INTERNATIONAL MARS ICE MAPPER MISSION: INVESTIGATING SUBSURFACE ICE ON MARS FOR SCIENCE AND HUMAN EXPLORATION

Introduction: Partner Agencies [Agenzia Spatiale Italiana (ASI), Canadian Space Agency (CSA), Japan Aerospace Exploration Agency (JAXA), and National Aeronautics and Space Administration (NASA)] are developing the International Mars Ice Mapper (I-MIM) mission concept to characterize adequate, accessible water-ice in the uppermost 0-10 m to meet human exploration goals (e.g., accessing the ice for science, identification of astrobiological targets, and ISRU) and to address science objectives across geology, climatology, and habitability as recommended by the U.S. Decadal and the international community.

Mission Concept: Based on inputs from its competitively selected international Measurement Definition Team (MDT), the I-MIM team is considering an updated mission architecture with three spacecraft hosting complementary payloads to achieve flagship-level science at smallsat-scale cost to each partner. A JAXA-provided bus would host two radar instruments: a CSA-provided polarimetric L-band (930 MHz) Synthetic Aperture Radar (SAR) as well as ASI-provided Very High Frequency Shallow Radar Sounder (100-250 MHz) and Large Deployable Reflector to act as part of the telecommunications subsystem. Additionally, the mission would include a JAXA-provided demonstration lander and a NASA-provided, free-flying smallsat with a high-res imager. JAXA would also provide atmospheric sensors, with NASA providing launch and delivery.

L-Band SAR Measurements & Decadal Science: The L-band SAR instrument allows interrogation of the subsurface to >6 m depth with vertical resolution (in sounder mode) of < 1 m depending on the physical properties of top-layer and subsurface materials. The hybrid, compact polarimetric design allows for the determination of the four essential Stokes parameters for distinguishing between scattering regimes and to measure the polarimetric signatures of subsurface ice (e.g., the coherent backscatter opposition effect for thick ice layers). The different SAR imaging and nadir sounding modes provide complementary measurements to further characterize subsurface electrical and physical properties.

As summarized in the I-MIM MDT Final Report, the baseline mission would satisfy the mission’s Reconnaissance Objectives and provide opportunities to conduct Decadal-level science.