Projet de recherche PX/8/SS/17 (Action de recherche PX)
(1) MaRS, Mars Express Radio Science: We use measurements of small changes in the frequency of radio-signals between the Earth and the Mars Express spacecraft in orbit around Mars to derive the static and time-variable gravity field of Mars. Mass heterogeneities at the surface and subsurface of Mars, seasonal mass redistribution between the atmosphere and the polar caps, and deformations of Mars due to the tides caused by the Sun affect the gravity field and change the radio frequencies. We are using the MaRS radio data to deduce properties of the subsurface material such as the density on particular targets such as Olympus Mons, to determine the mass involved in the CO2 transfer between the atmosphere and the polar caps, and to study interior properties of Mars such as the state of the core.
(2) VeRa, Venus Express Radio Science: Similar experiment as MaRS. We will use radio-signals between the Earth and Venus Express in orbit around Venus to study mass heterogeneities at particular regions of Venus not well covered by Magellan.
(3) MORE (Mercury Orbiter Radioscience Experiment), BELA (BepiColombo Laser Altimetry), SIMBIO-SYS (Spectrometers and Imagers for MPO BepiColombo Integrated Observatory SYStem) of the BepiColombo mission to Mercury: We will use the topography derived by the altimeter and the gravity field derived by the radioscience experiment in order to study the mass heterogeneities at the surface and subsurface of Mercury as done for MEX and VEX. We will use the radioscience data and the camera images to reconstruct the libration of Mercury (variations in Mercury’s rotation). These data provide information on interior properties of Mercury, such as the state, dimension, and composition of the core.
Satellite(s) or flight opportunity(ies):
- Mars Express (MEX)
- Venus Express (VEX)
- BepiColombo
Field of research:
Space Sciences: Planetary Geodesy
