Home - Projects - The NETLANDER Mission - Seismology experiment |
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| Scientific objectives of the seismic experiment |
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Main objectives of the seismic NetLander experiment are to determine :
- the mean value of shearing and incompressibility coefficients versus the depth, the core/mantle interface, the core state, the position and features of mantle discontinuities, and the crust thickness ;
- the mean attenuation and its variation with depth ;
- at a regional scale, or at least vertically to each station : crust thickness and other crustal interfaces, including markers associated to the 0°C isotherm inside pergelisol ;
- the level and geographical distribution of seismic activity on Mars and its link with surface tectonics.
Those seismic measurements combined with high resolution imaging will moreover allow :
- to specify geometry of tectonic structures,
- to model deformation mechanisms,
- to relate these mechanisms with volcanic activity,
- to constrain the models of the planet internal dynamics and geological evolution.
Together with the geodesy experiment (moments of inertia measurement) coupled to high pressure experiments, those results are expected to lead to an average model of the mineralogical composition of the planet versus the depth, and to an average temperature model. With 3 operational landers, preliminary information would be obtained about the amount of lateral heterogeneity, particularly thanks to the surface waves focusing-defocusing.
More about
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| The instrument |
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The proposed instrument consists of :
- two very broad band axes (V.B.B.) developed by the Institut de Physique du Globe de Paris (IPGP) in the framework of a CNES Research and Technology program ;
- micro-sensors developed by the jet Propulsion Laboratory (JPL) ;
- an electronic system developed by the Polytechnic School of Zurich (ETH) for experiment control and data acquisition.
The instrument benefits from the OPTIMISM experiment developed by the IPGP and the DT/INSU during the past mission Mars96.
This association will carry out a very broad band detector (VBB) (0.1mHz - 10Hz) of high performance with two measurement axes : horizontally and vertically, plus another horizontal broad band short period axe (BRB) (10mHz - 10Hz), offering then a tri-axial detection. Moreover, another sub-vertical JPL micro-sensor will provide a short period output (SP) (10mHz - 50Hz). The detection of tide signal will also be assumed by one of the VBB sensor outputs. Quasi-fullness of the seismic and gravimetric signals will thus be measured.
Seismometer data will be digitized at 20 samples per second for the two VBB components and the BRB component, and at 100 samples per second for the SP component. Those data will be stored in the lander mass memory, and will allow to calculate a filtered output at 1 sample per second of the vertical signal, and also regular measurements of the spectral amplitudes for frequencies over 1 Hz. This mass memory is able to store all signals recording during two weeks.
Vertical LP signal , continuous spectral measurements and tide signal will be regularly transmitted. Terrestrial operators will thus be able to identify temporal windows with interesting signals. High sampling rate signals VBB, BRB and SP will then be transmitted to Earth on request.
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Prototype 1 VBB seismometer axe (to the left)
JPL micro-sensor description (to the right) |
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The integration of VBB sensors and of one of JPL sensor takes place in a 18cm-diameter vacuum sphere. The seismic experiment whole mass (sensors + electronics) is 1750g.
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VBB and JPL prototypes seismometers performances and those expected for the flight models
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More about:
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| The SEISmometer-NetLander team |
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Scientific team |
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| Principal Investigator |
Philippe Lognonné |
IPGP, Saint Maur |
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Principal Co-Investigator, SP sensor |
Bruce Banerdt |
JPL, USA |
| Principal Co-Investigator, electronics | Domenico Giardini | ETH, Switzerland |
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Co-Investigators and responsability (shared with PIs) |
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| IPGP data center |
Jeaninne Gagnepain-Beyneix |
IPGP, Saint Maur, France |
| Calibration | Jacques Hinderer | EOPG Strasbourg, France |
| Jean-Jacques Lévêque | EOPG Strasbourg, France | |
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Luis Rivera |
EOPG Strasbourg, France |
| Link with geodesy | Véronique Dehant | ORB, Brussels, Belgium |
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Pascale Defraigne |
ORB, Brussels, Belgium |
| Thermal correction |
Paul Vauterin |
ORB, Brussels, Belgium |
| Mechanisms determination |
Anne Deschamps |
University of Nice, France |
| Tomographic models |
Jean Paul Montagner |
IPG Paris, France |
| Meteorites detection |
Jurgens Oberst |
DLR Berlin, Germany |
| Diffraction modeling and ground tests |
Michel Campillot |
Grenoble Observatory, France |
| Link with theoretical groups |
Doris Breuer |
Univ. Münster, Germany |
| Selection of landing sites |
Antoine Mocquet |
University of Nantes, France |
| Control of mechanical I/F |
Tilman Spohn |
Univ. Münster, Germany |
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Technical team SEISmometer-NetLander |
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| Project Manager SEISmometer NetLander |
Patrick Schibler |
IPGP, Saint Maur |
| VBB manager |
Jean François Karczewski |
IPGP, Saint Maur |
| System Engineer |
David Mimoun |
CNES/INSU, Saint Maur |
| Engineer, software & Electronics |
Alain Desautez |
IPGP, Saint Maur |
| Engineer, GSE, software |
Taoufik Gabsi |
IPGP, Saint Maur |
| Engineer, Electronics |
André Anglade |
IPGP, Saint Maur |
| Engineer Assistant, CAD, VBB, mechanisms |
Nicolas Striebig |
IPGP, Saint Maur |
| Engineer Assistant, Electronics |
Henri Vacherat |
CNES/INSU, Saint Maur |
| Technician, Integration, tests |
Olivier Pot |
IPGP, Saint Maur |