Soil simulant sourcing for the ExoMars rover testbed

► Three new Martian regolith simulants have been defined using widely available off-the-shelf products. ► Their micro-mechanical properties were determined and compared to in situ observations from the Martian surface. ► Post-processing techniques to obtain specific microscopic parameters were trialled in an effort to better simulate Martian surface material. ► The findings provide insight into the simulant selection requirements engineers on the ground must consider when developing test regimes for planetary exploration rovers.