The Mars Sample Return Analog Collection

Abstract

The Mars 2020 Perseverance rover continues to grow its cache of exciting samples that will potentially be returned as part of the Mars Same Return (MSR) campaign. As of sol 1224, 24 rock cores have been collected across a diverse set of lithologies that span rock types from sedimentary to igneous. In order prepare for these precious samples to potentially make their way to the more sophisticated labs on Earth, NASA and ESA jointly created an MSR Analog Collection, curated in the MSR Analog Sample Library (ASL) at the University of Oslo/Oslo Natural History Museum, and including characterization analyses by the Norwegian Geotechnical Institute (NGI). In 2023 the Rock Sample Team were chartered to identify field sites from which to collect physically representative Mars analogs, to serve engineering needs related to sample receiving and processing. Building on this to create a more robust, i.e., representative, MSR Analog Collection, the MSR Campaign Science Group (MCSG) was tasked with critically evaluating the current collection and identifying any areas that needed to be supplemented.

MCSG has focused on scientific analogs, i.e., that are compositionally like MSR samples, as opposed to the previously collected physical analogs. The MCSG approached the task by first evaluating if the current collection could also serve as viable scientific analogs and if not, could new analogs be collected to expand the collection. To best evaluate the compositional fit for MSR samples, an analog quality match criteria rubric was developed. Using this rubric, the team highlighted key features and attributes in the MSR cache and then performed a detailed exercise of running each current and proposed analog through this rubric to address assess the compositional fit.

Preliminary work by the MCSG has already identified some key recommendations to make the current MSR Analog collection more comprehensive. Moreover, MCSG team members have already conducted reconnaissance field campaigns to supplement the current MSR Analog collection, with sites in Iceland and Italy. The MCSG also plans to turn their attention to re-examine both the igneous and regolith samples analog quality match criteria rubric. Finally, we plan to continuously to build the MSR Analog collection as the Perseverance rover continues to diversify its cache.