Mars Sample Return Rock Sampling: Post-landing Extraction of Solid-core Samples.

A NASA-ESA Rock Sampling working group has been set up to determine plans for opening the Mars2020 sample tubes once they are returned to Earth. This team works under the oversight of the Mars Campaign Science Group (MCSG). The rocks sampled so far by the Perseverance Rover comprise igneous rocks like basalt and olivine cumulates that experienced various degrees of secondary water alteration; fluviolacustrine sedimentary rocks that show various levels of induration, and unconsolidated Mars regolith. Two main considerations weigh on the strategy that should be adopted for opening the sample tubes on Earth. These are (1) preservation of textural relationships and layering, and (2) minimizing metal and organic, magnetic contamination.

It is anticipated that the mechanical state of each sample, as received in the laboratory on Earth, will be assessed by computed tomography (CT) scanning techniques prior to opening.  The decision on how to open each sample tube can therefore be based on geological data collected by the Mars2020 team, tests done on analogue samples, as well as the penetrative imaging data obtained on Earth during basic characterization.

The Rock Sampling Team is considering radial and longitudinal cuts through the Ti alloy tubes but finds that a single approach will not be appropriate for all the various types of rock samples that are expected to be returned.  In the next stage of the MSR Rock Sampling Group’s work we will select appropriate Mars2020 analogues and test the proposed tube cutting protocols.

The decision to implement MSR will not be finalized until NASA’s completion of the National Environmental Policy Act (NEPA) process.