Gridded Ion Engine projects

Mars Space Ltd has developed a first prototype of RF ion engine (MIE) specifically designed to provide high delta-V and orbit control capabilities to 6U-24U Cubesat and Nanosat.

MIE has been tested and its performance characterised. Here below the most relevant technical specifications:

• RF power: 19 W
• Beam Current: 13 mA
• Thrust: 0.85 mN
• Specific impulse: 2500 s
• Mass <300g
• Propellant: xenon
• Volume: 61mmx61mmx64mm (without mounting flange)

The GIESEPP (Gridded Ion Engine Standardised Electric Propulsion Platform) project has been set up to develop, build and test to TRL5 the first European Plug and Play Gridded Ion Engine System to operate ArianeGroup and QinetiQ Space Ion Engines for LEO, GEO and Space Exploration Missions.

The approach to system standardisation will provide highly cost competitive and innovative Electric Propulsion Systems whilst meeting the technical requirements needed to address our customer needs for future satellite assets.

The Project will also describe the roadmap to higher TRL by 2024.   

In the frame of GIESEPP Mars Space will collaborate with QinetiQ to design and test of the T7 ring cusp ion thruster. Existing in-house 0D and 2D models will be modified and adapted to develop analytical and computational design tools capable of helping in the design of an optimised ring cusp discharge chamber. These tools will be then coupled with an existing state-of-the-art ion optics code to produce an overall optimised thruster design. Mars Space will also provide support to the thruster test and the data gathered during the experimental campaign will be used to validate the models developed in the design phase.

For further information please visit www.giesepp.com​

The aim of the HiPER project was to define a roadmap for the future of electric propulsion.

Several missions are under study, including a Mars sample return mission, rendezvous with Near Earth Objects, building of infrastructure on the Moon-Earth L1 point and building of infrastructure on Mars. Different electric propulsion subsystems are under study for these missions including Magneto Plasma Dynamic Thrusters (MPDTs), Hall Effect Thrusters (HETs) and Gridded Ion Engines (GIEs). The University of Southampton and Mars Space Ltd are working on the design of GIEs and in particular of a new concept of GIE called Dual Stage Gridded Ion Engine originally developed by the late D. G. Fearn based on a tetrode extraction system for high energy neutrals and ions used in tokamaks.

At the high end of the performance range of electric propulsion devices, analytical and numerical work is ongoing investigating the prototype design and the mission applications of a new type of Gridded Ion Engine (GIE), utilising 3 or 4 grids rather than the usual 2 or 3. Called Double-Stage 4-Grid (DS4G), this Ion Thruster was originally conceived by the late David G. Fearn built and tested by a team formed by ESA and the Australian National University for the first time at ESTEC in 2005. It can operate at much higher values of specific impulse (Isp ~ 10,000 s to 30,000 s) and power (hundreds of kW), but with lifetimes comparable to those of conventional GIEs, by separating ion extraction and acceleration, which in a conventional GIE are deeply interconnected, with an intrinsic compromise between maximum current density and Isp.​

Ion Optics numerical simulation and high-current HC modelling and design are among the current lines of research.  A study showed that the DS3G theoretically offers advantages over the conventional GIE in terms of thrust density if the voltage applied in the second stage is 0.6 times (or higher) the one in the first stage.