Mars high resolution Shallow Radar (SHARAD) for the MRO 2005 mission

The search for water is a primary focus of Mars exploration. At the surface of Mars, water is present as ice in the polar ice caps and in trace quantities in the atmosphere. To detect liquid water on Mars today probably requires searching below the surface. As noted in the MRO SDT Report, the unambiguous detection of liquid water in the upper crust of Mars and the profiling of ice in the subsurface, particularly within one kilometer of the surface, would be major discoveries in the exploration of Mars. To that end, the MRO SDT recommended that flight of a subsurface sounding radar be considered for MRO, if the radar could confidently detect liquid water and profile ice in the topmost 1 km of subsurface with approximately 10 in vertical resolution. In response to this recommendation a team of italian researchers, sponsored by the Italian Space Agency (ASI), has proposed a Shallow Radar sounder (SHARAD). In this paper the main features of the SHARAD (to be complementary to MARSIS) in terms of the expected penetration performance according to proposed models of the martian crust composition and surface scattering are described.