[wip] start crism

datasets/readme.md → datasets/README.md

 # Datasets
 
-## MEX-HRSC
+## MEX
+
+### HRSC
 
 FTP links for Mars Express missions can be found at:
 https://www.cosmos.esa.int/web/psa/ftp-browser#mex
 
 
+## MRO
+
+### CRISM
+
+We start at the [PDS Geosciences Node] page for [MRO CRISM] data access.
+
+First thing to cover is the [Data Product Software Interface Specification].
+
+
+[MRO CRISM]: https://pds-geosciences.wustl.edu/missions/mro/default.htm
+[PDS Geosciences Node]: https://pds-geosciences.wustl.edu/missions/mro/crism.htm
+[Data Product Software Interface Specification]: MRO/CRISM/crism_dpsis.pdf
+
+
 # Tools for ESA/NASA data users
 
 ## ESA/PSA