ESA Science & Technology - Focus on SESAME

Illustration, highlighting the Surface Electrical Sounding and Acoustic Monitoring Experiment (SESAME) on Rosetta's lander Philae. SESAME comprises three suites of instruments:

• CASSE – the Comet Acoustic Surface Sounding Experiment, which allows mechanical parameters of the surface to be deduced, along with details of the structure of the subsurface;
• DIM – the Dust Impact Monitor, which measures properties of impacting comet grains;
• PP – the Permittivity Probe, which determines one of the key electrical properties of the material beneath Philae, which is linked to the water ice content of the surface.

The sensors are located in the three feet as well as in the units of the APXS (centre) and MUPUS-Pen (to the upper right of centre) instruments.