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1. Planetary Exploration Horizon 2061 Report Chapter 5: Enabling technologies for planetary exploration

Author: Grande, Manuel, Guo, Linli, Blanc, Michel, Makaya, Advenit, Asmar, Sami, Atkinson, David, Bourdon, Anne, Chabert, Pascal, Chien, Steve, Day, John, Fairen, Alberto G., Freeman, Anthony, Genova, Antonio, Herique, Alain, Kofman, Wlodek, Lazio, Joseph, Mousis, Olivier, Ori, Gian Gabriele, Parro, Victor, Preston, Robert, Rodriguez-Manfredi, Jose A, Sterken, Veerle, Stephenson, Keith, Hook, Joshua Vander, Waite, Hunter, and Zine, Sonia
Subjects: Physics - Geophysics, Earth and Planetary Astrophysics (astro-ph.EP), FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Earth and Planetary Astrophysics, Geophysics (physics.geo-ph)
Abstract: The main objective of this chapter is to present an overview of the different areas of key technologies that will be needed to fly the technically most challenging of the representative missions identified in chapter 4 (the Pillar 2 Horizon 2061 report). It starts with a description of the future scientific instruments which will address the key questions of Horizon 2061 described in chapter 3 (the Pillar 1 Horizon 2061 report) and the new technologies that the next generations of space instruments will require (section 2). From there, the chapter follows the line of logical development and implementation of a planetary mission: section 3 describes some of the novel mission architectures that will be needed and how they will articulate interplanetary spacecraft and science platforms; section 4 summarizes the system-level technologies needed: power, propulsion, navigation, communication, advanced autonomy on board planetary spacecraft; section 5 describes the diversity of specialized science platforms that will be needed to survive, operate and return scientific data from the extreme environments that future missions will target; section 6 describes the new technology developments that will be needed for long-duration missions and semi-permanent settlements; finally, section 7 attempts to anticipate on the disruptive technologies that should emerge and progressively prevail in the decades to come to meet the long-term needs of future planetary missions., Comment: 100 pages, 23 figures, Horizon 2061 is a science-driven, foresight exercise, for future scientific investigations
Published: 2023
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2. The morphology of the topside ionosphere of Mars under different solar wind conditions: Results of a multi-instrument observing campaign by Mars Express in 2010

Author: Withers, Paul, Matta, M., Lester, Mark, Andrews, D., Edburg, N., Nilsson, H., Opgenoorth, H. J., Curry, Shannon, Lillis, Robert, Dubinin, E., Franz, M., Han, X., Kofman, Wlodek, Lei, L., Morgan, David, Patzold, M., Peter, Kirsten, Opitz, Andrea, Wild, Jim, and Witasse, O.
Subjects: Magnetosphere, Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, Solar wind, Physics::Space Physics, Mars, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Ionosphere, Physics::Geophysics
Abstract: Since the internally-generated magnetic field of Mars is weak, strong coupling is ex- pected between the solar wind, planetary magnetosphere, and planetary ionosphere. However, few previous observational studies of this coupling incorporated data that extended from the solar wind to deep into the ionosphere. Here we use solar wind, magnetosphere, and ionosphere data obtained by the Mars Express spacecraft dur- ing March/April 2010 to investigate this coupling. We focus on three case studies, each centered on a pair of ionospheric electron density profiles measured by radio occultations, where the two profiles in each pair were obtained from the same lo- cation at an interval of only a few days. We find that high dynamic pressures in the solar wind are associated with compression of the magnetosphere, heating of the magnetosheath, reduction in the vertical extent of the ionosphere, and abrupt changes in electron density at the top of the ionosphere. The first three of these associations are analogous to the behavior of the plasma environment of Venus, but the final one is not. These results reinforce the notion that changes in solar forc- ing influence the behaviors of all of the tightly coupled regions within the Martian plasma environment.
Published: 2016
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3. Interior of 67P/C-G comet as seen by CONSERT bistatic radar on Rosetta

Author: Kofman, Wlodek W., Hérique, Alain, Ciarletti, Valérie, Levasseur-Regourd, Anny Chantal, Lasue, Jeremie, Zine, Sonia, Plettemeier, Dirk, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Technische Universität Dresden (TUD), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU]Sciences of the Universe [physics]
Abstract: International audience; The scientific objectives of the Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) aboard ESA spacecraft’s Rosetta was to perform an interior characterization of comet 67P/C-G nucleus. This characterization is important to understand the formation and evolution of comets. The measurements were done by means of a bi-static sounding between Philae lander on the nucleus surface and Rosetta orbiter.CONSERT operated during 9 hours after Philae’s landing and made measurements through the small lobe (head) of 67P/ C-G. The analyses and interpretation have been done using the shape of the received signals and 3D modeling of the signal propagation. The propagation time inside the nucleus allowed us to derive the average permittivity value (1.27+/- 0.05 ) of the cometary interior. Permittivity data for ices and dust particles were compared with our measurements, providing constraints on the nucleus constituents (ices, silicates and organics) and the bulk porosity (70-85%). The shape of the received signals, very close to the calibration signal’s one, showed that no significant scattering by heterogeneities is occurring inside the nucleus. This indicates that the interior is homogeneous at a scale of a few CONSERT’s 3-m wavelengths. This conclusion lead to 3D simulations of the signal propagation in non-homogeneous nuclei models, to define the sensitivity of CONSERT to detect potential inhomogeneities and to find constrains on the internal structures in terms of size and composition at a scale commensurate with the wavelength. Given the high bulk porosity of 75% inside the sounded part of the nucleus, a likely model would be obtained by a mixture, at 3m-size scale, of voids (vacuum) and blobs with material made of ices and dust with a porosity above 60%. The absence of any pulse spreading by scattering excludes heterogeneities with higher contrast (0.25) and larger size (3m) (but remaining on the few wavelengths scale, since larger scales can be responsible for multipath propagation). These very important results provide clues to a better understanding of the comet formation processes.
Published: 2017

4. Characterizing the interior of 67P in the vicinity of Abydos

Author: Ciarletti, Valérie, Lasue, Jérémie, Lemonnier, Florentin, Herique, Alain, Kofman, Wlodek W., Guiffaut, Christophe, Levasseur-Regourd, Anny Chantal, Plettemeier, Dirk, IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), ESTER - LATMOS, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Systèmes RF (XLIM-SRF), XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Dresden (TUD), PLANETO - LATMOS, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract: International audience; Since the arrival of Rosetta at comet 67P, numerous pictures have been delivered by the cameras onboard both the main spacecraft and the Philae lander. They revealed, at the nucleus' surface and inside the walls of the deep pits, few-meters scale repeating structures, thus providing hints about the internal structure of the nucleus, and suggesting that primordial 'cometesimals' may be objects around 3m in size.The CONSERT (Comet Nucleus Sounding Experiment by Radiowave Transmission) experiment is a radar that has been designed to specifically sound the interior of the nucleus and to provide information on the nucleus internal structure. The work presented here is based on the CONSERT data collected during the First Science Sequence (FSS) and marginally during Philae’s Separation Descent and Landing (SDL) for comparison.During FFS, the smaller lobe of the nucleus in the vicinity of Abydos has been actually sounded by CONSERT’s electromagnetic waves at 90 MHz with a spatial resolution around 10 m. The propagation delays measured during FSS are consistent with a very low bulk permittivity value for the investigated cometary material, which confirms the high porosity of the nucleus. The sharp shape of the received pulses indicates that the electromagnetic waves suffered weak scattering when propagating through the nucleus. This suggests that the sounded part nucleus is thus fairly homogeneous on a spatial scale of tens of meters.We will present further results on the variation of the CONSERT’s pulse shape transmitted through the small lobe of the nucleus. For a more accurate analysis and interpretation of the data, we split the FSS data into two distinct sets corresponding to soundings performed West and East of Philae in order to investigate potential differences. Tentative interpretation in terms of nucleus internal structure based on propagation simulations performed in non-homogeneous nucleus numerical models will be presented.
Published: 2016

5. Mineralogical Implications of CONSERT Permittivity Characterization of 67P

Author: Herique, Alain, Kofman, Wlodek, Beck, Pierre, Bonal, Lydie, Buttarazzi, E., Heggy, Essam, Lasue, Jérémie, Levasseur-Regourd, Anny Chantal, Quirico, Eric, Zine, Sonia, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Planeto, Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract: International audience; On 12 November 2014, after the descent and rebounds of the lander Philae, COmet Nucleus Sounding Experiment by Radio Transmission (CONSERT) restarted operating at 18h56 UTC and continued until 04h06 UTC, providing the first investigation of the internal structure of the nucleus of a comet. The analysis of the signal that propagated throughout the upper part of “head” of 67P allows us to estimate an average permittivity of approximately 1.27 (Kofman et al., 2015). This average permittivity induces constraints on the permittivity of the dust components versus volume fraction of dust and ices. We analyze constraints on dust permittivity using mixing formulas and ice composition models. Additional comparisons to laboratory measurements will allow us to discuss the implication on composition and mineralogy of the 67P dust particules.
Published: 2016

6. What CONSERT measurements tell us about the interior of the 67/C-G comet ?

Author: Kofman, Wlodek, Herique, Alain, Ciarletti, Valérie, Lasue, Jérémie, Levasseur-Regourd, Anny Chantal, Heggy, Essam, Pasquero, Oudomsack Pierre, Plettemeier, Dirk, Rogez, Y., Zine, Sonia, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), ESTER - LATMOS, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), and Technische Universität Dresden (TUD)
Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract: International audience; The structure of the nucleus is one of major unknown in the cometary science. The scientific objectives of the Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) aboard ESA spacecraft Rosetta are to perform an interior characterization of comet 67P/Churyumov-Gerasimenko nucleus. This is done by means of a bi-static sounding between the lander Philae launched on the comet’s surface and the obiter Rosetta. During the first night after Philae landing CONSERT operated during 9 hours and have made the measurements through the small lobe (head) of the 67P/ C-G. We will describe measurements that explored the interior of the comet, discuss results and their interpretation in term of the internal structure. The analyses and interpretation have been done using the form of the received signals and then 2D and 3D modelling of the signal that propagated through the comet. This led us to conclusions that the comet is homogenous on the scale of the ten of wavelengths and perhaps slowly variable with the dielectric constant decreasing into interior of the comet. The measured value 1.27 +- 0.05 of the average dielectric constant permit us to interpret the composition of the materials in terms of porosity, dust to ice ratio and possible materials (Kofman et al, Science 2015, Ciarletti et al, A&A, 2015). In this presentation we will discuss all these results.
Published: 2016

7. Characterization of the permittivity of controlled porous water ice-dust mixtures to support the radar exploration of icy bodies

Author: Brouet, Yann, Neves, Luisa, Sabouroux, Pierre, Levasseur-Regourd, Anny Chantal, Poch, Olivier, Encrenaz, Pierre, Pommerol, Antoine, Thomas, Nicolas, Kofman, Wlodek, Physikalisches Institut [Bern], Universität Bern [Bern], HIPE (HIPE), Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Swiss National Science Foundation, Universität Bern [Bern] (UNIBE), PLANETO - LATMOS, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), and École normale supérieure - Paris (ENS Paris)
Subjects: porous media, 530 Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, ice, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], comets, 620 Engineering, permittivity, small bodies, radar
Abstract: The internal properties of porous and icy bodies in the solar system can be investigated by ground-penetrating radars (GPRs), like the COmet Nucleus Sounding Experiment by Radiowave Transmission instrument on board the Rosetta spacecraft which has sounded the interior of the nucleus of comet 67P/Churyumov-Gerasimenko. Accurate constraints on the permittivity of icy media are needed for the interpretation of the data. We report novel permittivity measurements performed on water ice samples and icy mixtures with porosities in the 31–91% range. The measurements have been performed between 50 MHz and 2 GHz with a coaxial cell on a total of 38 samples with a good reproducibility. We used controlled procedures to produce fine-grained and coarse-grained ice samples with a mean diameter of 4.5 μm and 67 μm, respectively, and to prepare icy mixtures. The JSC-1A lunar regolith simulant was used as the dust component in the mixtures. The results are focused on the real-part ⋲' of the permittivity, which constrains the phase velocity of the radio waves in low-loss media. The values of ⋲' show a nondispersive behavior and are within the range of 1.1 to 2.7. They decrease with the increasing porosity Φ according to E(1−Φ), with E equal to about 3.13 for pure water ice, and in the 3.8–7.5 range for ice-dust mixtures with a dust-to-ice volumetric ratio in the 0.1–2.8 range, respectively. These measurements are also relevant for radiometers operating in the millimeter-submillimeter domains, as suggested by the nondispersive behavior of the mixtures and of the pure components.
Published: 2016

8. The Rosetta mission: Clues on the origin of comet nuclei

Author: Davidsson, Bjorn, Stern, S. Alan, Kofman, Wlodek, Hilchenbach, Martin, Rotundi, Alessandra, Bentley, Mark, Hofstadter, Mark, Sierks, Holger, Altwegg, Kathrin, Nilsson, Hans, Burch, James L., Eriksson, Anders I., Glassmeier, Karl heinz, Henri, Pierre, Carr, Christopher M., Pätzold, Martin, Capaccioni, Fabrizio, Boehnhardt, Hermann, Bibring, Jean pierre, Fulle, Marco, Fulchignoni, Marcello, Gruen, Eberhard, Weissman, Paul R., Taylor, Matt, Buratti, Bonnie J., Choukroun, Mathieu, Altobelli, Nicolas, Snodgrass, Colin, and Rosetta Science Working Team
Published: 2016

9. Rosetta at 67P: what we have learned about cometary activity

Author: Vincent, Jean baptiste, Alice, Team, Stern, Alan, Consert, Team, Kofman, Wlodek, Cosima, Team, Hilchenbach, Martin, Giada, Team, Rotundi, Alessandra, Midas, Team, Bentley, Mark, Miro, Team, Hofstadter, Mark, Osiris, Team, Sierks, Holger, Rosina, Team, Altwegg, Kathrin, Rpc, Team, Nilsson, Hans, Burch, James, Eriksson, Anders, Heinz glassmeier, Karl, Henri, Pierre, Carr, Christopher, Rsi, Team, Paetzold, Martin, Virtis, Team, Capaccioni, Fabrizio, Lander, Team, Boehnhardt, Hermann, Bibring, Jean pierre, Ids, Team, Gruen, Eberhard, Fulchignoni, Marcello, Weissman, Paul, Project Scientist Team, Taylor, Matt, Buratti, Bonnie, Altobelli, Nicolas, Choukroun, Mathieu, Ground based Observations Team, and Snodgrass, Colin
Published: 2016

10. Physical interrelation of volatile and refractories in a cometary nucleus

Author: Fulle, Marco, Alice, Team, Stern, Alan, Constert, Team, Kofman, Wlodek, Cosima, Team, Hilchenbach, Martin, Giada, Team, Rotundi, Alessandra, Midas, Team, Bentley, Mark, Miro, Team, Hofstadter, Mark, Osiris, Team, Sierks, Holger, Rosina, Team, Altwegg, Kathrin, Rpc, Team, Nilsson, Hans, Burch, James, Eriksson, Anders, Heinz glassmeier, Karl, Henri, Pierre, Carr, Christopher, Rsi, Team, Paetzold, Martin, Virtis Team, Capaccioni, Fabrizio, Lander, Team, Boehnhardt, Hermann, Bibring, Jean pierre, Ids, Team, Gruen, Eberhard, Fulchignoni, Marcello, Weissman, Paul, Project Scientist Team, Taylor, Matt, Buratti, Bonnie, Altobelli, Nicolas, Choukroun, Mathieu, Ground based Observations Team, and Snodgrass, Colin
Published: 2016

11. Rosetta and Comet Composition of Volatile and Refractories in the Nucleus of 67P/Churyumov-Gerasimenko

Author: Calmonte, Ursina, Alice, Team, Stern, Alan, Constert, Team, Kofman, Wlodek, Cosima, Team, Hilchenbach, Martin, Giada, Team, Rotundi, Alessandra, Midas, Team, Bentley, Mark, Miro, Team, Hofstadter, Mark, Osiris, Team, Sierks, Holger, Rosina, Team, Altwegg, Kathrin, Rpc, Team, Nilsson, Hans, Burch, James, Eriksson, Anders, Heinz glassmeier, Karl, Henri, Pierre, Carr, Christopher, Rsi, Team, Paetzold, Martin, Virtis, Team, Capaccioni, Fabrizio, Lander, Team, Boehnhardt, Hermann, Bibring, Jean pierre, Ids, Team, Gruen, Eberhard, Fulchignoni, Marcello, Weissman, Paul, Project Scientist Team, Taylor, Matt, Buratti, Bonnie, Altobelli, Nicolas, Choukroun, Mathieu, Ground based Observations Team, and Snodgrass, Colin
Published: 2016

12. Dielectric map of the Martian northern hemisphere and the nature of plain filling materials

Author: Mouginot, Jeremie, Pommerol, Antoine, Beck, Pierre, Kofman, Wlodek, and Clifford, Stephen M.
Abstract: A number of observations suggest that an extended ocean once covered a significant part of the Martian northern hemisphere. By probing the physical properties of the subsurface to unprecedented depth the MARSIS/Mars Express provides new geophysical evidences for the former existence of a Late Hesperian ocean. The Vastitas Borealis formation located inside a putative shoreline of the ancient ocean has a low dielectric constant compared with that of typical volcanic materials. We show that the measured value is only consistent with low density sedimentary deposits massive deposits of ground ice or a combination of the two. In contrast radar observations indicate a distribution of shallow ground ice in equilibrium with the atmosphere in the south polar region. We conclude that the northern plains are filled with remnants of a late Hesperian ocean fed by water and sediments from the outflow channels about 3 Gy ago. Citation: Mouginot J. A. Pommerol P. Beck W. Kofman and S. M. Clifford (2012) Dielectric map of the Martian northern hemisphere and the nature of plain filling materials Geophys. Res. Lett. 39 L02202 doi:10.1029/2011GL050286.
Published: 2012

13. The CONSERT Instrument during Philae's Descent onto 67P/C-G’s surface: Insights on Philae’s Attitude and the Surface Permittivity Measurements at the Agilkia-Landing-Site

Author: Plettemeier, Dirk, Statz, Christoph, Hahnel, Ronny, Hegler, Sebastian, Herique, Alain, Pasquero, Pierre, Rogez, Yves, Zine, Sonia, Ciarletti, Valérie, Kofman, Wlodek, Technische Universität Dresden (TUD), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Cardon, Catherine
Subjects: [SDU.ASTR.IM] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract: International audience; The main scientific objective of the Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) aboard ESA spacecraft Rosetta is the dielectric characterization of comet 67P/Churyumov–Gerasimenko’s nucleus.This was done by means of bi-static radio propagation measurements of the CONSERT instrument between the lander Philae launched onto the comet’s surface and the orbiter Rosetta. The CONSERT unit aboard the lander was receiving and processing the radio signal emitted by the orbiter counterpart of the instrument. The lander unit was then retransmitting a signal back to the orbiter. This happened at a time scale of milliseconds.In addition to the operation at the first science sequence, CONSERT was operated during the separation and descent of Philae onto the comet's surface.During the descent phase of Philae the received CONSERT signal was a superposition of the direct propagation path between Rosetta and Philae and indirect paths caused by reflections of 67P/C-G’s surface.From peak power measurements of the dominant direct path between Rosetta and Philae during the descent we were able to reconstruct the lander’s attitude and estimate the spin rate of the lander along the descent trajectory. Certain operations and manoeuvres of orbiter and lander, e.g. the deployment of the lander legs and CONSERT antennas or the orbiter change of attitude in order to orient the science towards the assumed lander position, are also visible in the CONSERT data.The information gained on the landers attitude is used in the reconstruction of the dielectric properties of 67P/C-G’s surface and near subsurface (metric to decametric scale).During roughly the last third of the descent, the comet’s surface is visible for the CONSERT instrument enabling a mean permittivity estimation of the surface and near subsurface covered by the instruments footprint along the descent path. The comparatively large timespan with surface signatures exhibits a good spatial diversity necessary for the mapping of dominant signatures and the estimation of the dielectric properties of prominent features. From this data it is possible to create a contrast and permittivity mapping of the comet’s surface in the vicinity of the Agilkia landing site.
Published: 2015

14. investigating with the CONSERT bistatic radar a potential permittivity gradient at the Philae Landing site on 67P/Churyumov-Gerasimenko

Author: Ciarletti, Valérie, Levasseur-Regourd, Anny Chantal, Lasue, Jérémie, Statz, Christoph, Plettemeier, Dirk, Kofman, Wlodek, Herique, Alain, IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Technische Universität Dresden (TUD), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2015

15. Broadband permittivity measurements on porous planetary regoliths simulants, in relation with the Rosetta mission to 67P/C-G

Author: Brouet, Yann, Levasseur-Regourd, Anny Chantal, Encrenaz, Pierre, Sabouroux, Pierre, Heggy, Essam, Kofman, Wlodek, Thomas, Nick, Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), HIPE (HIPE), Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern], IMPEC - LATMOS, École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), California Institute of Technology (CALTECH)-NASA, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Cardon, Catherine, École normale supérieure - Paris (ENS Paris), and Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)
Subjects: [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract: International audience; The Rosetta mission has successfully rendezvous comet 67P/Churyumov-Gerasimenko (hereafter 67P) last year and landed Philae module on its nucleus on 12 November it 2014. Among instruments onboard Rosetta, MIRO [1], composed of two radiometers, with receivers at 190 GHz and 563 GHz (center-band), is dedicated to the measurements of the subsurface and surface brightness temperatures. These values depend on the complex relative permittivity (hereafter permittivity) with ε' and ε " the real and imaginary parts. The permittivity of the material depends on frequency, bulk density/porosity, composition and temperature [2]. Considering the very low bulk density of 67P nucleus (about 450 kg.m-3 [3]) and the suspected presence of a dust mantle in many areas of the nucleus [4], investigations on the permittivity of porous granular samples are needed to support the interpretation of MIRO data, as well as of other microwave experiments onboard Rosetta, e.g. CONSERT [5], a bistatic penetrating radar working at 90 MHz. We have developed a programme of permittivity measurements on porous granular samples over a frequency range from 50 MHz to 190 GHz under laboratory conditions (e.g. [6] and [7]). We present new results obtained on JSC-1A lunar soil simulant and ashes from Etna. The samples were split into several sub-samples with different size ranges covering a few to 500 µm. Bulk densities of the sub-samples were carefully measured and found to be in the 800-1400 kg.m-3 range. Sub-samples were also dried and volumetric moisture content was found to be below 0.6%. From 50 MHz to 6 GHz and at 190 GHz, the permittivity has been determined, respectively with a coaxial cell and with a quasi-optical bench mounted in transmission, both connected to a vector network analyzer. The results demonstrate the dispersive behaviours of ε' between 50 MHz and 190 GHz. Values of ε' remain within the 3.9-2.6 range for all sub-samples. At CONSERT frequency, ε " is within the 0.01-0.09 range for all sub-samples. The single-relaxation Debye model fits relatively well the global behaviour of ε' over the frequency range, thus validating the experimental setups and measurements obtained. Furthermore, results confirm that ε' decreases quasi-linearly with the decreasing bulk density at any frequency, as expected by the mixing formulae. Taking into account possible temperature variations within 67P nucleus [8] and the linear decrease of the permittivity with the temperature, as measured by [9] on JSC-1A sample, these results indicate that, on the near-surface of 67P covered by a free-ice dust mantle at the frequencies of MIRO and CONSERT
Published: 2015

16. CONSERT / Rosetta: status of the experiment

Author: Herique, Alain, Kofman, Wlodek, Goutail, Jean-Pierre, Zine, Sonia, Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU]Sciences of the Universe [physics]
Abstract: International audience; The primary scientific goal of the CONSERT experiment on the Rosetta / Philae space mission is to investigate the deep interior of the nucleus of comet 67P/Churyumov-Gerasimenko. This will be achieved through the use of long wavelength radio-waves transmitted by the Orbiter and returned from the Lander. In this poster, the experiment is reviewed: its scientific goals are revisited in association with the Consert operating modes; the in-time transponder technique is explained and the instrument design is shown. The status of the experiment is presented: the instrument and the preparation of the scientific measurements around the comet.
Published: 2010

17. Consert for Asteroid - radar tomography of Near Earth Asteroid

Author: Herique, Alain, Plettemeier, Dirk, Kofman, Wlodek, Ulamec, Stephan, Biele, Jens, Goutail, Jean-Pierre, Beck, Pierre, Lassue, Jérémie, Barucci, Antonella, Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Technische Universität Dresden = Dresden University of Technology (TU Dresden), DLR Microgravity User Support Center (MUSC), Deutsches Zentrum für Luft- und Raumfahrt (DLR), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU]Sciences of the Universe [physics]
Abstract: International audience; Consert for Asteroid is a radar to instrument the Mascot lander, which is proposed in the frame of future Near Earth Asteroid missions. This low frequency radar is a unique opportunity to sound the internal structure of the target. Its objective is to achieve the tomography both in transmission and in reflexion of the asteroid in order to determine its fracturing, its stratigraphy and its heterogeneity at different scales, for a better understanding of accretion and evolution phenomena. This talk reviews all the aspects of the proposed experiment. The problematics of the NEA is reviewed in order to demonstrate the interest of low frequency radar sounding. A consert-like bistatic experiment solution is proposed to fulfil the low mass budget constraints. The concept of this tomography between the lander and the orbiter is detailed, including its different operation modes, the measurements, the inversions and the addressed NEA issues. In the second part, we present the preliminary design of our instrument. This review starts from the existing Consert instrument on board the Rosetta and Philae probes. The main instrument trade offs are presented from the mission characteristics and the proposed target. The electronics are revisited and the budgets are updated. So some antenna designs are proposed for both lander and orbiter spacecrafts. Finally, a preliminary experiment budget is shown.
Published: 2010

18. North polar deposits of Mars: Extreme purity of the water ice

Author: Grima, Cyril, Kofman, Wlodek, Mouginot, Jeremie, Phillips, Roger, Hérique, Alain, Biccari, Daniela, Seu, Roberto, Cutigni, Marco, Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Southwest Research Institute [Boulder] (SwRI), Dipartimento INFOCOM [Roma], Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], and the European space agency (ESA) and the French space agency (CNES)
Subjects: [SDU]Sciences of the Universe [physics]
Abstract: International audience; The polar layered deposits are the largest reservoir of water on the surface of Mars. The physical properties of the ice and their spatial distribution are largely unknown. 140,000 data points from the sounding radar SHARAD on the Mars Reconnaissance Orbiter were analyzed over the Gemina Lingula region, one-fourth of the north polar layered deposits area. Maps of the dielectric properties of the bulk ice were drawn up. There is no basal melting signature. A drop of the dielectric constant in north-west of Gemina Lingula could be explained by an abrupt 250-meter uplift of the base. The bulk ice of the studied region has an average dielectric constant of 3.10 (σ = 0.12) and a loss tangent
Published: 2009

19. North polar deposits of Mars: Extreme purity of the water ice

Author: Cyril, Grima, Kofman, Wlodek, Mouginot, Jeremie, Phillips, Roger J., Alain, Herique, Daniela, Biccari, Seu, Roberto, and Marco, Cutigni
Published: 2009

20. Editorial

Author: Kofman, Wlodek, Laboratoire de Planétologie de Grenoble (LPG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2008

21. Editorial

Author: Kofman, Wlodek and Pibaret-Bourdon, Béatrice
Subjects: ComputingMilieux_MISCELLANEOUS
Published: 2008

22. Editorial

Author: Kofman, Wlodek, Laboratoire de Planétologie de Grenoble (LPG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2008

23. Editorial

Author: Kofman, Wlodek, Laboratoire de Planétologie de Grenoble (LPG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2007

24. Estimation of the total electron content of the Martian ionosphere using radar sounder surface echoes

Author: Safaeinili, Ali, Kofman, Wlodek, Mouginot, Jeremie, Gim, Y., Hérique, Alain, Ivanov, Anton, Plaut, Jeffrey, Picardi, Giovanni, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Dipartimento INFOCOM [Roma], and Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome]
Subjects: SUBSURFACE, [SDU]Sciences of the Universe [physics], Physics::Space Physics, MAGNETIC-FIELD, MARS, Astrophysics::Earth and Planetary Astrophysics, SOUNDINGS, Physics::Geophysics
Abstract: International audience; The Martian ionosphere's local total electron content (TEC) and the neutral atmosphere scale height can be derived from radar echoes reflected from the surface of the planet. We report the global distribution of the TEC by analyzing more than 750,000 echoes of the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS). This is the first direct measurement of the TEC of the Martian ionosphere. The technique used in this paper is a novel "transmission-mode'' sounding of the ionosphere of Mars in contrast to the Active Ionospheric Sounding experiment (AIS) on MARSIS, which generally operates in the reflection mode. This technique yields a global map of the TEC for the Martian ionosphere. The radar transmits a wideband chirp signal that travels through the ionosphere before and after being reflected from the surface. The received waves are attenuated, delayed and dispersed, depending on the electron density in the column directly below the spacecraft. In the process of correcting the radar signal, we are able to estimate the TEC and its global distribution with an unprecedented resolution of about 0.1 deg in latitude (similar to 5 km footprint). The mapping of the relative geographical variations in the estimated nightside TEC data reveals an intricate web of high electron density regions that correspond to regions where crustal magnetic field lines are connected to the solar wind. Our data demonstrates that these regions are generally but not exclusively associated with areas that have magnetic field lines perpendicular to the surface of Mars. As a result, the global TEC map provides a high-resolution view of where the Martian crustal magnetic field is connected to the solar wind. We also provide an estimate of the neutral atmospheric scale height near the ionospheric peak and observe temporal fluctuations in peak electron density related to solar activity.
Published: 2007

25. Editorial

Author: Kofman, Wlodek and Pibaret-Bourdon, Béatrice
Subjects: ComputingMilieux_MISCELLANEOUS
Published: 2007

26. Editorial

Author: Kofman, Wlodek, Laboratoire de Planétologie de Grenoble (LPG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2007

27. Unveiling the origin and evolution of dust in comets

Author: Levasseur-Regourd, Anny Chantal, Lasue, Jérémie, Hadamcik, Edith, Kofman, Wlodek, Service d'aéronomie (SA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie de Grenoble (LPG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2007

28. Editorial

Author: Kofman, Wlodek, Laboratoire de Planétologie de Grenoble (LPG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2006

29. Editorial

Author: Kofman, Wlodek, Laboratoire de Planétologie de Grenoble (LPG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2006

30. Évolution des personnels et des laboratoires

Author: Armengaud, M, Borsenberger, Jean, Chaintreuil, Sylviane, Cornilleau-Wehrlin, Nicole, Gille, P., Guyot, G., Kofman, Wlodek, Kouach, Driss, Le Contel, D., Le Quéau, D., Leroy, A., Pouliquen, Dominique, Scheidecker, J.P., Turon, Catherine, Vial, Jean-Claude, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: International audience
Published: 2003

31. Ozone isotopic composition: an angular effect in scattering processes?

Author: Chassefière, Eric, Bertaux, Jean-Loup, Berthelier, Jean-Jacques, Cabane, Michel, Ciarletti, Valérie, Durry, Georges, Forget, François, Hamelin, Michel, Leblanc, François, Menvielle, Mchel, Gerasimov, M., Korablev, O., Linkin, S., Managadze, G., Jambon, A., Manhès, G., Lognonne, Ph., Agrinier, P., Cartigny, P., Giardini, D., Pike, T., Kofman, Wlodek, Herique, Alain, Coll, Patrice, Person, A., Costard, F., Sarda, Ph., Paillou, Ph., Chaussidon, M., Marty, B., Robert, F., Maurice, S., Blanc, M., d’Uston, C., Sabroux, J.-Ch., Pineau, J.-F., Rochette, P., Service d'aéronomie (SA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude des environnements terrestre et planétaires (CETP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institute of Geophysics [ETH Zürich], Department of Earth Sciences [ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Imperial College London, Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie des Bassins Sédimentaires (LGBS), Université Pierre et Marie Curie - Paris 6 (UPMC), Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de minéralogie, Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Météo France-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Météo France-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS), Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Météo France, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), and Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA)
Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences
Abstract: International audience; The ratio of the differential scattering cross sections involving distinguishable and indistinguishable isotopes may exhibit non-mass dependent angular variations. A numerical application of this hypotheses to the ozone reaction rates reproduces some of the results observed in laboratory experiments. This theory could be tested through a cross beam experiment where the isotopic composition of the scattered products is recorded as a function of their scattering angles.
Published: 2001

32. Efficient Massively Parallel Prospection for ISRU by Multiple Near-Earth Asteroid Rendezvous using Near-Term Solar Sails and 'Now-Term' Small Spacecraft Solutions

Author: Grundmann, Jan Thimo, Bauer, Waldemar, Biele, Jens, Boden, Ralf, Ceriotti, Matteo, Cordero, Federico, Dachwald, Bernd, Dumont, Etienne, Grimm, Christian, Hercik, David, Herique, Alain, Ho, Tra-Mi, Jahnke, Rico, Koch, Aaron, Kofman, Wlodek, Koncz, Alexander, Krause, Christian, Lange, Caroline, Lichtenheldt, Roy, Maiwald, Volker, Mikschl, Tobias, Mikulz, Eugen, Montenegro, Sergio, Pelivan, Ivanka, Peloni, Alessandro, Plettemeier, Dirk, Quantius, Dominik, Reershemius, Siebo, Renger, Thomas, Riemann, Johannes, Ruffer, Michael, Sasaki, Kaname, Schmitz, Nicole, Seboldt, Wolfgang, Seefeldt, Patric, Spietz, Peter, Tom Sproewitz, Sznajder, Maciej, Tardivel, Simon, Toth, Norbert, Wejmo, Elisabet, Wolff, Friederike, Ziach, Christian, Graps, Amara, and van Dam, Tonie
Subjects: in-situ resource utilization (ISRU), Asteroid mapping, Gossamer-1, Raumfahrt-Systemdynamik, Multiple NEA Rendezvous, MASCOT, Systementwicklung und Projektbüro, Systemanalyse Raumtransport, Systemanalyse Raumsegment, Asteroid sample return, MASCOT2, Asteroid geological Survey, Nutzerzentrum für Weltraumexperimente (MUSC), Avioniksysteme, Land und Explorationstechnologie, Asteroid mining, solar sail, Mechanik und Thermalsysteme, OKEANOS Lander
Abstract: Physical interaction with small solar system bodies (SSSB) is key for in-situ resource utilization (ISRU). The design of mining missions requires good understanding of SSSB properties, including composition, surface and interior structure, and thermal environment. But as the saying goes "If you've seen one asteroid, you've seen one Asteroid": Although some patterns may begin to appear, a stable and reliable scheme of SSSB classification still has to be evolved. Identified commonalities would enable generic ISRU technology and spacecraft design approaches with a high degree of re-use. Strategic approaches require much broader in-depth characterization of the SSSB populations of interest to the ISRU community. The DLR-ESTEC GOSSAMER Roadmap Science Working Groups identified target-flexible Multiple Near-Earth asteroid (NEA) Rendezvous (MNR) as one of the missions only feasible with solar sail propulsion, showed the ability to access any inclination and a wide range of heliocentric distances as well as continuous operation close to Earth's orbit where low delta-v objects reside.

33. Flights Are Ten a Sail – Re-use and Commonality in the Design and System Engineering of Small Spacecraft Solar Sail Missions with Modular Hardware for Responsive and Adaptive Exploration

Author: Grundmann, Jan Thimo, Bauer, Waldemar, Boden, Ralf, Ceriotti, Matteo, Chand, Suditi, Cordero, Federico, Dachwald, Bernd, Dumont, Etienne, Grimm, Christian D., Heiligers, Jeannette, Herčík, David, Hérique, Alain, Ho, Tra-Mi, Jahnke, Rico, Kofman, Wlodek, Lange, Caroline, Lichtenheldt, Roy, McInnes, Colin, Meß, Jan-Gerd, Mikschl, Tobias, Mikulz, Eugen, Montenegro, Sergio, Moore, Iain, Pelivan, Ivanka, Peloni, Alessandro, Plettemeier, Dirk, Quantius, Dominik, Reershemius, Siebo, Renger, Thomas, Riemann, Johannes, Rogez, Yves, Ruffer, Michael, Sasaki, Kaname, Schmitz, Nicole, Seboldt, Wolfgang, Seefeldt, Patric, Spietz, Peter, Spröwitz, Tom, Sznajder, Maciej, Tóth, Norbert, Vergaaij, Merel, Viavattene, Giulia, Wejmo, Elisabet, Wiedemann, Carsten, Wolff, Friederike, and Ziach, Christian
Abstract: The exploration of small solar system bodies started with fast fly-bys of opportunity on the sidelines of missions to the planets. The tiny new worlds seen turned out to be so intriguing and different from all else(and each other) that dedicated sample-return and in-situ analysis missions were developed and launched. Through these, highly efficient low-thrust propulsion expanded from commercial use into mainstream and flagship science missions, there in combination with gravity assists. In parallel, the growth of small spacecraft solutions accelerated in numbers as well as individual spacecraft capabilities. The on-going missions OSIRIS-REx (NASA) or Hayabusa2 (JAXA) with its landers MINERVA-II and MASCOT, and the upcoming NEA scout mission are examples of this synergy of trends. The continuation of these and other related developments towards a propellant-less and highly efficient class of spacecraft for solar system exploration emerges in the form of small spacecraft solar sails designed for carefree handling and equipped with carried landers and application modules. These address the needs of all asteroid user communities– planetary science, planetary defence, and in-situ resource utilization – as well as other fields of solar system science and applications such as space weather warning and solar observations. Already the DLR-ESTEC GOSSAMER Roadmap for Solar Sailing initiated studies of missions uniquely feasible with solar sails such as Displaced L1 (DL1) space weather advance warning and monitoring and Solar Polar Orbiter(SPO) delivery, which demonstrate the capabilities of near-term solar sails to reach any kind of orbit in the inner solar system. This enables Multiple Near-Earth Asteroid (NEA) rendezvous missions (MNR),from Earth-coorbital to extremely inclined and even retrograde target orbits. For these mission types using separable payloads, design concepts can be derived from the separable Boom Sail Deployment Units characteristic of DLR GOSSAMER solar sail technology, nanolanders like MASCOT, or microlanders like the JAXA-DLR Jupiter Trojan Asteroid Lander for the OKEANOS mission which can shuttle from the sail to the targets visited and enable multiple NEA sample-return missions. These nanospacecraft scale components are an ideal match creating solar sails in micro-spacecraft format whose launch configurations are compatible with secondary payload platforms such as ESPA and ASAP. The DLR GOSSAMER solar sail technology builds on the experience gained in the development of deployable membrane structures leading up to the successful ground deployment test of a (20 m) solar sail at DLR Cologne in 1999 and in the 20 years since.

34. The WISDOM Radar: Unveiling the Subsurface Beneath the ExoMars Rover and Identifying the Best Locations for Drilling

Author: Valérie Ciarletti, Stephen Clifford, Dirk Plettemeier, Alice Le Gall, Yann Hervé, Sophie Dorizon, Cathy Quantin-Nataf, Wolf-Stefan Benedix, Susanne Schwenzer, Elena Pettinelli, Essam Heggy, Alain Herique, Jean-Jacques Berthelier, Wlodek Kofman, Jorge L. Vago, Svein-Erik Hamran, null the WISDOM Team, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Institute [Houston] (LPI), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut für Nachrichtentechnik [Dresden] (IfN), Centre for Earth, Planetary, Space and Astronomical Research [Milton Keynes] (CEPSAR), The Open University [Milton Keynes] (OU), Dipartimento di Matematica e Fisica [Roma], Università degli Studi Roma Tre, Ming Hsieh Department of Electrical Engineering [Los Angeles], USC Viterbi School of Engineering, University of Southern California (USC)-University of Southern California (USC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Forsvarets Forskningsinstitutt (FFI), IMPEC - LATMOS, Technische Universität Dresden (TUD), Dipartimento di Matematica e Fisica [Rome], Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Polska Akademia Nauk (PAN), Ciarletti, V., Clifford, S., Plettemeier, D., Le Gall, A., Herve, Y., Dorizon, S., Quantin-Nataf, C., Benedix, W. -S., Schwenzer, S., Pettinelli, E., Heggy, E., Herique, A., Berthelier, J. -J., Kofman, W., Vago, J. L., Hamran, S. -E., Ciarletti, Valérie, Clifford, Stephen, Plettemeier, Dirk, Le Gall, Alice, Hervé, Yann, Dorizon, Sophie, Quantin-Nataf, Cathy, Benedix, Wolf-Stefan, Schwenzer, Susanne, Pettinelli, Elena, Heggy, Essam, Herique, Alain, Berthelier, Jean-Jacque, Kofman, Wlodek, Vago, Jorge L., Hamran, Svein-Erik, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi Roma Tre = Roma Tre University (ROMA TRE), and Agence Spatiale Européenne = European Space Agency (ESA)
Subjects: 010504 meteorology & atmospheric sciences, Special Collection of Papers: ExoMars Rover MissionGuest Editor: Jorge L. Vago, Life on Mars, 01 natural sciences, Astrobiology, law.invention, Ground penetrating radar, law, 0103 physical sciences, Radar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Drill, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Drilling, Martian shallow subsurface, Mars Exploration Program, Regolith, Agricultural and Biological Sciences (miscellaneous), ExoMars, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Stratigraphy, 13. Climate action, Space and Planetary Science, Ground-penetrating radar, Geology
Abstract: International audience; The search for evidence of past or present life on Mars is the principal objective of the 2020 ESA-Roscosmos ExoMars Rover mission. If such evidence is to be found anywhere, it will most likely be in the subsurface, where organic molecules are shielded from the destructive effects of ionizing radiation and atmospheric oxidants. For this reason, the ExoMars Rover mission has been optimized to investigate the subsurface to identify, understand, and sample those locations where conditions for the preservation of evidence of past life are most likely to be found. The Water Ice Subsurface Deposit Observation on Mars (WISDOM) ground-penetrating radar has been designed to provide information about the nature of the shallow subsurface over depth ranging from 3 to 10 m (with a vertical resolution of up to 3 cm), depending on the dielectric properties of the regolith. This depth range is critical to understanding the geologic evolution stratigraphy and distribution and state of subsurface H2O, which provide important clues in the search for life and the identification of optimal drilling sites for investigation and sampling by the Rover's 2-m drill. WISDOM will help ensure the safety and success of drilling operations by identification of potential hazards that might interfere with retrieval of subsurface samples. Key Words: Ground penetrating radar—Martian shallow subsurface—ExoMars. Astrobiology 17, 565–584.
Published: 2017

35. Studies of ionospheric parameters by means of electron plasma lines observed by EISCAT

Author: Guio, Patrick, Guio, Patrick, Bjørnå, Noralv, Fourier, Joseph, Kofman, Wlodek, Université Joseph Fourier - Grenoble 1 (UJF), Université Joseph-Fourier - Grenoble I, and Wlodek Kofman
Subjects: [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Wave dispersion relation, dispersion relation, VDP::Mathematics and natural science: 400::Physics: 430::Space and plasma physics: 437, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Suprathermal electron, ondes Langmuir, Langmuir waves, dispersion de relation, [SDU.ASTR] Sciences of the Universe [physics]/Astrophysics [astro-ph], Incoherent Scattering, electron velocity distribution function, [SDU] Sciences of the Universe [physics], EISCAT, [SDU]Sciences of the Universe [physics], Physics::Plasma Physics, Physics::Space Physics, dispersion relation Langmuir waves, [SDU.STU] Sciences of the Universe [physics]/Earth Sciences, ondes de Langmuir, Ionosphere, Heat flow, distributions des vitesses électronique
Abstract: This work presents a study of the electron plasma lines observed by the incoherent scatter radar EISCAT. The work is focusing on two parts. On one hand, the design of a plasma line experiment for the EISCAT system with an improved spatial resolution. On the other hand, the comparison of the plasma line data collected with the EISCAT radar with an improved model for the intensity and the Doppler frequency shift of the plasma lines. In order to improve the spatial resolution of the plasma line experiment we have designed the first experiment that implements the recent technique of alternating code. The experiment has been run successfully with an altitude resolution of 3 km as opposed to 40-50 km obtained with the conventional techniques. Because it is very difficult to construct a self-consistent model of the velocity distribution function encompassing all of the relevant energy range, we have made an ad hoc model by separating the distribution into two parts: the thermal and the supra-thermal population. The thermal population is represented by the Spitzer function that takes into account the effect of an electric field and/or a temperature gradient. The supra-thermal population is derived from the angular energy flux of the supra-thermal electrons calculated by a numerical electron transport model. A numerical code has been developed to calculate the dielectric function and the reduced one-dimensional velocity distribution for any arbitrary two-dimensional velocity distribution which are needed to model the intensity and the Doppler frequency shift of the plasma lines. We have been able to reproduce peculiar features of the intensity as well as the Doppler shift of the plasma lines with data collected with the EISCAT VHF radar. Especially, two sharp peaks in the supra-thermal distribution were identified as the signature of photo-ionisation of N_2 and O and were observed in the measured data. The effect of the temperature gradient\ - which produces a decisive correction to the Doppler shift of the plasma lines - was taken into account more accurately than previously by numerical evaluation of the singular integrals rather than by the use of the first terms of a series expansion as done in other studies. This is important because it has allowed a model for the first time to reproduce accurately the intensity and the Doppler shift of the plasma line as measured by actual experiment., Ce travail présente une étude des raies de plasma observées à l'aide du radar à diffusion incohérente EISCAT. Le travail est centré sur deux points. Tout d'abord, la conception d'une expérience raies de plasma pour le radar EISCAT, avec une résolution spatiale améliorée. Puis, la comparaison de données raies de plasma acquises avec le radar EISCAT avec une théorie améliorée sur l'intensité et le décalage Doppler en fréquence des raies de plasma. Pour améliorer la résolution spatiale, nous avons conçu la première expérience raies de plasma mettant en oeuvre la technique du code alternatif. Cette expérience a été tournée avec succès avec une résolution spatiale de 3 km au lieu de 40-50 km obtenu avec les techniques conventionnelles. Parce qu'il est très difficile de construire un modèle cohérent de la fonction de distribution des vitesses des électrons satisfaisant tous les intervalles d'énergies pertinents, nous avons construit une représentation adéquate de la distribution des vitesses des électrons en séparant la distribution en deux populations : la thermique et la suprathermique. La population thermique est représentée par la fonction de Spitzer qui tient compte de l'effet d'un champ électrique et/ou d'un gradient de température. La population suprathermique est déduite du flux angulaire d'énergie calculé grâce à un modèle numérique du transport des électrons. Un code numérique a été développé pour calculer la fonction diélectrique et la fonction réduite de distribution des vitesses pour toutes distributions des vitesses à deux dimensions dont nous avons besoin pour modéliser l'intensité et le décalage Doppler en fréquence des raies de plasma. Nous avons pu reproduire les caractéristiques de l'intensité et du décalage Doppler en fréquence des raies de plasma avec des données mesurées avec le radar VHF EISCAT. En particulier, nous avons identifié deux pics étroits dans la distribution des vitesses des suprathermiques comme la signature de la photo-ionisation de N_2 et O. Ces pics ont été observés sur les données. L'effet d'un gradient de température - qui produit une correction importante au décalage Doppler des raies de plasma - a été pris en compte plus précisement que précédemment en calculant numériquement les intégrales singulières, au lieu d'utiliser les premiers termes d'une expansion en séries comme auparavant. C'est important car cela a permis pour la première fois à un modèle de reproduire précisément l'intensité et le décalage Doppler des raies de plasma mesurés par une expérience EISCAT.
Published: 1998

36. Overview and summary of the Spread F Experiment (SpreadFEx)

Author: Bela G. Fejer, E. R. de Paula, Cristiano Max Wrasse, Delano Gobbi, M. A. Abdu, H. Takahashi, B. R. Batista, Sharon L. Vadas, Barclay Clemesha, J. H. A. Sobral, Fabio Vargas, B. J. Fechine, Hanli Liu, Jennifer S. Haase, Fabiano S. Rodrigues, Thomas Dautermann, Pierre-Dominique Pautet, Paulo Batista, E. A. Kherani, Amauri Fragoso de Medeiros, P. P. Lima, Brian Laughman, F. T. São Sabbas, David C. Fritts, P. Stamus, Inez S. Batista, Ricardo Buriti, Dennis M. Riggin, Michael J. Taylor, Farzad Kamalabadi, and Kofman, Wlodek
Subjects: Convection, Atmospheric Science, Electron density, 010504 meteorology & atmospheric sciences, Perturbation (astronomy), Equatorial Spread F, 01 natural sciences, Instability, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Gravity wave, Rayleigh–Taylor instability, Ionosphere, lcsh:Science, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, Institut für Kommunikation und Navigation, 0105 earth and related environmental sciences, lcsh:QC801-809, Geology, Astronomy and Astrophysics, Geomagnetism, Geophysics, Navigation, lcsh:QC1-999, Plasma Bubbles, lcsh:Geophysics. Cosmic physics, Amplitude, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Mesopause, lcsh:Q, lcsh:Physics
Abstract: We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx) performed from September to November 2005, with primary measurements in Brazil. The motivation was to define the potential role of neutral atmosphere dynamics, specifically gravity wave motions propagating upward from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI) and plasma bubbles extending to higher altitudes. Campaign measurements focused on the Brazilian sector and included ground-based optical, radar, digisonde, and GPS measurements at a number of fixed and temporary sites. Related data on convection and plasma bubble structures were also collected by GOES 12, and the GUVI instrument aboard the TIMED satellite. Initial results of our SpreadFEx analyses are described separately by Fritts et al. (2009). Further analyses of these data provide additional evidence of 1) gravity wave (GW) activity near the mesopause apparently linked to deep convection predominantly to the west of our measurement sites, 2) small-scale GWs largely confined to lower altitudes, 3) larger-scale GWs apparently penetrating to much higher altitudes, 4) substantial GW amplitudes implied by digisonde electron densities, and 5) apparent influences of these perturbations in the lower F-region on the formation of equatorial spread F, RTI, and plasma bubbles extending to much higher altitudes. Other efforts with SpreadFEx data have also yielded 6) the occurrence, locations, and scales of deep convection, 7) the spatial and temporal evolutions of plasma bubbles, 8) 2-D (height-resolved) structures in electron density fluctuations and equatorial spread F at lower altitudes and plasma bubbles above, and 9) the occurrence of substantial tidal perturbations to the large-scale wind and temperature fields extending to bottomside F-layer and higher altitudes. Collectively, our various SpreadFEx analyses suggest direct links between deep tropical convection and large GW perturbations at large spatial scales at the bottomside F-layer and their likely contributions to the excitation of RTI and plasma bubbles extending to much higher altitudes.

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