Investigating Constraints on Induction in Cryospheres with a Lander for Electromagnetic Sounding (ICICLES)

We propose to develop a remotely operated magnetotelluric (MT) lander with autonomous capability to collect electric and magnetic field data on the surface of icy moons, which are of particular interest in planetary science, because their ocean worlds may support life. MT data from icy moons would provide robust constraints on the laterally variable thicknesses and internal structures of their cryospheres and the salinities, temperatures and circulation of their internal oceans that are indeterminable from orbital magnetometer data alone.

Imperial's space laboratory team has extensive experience of developing magnetometers for spacecraft observations of magnetic fields. The challenge will be to develop telluric amplifiers connected to electrodes capable of being deployed autonomously to measure electric fields on the highly resistive surfaces of icy moons. Based on computer models, we will be aiming to develop a system that samples at 128 Hz and detects magnetic fluctuations >1 nT and electric signals >1 µV/m.

MT is a well-established geophysical method that has provided insight into Earth's crustal and mantle electrical conductivity structure below continents and the seafloor, but modifications to available technology will be required to address the high ice-electrode contact resistance expected on the surface of icy moons, autonomous deployment style and operating temperature range. A particular question to address will be how to deploy the electrodes autonomously at sufficient spatial separations to ensure that natural electric field (measured by dividing the potential differences between paired electrodes by their distance apart) fluctuations are detectable above the sources of electrode and telluric amplifier noise.

Possible solutions are to deploy electrodes ballistically or on booms. Therefore, measurements on ice that we will carry out on Svalbard with different designs of electrodes, telluric lengths, deployment styles and mechanisms will be central to the success of our research and development program. Data will be transmitted by GPS, which is standard on modern MT systems.

We assess the current technology readiness level of our proposed system to lie between TRL1 and TRL2. We will test our MT lander both in the laboratory and on Svalbard, advancing our technology to a rating of TRL5 by the end of the project. We anticipate applying for follow-on funding a few months prior to the end of the project to enable us to develop our MT prototype to the next stage, which should include testing in an extraterrestrial environment (e.g., on the Moon).