SILOE, an SSPA project selected by ESA and an ESPACE grant for Alexia Duchêne

After graduating with a degree in mechanics, Alexia Duchêne joins ISAE-SUPAERO to study for a Master’s degree in Aerospace Engineering, which she achieves in 2022. From 2023, she will continue with a Master’s degree in Astrophysics (ASEP) at the University of Toulouse. Now a doctoral student in planetary sciences, she is working under the supervision of Naomi Murdoch on "Determining the mechanical properties of asteroids”, her thesis subject.

The SILOE project

Alexia Duchêne’s research focuses on determining the mechanical properties of asteroids through morphological analysis of surface rocks. This is the background to the SILOE project, for which she is project leader alongside Colas Robin, also a PhD student, and 3 MAE students.

The aim of this experimental drop-tower project, which enables experiments to be carried out at zero and reduced gravity, is to study the cohesion of planetary surfaces. The aim of the students’ work is to gain a better understanding of the behavior of a granular medium, a medium made up of grains of rock and dust with little or no cohesion.

By quantifying the importance of these cohesive forces as a function of gravity, particularly as gravity decreases, Alexia Duchêne and her team aim to better understand the mechanical properties of asteroids, to better predict interactions with them. “The behaviour of the surfaces of small bodies is currently poorly understood and difficult to predict, not least because of the potentially major role played by cohesive forces at these gravity scales”, explains the PhD student.

The results of this research could therefore be invaluable in predicting the reaction of the surface when it comes into contact with another body.

And help reduce the risks of space missions involving, for example, the landing of a Cubesat or a rover such as Idefix®, the rover on the MMX mission. They could also be invaluable for the advancement of planetary defense research, for asteroid deflection missions. "In addition to providing students with hands-on experience in experimental design, engineering, data analysis and project management, the SILOE project will provide answers to very important questions in planetary science and space exploration,” says Naomi Murdoch.

A project supported by ESA and an ESPACE grant

This experimental project, which began in November 2023 and will be completed in April 2025, is divided into several phases: design, manufacture, experimentation, and reporting of results. The design phase, which took many months to complete, has just been completed. The students are currently working on manufacturing the caisson that will be used for the drop tower experiments at ZARM, an institution of the University of Bremen, located in Germany.

“The experiment will be carried out in a vacuum chamber to recreate an environment similar to that of planetary bodies without atmosphere, such as the moon and asteroids”, adds Alexia Duchêne. The experimental phase, in reduced-gravity conditions, will take place in December 2024, and “will enable us to measure the penetration of a projectile on the surface of a granular medium and to highlight the role of cohesion according to the level of gravity" adds the PhD student.

The SILOE project has been selected by the ESA Academy Experiments program. This program enables universities and "Grandes Écoles" to design and develop experiments to be carried out on a series of gravity platforms and in space.

Following the call for proposals, ESA received numerous applications of “exceptional quality” from universities and schools across Europe. The shortlisted teams were invited to present their projects to a panel of ESA experts, and answered the experts’ questions on the scientific, technical and management aspects of their proposals. The SILOE project was one of the seven European projects selected. And it’s the only one that will benefit from the fall tower!

Alexia Duchêne was also awarded the ESPACE Excellence Scholarship by the Fondation des Ailes de France. In partnership with CNES and Eutelsat Group, and with the support, this year, of the Fondation Antoine de Saint-Exupéry pour la Jeunesse, this ESPACE scholarship program contributes to the knowledge and promotion of the aeronautics and space sphere, by supporting educational, scientific, cultural and sustainable development projects.

It rewards and supports “cutting-edge, varied and ambitious” projects such as space physiology, space vehicle design, cosmology, a thermal energy recovery system, etc. Last June, the doctoral student was presented with her Excellence Scholarship at a dedicated ceremony, by a number of high-profile personalities, including Claudie Haigneré.

The results of this project will be published in April 2025!