Planetary and Space Science 164 (2018) 106-126
John A. Grant, Matthew P. Golombek, Sharon A. Wilson, Kenneth A. Farley, Ken H. Williford, Al Chen
The process of identifying the landing site for NASA’s Mars 2020 rover began in 2013 by defining threshold mission science criteria related to seeking signs of ancient habitable conditions, searching for biosignatures of past microbial life, assembling a returnable cache of samples for possible future return to Earth, and collecting data for planning eventual human missions to the surface of Mars. Mission engineering constraints on elevation and latitude were used to identify candidate landing sites that addressed the scientific objectives of the mission. However, for the first time these constraints did not have a major influence on the viability of candidate sites and, with the new entry, descent, and landing capabilities included in the baseline mission, the vast majority of sites were evaluated and down-selected on the basis of science merit. More than 30 candidate sites with likely acceptable surface and atmospheric conditions were considered at a series of open workshops in the years leading up to the launch. During that period, iteration between engineering constraints and the evolving relative science potential of candidate sites led to the identification of three final candidate sites: Jezero crater (18.4386N, 77.5031E), northeast (NE) Syrtis (17.8899N,77.1599E) and Columbia Hills (14.5478S, 175.6255E). The final landing site will be selected by NASA’s Associate Administrator for the Science Mission Directorate. This paper serves as a record of landing site selection activities related primarily to science, an inventory of the number and variety of sites proposed, and a summary of the science potential of the highest-ranking sites.