Postflight Analysis of Atmospheric Properties from Mars 2020 Entry, Descent, and Landing

Abstract

The Mars 2020 spacecraft landed the Perseverance rover and Ingenuity helicopter successfully in Jezero crater on Feb. 18, 2021. The entry, descent, and landing (EDL) sequence of the spacecraft largely leveraged the previous 2012 Mars Science Laboratory (MSL) mission. The atmospheric modeling approach for Mars 2020 was also borrowed from MSL. It consisted of two mesoscale atmospheric models of the target site and a statistical model of the pressure, density, temperature, and winds based on the mesoscale model data. This paper briefly describes the preflight atmospheric models used for Mars 2020, but focuses on the postflight assessment of these models and comparison to near-landing day orbiter sounder and other onboard atmospheric measurements. Observations from postflight analysis showed that density was underpredicted in the upper atmosphere, but within the altitudes covered by the mesoscale models, the preflight modeling matched postflight results, including for quantities like wind velocities. Potential improvements to address the upper atmosphere and other deficiencies of the Mars 2020 preflight model are also discussed.