MARSWRF Prediction of Entry Descent Landing Profiles: Applications to Mars Exploration

Abstract

One of the most critical stages of a mission to another planet is the Entry, Descent and Landing (EDL) stage. If not successful, the entire mission will be deemed a failure. The thin atmosphere, unpredictable winds, variable dust content, and rough terrain make an EDL on Mars particularly challenging. In this paper, a simplified Martian mesoscale model is used to simulate the EDL conditions encountered by six past missions to the planet with the model predictions evaluated against the observed measurements. By and large, the model successfully captures the observed density, temperature, pressure, and horizontal wind vertical profiles in the lowest 30 km, where the most critical phase of the EDL takes place. The main discrepancy with respect to the observed profiles is for heights above 15 km and is probably due to an incorrect representation of the vertical profile of atmospheric dust, which strongly affects heating rates and hence other variables. The model is subsequently run for the proposed landing sites of ExoMars 2020 (Oxia Planum) and Mars 2020 (Jezero Crater) missions and for the expected time of EDL. For both sites, the model predictions indicate a strong sensitivity to the dust loading, with the most favorable time for the EDL, that is, when the horizontal wind speed is generally the weakest with smaller shifts in wind direction, being the late morning and early afternoon.