Sampling Strategy for a Possible Mars Sample Return Mission

Mars Sample Return (MSR) would be a mission devoted to the collection of rock and regolith samples from the martian surface, and their transport back to Earth. The iMARS Working Group is developing potential plans for MSR that could be implemented on an international basis. A critical subsystem for MSR would be the sample collection hardware that would need to operate on the martian surface. The landed package is proposed to consist of a fixed platform and a mid-range rover. In order to avoid surficial weathering, primary sampling would be achieved by a coring device, placed on the rover, that would be able to penetrate rocks to a depth of several cm. The selection of the sampling sites would need to be supported by an array of instruments in order to provide geo-mineralogical context. These instruments would provide large- to medium-scale data about the sampling area in order to identify the main geological units, their geometries and their stratigraphic relationships. Close optical investigation would reveal the gross lithologies and fine-scale structures (e.g. stratification). Geochemical and mineralogical analysis would complement these observations. The sampling strategy would be very similar to the way in which “terrestrial” geologists map an area and sample rocks. In addition, it would be valuable to have a platform-mounted subsurface system (a drill) able to collect samples of regolith, unconsolidated sediment and rocks to a depth of a few meters.