A radar package for asteroid subsurface investigations: Implications of implementing and integration into the MASCOT nanoscale landing platform from science requirements to baseline design

Abstract : The internal structure of asteroids is still poorly known and has never been analyzed directly by measurements. Our knowledge relies entirely on inferences from remote sensing observations of the surface and theoretical modeling. Direct measurements are crucial to characterize an asteroid's internal structure and heterogeneity from sub-metric to global scale. The radar package developed in the frame of the phase A/B1 of the Asteroid Impact Mission (AIM) as part of the larger Asteroid Impact & Deflection Assessment (AIDA) mission is a mature instrument suite to answer this question and to improve our ability to understand and model the mechanisms driving Near Earth Asteroids (NEA). It is of main interest for science, exploration and planetary defense. This instrument suite consists of a monostatic high frequency radar (HFR) to investigate the stratigraphy of surface regolith and a bistatic low frequency radar (LFR) to characterize the deep interior. The chosen platform to deliver the surface unit of the LFR and other instruments for a close-up study of the target asteroid is the MASCOT nanolander, which already flies on Hayabusa2 (HY2) in a mineralogy scout configuration. In this paper, we present the chosen instrumentation for radar science, baseline mission requirements and the initial design for integration into the lander platform, including all peculiarities and constraints.