In recent years, the satellite market has grown rapidly, especially for telecom and Earth observation satellites. This is due to the entry of new players and the development of new satellite constellations, like OneWeb and Starlink. Electric propulsion technology has also become important in the industry because it improves the cost efficiency of satellites, particularly with respect to launch costs, by allowing more satellites to be launched per vehicle. However, the additional costs of electric propulsion subsystems, mainly from the complexity of the required electronics (PPU) and high cost of the gas propellants like xenon, which is a type of gas used to fuel electric propulsion systems, can offset these savings. The conflict in Ukraine has also led to an increase in the cost of xenon propellants.
To make electric propulsion more cost-effective and competitive, iFACT researchers proposed developing a new subsystem called the iodine Fed Advanced Cusp field Thruster (iFACT). This subsystem was developed in the frame of the project and relies on the use of iodine as a propellant, which simplifies the propellant feeding subsystem architecture and reduces its mass due to its high storage density. The project focused on the maturation of a new type of thruster called the Advanced Cusp Field Thruster (ACFT) that can run on iodine. To further improve the efficiency of the subsystem, a material with a lower work function was required, and calcium aluminate (C12A7) was found to be a promising alternative. Additionally, iFACT team tried to reduce the complexity of the required electronics (PPU) and make electric propulsion more efficient.
One of the objectives of the project was also to investigate the compatibility of iodine propellant with test facilities and diagnostics, and to design and validate a dedicated testing infrastructure with a special focus on safety procedures to protect the environment. This information and the entire project results will be crucial for future European industrial programs that involve this technology. Iodine is also being considered as a promising candidate for the IRIS^2 constellation, a satellite constellation project.
The Advanced Cusp Field Thruster (ACFT) is a type of thruster that works well with iodine as a propellant. However, scientists wanted to improve the efficiency of the thruster system, so they looked for a better material for the cathode. They found that calcium aluminate (C12A7) could be a promising alternative, because it has a very low work function of 2 eV in theory and it shouldn't be affected by the iodine. The iFACT program made it possible to use C12A7 in cathodes in the future, which could improve the efficiency of the thruster system even more. The program's success could lead to major advancements in satellite technology and pave the way for a more sustainable space industry.
