  Mars Sample Return consists of three separate missions, the first of which is
the Mars2020 rover which will land at Jezero crater on February 18, 2021. We
describe here our remote sensing study of a particular unit that outcrops in
Jezero crater that is likely to be part of the return sample suite. We report
on our efforts to characterize the olivine unit using data from the CRISM
instrument, including the grain size and Fe/Mg (Fo) number of the olivine. We
also discuss the astrobiological significance of the unit by analogy with the
stromatolite-bearing early Archean Warrawoona group in Western Australia. We
also discuss the current state of the MSR architecture.
