Ph.D. student Position -MISCEA thesis offer ESR17 – The thermo-mechanical behaviour of planetary soils: Mars and the Moon

The geotechnical group of Lab Navier (CERMES) has been deeply involved in the InSight mission on Mars (NASA with CNES and DLR[1], 2018 – 2022), with significant contributions on the properties of the surface regolith on the site of the mission[2]. These included Juan-Pablo Castillo-Betancourt’s co-supervised thesis[3], devoted to the study of the thermo-mechanical behaviour of the Martian regolith. This thesis offer is aimed at maintaining the leading role acquired in planetary geotechnics by CERMES during the InSight mission (see references in notes below).

InSight is a geophysical mission mainly based on the use of a seismometer supplied by France (CNES/IPGP, Institut de Physique du Globe de Paris), that also provided a wealth of information on the nature and properties of the regolith on the surface of the InSight site2. Alongside the study of the interaction[4] between the seismometer and the regolith, and the correct estimation of surface seismic velocities on Mars[5],[6],[7], an important contribution of Castillo’s thesis was the investigation of the coupling between wave and heat transfers within the regolith. This original idea proposed by CERMES would make it possible to improve the determination of the surface properties of the rocky planets in the solar system through the combined use of thermal measurements (easy to get from orbiters) and seismic velocity measurements, such as those carried out on Mars and planned on the Moon within the Artemis programme. An original apparatus, dedicated to these coupled measurements and developed at UniAndes as part of the thesis, has given good thermal results, but requires further development for seismic velocities.

The CERMES group is now involved, along with IPGP, Isae Supaéro and CNES, in investigating the properties of the regolith at the Moon’s south pole, with a view to the NASA Artemis IV mission, scheduled for launch in 2028. A collaboration with DLR (Dr. B. Knappmeyer-Endrun) is also planned, through the use of the EAC-1 simulant, presently used in the Luna facility[8] (ESA-DLR) in Köln. CNES plans to propose a joint project with the Jet Propulsion Laboratory (NASA/CalTech), an InSight partner, to send to the Moon a spare SEIS seismometer originally built for InSight. The project also includes the installation of geophones to measure wave speeds in the lunar surface regolith. In this context, it is essential to study the properties of the surface soil in order to design the shape of the feet of the device supporting the seismometer, and to optimise the shape of the geophones, through experimental devices developed at CERMES (see Ref. 6).

The thesis, planned to be carried out in collaboration with UniAndes Bogota, would be devoted to experimentally investigate various aspects of the Moon regolith properties at the south pole of the Moon. The effects of both the extreme angularity of the grains and the significant dust fraction of Moon regolith (particle diameter around 10 µm) will require specific attention, since they are not commonly considered in granular materials on the Earth. They have an important role in the regolith response, as already observed on the Moon (Apollo programmes) and at Luna. The investigation of wave properties at very low stress (cf. refs 8 and 9) will also be extended, both on experimental and theoretical aspects. Thermal transfers will be also investigated with the device developed during Castillo’s thesis, in conjunction with colleagues from DLR involved in InSight (Dr. M. Grott). The coupling between wave and heat transfer, considered as a strong and powerful new concept pushed forward by the CERMES group, will also be given deep attention. 

The expertise and solid international reputation acquired by CERMES in extraterrestrial geotechnics through their participation in the InSight mission will thus be maintained in a field whose growing strategic importance was recently illustrated in France by the launch of the Objectif Lune project. Participation in a NASA Artemis mission, in conjunction with partners such as CNES, IPGP, Supaéro and, eventually, the JPL (NASA/Caltech), will be a strong marker in terms of communication and display of the scientific activities of the Navier laboratory as was participation in the InSight mission.

Requirements

Research FieldEngineering » Mechanical engineeringEducation LevelMaster Degree or equivalent

Skills/Qualifications

Interest for experimental and theoretical investigationsLanguagesENGLISHLevelGood

Additional Information

Eligibility criteria

Description of the project and the candidates’ eligibity criteria:

This position will be part of the EU-funded project MISCEA, which is an ambitious inter- and multidisciplinary Doctoral Training Network under the Horizon-Europe Marie Skłodowska-Curie Actions. 

PhD candidates’ can be of any anationality but you have to meet these eligibity criteria :

• Not being a current employee working at ENPC.
• Not having resided or carried out their main activity (work, studies, etc) in France for more than 12 months during the past 36 months immediately before the deadline of the MISCEA Programme’s call. Compulsory national service, short stays such as holidays and time spent as part of a procedure for obtaining refugee status under the Geneva Convention are not taken into account.
• Holding a Master’s degree (or about to obtain one) or having a University degree equivalent to a European Master’s degree (5-year duration) at the deadline of the MISCEA Programme’s call.
• Researchers must be doctoral candidates, i.e. not already in possession of a doctoral degree at the deadline of the co-funded programme’s call. Researchers who have successfully defended their doctoral thesis but who have not yet formally been awarded the doctoral degree will NOT be considered eligible.
• Signing a declaration of the veracity of the information provided (Declaration of honour, free of form).

If you comply with the eligibility criteria and you wish to submit your application, you must :

• Contact the thesis supervisor and explain your thesis project to her/him so that she/he validates your application.
• Submit a 5-pages thesis proposal under the proposed research areas, with the agreement of the future supervisor. Additionally, to the submission of the 5-pages thesis proposal, the applicant will have to complete an ethics checklist based on ethics guidance from the HorizonEurope programme guide.
• English-translated transcripts from the master’s degree or equivalent.
• Any specific requirements of the Doctoral School corresponding to the targeted MISCEA
  fellowship offer.
• English curriculum vitae, including information about the level on English language knowledge.
• A motivation letter. 
• One letter of reference, at least.

Templates are available on the MISCEA website (link).

Then your candidature is complete, please send inquiries to miscea-program@enpc.fr

Additional comments

The present offer of a doctoral contract in France is for a period of three years.

Full-Time employment : estimated monthly brut salary : ~2700euros (estimated monthly net salary before income taxes: ~2100euros)