THE SCIENCE PROCESS FOR SELECTING THE LANDING SITE FOR THE 2020 MARS ROVER

The Mars 2020 rover will evaluate surface materials to achieve mission science objectives that include: exploration of an ancient astrobiologically relevant environment preserving information on the geological record, including past habitability and biosignature preservation potential; searching for potential biosignatures; and caching samples for possible future Earth return.

Landing site selection activities serve to maximize the probability of landing safely with access to high-priority science targets and many engineering constraints are comparable to those on the Mars Science Laboratory. However, the higher atmospheric density expected on arrival at Mars in 2021, inclusion of Range Trigger, and Terrain Relative Navigation (TRN) EDL capabilities enables a smaller landing ellipse at higher elevation and provides access to locales where surface hazards precluded landing by MSL. As a result and for the first time, engineering constraints did not have a major influence on candidate site viability.

Four open workshops in the years leading up to launch enabled the science community to assist in the assessment of a total of ~30 candidate landing sites with likely acceptable surface and atmospheric conditions. Assessment employed mission-relevant science criteria and helped to reduce the sites remaining under consideration to eight after the second workshop and three after the third workshop. The focus of the fourth workshop was on the final three sites: Jezero crater (18.45ºN, 77.46 ºE), Columbia Hills (Gusev crater, 14.57 ºS, 175.44 ºE), Northeast (NE) Syrtis Major (17.89 ºN, 77.16ºE) and an additional landing site within the NE Syrtis region dubbed “Midway.” Midway (18.28 ºN, 77.05ºE) is located closer to Jezero crater than the original NE Syrtis ellipse. Midway was proposed as a site by the Mars 2020 Science Team and might enable achieving the science objectives of the mission by accessing Regions of Interest (ROIs) relevant to both Jezero crater and NE Syrtis. The output of the last workshop provides the final community input to site selection: the Mars 2020 Project will consider a number of factors in making a final recommendation to NASA who will select the landing site.