PITMS can characterize the lunar exosphere after descent and landing, and throughout the lunar day, 
            to understand the release and movement of volatile species. Previous missions have demonstrated the presence 
            of volatiles at the lunar surface, but significant questions remain about the where those volatiles came from 
            and how they are transported across the lunar surface. Investigating how the lunar exosphere changes over the 
            course of a lunar day can provide insight into the transport process for volatiles on the Moon. The instrument 
            has the ability to measure the low level of gases expected in the lunar exosphere and released by regolith 
            interaction with surface disturbances, like rovers.
            The PITMS sensor has direct heritage from the Ptolemy mass spectrometer that made the first in situ measurements 
            of volatiles and organics on comet 67P with the Rosetta lander, Philae. PITMS operates in a passive sampling mode, 
            where molecules fall into the zenith-facing aperture and are trapped by a radiofrequency field, then sequentially 
            released for analysis. PITMS has a unit mass resolution up to an upper mass-to-charge (m/z) limit of 150 Da.
            The PITMS investigation will provide time-resolved variability of OH, H2O, noble gases, nitrogen, and sodium 
            compounds released from the soil and present in the exosphere over the course of a lunar day. PITMS is a joint 
            NASA-ESA project implemented by NASA?s Goddard Space Flight Center (GSFC) and ESA?s contractors Open University 
            (OU) and STFC RAL Space, with coordination and support provided by ESA?s Space Research and Technology Centre (ESTEC). 
            The integrated PITMS payload and science investigation will be operated by GSFC with an international team of 
            scientists.