Fachbereich 14 - Geowissenschaften
Institut für Planetologie
Experimentelle Weltraumforschung

SPICE: A Thermal Probe for the Netlander Mission to Mars

The Netlander mission offers a unique opportunity to study the surface and the interior of Mars at four different locations at the same time. In addition to real "network"-science, where the presence of four stations is a 'must' to address global science as-pects, local, landing site-related instruments can more than double our knowledge of the surface of Mars, compared to the three landing sites (Viking 1 and 2, Pathfinder) we are currently familiar with. The SPICE instrument will characterize the soil at the landing sites. Force sensors integrated into the seismometer legs (three per station) will determine the mechanical strength of the soil. Thermal sensors will measure the local soil temperature, the thermal inertia and the thermal diffusivity independently, thus allowing us to determine the thermal conductivity and the volumetric heat capacity of the soil. These properties will tell us about (1) soil cementation("duricrust"), (2) volatile exchange with the atmosphere, (3) grain size, (4) near-surface stratigraphy, and (5) will finally provide ground truth for remote sensing data such as that from Mars Global Surveyor's thermal emission spectrometer. SPICE consists of the "mechanical properties" part, which will be provided by our cooperation partner, Institut für Weltraumforschung in Graz, and the "thermal properties" part, which will be developed by us. The thermal probe consists of a 5 cm long and 1 cm wide hollow tube that carries two temperature sensors. The probe is mounted at the tip of a deployment boom that will bring the probe at a distance of about 1 m from the spacecraft and will press it into the Martian soil. Each of the two sensors can be employed as a heater, and the self-heating of the heater is a measure for the thermal diffusivity of the surrounding material. The overall mass of the thermal probe -including cables - is only 50 g or less. Additional information about the Netlander mission, that will carry the SPICE instrument, is provided on this Website (see Planetenphysik, Netlander).

Beteiligte Wissenschaftler:

Prof. Dr. Tilman Spohn, Dr. Karsten Seiferlin , Dipl. Ing. Riccardo Nadalini

Veröffentlichungen:

Hagermann, A., T. Spohn, A.J. Ball, D. Breuer, V. Klemann,K. Seiferlin, F. Sohl, M. Banaszkiewicz, S. Gadomski, J. Grygorczuk W. Marczewski, N. I. Koemle, G. Kargl, J. Benkhoff: Thermal Inertia and Cohesion of Martian Soil: The SPICE Experiment for the Netlander Mission, Abstract Vernadski-BrownSymposium Moskow, 2000

Seiferlin, K., Spohn, T., Ball, A. J., Kargl, G.,Kömle, N. I. and Hagermann, A.: Thermal Inertia and Cohesion of Martian Soil:Scientific Aspects of the SPICE Experiment on Netlander. Presented at the EuropeanGeophysical Society, Nice, 25-30 April 2001. Abstract in Geophys. Res. Abstracts3, 7206, 2001

Kargl, G., K. Seiferlin, A. J. Ball, T. Spohn, N. I. Kömle, and A. Hagermann: Technical Aspects of the SPICE Experiment on Netlander, EGS2001:XXVI General Assembly, Geophysical Research Abstracts, 2001

Seiferlin, K.,Spohn, T. and the SPICE team, 2002: SPICE in Martian Soil. Presented at the EuropeanGeophysical Society, Nice, 21-26 April 2002. Abstract EGS02-A-05613 in Geophys. Res.Abstracts 4