An MVP-SEM will provide the ISS with an additional on-orbit analytical tool which will allow for increased capacity of on-orbit analysis, thereby reducing the number of samples that must be returned to Earth. The variable-pressure SEM is a cross-cutting tool for in situ topographical imaging and compositional X ray fluorescence mapping of uncoated conductive and non-conductive samples useful to multiple disciplines, including nondestructive imaging of materials (inorganic and organic), surface contamination studies, and scientific analyses. This tool would also provide the ISS with a new capability for maintaining and understanding ISS structures (e.g., space weathering) and for scientific studies, thus reducing the required number of sample returns to the Earth. For Mars exploration, a variable-pressure SEM will allow for the simultaneous study of organisms and the geological substrates they might live on, provide shape and size-scale information, detail how they interact with their environment, and impart context for other studies that provide detailed chemical information. Morphological and chemical characterization of lunar regolith in laboratories on Earth has been routinely accomplished using a SEM and Energy Dispersive X-ray Spectroscopy (EDS). Our SEM would allow similar analysis in situ. A miniature variable pressure SEM would support both Medium (New Frontiers) and Large (Max-C) type missions, as outlined in the Planetary Science Decadal Survey 2013-2022.