{"id":6738,"date":"2024-09-09T16:42:11","date_gmt":"2024-09-09T14:42:11","guid":{"rendered":"https:\/\/ingenius.ecoledesponts.fr\/?p=6738"},"modified":"2025-07-29T16:16:04","modified_gmt":"2025-07-29T14:16:04","slug":"insight-mission-at-the-heart-of-mars","status":"publish","type":"post","link":"https:\/\/ingenius.ecoledesponts.fr\/en\/articles\/insight-mission-at-the-heart-of-mars\/","title":{"rendered":"InSight Mission – At the heart of Mars"},"content":{"rendered":"\n\n\n
\"\"
InSight mission. Credit: Shutterstock_joshimerbin<\/figcaption><\/figure>\n\n\n\n

In a few words, tell us about InSight mission to Mars. <\/strong><\/p>\n\n\n\n

The InSight mission is a geophysical mission coordinated by NASA with the participation of the Centre National d’\u00c9tudes Spatiales and DLR (the French and German space agencies, respectively). The mission consisted in sending on Mars a lander carrying two main instruments: a thermal probe supplied by DLR and a seismometer designed at the Institut de Physique du Globe de Paris (IPGP), and supplied by CNES. These instruments were placed on Mars using an articulated arm.<\/p>\n\n\n\n

The thermal probe (named HP3<\/sup>) was to penetrate to a depth of 5 meters to take thermal measurements and gain a more precise idea of the planet\u2019s thermal radiation. Unfortunately, the probe, designed to penetrate sand by friction, had to pass through an unexpected 30 cm thick layer of very loose cohesive material at the surface, that impeded the penetration. The probe was nevertheless able to take thermal conductivity measurements on the surface and deduce its density, which turned out to be very low: 1.2 compared with water (1) and soils on Earth (around 1.8).<\/p>\n\n\n\n

The role of the seismometer (called SEIS), is to detect seismic waves from earthquakes1<\/a><\/sup> on Mars, as well as meteorite impacts. In two years of measurements, the highest magnitude recorded was 5.5.  Analysis of the seismic waves has enabled us to define the planet\u2019s structure by specifying the radius of its metallic liquid core and the dimensions of its mantle and crust. A large impact in December 2021 revealed an incredible discovery<\/a> never seen before in the solar system: the existence within the mantle of a liquid mineral layer around 150 km thick, surrounding a core whose diameter is estimated at 1,650 km2<\/a><\/sup>.<\/p>\n\n\n\n

You are a researcher in soil mechanics. What was your role in this mission ?<\/strong><\/p>\n\n\n\n

We had two objectives. The first was to carry out wave velocity measurements on a simulant of the soil of Mars. After tests on sands sent by NASA and DLR, we realized that the Fontainebleau sand proved to be the ideal candidate: a grain size estimated of 170 microns on Mars, compared with 220 microns at Fontainebleau, and a rounded shape due to saltation movements of grains generated on Mars by the wind, under a very low atmospheric pressure of 6 mb (compared with an average of 1015 mb on Earth).<\/p>\n\n\n\n

Secondly, our role was to study the interaction between the seismometer and the soil of Mars, to design the shape of the foot of the device.  The SEIS seismometer is much more accurate than those used on the Apollo mission in the 70s, thanks to major technological advances made since then; for example, placed in a mine at a depth of 500 meters in Bavaria in central Europe, it can detect the waves emitted by waves breaking on the North Sea beaches at Hamburg. <\/p>\n\n\n\n

How did you proceed ?<\/strong><\/p>\n\n\n\n

To measure wave velocity, small piezo-ceramic vibrating plates (bender elements) are placed on either side of a cylindrical specimen of sand; one emits the waves, while the other detects them after they have passed through the specimen. A wave speed of 128 meters per second was measured, comparable to that subsequently measured on the surface of Mars. In fact, we were very lucky, as direct observation of the soil on Mars (known as regolith) after landing revealed that it was not sand, but a fine sandy matrix with a certain cohesion, containing small pebbles. This cohesive soil resisted the thrust of the retrorockets during landing, and did not disperse as sand (non-cohesive, i.e. with no cementing links between its grains) would have done.<\/p>\n\n\n\n

To design the seismometer foot, we carried out laboratory tests, here at the \u00c9cole nationale des ponts et chauss\u00e9es, using a specially developed system to measure the force required for different foot shapes to penetrate sand. In this way, we were able to determine the optimum shape of the small spike placed in the centre of a disk with an imposed diameter of 60 mm. We also had to determine the spring constant equivalent to the elastic reaction of the seismometer’s foot on the ground, necessary for the analysis of its data.<\/p>\n\n\n\n

\"\"
Photo taken by the lander on mission day 1170, showing the two devices and the articulated arm (IDA) (Image credit : NASA-JPL)<\/figcaption><\/figure>\n\n\n\n

Can you tell us how you came to work on this mission ?<\/strong><\/p>\n\n\n\n

In June 2012, I received an email from the Institut de Physique du Globe in Paris, a nationally and internationally renowned geophysics institute, asking if I would be willing to work on a Martian soil simulant. At first, I thought it was a joke, but after checking, the email turned out to be from Philippe Lognonn\u00e9, designer and scientific manager of the seismometer, to whom my name had been passed by a colleague I had met at a thesis defence. Philippe and his colleagues have been trying to send a seismometer to Mars for over 20 years, with a first failed attempt in 1996. So, without really expecting it, I found myself taking part in an initial meeting at NASA in California in February 2013 with the 80-strong mission science team. When I presented my tests, they were amazed at how quickly we had achieved our results, which were of great importance to the mission. For them, who were not specialists in the field, this was unexpected – they expected it to take longer and cost a lot more !<\/p>\n\n\n\n

Did you get any unexpected results ?<\/strong><\/p>\n\n\n\n

Yes: towards the end of the mission, CNES and IPGP suggested covering with a layer of soil the tether connecting the seismometer to the lander3<\/a><\/sup>, which carries the energy on one side and recovers the signals on the other. The aim was to improve insulation to reduce the disturbances of the seismic signals caused by wind and surface temperature variations.<\/p>\n\n\n\n

The person in charge of the lander\u2019s articulated arm, at the end of which was placed a small scoop that could act as a shovel, had to program the operation, which was not initially planned. Using the camera on the arm, we were able to estimate the amount of soil scrapped and dumped, and found that some was missing. Why? Because during the operation, there was a 5 m\/s wind, detected by the weather station also on board the lander, that blew away the lightest grains. According to calculations made by Nicolas Verdier, a CNES engineer, the 900-micron particles fell almost directly downwards, while the 300-micron particles were slightly deflected by the wind since the finer the particle, the greater the effect of the wind compared to gravity (equal on Mars to 3.721 m\/s2<\/sup>)4<\/a><\/sup>. A 100-micron grain can be transported over 4 meters, while smaller grains are blown away by the wind. These observations have given us important information on the regolith grain size distribution.<\/a><\/p>\n\n\n\n

The mission has come to an end. Will your research benefit other space or terrestrial missions ?<\/strong><\/p>\n\n\n\n

The mission was officially planned for two years and was renewed once. It could have gone for longer, but was unfortunately stopped in December 2022 due to the presence of dust gradually accumulating on the solar arrays that supplied the lander’s energy. This was unfortunate, as it would have been interesting to be able to record marsquakes and impacts over a longer period, bearing in mind that some NASA missions to Mars have lasted more than 10 years.<\/p>\n\n\n\n

Knowing more about the structure of the rocky planets helps us to better understand how they were formed, and consequently about the genesis of the solar system. This new information on Martian regolith, obtained through the InSight mission, will be useful for future missions on Mars, and in the longer term for setting up human bases there. And this success on Mars will soon hopefully be repeated on the Moon with NASA’s FSS (the Far Side Seismic Suite5<\/a><\/sup>) mission, where the InSight’s spare seismometer will be used to further analyse moonquakes and the effects of impacts on the Moon.<\/p>\n\n\n\n

Interview by Ad\u00e8le Mazurek, Science Communicator at \u00c9cole nationale des ponts et chauss\u00e9es<\/em><\/p>\n\n\n

  1. Marsquakes are not caused by the movement of tectonic plates, which do not exist on Mars due to its thick crust, but by active faults. \u21a9\ufe0e<\/a><\/li>
  2. The rocky planets of the solar system – Mercury, Venus, Earth and Mars – consist of a metallic liquid core – with a solid central \u201cseed\u201d for Earth – surrounded by a mineral mantle and crust. On the recent discovery of the liquid mineral layer, see the article in the journal Nature : https:\/\/www.nature.com\/articles\/s41586-023-06601-8 \u21a9\ufe0e<\/a><\/li>
  3. A CNES-led operation \u21a9\ufe0e<\/a><\/li>
  4. See https:\/\/www.insu.cnrs.fr\/fr\/cnrsinfo\/histoire-de-sables-de-poussieres-et-de-vent-sur-mars<\/a> (in French) \u21a9\ufe0e<\/a><\/li>
  5. See https:\/\/www.jpl.nasa.gov\/missions\/the-farside-seismic-suite \u21a9\ufe0e<\/a><\/li><\/ol>","protected":false},"excerpt":{"rendered":"

    In a few words, tell us about InSight mission to Mars. The InSight mission is a geophysical mission coordinated by […]<\/p>\n","protected":false},"author":6,"featured_media":6731,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_related_content_post":[],"_related_content_subject":[124],"_related_content_author":[],"_related_content_category":[1720],"_related_content_folder":[6755],"_excerpt":"Pierre Delage, emeritus research director in Soil mechanics in the geotechnics team - CERMES at the Navier laboratory, looks back at his research work carried out as part of the InSight mission, launched in May 2018 by NASA to study the structure of the planet Mars.<\/strong>","_duration":6,"_manual_duration":false,"footnotes":"[{\"content\":\"Marsquakes are not caused by the movement of tectonic plates, which do not exist on Mars due to its thick crust, but by active faults.\",\"id\":\"9517bc26-86f7-4a07-bced-9f7b8d878702\"},{\"content\":\"The rocky planets of the solar system - Mercury, Venus, Earth and Mars - consist of a metallic liquid core - with a solid central \u201cseed\u201d for Earth - surrounded by a mineral mantle and crust. On the recent discovery of the liquid mineral layer, see the article in the journal Nature : https:\/\/www.nature.com\/articles\/s41586-023-06601-8\",\"id\":\"caaa3454-385d-44a9-8bcc-4cac2381bd7e\"},{\"content\":\"A CNES-led operation\",\"id\":\"64fec4dc-0695-4cf3-bb16-c8c5abf5386d\"},{\"content\":\"See https:\/\/www.insu.cnrs.fr\/fr\/cnrsinfo\/histoire-de-sables-de-poussieres-et-de-vent-sur-mars<\/a> (in French)\",\"id\":\"ba50240b-8cd1-426c-b150-f7117c6dedbc\"},{\"content\":\"See https:\/\/www.jpl.nasa.gov\/missions\/the-farside-seismic-suite\",\"id\":\"4b80539e-d931-4b59-854d-1f413ae68a50\"}]"},"article-types":[13],"class_list":["post-6738","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","article-types-article"],"has_blocks":true,"block_data":[{"blockName":"enpc\/excerpt","attrs":{"lock":[],"metadata":[],"className":"","style":""},"innerBlocks":[],"innerHTML":"","innerContent":[],"rendered":""},{"blockName":"core\/image","attrs":{"id":6745,"width":"748px","height":"auto","sizeSlug":"large","linkDestination":"none","blob":"","url":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2024\/09\/Ph-shutterstockjoshimerbin-1024x576.jpg","alt":"","caption":"InSight mission. Credit: Shutterstock_joshimerbin","lightbox":[],"title":"","href":"","rel":"","linkClass":"","aspectRatio":"","scale":"","linkTarget":"","lock":[],"metadata":[],"align":"","className":"wp-block-image size-large is-resized","style":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    \"\"
    InSight mission. Credit: Shutterstock_joshimerbin<\/figcaption><\/figure>\n","innerContent":["\n
    \"\"
    InSight mission. Credit: Shutterstock_joshimerbin<\/figcaption><\/figure>\n"],"rendered":"\n
    \"\"
    InSight mission. Credit: Shutterstock_joshimerbin<\/figcaption><\/figure>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"In a few words, tell us about InSight mission to Mars. ","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    In a few words, tell us about InSight mission to Mars. <\/strong><\/p>\n","innerContent":["\n

    In a few words, tell us about InSight mission to Mars. <\/strong><\/p>\n"],"rendered":"\n

    In a few words, tell us about InSight mission to Mars. <\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The InSight mission is a geophysical mission coordinated by NASA with the participation of the Centre National d'\u00c9tudes Spatiales and DLR (the French and German space agencies, respectively). The mission consisted in sending on Mars a lander carrying two main instruments: a thermal probe supplied by DLR and a seismometer designed at the Institut de Physique du Globe de Paris (IPGP), and supplied by CNES. These instruments were placed on Mars using an articulated arm.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The InSight mission is a geophysical mission coordinated by NASA with the participation of the Centre National d'\u00c9tudes Spatiales and DLR (the French and German space agencies, respectively). The mission consisted in sending on Mars a lander carrying two main instruments: a thermal probe supplied by DLR and a seismometer designed at the Institut de Physique du Globe de Paris (IPGP), and supplied by CNES. These instruments were placed on Mars using an articulated arm.<\/p>\n","innerContent":["\n

    The InSight mission is a geophysical mission coordinated by NASA with the participation of the Centre National d'\u00c9tudes Spatiales and DLR (the French and German space agencies, respectively). The mission consisted in sending on Mars a lander carrying two main instruments: a thermal probe supplied by DLR and a seismometer designed at the Institut de Physique du Globe de Paris (IPGP), and supplied by CNES. These instruments were placed on Mars using an articulated arm.<\/p>\n"],"rendered":"\n

    The InSight mission is a geophysical mission coordinated by NASA with the participation of the Centre National d'\u00c9tudes Spatiales and DLR (the French and German space agencies, respectively). The mission consisted in sending on Mars a lander carrying two main instruments: a thermal probe supplied by DLR and a seismometer designed at the Institut de Physique du Globe de Paris (IPGP), and supplied by CNES. These instruments were placed on Mars using an articulated arm.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The thermal probe (named HP3) was to penetrate to a depth of 5 meters to take thermal measurements and gain a more precise idea of the planet\u2019s thermal radiation. Unfortunately, the probe, designed to penetrate sand by friction, had to pass through an unexpected 30 cm thick layer of very loose cohesive material at the surface, that impeded the penetration. The probe was nevertheless able to take thermal conductivity measurements on the surface and deduce its density, which turned out to be very low: 1.2 compared with water (1) and soils on Earth (around 1.8).","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The thermal probe (named HP3<\/sup>) was to penetrate to a depth of 5 meters to take thermal measurements and gain a more precise idea of the planet\u2019s thermal radiation. Unfortunately, the probe, designed to penetrate sand by friction, had to pass through an unexpected 30 cm thick layer of very loose cohesive material at the surface, that impeded the penetration. The probe was nevertheless able to take thermal conductivity measurements on the surface and deduce its density, which turned out to be very low: 1.2 compared with water (1) and soils on Earth (around 1.8).<\/p>\n","innerContent":["\n

    The thermal probe (named HP3<\/sup>) was to penetrate to a depth of 5 meters to take thermal measurements and gain a more precise idea of the planet\u2019s thermal radiation. Unfortunately, the probe, designed to penetrate sand by friction, had to pass through an unexpected 30 cm thick layer of very loose cohesive material at the surface, that impeded the penetration. The probe was nevertheless able to take thermal conductivity measurements on the surface and deduce its density, which turned out to be very low: 1.2 compared with water (1) and soils on Earth (around 1.8).<\/p>\n"],"rendered":"\n

    The thermal probe (named HP3<\/sup>) was to penetrate to a depth of 5 meters to take thermal measurements and gain a more precise idea of the planet\u2019s thermal radiation. Unfortunately, the probe, designed to penetrate sand by friction, had to pass through an unexpected 30 cm thick layer of very loose cohesive material at the surface, that impeded the penetration. The probe was nevertheless able to take thermal conductivity measurements on the surface and deduce its density, which turned out to be very low: 1.2 compared with water (1) and soils on Earth (around 1.8).<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The role of the seismometer (called SEIS), is to detect seismic waves from earthquakes1 on Mars, as well as meteorite impacts. In two years of measurements, the highest magnitude recorded was 5.5. \u00a0Analysis of the seismic waves has enabled us to define the planet\u2019s structure by specifying the radius of its metallic liquid core and the dimensions of its mantle and crust. A large impact in December 2021 revealed an incredible discovery never seen before in the solar system: the existence within the mantle of a liquid mineral layer around 150 km thick, surrounding a core whose diameter is estimated at 1,650 km2.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The role of the seismometer (called SEIS), is to detect seismic waves from earthquakes1<\/a><\/sup> on Mars, as well as meteorite impacts. In two years of measurements, the highest magnitude recorded was 5.5.  Analysis of the seismic waves has enabled us to define the planet\u2019s structure by specifying the radius of its metallic liquid core and the dimensions of its mantle and crust. A large impact in December 2021 revealed an incredible discovery<\/a> never seen before in the solar system: the existence within the mantle of a liquid mineral layer around 150 km thick, surrounding a core whose diameter is estimated at 1,650 km2<\/a><\/sup>.<\/p>\n","innerContent":["\n

    The role of the seismometer (called SEIS), is to detect seismic waves from earthquakes1<\/a><\/sup> on Mars, as well as meteorite impacts. In two years of measurements, the highest magnitude recorded was 5.5.  Analysis of the seismic waves has enabled us to define the planet\u2019s structure by specifying the radius of its metallic liquid core and the dimensions of its mantle and crust. A large impact in December 2021 revealed an incredible discovery<\/a> never seen before in the solar system: the existence within the mantle of a liquid mineral layer around 150 km thick, surrounding a core whose diameter is estimated at 1,650 km2<\/a><\/sup>.<\/p>\n"],"rendered":"\n

    The role of the seismometer (called SEIS), is to detect seismic waves from earthquakes1<\/a><\/sup> on Mars, as well as meteorite impacts. In two years of measurements, the highest magnitude recorded was 5.5.  Analysis of the seismic waves has enabled us to define the planet\u2019s structure by specifying the radius of its metallic liquid core and the dimensions of its mantle and crust. A large impact in December 2021 revealed an incredible discovery<\/a> never seen before in the solar system: the existence within the mantle of a liquid mineral layer around 150 km thick, surrounding a core whose diameter is estimated at 1,650 km2<\/a><\/sup>.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"You are a researcher in soil mechanics. What was your role in this mission ?","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    You are a researcher in soil mechanics. What was your role in this mission ?<\/strong><\/p>\n","innerContent":["\n

    You are a researcher in soil mechanics. What was your role in this mission ?<\/strong><\/p>\n"],"rendered":"\n

    You are a researcher in soil mechanics. What was your role in this mission ?<\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"We had two objectives. The first was to carry out wave velocity measurements on a simulant of the soil of Mars. After tests on sands sent by NASA and DLR, we realized that the Fontainebleau sand proved to be the ideal candidate: a grain size estimated of 170 microns on Mars, compared with 220 microns at Fontainebleau, and a rounded shape due to saltation movements of grains generated on Mars by the wind, under a very low atmospheric pressure of 6 mb (compared with an average of 1015 mb on Earth).","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    We had two objectives. The first was to carry out wave velocity measurements on a simulant of the soil of Mars. After tests on sands sent by NASA and DLR, we realized that the Fontainebleau sand proved to be the ideal candidate: a grain size estimated of 170 microns on Mars, compared with 220 microns at Fontainebleau, and a rounded shape due to saltation movements of grains generated on Mars by the wind, under a very low atmospheric pressure of 6 mb (compared with an average of 1015 mb on Earth).<\/p>\n","innerContent":["\n

    We had two objectives. The first was to carry out wave velocity measurements on a simulant of the soil of Mars. After tests on sands sent by NASA and DLR, we realized that the Fontainebleau sand proved to be the ideal candidate: a grain size estimated of 170 microns on Mars, compared with 220 microns at Fontainebleau, and a rounded shape due to saltation movements of grains generated on Mars by the wind, under a very low atmospheric pressure of 6 mb (compared with an average of 1015 mb on Earth).<\/p>\n"],"rendered":"\n

    We had two objectives. The first was to carry out wave velocity measurements on a simulant of the soil of Mars. After tests on sands sent by NASA and DLR, we realized that the Fontainebleau sand proved to be the ideal candidate: a grain size estimated of 170 microns on Mars, compared with 220 microns at Fontainebleau, and a rounded shape due to saltation movements of grains generated on Mars by the wind, under a very low atmospheric pressure of 6 mb (compared with an average of 1015 mb on Earth).<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Secondly, our role was to study the interaction between the seismometer and the soil of Mars, to design the shape of the foot of the device.\u00a0 The SEIS seismometer is much more accurate than those used on the Apollo mission in the 70s, thanks to major technological advances made since then; for example, placed in a mine at a depth of 500 meters in Bavaria in central Europe, it can detect the waves emitted by waves breaking on the North Sea beaches at Hamburg.\u00a0","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Secondly, our role was to study the interaction between the seismometer and the soil of Mars, to design the shape of the foot of the device.  The SEIS seismometer is much more accurate than those used on the Apollo mission in the 70s, thanks to major technological advances made since then; for example, placed in a mine at a depth of 500 meters in Bavaria in central Europe, it can detect the waves emitted by waves breaking on the North Sea beaches at Hamburg. <\/p>\n","innerContent":["\n

    Secondly, our role was to study the interaction between the seismometer and the soil of Mars, to design the shape of the foot of the device.  The SEIS seismometer is much more accurate than those used on the Apollo mission in the 70s, thanks to major technological advances made since then; for example, placed in a mine at a depth of 500 meters in Bavaria in central Europe, it can detect the waves emitted by waves breaking on the North Sea beaches at Hamburg. <\/p>\n"],"rendered":"\n

    Secondly, our role was to study the interaction between the seismometer and the soil of Mars, to design the shape of the foot of the device.  The SEIS seismometer is much more accurate than those used on the Apollo mission in the 70s, thanks to major technological advances made since then; for example, placed in a mine at a depth of 500 meters in Bavaria in central Europe, it can detect the waves emitted by waves breaking on the North Sea beaches at Hamburg. <\/p>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"How did you proceed ?","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    How did you proceed ?<\/strong><\/p>\n","innerContent":["\n

    How did you proceed ?<\/strong><\/p>\n"],"rendered":"\n

    How did you proceed ?<\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"To measure wave velocity, small piezo-ceramic vibrating plates (bender elements) are placed on either side of a cylindrical specimen of sand; one emits the waves, while the other detects them after they have passed through the specimen. A wave speed of 128 meters per second was measured, comparable to that subsequently measured on the surface of Mars. In fact, we were very lucky, as direct observation of the soil on Mars (known as regolith) after landing revealed that it was not sand, but a fine sandy matrix with a certain cohesion, containing small pebbles. This cohesive soil resisted the thrust of the retrorockets during landing, and did not disperse as sand (non-cohesive, i.e. with no cementing links between its grains) would have done.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    To measure wave velocity, small piezo-ceramic vibrating plates (bender elements) are placed on either side of a cylindrical specimen of sand; one emits the waves, while the other detects them after they have passed through the specimen. A wave speed of 128 meters per second was measured, comparable to that subsequently measured on the surface of Mars. In fact, we were very lucky, as direct observation of the soil on Mars (known as regolith) after landing revealed that it was not sand, but a fine sandy matrix with a certain cohesion, containing small pebbles. This cohesive soil resisted the thrust of the retrorockets during landing, and did not disperse as sand (non-cohesive, i.e. with no cementing links between its grains) would have done.<\/p>\n","innerContent":["\n

    To measure wave velocity, small piezo-ceramic vibrating plates (bender elements) are placed on either side of a cylindrical specimen of sand; one emits the waves, while the other detects them after they have passed through the specimen. A wave speed of 128 meters per second was measured, comparable to that subsequently measured on the surface of Mars. In fact, we were very lucky, as direct observation of the soil on Mars (known as regolith) after landing revealed that it was not sand, but a fine sandy matrix with a certain cohesion, containing small pebbles. This cohesive soil resisted the thrust of the retrorockets during landing, and did not disperse as sand (non-cohesive, i.e. with no cementing links between its grains) would have done.<\/p>\n"],"rendered":"\n

    To measure wave velocity, small piezo-ceramic vibrating plates (bender elements) are placed on either side of a cylindrical specimen of sand; one emits the waves, while the other detects them after they have passed through the specimen. A wave speed of 128 meters per second was measured, comparable to that subsequently measured on the surface of Mars. In fact, we were very lucky, as direct observation of the soil on Mars (known as regolith) after landing revealed that it was not sand, but a fine sandy matrix with a certain cohesion, containing small pebbles. This cohesive soil resisted the thrust of the retrorockets during landing, and did not disperse as sand (non-cohesive, i.e. with no cementing links between its grains) would have done.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"To design the seismometer foot, we carried out laboratory tests, here at the \u00c9cole nationale des ponts et chauss\u00e9es, using a specially developed system to measure the force required for different foot shapes to penetrate sand. In this way, we were able to determine the optimum shape of the small spike placed in the centre of a disk with an imposed diameter of 60 mm. We also had to determine the spring constant equivalent to the elastic reaction of the seismometer's foot on the ground, necessary for the analysis of its data.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    To design the seismometer foot, we carried out laboratory tests, here at the \u00c9cole nationale des ponts et chauss\u00e9es, using a specially developed system to measure the force required for different foot shapes to penetrate sand. In this way, we were able to determine the optimum shape of the small spike placed in the centre of a disk with an imposed diameter of 60 mm. We also had to determine the spring constant equivalent to the elastic reaction of the seismometer's foot on the ground, necessary for the analysis of its data.<\/p>\n","innerContent":["\n

    To design the seismometer foot, we carried out laboratory tests, here at the \u00c9cole nationale des ponts et chauss\u00e9es, using a specially developed system to measure the force required for different foot shapes to penetrate sand. In this way, we were able to determine the optimum shape of the small spike placed in the centre of a disk with an imposed diameter of 60 mm. We also had to determine the spring constant equivalent to the elastic reaction of the seismometer's foot on the ground, necessary for the analysis of its data.<\/p>\n"],"rendered":"\n

    To design the seismometer foot, we carried out laboratory tests, here at the \u00c9cole nationale des ponts et chauss\u00e9es, using a specially developed system to measure the force required for different foot shapes to penetrate sand. In this way, we were able to determine the optimum shape of the small spike placed in the centre of a disk with an imposed diameter of 60 mm. We also had to determine the spring constant equivalent to the elastic reaction of the seismometer's foot on the ground, necessary for the analysis of its data.<\/p>\n"},{"blockName":"core\/image","attrs":{"id":6806,"width":"591px","height":"auto","sizeSlug":"full","linkDestination":"none","align":"center","blob":"","url":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2024\/09\/Figure-5-1.png","alt":"","caption":"Photo taken by the lander on mission day 1170, showing the two devices and the articulated arm (IDA) (Image credit : NASA-JPL)","lightbox":[],"title":"","href":"","rel":"","linkClass":"","aspectRatio":"","scale":"","linkTarget":"","lock":[],"metadata":[],"className":"wp-block-image aligncenter size-full is-resized","style":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    \"\"
    Photo taken by the lander on mission day 1170, showing the two devices and the articulated arm (IDA) (Image credit : NASA-JPL)<\/figcaption><\/figure>\n","innerContent":["\n
    \"\"
    Photo taken by the lander on mission day 1170, showing the two devices and the articulated arm (IDA) (Image credit : NASA-JPL)<\/figcaption><\/figure>\n"],"rendered":"\n
    \"\"
    Photo taken by the lander on mission day 1170, showing the two devices and the articulated arm (IDA) (Image credit : NASA-JPL)<\/figcaption><\/figure>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"Can you tell us how you came to work on this mission ?","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Can you tell us how you came to work on this mission ?<\/strong><\/p>\n","innerContent":["\n

    Can you tell us how you came to work on this mission ?<\/strong><\/p>\n"],"rendered":"\n

    Can you tell us how you came to work on this mission ?<\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"In June 2012, I received an email from the Institut de Physique du Globe in Paris, a nationally and internationally renowned geophysics institute, asking if I would be willing to work on a Martian soil simulant. At first, I thought it was a joke, but after checking, the email turned out to be from Philippe Lognonn\u00e9, designer and scientific manager of the seismometer, to whom my name had been passed by a colleague I had met at a thesis defence. Philippe and his colleagues have been trying to send a seismometer to Mars for over 20 years, with a first failed attempt in 1996. So, without really expecting it, I found myself taking part in an initial meeting at NASA in California in February 2013 with the 80-strong mission science team. When I presented my tests, they were amazed at how quickly we had achieved our results, which were of great importance to the mission. For them, who were not specialists in the field, this was unexpected - they expected it to take longer and cost a lot more !","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    In June 2012, I received an email from the Institut de Physique du Globe in Paris, a nationally and internationally renowned geophysics institute, asking if I would be willing to work on a Martian soil simulant. At first, I thought it was a joke, but after checking, the email turned out to be from Philippe Lognonn\u00e9, designer and scientific manager of the seismometer, to whom my name had been passed by a colleague I had met at a thesis defence. Philippe and his colleagues have been trying to send a seismometer to Mars for over 20 years, with a first failed attempt in 1996. So, without really expecting it, I found myself taking part in an initial meeting at NASA in California in February 2013 with the 80-strong mission science team. When I presented my tests, they were amazed at how quickly we had achieved our results, which were of great importance to the mission. For them, who were not specialists in the field, this was unexpected - they expected it to take longer and cost a lot more !<\/p>\n","innerContent":["\n

    In June 2012, I received an email from the Institut de Physique du Globe in Paris, a nationally and internationally renowned geophysics institute, asking if I would be willing to work on a Martian soil simulant. At first, I thought it was a joke, but after checking, the email turned out to be from Philippe Lognonn\u00e9, designer and scientific manager of the seismometer, to whom my name had been passed by a colleague I had met at a thesis defence. Philippe and his colleagues have been trying to send a seismometer to Mars for over 20 years, with a first failed attempt in 1996. So, without really expecting it, I found myself taking part in an initial meeting at NASA in California in February 2013 with the 80-strong mission science team. When I presented my tests, they were amazed at how quickly we had achieved our results, which were of great importance to the mission. For them, who were not specialists in the field, this was unexpected - they expected it to take longer and cost a lot more !<\/p>\n"],"rendered":"\n

    In June 2012, I received an email from the Institut de Physique du Globe in Paris, a nationally and internationally renowned geophysics institute, asking if I would be willing to work on a Martian soil simulant. At first, I thought it was a joke, but after checking, the email turned out to be from Philippe Lognonn\u00e9, designer and scientific manager of the seismometer, to whom my name had been passed by a colleague I had met at a thesis defence. Philippe and his colleagues have been trying to send a seismometer to Mars for over 20 years, with a first failed attempt in 1996. So, without really expecting it, I found myself taking part in an initial meeting at NASA in California in February 2013 with the 80-strong mission science team. When I presented my tests, they were amazed at how quickly we had achieved our results, which were of great importance to the mission. For them, who were not specialists in the field, this was unexpected - they expected it to take longer and cost a lot more !<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"Did you get any unexpected results ?","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Did you get any unexpected results ?<\/strong><\/p>\n","innerContent":["\n

    Did you get any unexpected results ?<\/strong><\/p>\n"],"rendered":"\n

    Did you get any unexpected results ?<\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Yes: towards the end of the mission, CNES and IPGP suggested covering with a layer of soil the tether connecting the seismometer to the lander3, which carries the energy on one side and recovers the signals on the other. The aim was to improve insulation to reduce the disturbances of the seismic signals caused by wind and surface temperature variations.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Yes: towards the end of the mission, CNES and IPGP suggested covering with a layer of soil the tether connecting the seismometer to the lander3<\/a><\/sup>, which carries the energy on one side and recovers the signals on the other. The aim was to improve insulation to reduce the disturbances of the seismic signals caused by wind and surface temperature variations.<\/p>\n","innerContent":["\n

    Yes: towards the end of the mission, CNES and IPGP suggested covering with a layer of soil the tether connecting the seismometer to the lander3<\/a><\/sup>, which carries the energy on one side and recovers the signals on the other. The aim was to improve insulation to reduce the disturbances of the seismic signals caused by wind and surface temperature variations.<\/p>\n"],"rendered":"\n

    Yes: towards the end of the mission, CNES and IPGP suggested covering with a layer of soil the tether connecting the seismometer to the lander3<\/a><\/sup>, which carries the energy on one side and recovers the signals on the other. The aim was to improve insulation to reduce the disturbances of the seismic signals caused by wind and surface temperature variations.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The person in charge of the lander\u2019s articulated arm, at the end of which was placed a small scoop that could act as a shovel, had to program the operation, which was not initially planned. Using the camera on the arm, we were able to estimate the amount of soil scrapped and dumped, and found that some was missing. Why? Because during the operation, there was a 5 m\/s wind, detected by the weather station also on board the lander, that blew away the lightest grains. According to calculations made by Nicolas Verdier, a CNES engineer, the 900-micron particles fell almost directly downwards, while the 300-micron particles were slightly deflected by the wind since the finer the particle, the greater the effect of the wind compared to gravity (equal on Mars to 3.721 m\/s2)4. A 100-micron grain can be transported over 4 meters, while smaller grains are blown away by the wind. These observations have given us important information on the regolith grain size distribution.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The person in charge of the lander\u2019s articulated arm, at the end of which was placed a small scoop that could act as a shovel, had to program the operation, which was not initially planned. Using the camera on the arm, we were able to estimate the amount of soil scrapped and dumped, and found that some was missing. Why? Because during the operation, there was a 5 m\/s wind, detected by the weather station also on board the lander, that blew away the lightest grains. According to calculations made by Nicolas Verdier, a CNES engineer, the 900-micron particles fell almost directly downwards, while the 300-micron particles were slightly deflected by the wind since the finer the particle, the greater the effect of the wind compared to gravity (equal on Mars to 3.721 m\/s2<\/sup>)4<\/a><\/sup>. A 100-micron grain can be transported over 4 meters, while smaller grains are blown away by the wind. These observations have given us important information on the regolith grain size distribution.<\/a><\/p>\n","innerContent":["\n

    The person in charge of the lander\u2019s articulated arm, at the end of which was placed a small scoop that could act as a shovel, had to program the operation, which was not initially planned. Using the camera on the arm, we were able to estimate the amount of soil scrapped and dumped, and found that some was missing. Why? Because during the operation, there was a 5 m\/s wind, detected by the weather station also on board the lander, that blew away the lightest grains. According to calculations made by Nicolas Verdier, a CNES engineer, the 900-micron particles fell almost directly downwards, while the 300-micron particles were slightly deflected by the wind since the finer the particle, the greater the effect of the wind compared to gravity (equal on Mars to 3.721 m\/s2<\/sup>)4<\/a><\/sup>. A 100-micron grain can be transported over 4 meters, while smaller grains are blown away by the wind. These observations have given us important information on the regolith grain size distribution.<\/a><\/p>\n"],"rendered":"\n

    The person in charge of the lander\u2019s articulated arm, at the end of which was placed a small scoop that could act as a shovel, had to program the operation, which was not initially planned. Using the camera on the arm, we were able to estimate the amount of soil scrapped and dumped, and found that some was missing. Why? Because during the operation, there was a 5 m\/s wind, detected by the weather station also on board the lander, that blew away the lightest grains. According to calculations made by Nicolas Verdier, a CNES engineer, the 900-micron particles fell almost directly downwards, while the 300-micron particles were slightly deflected by the wind since the finer the particle, the greater the effect of the wind compared to gravity (equal on Mars to 3.721 m\/s2<\/sup>)4<\/a><\/sup>. A 100-micron grain can be transported over 4 meters, while smaller grains are blown away by the wind. These observations have given us important information on the regolith grain size distribution.<\/a><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"style":{"elements":{"link":{"color":{"text":"var:preset|color|red"}}}},"textColor":"red","align":"","content":"The mission has come to an end. Will your research benefit other space or terrestrial missions ?","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-red-color has-text-color has-link-color","backgroundColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The mission has come to an end. Will your research benefit other space or terrestrial missions ?<\/strong><\/p>\n","innerContent":["\n

    The mission has come to an end. Will your research benefit other space or terrestrial missions ?<\/strong><\/p>\n"],"rendered":"\n

    The mission has come to an end. Will your research benefit other space or terrestrial missions ?<\/strong><\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"The mission was officially planned for two years and was renewed once. It could have gone for longer, but was unfortunately stopped in December 2022 due to the presence of dust gradually accumulating on the solar arrays that supplied the lander's energy. This was unfortunate, as it would have been interesting to be able to record marsquakes and impacts over a longer period, bearing in mind that some NASA missions to Mars have lasted more than 10 years.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    The mission was officially planned for two years and was renewed once. It could have gone for longer, but was unfortunately stopped in December 2022 due to the presence of dust gradually accumulating on the solar arrays that supplied the lander's energy. This was unfortunate, as it would have been interesting to be able to record marsquakes and impacts over a longer period, bearing in mind that some NASA missions to Mars have lasted more than 10 years.<\/p>\n","innerContent":["\n

    The mission was officially planned for two years and was renewed once. It could have gone for longer, but was unfortunately stopped in December 2022 due to the presence of dust gradually accumulating on the solar arrays that supplied the lander's energy. This was unfortunate, as it would have been interesting to be able to record marsquakes and impacts over a longer period, bearing in mind that some NASA missions to Mars have lasted more than 10 years.<\/p>\n"],"rendered":"\n

    The mission was officially planned for two years and was renewed once. It could have gone for longer, but was unfortunately stopped in December 2022 due to the presence of dust gradually accumulating on the solar arrays that supplied the lander's energy. This was unfortunate, as it would have been interesting to be able to record marsquakes and impacts over a longer period, bearing in mind that some NASA missions to Mars have lasted more than 10 years.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"align":"","content":"Knowing more about the structure of the rocky planets helps us to better understand how they were formed, and consequently about the genesis of the solar system. This new information on Martian regolith, obtained through the InSight mission, will be useful for future missions on Mars, and in the longer term for setting up human bases there. And this success on Mars will soon hopefully be repeated on the Moon with NASA's FSS (the Far Side Seismic Suite5) mission, where the InSight's spare seismometer will be used to further analyse moonquakes and the effects of impacts on the Moon.","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","gradient":"","fontSize":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Knowing more about the structure of the rocky planets helps us to better understand how they were formed, and consequently about the genesis of the solar system. This new information on Martian regolith, obtained through the InSight mission, will be useful for future missions on Mars, and in the longer term for setting up human bases there. And this success on Mars will soon hopefully be repeated on the Moon with NASA's FSS (the Far Side Seismic Suite5<\/a><\/sup>) mission, where the InSight's spare seismometer will be used to further analyse moonquakes and the effects of impacts on the Moon.<\/p>\n","innerContent":["\n

    Knowing more about the structure of the rocky planets helps us to better understand how they were formed, and consequently about the genesis of the solar system. This new information on Martian regolith, obtained through the InSight mission, will be useful for future missions on Mars, and in the longer term for setting up human bases there. And this success on Mars will soon hopefully be repeated on the Moon with NASA's FSS (the Far Side Seismic Suite5<\/a><\/sup>) mission, where the InSight's spare seismometer will be used to further analyse moonquakes and the effects of impacts on the Moon.<\/p>\n"],"rendered":"\n

    Knowing more about the structure of the rocky planets helps us to better understand how they were formed, and consequently about the genesis of the solar system. This new information on Martian regolith, obtained through the InSight mission, will be useful for future missions on Mars, and in the longer term for setting up human bases there. And this success on Mars will soon hopefully be repeated on the Moon with NASA's FSS (the Far Side Seismic Suite5<\/a><\/sup>) mission, where the InSight's spare seismometer will be used to further analyse moonquakes and the effects of impacts on the Moon.<\/p>\n"},{"blockName":"core\/paragraph","attrs":{"fontSize":"small","align":"","content":"Interview by Ad\u00e8le Mazurek, Science Communicator at \u00c9cole nationale des ponts et chauss\u00e9es","dropCap":false,"placeholder":"","direction":"","lock":[],"metadata":[],"className":"has-small-font-size","style":"","backgroundColor":"","textColor":"","gradient":"","fontFamily":"","borderColor":"","anchor":""},"innerBlocks":[],"innerHTML":"\n

    Interview by Ad\u00e8le Mazurek, Science Communicator at \u00c9cole nationale des ponts et chauss\u00e9es<\/em><\/p>\n","innerContent":["\n

    Interview by Ad\u00e8le Mazurek, Science Communicator at \u00c9cole nationale des ponts et chauss\u00e9es<\/em><\/p>\n"],"rendered":"\n

    Interview by Ad\u00e8le Mazurek, Science Communicator at \u00c9cole nationale des ponts et chauss\u00e9es<\/em><\/p>\n"},{"blockName":"core\/footnotes","attrs":{"lock":[],"metadata":[],"className":"","style":"","backgroundColor":"","textColor":"","fontSize":"","fontFamily":"","borderColor":""},"innerBlocks":[],"innerHTML":"","innerContent":[],"rendered":""}],"seo":{"title":"InSight Mission - At the heart of Mars"},"media":{"img":"\"\"","src":"https:\/\/ingenius.ecoledesponts.fr\/wp-content\/uploads\/2024\/09\/2024_DDAP_outilsmediation-10-1.jpg"},"url":"\/en\/articles\/insight-mission-at-the-heart-of-mars\/","related":{"post":[],"author":[],"subject":[{"title":"Economics & Society","url":"\/en\/subjects\/economics-society\/","id":"124","media":"\"\"","slug":"economics-society"}],"category":[{"title":"Article collection","url":"\/en\/articles\/category\/dossier\/","id":"1720","media":"","slug":"dossier","_related_post_type":"folder"}],"folder":[{"title":"Space: a unique platform for scientific observation and experimentation","url":"\/en\/folders\/space-a-unique-platform-for-scientific-observation-and-experimentation\/","id":"6755","media":"\"\"","slug":"space-a-unique-platform-for-scientific-observation-and-experimentation"}]},"translated":"https:\/\/ingenius.ecoledesponts.fr\/articles\/mission-insight-au-coeur-de-mars\/","icon":"icon-article","duration":"6","custom_excerpt":"Pierre Delage, emeritus research director in Soil mechanics in the geotechnics team - CERMES at the Navier laboratory, looks back at his research work carried out as part of the InSight mission, launched in May 2018 by NASA to study the structure of the planet Mars.<\/strong>","duration_type":"","_links":{"self":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts\/6738","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/comments?post=6738"}],"version-history":[{"count":4,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts\/6738\/revisions"}],"predecessor-version":[{"id":8989,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/posts\/6738\/revisions\/8989"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/media\/6731"}],"wp:attachment":[{"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/media?parent=6738"}],"wp:term":[{"taxonomy":"article-types","embeddable":true,"href":"https:\/\/ingenius.ecoledesponts.fr\/en\/wp-json\/wp\/v2\/article-types?post=6738"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}