MUPUS on the Rosetta Lander Philae: First Results

Abstract:

The Rosetta lander Philae is planned to land on he nucleus of comet Churyumov-Gerasimenko on Nov 11 2014 and start its battery powered first science sequence. The "MUlti-PUrpose probe for surface and sub-surface Science" MUPUS will measure the temperature profile up to a depth of 30cm and the thermal conductivity using a self-penetrating needle-probe, the surface brightness temperature using a radiometer, the hardness of the comet soil by measuring the progress of insertion of the probe and the deceleration of the two anchors that will be shot to fix the lander. The anchors are equipped with an accelerometer and a temperature sensor each. The self-penetrating needle-probe, or penetrator for short, has an electro-magnetically driven hammer mechanism on top and a rod of about 1cm diameter and 32cm length equipped with 16 temperature sensors that can also be heated with controlled power of up to 2W to measure the thermal conductivity. MUPUS is stored on the lander but will be deployed to a distance of about 1m from the lander using a motor driven deployment device that extends from the lander balcony. The science goals of the instrument are to measure the temperature profile in the near surface layers of the comet and the heat flow into the comet nucleus to complement the surface energy balance of the nucleus with a quantity that is difficult to measure remotely or to estimate. The thermal conductivity can be further used to characterize the near surface layers and possibly determine the depth to pristine ice. The first science sequence will allow for insertion of the probe and for a first series of temperature and thermal conductivity measurements. MUPUS is looking at the long-term science sequence to complement these data. At the AGU fall meeting – assuming a successful landing and installation of the probe - we will report on results from the first science sequence.