International Electric Propulsion Conference (IEPC) 2024 in Toulouse

In 2023, we supervised an M2 trainee, Célia Bouyssou, whom we are now supervising for a thesis on the following topic: “Analysis of the electromagnetic behavior of vacuum chambers in the presence of space electric thruster feathers”. This thesis is being carried out at ISAE-SUPAERO, funded by an AID school project. This thesis topic is part of the recent “New-Space” context.This new paradigm has opened up access to space exploration to private players, leading to an increase in the number of satellites in space.

In order to reduce manufacturing and launch costs, the size of satellites has been reduced thanks to the development of cubsats and nanosats. The reduction in satellite size leads to problems of electromagnetic compatibility (EMC) between thrusters and communications systems. One of the main sources of interference is electromagnetic radiation from the thruster. To measure this radiation on earth, it is necessary to operate the thruster in a metallic vacuum chamber. This chamber has a significant impact on the behavior of electromagnetic waves propagating inside it.

Facilities have been developed to study the behavior of waves in the presence of the ground thruster (Aerospazio in Italy, Aerospace Corporation in the USA and RIAME in Russia). They couple an electromagnetic anechoic chamber with a special metallic vacuum chamber. Part of the vacuum chamber is made of dielectric material, enabling the antenna to capture the thruster’s radiation while limiting reflections from the vacuum chamber.

However, these installations are very costly and the measurements required are complex. In the projects we are supervising at ISAE-SUPAERO, we are seeking to develop a method for measuring thruster radiation directly in the vacuum chamber. This work fits in perfectly with the themes addressed by IECP 2024.

So I approached the Fondation ISAE-SUPAERO as a member of the local organizing committee for the IEPC 2024 (International Electric Propulsion Conference).

Can you explain what IEPC is?

The IEPC 2024 conference took place in Toulouse from June 23 to 28, 2024. This is a key event in the field of space electric propulsion. Around 750 people attended the event, which brought together companies, startups, space agencies, engineers, researchers, academics and PhD students. In addition to discussing needs, trends and challenges in the field of space propulsion, the conference also included informative and educational events with renowned speakers, social events and technical tours of various nearby sites. The main aim of the conference is to “prepare the future of space propulsion and missions, and transfer knowledge to the next generation of players”.

NewSpace is a key issue for ISAE-SUPAERO, as demonstrated by its participation in the collective organization of the Assises du NewSpace français in recent years. In this context, the Institute is positioning itself as a major player in the transition of the aerospace sector. One of its objectives is to prepare “the future generation of engineers who will shape the French NewSpace”. Given that space electric propulsion lies at the heart of this new NewSpace paradigm, supporting IECP fits perfectly into the Institute’s approach.

Institutional supporters of IECP 2024 include CNRS and Paul Sabatier University, CNES, and the LAPLACE and ICARE laboratories. These are the major national players in the field of electric space propulsion. ISAE-SUPAERO’s support for this international conference has enabled the institute to be identified by the international community as a major player in this field.

How did the event go?

The conference went very well, and many of us from Toulouse took part. All the players from Toulouse working on electric propulsion for satellites took part in this international conference, and I personally had three contributions to make.

• The first (” Characterization of the electromagnetic behavior of PIVOINE-2G vacuum chamber in the microwave regime “) is a paper I wrote in collaboration with the LAPLACE (plasma and energy conversion laboratory) in Toulouse and ICARE (Institut de Combustion, Aérothermique, Réactivité et Environnement) in Orléans. This article reports on measurements we made at ICARE on the PIVOINE test facility, which is the largest French test facility for studying electric satellite thrusters. This test facility is financed by the CNRS and CNES, and is operated by a number of manufacturers, including Safran and Exotrail (a start-up in the field of electric propulsion for satellites). We therefore took measurements of the electromagnetic behavior of this device, which had never been done before. The aim of these measurements is to study the clean radiation emitted by thrusters, which is a topical issue of concern to the Newspace industry. We have carried out these initial measurements, and I presented the results during the “S1-3: Facilities” session.
• The second contribution (” Simulating the electromagnetic behaviour of a vacuum chamber in the presence of a thruster’s plume: comparison with experimental measurements “) is a paper by Célia Bouyssou, a PhD student I’m supervising at ISAE-SUPAERO, who is working on characterizing the natural radiation of electric satellite thrusters. In her article, Célia compares simulation and experimental results. The latter were obtained on the LAPLACE laboratory’s vacuum chamber, in which we ignited an electric satellite thruster (in particular, a Hall current thruster). Simulation results were obtained using an electromagnetic simulation software package we have at ISAE-SUAPERO: HFFS (High Frequency Structure Simulator). The very encouraging results she obtained enabled her to make an oral presentation of these results, in session “S1-3: Facilities”.
• The third contribution (“ Spectral Dependencies of GHz Electromagnetic Emission from Hall Thrusters Inside a Metallic Vacuum Chamber “) is a paper by François Réot, a PhD student in the LAPLACE laboratory. François is working on characterizing the natural radiation of satellite thrusters at GHz and its link with low-frequency instabilities. François presented his results in the form of a poster. His work was greatly appreciated, as we were awarded the 2024 IEPC Best Poster Award.

What do you retain from this experience?

During the conference, we were fortunate to be able to exchange views with researchers from the University of Giessen in Germany, whose work we knew about, but had never met. They are also working on the characterization of the clean radiation of thrusters (as part of a European project) with different approaches, and we were able to discuss how our approaches were complementary. This will certainly open up interesting collaborations in the future. What’s more, these discussions were very interesting for Célia Bouyssou, as it was her first international conference and therefore the first time she had been able to interact with researchers at this level. Recognition of the work carried out under François Réot’s supervision by the conference’s best poster award also served to highlight the quality of the work carried out on the Toulouse site, notably by ISAE-SUPAERO. This conference was therefore an enormous opportunity for me to show our work to the international community, and to launch discussions which I hope will lead to international collaborations, notably with researchers at the University of Giessen, who are working on the same problem as us, but with different approaches. Such collaborations would contribute to the Institute’s reputation and would be of great interest to ISAE-SUAPERO doctoral students working in the Newspace context.

Any final words?

The Fondation ISAE-SUPAERO’s support for this international conference has enabled the institute to be identified by the international community as a major player in this field. The presentations we made showed the international community working on electric satellite propulsion that ISAE-SUPAERO is positioning itself on innovative, topical subjects, and demonstrated the methods we deploy at ISAE-SUPAERO, which are unique and new.

Taking part in this conference was very interesting for me as a researcher and as a supervisor of PhD students, as it enabled them to discuss with researchers at an international level and even to be recognized for their work with the conference’s best poster award.