propellant, including mass flow rates and power consumption. Next, I will describe our experiments and results on direct thrust measurement using a thrust balance within the space simulation chamber, where we individually determined and benchmarked thrust in both cold-gas (unpowered) and plasma (powered) modes against a baseline inert gas. And finally, I will cover the indirect method of thrust measurement, which involves estimating gas temperature via optical emission spectroscopy to infer thrust