Optimizing ExoMars PanCam Multispectral Science: Cross-Rover Mission Comparison

Introduction: The ESA/Roscosmos ExoMars Rosalind Franklin rover is due to launch in 2022, and land in the Oxia Planum region of Mars in June 2023. The rover is designed to retrieve a sample from a depth of up to 2 m, to fulfil its primary objective of searching for signs of life [1]. Here we outline one of several studies focused on optimizing the multispectral science that can be achieved with PanCam, one of the remote sensing context instruments on the rover. PanCam: The PanCam instrument is mounted on the mast of the rover, at approximately 2 m above the ground. The main objective of this instrument is to establish the geological and morphological context for the mission, and supporting the choice of sampling location [2]. PanCam will measure the visible/nearinfrared (VNIR) reflectance of the surface through a multispectral suite of 12 narrowband filters, the wavelengths of which were optimized for identifying a broad selection of minerals expected to be encountered on Mars [3]. The goal of this study is to measure the performance of these filters across a wide range of mineral compositions, in order to refine and optimize the choice of spectral parameters, and to also compare the theoretical spectral response to that of other similar instruments, Mastcam on the Mars Science Laboratory Curiosity rover, and Mastcam-Z on the Perseverance Rover. Method: We used the Western Washington University (WWU) VNIR Spectroscopy Database to acquire relevant mineral laboratory spectra. Figure 1. (Below Left) The 163 spectra from the WWU database used in this study, split into rock or mineral type. Shown in each case is the resampled PanCam reflectance (circles and thick dashed lines) and the full laboratory spectra (thin sold line).