Selected past projects
This project achieved the first demonstration of stable RIT (Radiofrequency Ion Thruster) operation using atmospheric gases as propellants. The campaign provided essential lifetime and erosion data relevant for Very Low Earth Orbit (VLEO) missions.
This ESA-funded activity focused on design, development and testing of a miniaturised gridded ion engine (GIE / RIT-3.5) engineering model (EM) capable of delivering extremely broad thrust dynamic range from 50 µN up to 2,5 mN of thrust for lateral drag compensation, attitude control and low-noise force actuation in the Next-Generation Gravity Mission (NGGM) and similar Earth-observation formations. The work addressed improvements in dynamic thrust range, fast fine controllability with a slew rate of over 0.5 mN/s, resolution of 0.5 μN, and a rise and fall time of <2ms, as well as specific power and specific impulse. Additionally, it reduced thrust noise to below 1 μN/√Hz above 0.08 Hz. The lifetime performance within this project was also confirmed to exceed 200 kN*s of total impulse, equivalent to approximately 10 years of continuous operation.
Under the ESA-funded VISP project, IQM developed a Variable Isp Ion Optic System (IOS) for the RIT-3.5 mini ion engine, enabling independent control of thrust and specific impulse over a broad operational envelope. Testing demonstrated that the system not only met but exceeded the specified thrust requirements, increasing from approximately 7 microNewtons to around 2.8 milliNewtons. Additionally, the specific impulse (Isp) performance was highly flexible, achieving values up to 5000 seconds and beyond. The system proved to have a smooth start, maintained stable operation throughout, and showed impeccable erosion behaviour during extended firing periods.
IQM contributed to the AETHER project by developing and testing a Radio Frequency Plasma Generator combined with a Charge Separation Accelerator Stage (CSAS) for thrust generation for RAM-EP operation. The campaign demonstrated stable ignition and sustained operation with xenon and atmospheric gas mixtures, validated thruster resilience across diverse propellants, and confirmed performance in the 7–20 mN range under a 1000 W power envelope. The work also pioneered operation with correct orbital compositions for every chosen altitude, generic spectroscopic diagnostics, and the generation of low-energy particle flows, paving the way for future Very Low Earth Orbit (VLEO) missions. For the very first time, the high sensitivity of plasma processes within propulsion systems to the incoming atmospheric propellant composition was demonstrated. Another outcome of this project was the demonstration of the feasibility of using the radiofrequency ion sources as particle flow generators, providing a flow of atmospheric propellant with representative energies.
IQM developed the unprecedented Impulse Transfer Thruster (ITT), the gridded ion thruster with a centrally mounted cathode, tailored for ion beam shepherd missions in active debris removal. The capability of impulse transfer over long distances was experimentally verified, along with a unique set of performances characterised by remarkably low divergence (below 5 degrees) in both the near and far fields, which has never been demonstrated worldwide before. The alternative double-sided RF ion thruster design enables the generation of two counter-directed ion beams from a single device, providing contactless momentum transfer to space debris while balancing spacecraft thrust. Ground testing validated stable dual-beam operation and scalability of the concept for orbital debris removal and planetary defence applications.
Within the ESA M-ARGO project, the TransMIT IQM team participated in intensive co-engineering and testing activities aimed at adapting the µRIT3.5 Radio-Frequency Ion Thruster as the core electric propulsion system for the M-ARGO 12-U deep-space CubeSat. The work addressed the demanding constraints of a compact 12U platform (approximately 22 × 22 × 34 cm) while meeting extreme requirements for thrust, specific impulse, mass, and power. As part of the propulsion development, IQM carried out extensive performance characterisation of the µRIT3.5 using krypton (Kr) and xenon (Xe) propellants, providing detailed data on thrust, efficiency, and beam properties under deep-space operating conditions. This testing verified the thruster’s stable operation and scalability for small-satellite propulsion, strengthening its role as a flight-ready subsystem for future CubeSat missions. The project ultimately produced a compact, high-efficiency hybrid propulsion solution that combines electric and cold-gas systems, enabling independent cruise and asteroid rendezvous capability. Achieving the required thrust range (~0.8–2.2 mN) at 90–120 W and 1 AU with a specific impulse of 3000–4000 s demonstrated the feasibility of deep-space CubeSat missions with radio-frequency ion propulsion. The M-ARGO mission established a technological foundation for upcoming ESA planetary defence and asteroid exploration programs, including HENON and SATIS, confirming its role as a key pathfinder for next-generation miniaturised electric propulsion in Europe.