IWF Graz … 1 Report at Midterm Meeting April Meltingprobe Midterm Meeting: Development of a melting probe for Mars and Europa Norbert I. Kömle Project overview

IWF Graz … 2 Scientific Goals Meltingprobe Midterm Meeting: Explore vertical layering of deep ice sheets under low pressure conditions  Composition  Texture  Dust content  Traces of organics Reconstruct geological history and climate evolution of planetary bodies  Thermal properties  Optical properties  Electrical properties  Density  Pressure Geocryology for icy moons and planets

Overview Meltingprobe Midterm Meeting: Administration Characterization of targets Scientific requirements Technical requirements Payload candidates

IWF Graz … 4 Administration Meltingprobe Midterm Meeting: September Kickoff Meeting IWF Graz November 2005 ESTEC contract signed by all parties (ÖAW, ESTEC) Dr. Erika Kaufmann 100 % working contract funded from project (current funding period: 12 months) November April 2006 Draft documents created: TARGET CHARACTERIZATION, SCIENTIFIC REQUIREMENTS AND PAYLOAD CANDIDATES MECHANICAL AND THERMAL DESIGN ELECTRONICS DESIGN February First melting test in vacuum with existing probe April Midterm Meeting IWF Graz

IWF Graz … 5 Targets diameter6794 km mass0.108 M E solar distance1.52 AU max. solar radiation591 W/m 2 gravitational acceleration 0.38 g Meltingprobe Midterm Meeting: MARS EUROPA diameter3138 km mass0.008 M E solar distance5.20 AU max. solar radiation51 W/m 2 gravitational acceleration g

IWF Graz … 6 Target description: MARS Polar Areas Meltingprobe Midterm Meeting: North perennial ice cap South perennial ice cap

IWF Graz … 7 Target description: EUROPA 1 Meltingprobe Midterm Meeting: Interior structure

IWF Graz … 8 Target description: EUROPA 2 Meltingprobe Midterm Meeting: Triple bands and ice cracks

IWF Graz … 9 Target description: EUROPA 3 Meltingprobe Midterm Meeting: Suspicion: Around ice cracks ice layer may be thin Access to subsurface ocean by means of a melting probe?

IWF Graz … 10 Technical requirements for first prototype Meltingprobe Midterm Meeting:  Use of standard components for electronics: Cross section not too small, chosen dimensions: diameter 6 cm, length 20 cm  Length of tether: ca. 30 m (long enough to test functionality of tether deployment and internal power dissipation  Power supply: 28V, 70W maximum (to avoid use of high voltage components in laboratory testing  Payload: Simple strawman payload, A/D conversion of sensor data inside probe and data transfer through power cable

IWF Graz … 11 Payload Candidates Meltingprobe Midterm Meeting: Temperature sensors housekeeping and natural temperature profile during non- heating periods (evaluation of thermal properties) Tilt sensors housekeeping (reconstruct path of probe in the ice) ISFET chemical sensors PH-value of meltwater, trace elements Miniature mass spectrometer (Open University) elemental composition Miniature TOF mass spectrometer (Physikalisches Institut, Uni Bern) elemental composition CBD-densitometer (Open University) material density around by measuring Compton backscattering of a gamma source Optical/IR sensors albedo variations along melt path as indicator for contaminations

IWF Graz … 12 Present status of prototype construction Meltingprobe Midterm Meeting: ItemStatus Mechanical design drawingsready Electronics designunder consideration, partially ready Mechanical parts for prototypeordered Electronics parts for prototypeordered, partially available Components for tetherpartially available Heater foils (MINCO)available PT100 sensors (MINCO)available ADXL tilt sensoravailable ISFET PH sensoravailable

IWF Graz … 13 First melting test at IWF: Meltingprobe Midterm Meeting: Temperature evolution of different parts of melting probe and ice sample during the experiment

IWF Graz … 14 Test results Meltingprobe Midterm Meeting: Heating power: 60 W Ice temperature: -30°C Hot tip temperature when in contact with ice: 30°C Hot tip temperature after loss of ice contact: > 130°C Temperature of probe rear end (still outside ice): 80°C  Power of 70 W appropriate for 6 cm cross section  Launch pad must be improved  Rear end may become too hot as long as probe not fully inside ice Lessons from test: