Science Objectives and Site Selection Criteria for a Human Mission to Mars

NASA recently requested that MEPAG evaluate the scientific objectives and the science-related landing site criteria that could be used to support preliminary landing site evaluation for a human mission to Mars in the late 2030's. These requests were addressed by the Human Science Objectives Science Analysis Group, or HSO-SAG 2015, consisting of members of the Mars science and human exploration communities. A set of candidate scientific objectives was identified by the SAG considering intrinsic scientific merit, magnitude of the benefit of a proximal human, opportunities to make simultaneous observations from different vantage points, and opportunities to deliver scientific payloads of higher mass/complexity. These science objectives were then used to construct a set of landing site criteria that can be used to identify potential human landing sites on Mars with high potential for substantial scientific discovery. A future human landing site will lie in the center of a 100 km radius 'exploration zone' and scientific regions of interest within this exploration zone can be considered candidate sites for human exploration. HSO-SAG determined that potential landing sites on Mars should have access to the following: 1) deposits with a high preservation potential for evidence of past habitability and/or sites that are promising for present habitability; 2) Noachian and/or Hesperian rocks that can be used to understand past atmospheres; 3) exposures of at least two crustal units that are suitable for radiometric dating; 4) access to outcrops with signatures indicative of aqueous processes; 5) identifiable stratigraphic contacts and cross-cutting relationships from which relative ages can be determined. These criteria will be used along with other criteria developed from engineering and exploration objectives to help prioritize candidate landing sites for future human missions to Mars. The first landing site workshop will occur on October 27-30, 2015 in Houston, TX. Please visit http://www.hou.usra.edu/meetings/explorationzone2015/ for more information.