Magnetism of Ganymede Environmental Conditions on Ganymede Magnetic field measurement on a Lander

1. Magnetic Field Measurement Onboard a Ganymede LanderExperiment Proposal Based on Experiences with Lander Magnetometers for the Missions Mars 96/98, Rosetta and Hayabusa-2Uli Auster & Karl Heinz Glaßmeier for the JUICE J-MAG Team(TU-BS Germany, IWF Austria and IC UK) • Magnetism of Ganymede • Environmental Conditions on Ganymede • Magnetic field measurement on a Lander • Summary

2. Magnetic Field at Ganymede Courtesy of Jia and Kivelson

3. Courtesy Ben Weiss Lander Contribution to investigate intrinsic fields • Decay of field during descent

4. -100km -200km -500km -1000km Lander Contribution to investigate induced fields • Induced Signal in dependency on source region Ocean at @ Ganymede surface @ JUICE Orbit

5. Condition at Ganymed Environmental Conditions on Ganymed: Cold and high Radiations Recent work for JUICE might solve some problems. • Temperature: Test facilities have been refurbished for tests and calibration in a wide temperature range • Radiation: Tolerant electronics is needed, Hybrids (ITAR free) for AD and DA conversion have been developed

6. Test Facilities Magnetsrode near Braunschweig IWF Graz Magnetsrode: scale values, linearity and orthogonality from -190°C to +180°C Graz: zero levels, noise density and transfer function at temperature range of +/-150°C

7. Radiation tolerant electronics • Radiation tolerant Hybrids (ITAR free) for AD and DA conversion

8. Radiation tolerant electronics • Design of Shielding Simulation with Mulassis (SPENVIS) Truscott et al., 2010 Courtesy of Evelyn Liebert

9. Digital Fluxgate – Simple and Robust

10. Data processing in FPGA ADC DAC • Controlling of AD and DA conversion • Calculating of physical units • Pre-calibration • Packaging • Timing • HK processing Data interface ADC Power interface DAC Common Electronics & Combination of Sensors Romap on Rosetta Lander (landing on Comet CG in 2014) Measuring dB/dt Excitation Feedback Counting Current measurement HighVoltage Control

11. Data processing in FPGA ADC DAC • Controlling of AD and DA conversion • Calculating of physical units • Pre-calibration • Packaging • Timing • HK processing Data interface ADC Power interface DAC Common Electronics & Combination of Sensors L-DEPP on Lunar Lander (ESA concept study) Measuring dB/dt Excitation Feedback Current measurement Voltage Sweep

12. Data processing in FPGA ADC DAC • Controlling of AD and DA conversion • Calculating of physical units • Pre-calibration • Packaging • Timing • HK processing Data interface ADC Power interface DAC Common Electronics & Combination of Sensors Proposal for Ganymed Lander (e.g. a combined B/E field experiment) Measuring dB/dt Excitation Feedback E-field measurement active Stimulation

13. Resources

14. Heritage Mascot Rosetta Mars 96 Lander and Balloon

15. Summary Magnetometer on Lander – in combination with J-MAG on JUICE • Can improve science output significantly • Particularly for characterisation of internal field and induced field components Temperature conditions and high radiation dose can be handled. • Facilities for testing at extreme low temperatures exist in Brauschweig and Graz • Radiation tolerant hybrids have been developed for use up to 300-700krad • ADC and DAC parts might be of interest even for other experiments TU-BS has a long Heritage with Lander magnetometers • First steps were done together with IKI and IZMERAN colleagues for Mars 96. • Currently two Lander magnetometers are on the way (Rosetta & Hayabusa II) • Possible synergy with JUICE magnetometer in hardware and science