Space technologies: the Mistral project is testing a new propulsion system that combines the Earth's atmosphere and solar energy to enable satellites to fly longer in very low orbits
The final results of the MISTRAL project, coordinated by the Sant'Anna School spin-off Celeste S.r.l., in collaboration with the Institute of Mechanical Intelligence, have been presented. “We have achieved a pioneering milestone that opens up new prospects for operating in low orbits and lays the foundations for in-orbit demonstration of the technology".
The MISTRAL project, funded by the European Space Agency (ESA) as part of the DISCOVERY program, has concluded with very promising results. The project is led by Celeste S.r.l., a spin-off of the Sant'Anna School, and partnered by the Space Technologies group of the Institute of Mechanical Intelligence of the School. At the final meeting, held at the European Space Research and Technology Centre (ESTEC) in Noordwijk, the operation of an innovative ‘air-breathing’ propulsion system was presented for the first time. This system is capable of using the thin atmosphere available and solar energy to operate nanosatellites in very low orbits for long periods of time, improving the quality of Earth observation and telecommunications services with a more sustainable approach to space.
Specifically, air-breathing electric propulsion combines the rarefied atmosphere present in very low Earth orbits (VLEO), collected by the satellite through an air intake, with solar energy, which is used by the thruster to accelerate the collected air and overcome atmospheric resistance. This type of propulsion, still under development in various research centers around the world, would allow satellites to operate for long periods of time in very low orbits, between 200 and 400 km, using renewable resources, significantly improving Earth observation and telecommunications performance, among other things.
The MISTRAL project, based on preliminary results obtained by Celeste S.r.l. with a proprietary plasma source technology called VOLTA, involved the study of satellite missions in VLEO, the design and construction of an innovative prototype air-breathing propulsion system and its experimental verification, carried out using an innovative testing technique developed at the Sant'Anna School by the research group coordinated by Tommaso Andreussi, full professor of Aerospace Engineering.
During the final presentation of the project to the European Space Agency, which was also attended by representatives of the Italian Space Agency and Freezz, a company investing in the creation of a satellite constellation in VLEO, Vittorio Giannetti and Eugenio Ferrato, co-founders of Celeste S.r.l. and researchers at the Sant'Anna School, illustrated the results, highlighting the project's successes. “We have achieved a pioneering milestone, demonstrating the production of a net positive thrust from a propulsion system tested under conditions representative of air-breathing space flight. This success opens up new prospects for operating in very low orbits and lays the foundations for in-orbit demonstration of the technology”, said Dr. Giannetti, CEO of Celeste, during the meeting.
The research group at the Sant'Anna School and Celeste S.r.l. possess unique expertise in the field of very low orbit missions and air-breathing satellite propulsion, which is also the subject of the BRIDGE project funded by the European Research Council (ERC). As reported by Prof. Andreussi: “The possibility of lowering the operating altitude of satellite constellations to altitudes where the atmosphere does not allow space debris to accumulate would make our relationship with space more sustainable.”
