Phobos regolith simulants PGI-1 and PCA-1

•We developed two Phobos regolith simulants: PCA-1 and PGI-1.•The compositions of these represent the two leading hypotheses for Phobos’s origin.•The mineralogies of PCA-1 and PGI-1 are based on remote sensing and numerical models.•We describe the methodology used to develop and characterize PCA-1 and PGI-1.•We report physical and geotechnical properties of PCA-1 and PGI-1.