Papers by Jean-luc Josset
Planetary and Space Science, 2002
The lunar surface reveals a sharp opposition effect, which is to be explained by the shadowing an... more The lunar surface reveals a sharp opposition effect, which is to be explained by the shadowing and coherent backscattering mechanisms. Generalizing the radiative transfer theory via Monte Carlo methods, we are carrying out studies of backscattering in regolith-like scattering media. We have also started systematic laboratory measurements of structural simulators of lunar regolith. The SMART-1 AMIE and D-CIXS/XSM experiments provide
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<p>CLUPI, the high-performance colour close-up imager, on board the 2020 ExoMars Ro... more <p>CLUPI, the high-performance colour close-up imager, on board the 2020 ExoMars Rover plays an important role in attaining the mission objectives: it is the equivalent of the hand lens that no geologist is without when undertaking field work. CLUPI is a powerful, highly integrated miniaturized (<900g) low-power robust imaging system, able to sustain very low temperatures (–120°C). CLUPI has a focus mechanism allowing a working distance from 11.5cm to infinite providing outstanding pictures with a color detector of 2652x1768x3. At 11.5cm, the spatial resolution is 8 micrometer/pixel in color (Josset et al, 2017). The concept benefits from well-proven heritage: Proba-1, Rosetta, MarsExpress and Smart-1 missions…The CLUPI payload accommodation on the drill box of the rover allows to perform several key science operations configuration thanks to the two degrees of freedom movement of the drill, height and rotation. (Fig. 1).</p> <p>In a typical field scenario, the geologist will use his/her eyes to make an overview of an area and the outcrops within it to determine sites of particular interest for more detailed study. In the ExoMars scenario, after having made a preliminary general evaluation, the geologist will approach a particular outcrop for closer observation of structures at the decimetre to subdecimeter scale before finally getting very close up to the surface with a hand lens (CLUPI), and/or taking a hand specimen, for detailed observation of textures and minerals. Using structural, textural and preliminary compositional analysis, the geologist identifies the materials and makes a decision as to whether they are of sufficient interest to be subsampled for laboratory analysis (using the ExoMars drill and laboratory instruments).</p> <p>Given the time and energy expense necessary for drilling and analysing samples in the rover laboratory, preliminary screening of the materials to choose those most likely to be of interest is essential. ExoMars will be choosing the samples exactly as a field geologist does – by observation (backed up by years and years of field experience in rock interpretation in the field). Because the main science objective of ExoMars concerns the search for life, whose traces on Mars are likely to be cryptic, close up observation of the rocks and granular regolith will be critical to the decision as whether to drill and sample the nearby underlying materials.  Thus, CLUPI is the essential final step in the choice of drill site. But not only are CLUPI’s observations of the rock outcrops important, but they also serve other purposes. CLUPI, could observe the placement of the drill head. It will also be able to observe the fines that come out of the drill hole, including any colour stratification linked to lithological changes with depth. Finally, CLUPI will provide detailed observation of the surface of the core drilled materials when they are in the sample drawer at a spatial resolution of about 17 micrometer/pixel in color. All of these investigations are summarized in the figure 1 describing the CLUPI science operational configurations.</p> <p>After a brief description of these science observation configurations of CLUPI, the first promising results of the operations preparations and simulations in order to optimize the science return will be detailed. Indeed, the science operation simulations are performed by using a CLUPI flight model representative together with a drill/rover simulator, all inside a dedicated laboratory of the Space Exploration Institute based in Microcity, Neuchatel in Switzerland. The relevant results are of prime importance for the future science exploitation of CLUPI. It demonstrates the CLUPI capabilities to provide information significantly contributing to the understanding of the geological environment and could identify outstanding potential biofabrics of past life on Mars.</p> <p><img src="" alt="" /></p> <p>Figure 1: CLUPI science operational configurations. (a) On the platform, (b) geological environment survey, (c) Close-up outcrops observation, (d) drilling area observation, (e) drilling operation observation, (f) Drill hole and fines observation, (g) drilled core sample observation and (h) calibration: calibration target imaging. Images credit: ESA/SEI-TJ</p> <p><img src="" alt="" /></p> <p>Figure 2: SEI CLUPI Science Operations Laboratory based in Microcity Neuchatel. Simulations using a CLUPI flight model representative. Images Credit: Space Exploration Institute (SEI)</p> <p><img src="" alt="" /></p> <p>Figure 3: Left: CLUPI on the drill/rover simulator, sample observation configuration. Right: CLUPI output data, mosaic of three images. Images Credit: Space Exploration Institute (SEI). CLUPI Science Operations Laboratory based in Microcity Neuchatel.…
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Lunar and Planetary Science Conference, Mar 1, 2021
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Seventh International Conference on Mars, Jul 1, 2007
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Lunar and Planetary Science Conference, Mar 1, 2008
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Beagle2 is the UK-led lander element on ESA's Mars Express mission, which will reach Mars in... more Beagle2 is the UK-led lander element on ESA's Mars Express mission, which will reach Mars in late December 2003. After separation from the Mars Express orbiter 6 days before the atmospheric entry, Beagle2 will descend to the Martian surface by means of ablative heat shields and parachutes. The impact will be cushioned by a set of airbags. The selected landing site at 11.6 deg N/90.75 deg E (IAU 2000 coordinates) is situated in the south-east of the center of Isidis Planitia, a sedimentary basin which is expected to meet the requirements of Beagle's scientific mission, the lander operations, and the entry, descent and landing systems. The exact determination of the Beagle2 landing site is important not only for the Beagle2 and MEX orbiter science investigations, but also for the reconstruction of Beagle's entry and descent trajectory. A precise determination of the Beagle2 position is not possible via the MELACOM radio link. Instead, a novel method based on celestial navigation is employed, which utilizes the Stereo Camera System on the lander for imaging the Martian night sky. The position data is then refined by comparing the landing site panorama images with high resolution orbiter images and laser altimeter data. This combination of celestial navigation with image data analysis for precision position determination will be applicable for many future missions as well.
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Astrobiology, Jun 1, 2008
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Advances in Space Research, Jun 1, 2023
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LPI, Mar 1, 2020
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European Planetary Science Congress, Sep 1, 2013
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EGS - AGU - EUG Joint Assembly, Apr 1, 2003
Each planetary mission brings its specific needs and environmental conditions: high temperature a... more Each planetary mission brings its specific needs and environmental conditions: high temperature and radiations for Mercury, shock, thermal cycles and low temperature operation for Mars, long vacuum cruise phase and very low temperature for comet nucleus. Nevertheless, all the missions share the same interests in term of low mass, low power and harsh environmental conditions. When a mission includes a
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<ul> <li><strong> </strong><strong... more <ul> <li><strong> </strong><strong>Introduction</strong></li> </ul> <p> </p> <p><img src="" alt="" /></p> <p>Figure 1: Rosalind Franklin rover . (a) CLUPI on the drill box (red rectangle, Image credit ESA/SEI-TJ). (b) CLUPI flight model representative (EM+) mounted in the stowed drill configuration, Image credit SEI.</p> <p>Therefore, for this scientific goal, the objective is to reconstruct topographical and 3D data from the CLUPI data, using specific CLUPI operating configurations. This project is in collaboration with the Laboratoire d’Astrophysique de Marseille (LAM, France).</p> <ul> <li><strong> </strong><strong>3D and stereo with CLUPI</strong></li> </ul> <p>CLUPI 8 configurations are linked to the drill box positions (Fig.2, Josset et al., 2017). In order to constrain the topographical data from the images acquired by CLUPI we will used the stereogrammetry method (Beyer et al., 2018). To perform that we need several images of the same geological target but with different stereo-angle (i.e. the angle between the target and CLUPI in the target repository (Fig.3)). CLUPI is a mono optics camera system. Thus, the different shots resulting in different stereo angles will come from the movement of the drill box and/or the rover itself. So, the main question of this project is how to define the optimal geometries parameters to obtain stereo images of the same target according to the 8 CLUPI operating configurations?<strong> </strong></p> <ul> <li><strong> </strong><strong>Experimentation and preliminary result</strong></li> </ul> <p>In order to simulate the operation environment of CLUPI, we are using the EM+ flight model representative in the Space Exploration Institute CLUPI science operation lab based in Microcity, Neuchâtel, Switzerland. The CLUPI EM+ is adapted on a geometric drill simulator, corresponding to the ExoMars Rover mission (Josset et al., 2017). The objectives of this experimentation are to (1) recreate the CLUPI operating configurations, (2) vary parameters such as: the angle of incidence, the working distance and the CLUPI height relative to the ground; the illumination (studied in Marslabor, University of Basel; Bontognalli et al., 2021), and (3) derived the best geometrical position of the rover in order to reconstruct topographical data (Fig.3a).</p> <p><img src="" alt="" /></p> <p>Figure 2: CLUPI eight operational configurations. (a) On the platform, (b) geological environment survey, (c) Close-up outcrops observation, (d) drilling area observation, (e) drilling operation observation, (f) Drill hole and fines observation, (g) drilled core sample observation and (h) calibration: calibration target imaging. Images credit: ESA/SEI-TJ</p> <p> </p> <p><img src="" alt="" /></p> <p>Figure 3: Experiment with the EM+. (a) Simulation of the second configuration. (b) Simulation of the second configuration after the calculated translation and rotation of the "rover", with a stereo angle (red) and the same working distance (yellow). The green and blue points correspond, respectively to the EM+ position before and after the translation/rotation.</p> <ul> <li><strong> </strong><strong>Illumination study (Basel University)</strong></li> </ul> <p>The total light and direction of incidence light plays an important role in allowing the identification of different rock textures, morphological features, and mineralogical distribution. The effect of different solar angles in relation to the target rock is studied with  CLUPI analogue camera - Canon EOS M50. The most recent results show that to identify sedimentary structures, such as cracks, laminations and other morphological features in sedimentary rocks, the lower angle of 25° of direct light is preferable (sunset conditions on Mars, Fig.4a, c). In contrast, the distribution of the minerals within the rock, the incident/direct light shall be around 70° to the rock surface (mid-day conditions on Mars, Fig.4b,d).</p> <p><img src="" alt="" /></p> <p>Figure 4. Close-up images in third configuration of basaltic tuff (A&B) and dry cracks in sedimentary rock (C&D) taken with Canon EOS M50 in Marslabor at University of Basel. (a) and (c)  direct light of the angle 25 °. (b) and (d) direct light of an angle 70 °. Each to the rock surface. The total proportion of the light was 5:1 of direct and diffused light - 5000 LUX and 1000 LUX respectively, after Bontognali et al., 2021. With a working distance of 650 mm and camera angle of 11 °. (e) and (f) are…
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Space Science Reviews, 2018
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Astrobiology, 2017
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ABSTRACT
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Planetary and Space Science, 2015
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Papers by Jean-luc Josset