Just read about something, growing mosses and lichens on a martian surface (terraforming)..
so as a side mission, how about we have a sealed glass chamber which can simulate the earth conditions and that of the martian surface, which players place mars soil,rocks (these are collected and sealed, then loaded into chamber)
Then attempt to grow lichens+mosses (brought from eath of course), altering the 'bio-chambers' conditions (atmoshphere mix/pressure, temp,humidity etc) to try a get the plants to take. The conditions could start earth like and be changed in stages to mars like
Mosses+lichens that sucseed in the chamber can be used/altered to 'breed' a stronger strain for next test.
why? its a side line, scientific quest to see if you can grow lichens/mosses on mars surface.
benifits? none really, maybe medicines, fishfood.