Analysis of Cylindrical Multi-Probes for Determination of Thermal Properties in Extreme Environments

The thermal conductivity is a key property of any existing solid  material and it often needs to be known for modelling planetary surfaces and for understanding energy balances on planetary bodies, like planets, asteroids and comets. The goal oft this project is the development of methods for measuring thermal conductivity of materials residing on planetary surfaces. Examples of such materials are the fine regolith powder covering the lunar surface, the reddish sand covering large parts of the surface of Mars, or icy surfaces as they exist in the polar regions of Mars, but also on icy satellites like Jupiter’s moon Europa or Saturn’s moon Enceladus. The hot needle method in different variants (single needle as well as multiple needle techniques) is suitable for application in rugged environments and is considered as the preferred method to be applied in the frame of planetary lander missions. Therefore in this project the performance and accuracy of such sensors is studied both by applying numerical models and by performing laboratory experiments in an artificial planetary environment.

Heat conduction measurement system using 4 identical robust steel needles (manufactured by the Dutch company Hukseflux). One needle is actively heated while the other needles are passive.
Thermal conductivity measurements in an ice sample using different thermal conductivity sensors.
Calibration measurement for the custom-made Hukseflux thermal conductivity sensors, using well-characterized materials.

Project leader

Norbert Kömle