Ganymede Lander Page 1 - Magnetometer Proposal -Moscow, Magnetic Field Measurement Onboard a Ganymede Lander Experiment Proposal Based on Experiences with Lander Magnetometers for the Missions Mars 96/98, Rosetta and Hayabusa-2 Uli 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

Ganymede Lander Page 2 - Magnetometer Proposal -Moscow, Magnetic Field at Ganymede Scientific ObjectiveExpected Signal Intrinsic dynamo field1400nT at poles Jovian magnetospheric field at Ganymede’s orbital distance+/-100nT Ganymeds magnetospheric and plasma interaction signal+/- 180nT Induced signal at 500km altitude, T= 10,5hours T= 171hours T= 27days Induced signal core (w/o T= 10,5hours Courtesy of Jia and Kivelson

Ganymede Lander Page 3 - Magnetometer Proposal -Moscow, Lander Contribution to investigate intrinsic fields  Decay of field during descent Courtesy Ben Weiss

Ganymede Lander Page 4 - Magnetometer Proposal -Moscow, Lander Contribution to investigate induced fields  Induced Signal in dependency on source JUICE Ganymede surface -100km -200km -500km -1000km Ocean at

Ganymede Lander Page 5 - Magnetometer Proposal -Moscow, 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

Ganymede Lander Page 6 - Magnetometer Proposal -Moscow, Test Facilities Magnetsrode near BraunschweigIWF Graz Graz: zero levels, noise density and transfer function at temperature range of +/-150°C Magnetsrode: scale values, linearity and orthogonality from -190°C to +180°C

Ganymede Lander Page 7 - Magnetometer Proposal -Moscow, Radiation tolerant electronics  Radiation tolerant Hybrids (ITAR free) for AD and DA conversion AD-ConverterDA Converter AD converter with preamplifier and latch up protection Two cascaded DA converter with sum-up and current source option Resolution18bit, 1MHzResolution16 bit each Power consumption40mW + 25mWPower consumption60mW Input Noise:2nV/Sqrt(Hz)Non Linearity:<5 x Tested (on die) up to30kradTested (on die) up to60krad

Ganymede Lander Page 8 - Magnetometer Proposal -Moscow, Radiation tolerant electronics  Design of Shielding Shielding Factor Mass g/cm² Thickness of Z low layer µm Al-Ta11,061,88731,00 Al-W12,272,05750,00 Al-WCu10,901,82700,00 Ti-Ta11,911,99850,00 Ti-W13,002,14780,00 Ti-WCu12,762,09600,00 Simulation with Mulassis (SPENVIS) Courtesy of Evelyn Liebert Truscott et al., 2010

Ganymede Lander Page 9 - Magnetometer Proposal -Moscow, Digital Fluxgate – Simple and Robust

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

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

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

Ganymede Lander Page 13 - Magnetometer Proposal -Moscow, Resources Experiment / Mission (Year of Development) Power (W) Mass(g) sensor / boom / electr. Range / resolution (nT) Optimism / Mars 96 (1994)0,2 (w/o DPU)115 / 180 / / 0,250 Magibal / Mars 98 (1996)1,0400g (2 sensors, boom)2 000 / 0,025 Romap / Rosetta (2002)0,950 / 120 / / 0,010 L-DEPP / Lunar Lander (2012)0,850 / 400 / / 0,008 Mascot / Hayabusa II (2013)0,850 / ---- / / 0,008 … / Ganymede Lander (2020)0,850 / ??? / / 0,008

Ganymede Lander Page 14 - Magnetometer Proposal -Moscow, Heritage Mascot Rosetta Mars 96 Lander and Balloon

Ganymede Lander Page 15 - Magnetometer Proposal -Moscow, 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 krad  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