Joanna V. Clark is an American geoscientist working for Geocontrols Systems Inc on the JETS Contract at NASA Johnson Space Center. She is collaborator on the Sample Analysis at Mars (SAM) and Mars Science Lab (MSL) science teams. Her research includes oxychlorines, chlorides, phyllosilicates, manganese oxides and has also been involved with martian simulant development for In-Situ Resource Utilization.