Time：15:00 p.m.,May 11, 2019
Place：Lecture Hall of An-zhong Building,Zijingang Campus,Zhejiang University
Topic：The mechanics of Martian soils: InSights from the InSight mission
Biography
Pierre Delage, Professor of Geotechnical Engineering at Ecole des Ponts ParisTech, contributed to the development of CERMES (the geotechnical group of Ecole des Ponts, now included in Laboratoire Navier), that he directed from 2003 to 2010. He developed researches on the fundamentals mechanisms governing the macroscopic response of multi-phase soils and rocks submitted to changes in stress, water content and temperature, with some pioneering contributions on the role of the changes in pore size distribution in the volume change behaviour of soils, the stress-strain and failure behaviour of unsaturated soils or the thermal behaviour of claystones. His researches concerned sensitive clays, deep marine sediments, unsaturated soils, compacted soils, loess, oil reservoir chalks, oil sands, claystones and shales and, more recently, Martian regoliths, in the framework of the NASA mission InSight on Mars (landing planned on 26 November 2018).
He is a corresponding member of the French Academy of Agriculture, has been Chief editor of the “Revue Française de Géotechnique” and “Géotechnique Letters”. He has been or still is member of various editorial panels (Géotechnique, Computers and Geotechnics, Geotechnical Testing Journal, Geomechanics and Geoengineering, Rivista Geotecnica Italiana). He organised, with E. Alonso, the 1st International Conference on Unsaturated Soils in Paris (1995), played an active role in the 18th International Conference on Soil Mechanics and Geotechnical Engineering (Paris 2013) and chaired the 3rd European Conference on Unsaturated Soils (Paris 2016). He serves since 2013 as Chair of the Technical Oversight Committee of the International Society of Soil Mechanics and Geotechnical Engineering, in charge of supervising the activities of the 32 Technical Committees of the ISSMGE, under both Roger Frank and Charles Ng’s Presidential terms.
Abstract
The InSight lander, sent by NASA on Mars and managed by the Jet Propulsion Laboratory (NASA - CalTech), successfully landed on Mars on 26 November 2018. InSight is a geophysical mission aimed at exploring the structure of Mars so as to get a better understanding on the formation of the rocky planets of the Solar system. To do so, various instruments, including the SEIS seismometer (Seismic Experiment for Interior Structure, designed by the Institute of Earth Physics of Paris and funded by the French Space Agency - CNES) and the HP3 device (Heat flow and Physical Properties Probe, provided by the German Space Agency - DLR, designed to dynamically drive a mole down to a depth of 5 m to determine the temperature gradient profile at the surface) have been placed on the surface of Mars. For both instruments, a detailed investigation of their mechanical interaction with the Martian regolith is required: elastic properties for the SEIS/soil interactions, density and penetrability for HP3. The presentation will detail how this investigation is being conducted, from orbiter observations (surface thermal inertia monitoring), from data from former missions (i.e. Viking and Phoenix landers, Parthfinder, Opportunity and Curiosity rovers), from laboratory tests conducted on Martian regolith simulants, and from feedbacks just gained from the InSight landing site (photos, back analysis of data from lander and instruments).
